Q3) Is there any regulation about air compressors - time required to fill the Air Bottles? Ans) Two starting compressors must be fitted, of sufficient total capacity to meet the engine requirements. Each compressor must be able to press up Air receiver from 15 bars to 25 bars in 30 minutes. Two air receivers must to be provided. Total air receiver capacity is to be sufficient for Twelve (12) starts of Reversible engines and six (6) starts for non-reversible engines.
Q4) TYPES OF EVAPORATORS IN REFRIGERATION SYSTEM? ANS) In the large refrigeration and air conditioning plants the evaporator is used for chilling the water. In such cases shell and tube type of heat exchangers are used as the evaporators. In such plants the evaporators or the chillers are classified as: 1) Dry expansion type of evaporators 2) Flooded type of the evaporators In case of the dry expansion type of chillers or evaporators the expansion valve controls the flow of the refrigerant to the evaporators. The expansion valve allows the flow of the refrigerant depending on the refrigeration load. In case of the shell and tube type of evaporators the refrigerant flows along the tube side, while the substance to be chilled (usually water or brine) flows long the shell side. In case of the flooded the evaporator is filled with the refrigerant and constant level of the refrigerant is maintained inside it. In these evaporators or the chillers the refrigerant is along shell side while the substance to be chilled or freezer flows along the tube side of the heat exchanger.
Though this classification is also applicable to the domestic refrigerators and the air conditioners, the evaporators used in these systems are classified based on their construction. The evaporators are classified based on the construction as: 1) Bare tube evaporators 2) Plate surface evaporators 3) Finned evaporators
The bare tube evaporators are the simple copper coil evaporators over which the substance to be cooled flows. The plate surface evaporators are commonly used in the household refrigerators. These evaporators are also in the form of coil, which is attached to the plate. The finned evaporators are also made of copper coil with fins on the external surface as well on the internal surface.
BARE TUBE
PLATE TYPE
FIN
Q5) WHAT IS ERMATO JOINT? ANS) It is a kind of coupling to absorb vibration, fitted on pipes like scavenge drain pipe, in tank’s steam heating coils.
Q6) EXPLAIN PROPELLER SHAFT WITH DIAGRAM? ANS)The propeller shaft is bolted to the main engine flywheel, passing through the thrust block then along the shaft tunnel. Here it is supported by the shaft bearings before passing through the stern tube to drive the ship's propeller. The shaft is manufactured from forged steel, complete with coupling flanges. It is machined leaving a larger diameter at the location of the shaft bearings; this section has to have a fine finish to run within the white metal bearing. The shaft coupling flange faces are accurately machined and the bolt holes reamed to accept fitted bolts. They are bolted together using high tension bolting, which is tightened using hydraulic tensioning gear. The supporting bearings are cast in two halves and are usually white metal lined. These have oil scrolls cut into them to distribute the splash lubrication. Nowadays ball bearing shaft supports are being used, but they have been reported as being quite noisy with a tendency to run hot. A typical prop shaft white metal bearing with splash lubrication is shown here.
Q7) EXPLAIN RUDDER CARRIER BEARING WITH DIAGRAM? ANS) The rudder carrier bearing takes the weight of the rudder on a grease lubricated thrust face. The rudderstock is located by the journal, also grease lubricated. Support for the bearing is provided by a doublers plate and steel chock. Wedge type side chocks, welded to the deck stiffening, locate the base of the carrier bearing. The carrier is of meehanite with a gunmetal thrust ring and bush. Carrier bearing components are split as necessary for removal or replacement. Screw down lubricators is fitted, and the grease used for lubrication is of a water resistant type (calcium soap based with graphite).
Wear down A small allowance is made for wear down, which must be periodically checked. This may be measured either between pads welded on top of the rudder and onto the rudder horn, or between the top of the rudder stock and a fixed mark on the inner structure of the th steering gear flat. The latter generally involves the use of a 'Trammel gauge' which takes the form of a 'L' shaped rod ade to fit the new condition of the gear. As wear down occurs it can easily be checked with this gauge. The rudder is prevented from jjumping umping by rudder stops welded onto the stern frame. Rudder movement stops Rudder stops are arranged as follows; Angle from centreline
Position of stop
Note
35o
On telemotor system
Normal limit
37o
On steering gear
Prevents rudder striking external stops
39o
External, on stern frame
Emergency stop to protect propeller
These limits refer to rudders of traditional design and are governed by both the physical layout of the rudder and actuator but also due to the stall angles of the rudder. i.e. the angle at which lift ( turning moment ) is reduced or lost with increasing angle of attack. There are designs of rudder such as Becker flap which have increased stall angles up to 45o
Reasons for critical contouring of thrust face; I. For lubrication
ii. Conical in order to prevent sideslip and centralize rudder iii. Projected area gives greater bearing area allowing smaller diameter bearing
Q8) WHAT ARE STABILIZERS? WHAT IS ITS PURPOSE? ON WHICH SHIPS THEY ARE REQUIRED MORE? ANS)Ship stabilizers are fins moun mounted ted beneath the waterline and emerging laterally. In contemporary vessels, they may be gyroscopically controlled active fins, which have the capacity to change their angle of attack to counteract roll caused by wind or waves acting on the ship.
Location and diagram of retractable fin stabilizers on a ship.
Purpose The purpose of cruise ship stabilizers is to reduce the rocking motion of the ship. They help a ship move more smoothly, which cuts down the chance of seasickness for passengers. When there is a great deal of movement, it can cause a discrepancy between what at a person sees and what her inner ear senses. This is what causes
seasickness. The smoother the ride, the less chance for this to happen.
Function Cruise ship stabilizers extend out below the water line on the port and starboard sides of the ship. They prevent it from rolling to the left and right as it moves through the water. They act much, as do airplane wing flaps, which can be adjusted to reduce turbulence. Although no stabilizers can prevent 100 percent of a cruise ship's movement, they can significantly reduce it. This is especially desirable in rough conditions when the waves are high or the wind is strong.
How Cruise Ship Stabilizers Workfin Work stabilizer
Q9) EXPLAIN FREEBOARD? ANS) The distance from the waterline to the upper deck level, measured at the lowest point of sheer where water can enter the boat or ship. In commercial vessels, the latter criteria measured relative to the Ship's load line, regardless of deck arrangements is the mandated and regulated meaning. In yachts, a low freeboard is often found on racing boats, for weight reduction and therefore increased speed. A higher freeboard will give more room in the cabin, but will increase weight and may compromise speed. A higher freeboard also helps weather waves and reduces the likelihood of green seas on the weather deck. A low freeboard boat is susceptible to swamping in rough seas. Freighter ships and warships use high-freeboard designs to increase internal volume, which also allows them to satisfy IMO damage stability regulations due to increased reserved buoyancy.
Graphical representation of the dimensions used to describe a ship. f is the freeboard
Q 10) WHAT IS SHEER? ANS)The sheer is a measure of longitudinal main deck curvature, in naval architecture. The practice of building sheer into a ship dates back to the era of small sailing ships. These vessels were built with the decks curving upwards at the bow and stern in order to increase stability by preventing the ship from pitching up and down.
Dimensions of a hull
Q11) WHAT IS CAMBER? ANS) The camber is a measure of lateral main deck curvature in naval architecture. architecture The practice of adding camber to a ship's deck originated in the era of small sailing ships. ships These vessels were built with the decks curving downwards at the sides in order to allow water that washed onto the deck to spill off.
Q12) WHAT IS TUMBLEHOME?
ANS)In ship designing, the tumblehome is the narrowing of a ship's hull with greater distance above the water line. Expressed more technically, it is present when the beam at the uppermost deck is less than the maximum beam of the ves vessel. A small amount of tumblehome is normal in many designs in order to allow any small projections at deck level to clear wharves (structure on the shore of a harbor where ships may dock to load and unload cargo or passengers)
Length overall (LOA)) is the extreme length from one end to the other. Length at the waterline (LWL LWL)) is the length from the forward most point of the waterline measured in profile to the stern stern-most point of the waterline. Length Between Perpendiculars ndiculars (LBP or LPP)) is the length of the summer load waterline from the stern post to the point where it crosses the stem. Beam or breadth (B) iss the width of the hull. (ex: BWL is the maximum beam at the waterline) Depth or moulded depth (D D)) is the vertical distance measured from the top of the keel to the underside of the upper deck at side. Draft (d) or (T)) is the vertical distance from the bottom of the hull to the waterline. waterline Freeboard (FB)) is the difference between Depth and draft
Q13) EXPLAIN MOULDED BREADTH, MOULDED DEPTH, AND DRAUGHT? ANS)Breadth (extreme): The extreme breadth, recorded in meters to two decimal places. This is the maximum breadth to the outside of the ship's structure. Breadth (moulded): The moulded breath, recorded in meters to two decimal places. This is the greatest breadth at amidships from heel of frame to heel of frame. This will only be displayed when breadth extreme is not available.
Moulded Depth: The moulded depth, recorded in meters to two decimal places. This is the vertical distance at amidships from the top of the keel to the top of the upper deck beam at side.
Draught:
The draft (or draught) of a ship's hull is the vertical distance between the waterline and the bottom of the hull (keel), with the thickness of the hull included; in the case of not being included the draft outline would be obtained. Draft determines the minimum depth of water a ship or boat can safely navigate. The draft can also be used to determine the weight of the cargo on board by calculating the total displacement of water and then using Archimedes' principle. A table made by the shipyard shows the water displacement for each draft. The density of the water (salt or fresh) and the content of the ship's bunkers have to be taken into account. The closely related term "trim" is defined as the difference between the forward and after drafts.
Draft marks on a ship's bow
Q14) WHAT IS RECENT AMENDMENT TO SOLAS WITH RESPECT TO MSDS, LIFEBOAT & ETA? ANS) MSDS: MATERIAL SAFETY DATA SHEET: DATE OF ENTRY IN FORCE: 01-JULY-2009 AMENDMENT OF OCTOBER 2007 TO SOLAS: Amendment to SOLAS chapter 6, to add new regulation 5-1 on material safety data sheet (MSDS) to require ships carrying MARPOL Annex 1 cargo (oil) & also marine fuel oils to be provided with material safety data sheet prior to loading such cargoes. The regulation refers to the Recommendations for material safety data sheet (MSDS) for MARPOL Annex 1 cargoes & marine fuel oils, adopted by the organization through resolution MSC 150 (77)
Prevention of accidents involving lifeboats: An amendment to SOLAS regulation III concerns provisions for the launch of free-fall lifeboats during abandon-ship drills. The amendment will allow, during the abandon-ship drill, for the lifeboat to either be free-fall launched with only the required operating crew on board, or lowered into the water by means of the secondary means of launching without the operating crew on board, and then maneuvered in the water by the operating crew. The aim is to prevent accidents with lifeboats occurring during abandon-ship drills. The amendment is expected to enter into force on 1 July 2008.
Q15) WHAT ARE THE SAFETY FEATURES IN AIR COMPRESSORS? ANS)Every Air compressor on a ship is fitted with several safety features to avoid abnormal and dangerous operational errors of the equipment. If safety, alarms and trips are not present on the air compressor, abnormal operation may lead to breakdown of the compressor and may also injure a person working on or around it. 1.Relief valve: Fitted after every stage to release excess pressure developed inside it. The setting of the lifting pressure increases after every ascending stage. 2.copper Bursting disc:A bursting disc is a copper disc provided at the airside of the compressor. It is a safety disc, which bursts when the pressure exceeds over the predetermined value. 3.Fusible plug:Generally located on the discharge side of the compressor, it fuses if the air temperature is higher than the operational temperature. The fusible plug is made up of material, which melts at high temperature. 4.Lube Oil low-pressure alarm and trip:If the lube oil pressure goes lower than the normal, the alarm is sounded followed by a cut out trip signal to avoid damage to bearings and crank shaft. 5.Water high temperature trip:If the intercoolers are choked or the flow of water is less,
then the air compressor will get over heated. To avoid this situation high water temperature trip is activated which cut offs the compressor. 6.Water no-flow trip:If the attached pump is not working or the flow of water inside the intercooler is not enough to cool the compressor then moving part inside the compressor will get seized due to overheating. A no flow trip is provided which continuously monitor the flow of water and trips the compressor when there is none. 7.Motor Overload trip:If the current taken by motor during running or starting is very high then there is a possibility of damage to the motor. An overload trip is thus fitted to avoid such situation. 8.High Air Temperature Trip
Q16) PROCEDURE FOR OVERHAUL OF A/E? ANS)D'carb of auxiliary engine is nothing but the carrying out of certain routines at intervals prescribed by the manufacturer or experience. Normally the following should be done during a marine decarb to free the engine from anomalies Every 3000hrs 1. take out cylinder head, take the worn out mountings and/or over haul the mountings 2.All units cylinder head, piston, connecting rod, and 3.turbocharger to be overhauled 4.Clean sump tank and fill with fresh lube oil 5.Take crank shaft deflection before and after removal of bearings 6.Whatever actions taken should be recorded in the maintenance record book D'carb preparation:1.Make sure the all stand by auxiliary engines are ready 2.Keep all the special tools and other tools ready 3.Go through the previous records/manual for clearance and adjustments 4.Put the display card "MEN AT WORK", "DON'T START" 5.Close air bottle valve to auxiliary engine and engine start and stop valve 6.See that the turning bar is not in the flywheel and should be in place 7.Open the indicator cocks 8.If the main bearing is to be removed, check crank shaft deflections
9.Close lube oil, fuel oil, fresh water inlet/outlet valve, drain the cooling water line and remove connections A) Removal of cylinder head:Scavenge manifold, exhaust manifold , rocker arm, lube oil drain connection from rocker arm, rocker arm tank and cover connection to be removed Fuel oil high pressure connection from fuel pump to the injector, fuel valve cooling connections in and out (either diesel or water) to be removed Remove the rocker arm assembly and the push rod. Remove all the mountings such as starting valve, indicator cock, relief valve and exhaust valve assembly Remove the rocker cover and check any marking on cylinder head nuts and studs. If no torque spanner is available, note down the markings. Open the cylinder head nut with box spanner and extension rod. Never use the torque spanner. With box spanner available note down the marking. Put the cylinder head lifting tool and before lifting make sure all the connections are removed. Also ensure that the liner is not removed along with the cylinder head Take out the copper joint between the head and the liner
CYLINDER HEAD BEFORE CLEANING
EXHAUST V/V BEFORE CLEANING Removal of piston and connecting rod:After lifting the head, check the liner surface for score marks, blow past etc. Crack remove the ridges or deposits if any on the top surface to avoid the lifting of liner along with the piston and breakage of piston rings while lifting piston Open the crank case door and remove the bottom end bearing bolts after removing the lock arrangement and the remove the bolts Remove the bottom half of the bottom end bearing Bring the piston to TDC. Make sure the bolt holes on the piston top; lifting tool holes must be cleared from carbon deposits. Threads should also be checked and cleared Put the piston lifting tools and tighten the bolts Lift the piston and remove top shell of bottom end bearing Place the piston on the piston stand and cover the crankcase pin to avoid the foreign material damaging the crank pin.
PISTON WITH RINGS B4 CLEANINGPISTON WITHOUT RING B4 CLEANING
PISTON AFTER CLEANING
CONNECTING ROD REMOVAL
Cleaning the carbon content on all the parts of engine:Clean the piston rings, measure dimensions and keep them in order Clean the piston ring grooves thoroughly and measure the groove thickness at 3 different points Check for the deposits on piston crown (Sulphur, carbon or thick vanadium deposits) and measure the dimensions Remove the gudgeon pin and clean the gudgeon lube oil holes as well as the bush or small end bearing Check the bolts of connecting rod for any cracks Every 20,000 hrs engine connecting rod bolt must be replaced If new piston rings are going to be replaced, then there is no need for measurement Calibrate the liner thickness by using template
LINER B4 CLEANINGCOOLING WATER SIDE OF LINER (EXTERNAL VIEW)
COOLING WATER SPACE INSIDE ENGINE PROCESS
PISTON PIN REMOVAL CONNECTING ROD CLEANING
LINER AFTER HONING
BOTTOM END BEARING BEFORE CLEANING CLEANING
BOTTOM END BEARING AFTER
Assembly of the engine parts:First put the piston rings one by one and measure the butt clearance for all the rings Then measure the axial clearance between piston rings & grooves Place the piston guide on top of the liner and bring the particular crankshaft to TDC. Apply sufficient lube oil and start lowering the piston. Make sure that butt gap should not be in line it may cause blow past Before engaging check the crankpin for any cracks or scratch Check the bottom end bearing clearance and if needed measure the main bearing clearance as well Taper clearance is checked Check for any cracks in the water jacket and in the cylinder head Replace all rubber joints and copper gasket to be put on the cylinder cover Put the cylinder head gasket in the top of the cylinder Anti-seizure coating or powder like molycote, copper slip should be used. It is applied to avoid any seizure mainly on the threads or joints and it will be easier while removal Tighten the cylinder mounting according to torque specified as in manual and make all connection like lube oil, fuel, jacket cooling water connections etc Fit the rocker arm back
DECARB IS DONE TO INCREASE THE EFFICIENCY OF ENGINE.
Q17) HOW WILL YOU DECIDE TO CHANGE THE PISTON RING? ANS) 1. BY CHECKING THE BUTT CLEARANCE. IF ITS VALUE HAS BEEN INCREASED THAN THE NORMAL RANGE. 2. IF ITS AXIAL CLEARANCE HAS BEEN INCREASED THAN THE NORMAL RANGE. 3. BY CHECKING THE VISUAL CONDITION OF PISTON RING.
Q18) WHAT ALL CHECKS TO BE DONE IN LIFTING GEAR? (E/R LIFTING CRANE) ANS) 1. 2. 3. 4. 5. 6. 7. 8.
CHECK THE CONDITION OF WIRE ROPE & GREASE IT. CHECK THE VISUAL CONDITION OF CHAIN. CHECK THE LIMIT SWITCHES IN FORWARD, AFT, PORT & STBD DIRECTION ARE WORKING. CHECK THE PROPER WORKING OF EMERGENCY BUTTON. CHECK THE VISUAL CONDITION OF INSULATED COVER. CHECK OVERLOAD TRIP WORKING SATISFACTORY. CHECK VISUAL CONDITION OF CHAIN BLOCK, NO CRACKS SHOULD BE THERE. CHECK THAT SAFETY LATCH IS THERE ON CHAIN BLOCK.
Wire rope, limit switches ,chain, chain block, overload trip, emergency button, safety latch
Q19) WHAT ALL CHECKS TO BE DONE ON PISTON? ANS)Piston inspection on ships is part of the engine planned maintenance schedule (PMS) carried out to ensure the components is within the allowed tolerances. There are two methods of inspection: when the piston has been removed from the liner or inspection through the liner scavenges ports.
a)Piston Removed for Inspection:This examination will be under taken in a modular format, since the piston can be divided into various components.
Piston Crown Check for any burning at top part of the piston. Check any wear at the sidewalls of the crown and on ring grooves. Check for any cracks at top due to the thermal and mechanical stress, check also for high temperature corrosion. Check any signs of hot corrosion at the top surface and acidic corrosion at the lower part. Piston Rings and Grooves Check for the free movement of the piston rings. Check the ring clearance / groove clearance. Inspect for any wear, stepping and for scuffing. Piston Skirt and Side-wall Check for any rubbing marks. Inspect for any wear down of wear rings. Cooling Water Passage Check for any scale due to poor water treatment. Choking due to high temperature. Finally inspect the locking bolts; wires, studs and ‘O’ ring condition
b)Maintenance Schedule:Periodic inspection has to be done when the engine is not running. It can be carried out as above or by entering the scavenge space and inspecting the piston and piston rings through the scavenge ports, with the piston brought in line by rotating the engine via a turning gear.
Overhauling the piston as per Planned Maintenance Schedule (PMS). Monitoring of the condition of the piston and the piston rings by the compression curve of the indicator diagram through process analysis. The images shown below show examples of two means of inspection.
Inspection of piston and rings through the scavenge port
Piston removed for closer inspection
Emergency Repair of Piston Crown:Once the above checks have been carried out, what actions can be taken if some values or observations are out with the specifications? Given below is a list of common faults that might be found during inspection and means to make temporary emergency repairs. Gauge piston crown and ascertain shape and wear-down. If it is beyond recommended limits, replace the piston if there is a spare available. If not, rebuild the engine and proceed to the nearest port at reduced revolutions and arrange replacement. The crown head should not be welded except in a dire emergency- and even then only by an experienced welder. Remember that modern diesel engine pistons have a special lining of high temperature alloy on the top of the crown. This measure improves resistance to corrosion as well as to high combustion temperatures that the piston top is exposed to Examine the crown for fractures or cracks, and if found the piston should be changed. If no spare is available these can be welded to manufacturer’s specifications; using the correct alloy welding rods, again as a means to proceed to the nearest port at reduced revolutions for a replacement. Dismantled piston rings should be kept in sequential order so as not to interchange the rings when re-fitting to the piston. Once repairs are complete, replace the piston rings and check for normal butt clearance. If the butt clearance is more or less than the normal range, then replace the piston rings with new set of piston rings. Note: It would be an extraordinary predicament to be in where as a Chief Engineer you sailed without main engine piston spares. However, strange things happen at sea, maybe the spares have been already used, and you're awaiting delivery of replacements.
If any of the above repairs are carried out, it is imperative that a close watch is carried out on the appropriate cylinder with the exhaust temperatures closely monitored as well as the piston cooling medium temperatures.
Q23) WHAT IS PURPOSE OF TAPPET CLEARANCE & HOW IT IS DONE? ANS) Tappet clearance is a space between the top of the valve stem and the rocker arm. Its purpose is to allow for some mechanical expansion and lengthening of the valve stem and push rods as the engine warms up. This clearance is also called valve lash. If insufficient(lower clearance) valve lash is set when the engine is cold the valves will not properly close when the engine warms up or early opening of the valve.. If too much lash is
provided (additional clearance) then even after the engine warms up there will be some clearance, which will result in lost motion. Lost motion mean that as the cam tries to open the valve the push rod and rocker arm moves to first take up the clearance before touching the valve to open the valve. The result is late opening of the valve. When checking tappet clearance on marine engines, we have to ascertain that the piston is at TDC. Though markings are provided on the flywheel, the marine engineer must know the other methods for this like inspection of the camshaft and the fuel pump window. During the maintenance of a four stroke marine diesel engine there are times when we must know whether the particular unit’s piston is at the top dead center or not. For example when checking the tappet clearances of the engine it is important to know which unit is at TDC. Referring to the flywheel would indicate two units, but only one can be at injection TDC. So which one is it? Flywheel Method: The flywheel is the simplest method to know which unit is at TDC. If the flywheel shows two units, simply open the bonnet covers and checks visually. The unit at TDC will have both the inlet and the exhaust valve closed and hence relaxed springs; the other unit would have both the arms of the rocker arm at different levels. In addition the push rods of the unit at TDC would be loose and can be turned by hand because of the release of the clearances. There is a word of caution however: this method is only useful in a working generator, which you have just stopped to check the tappet clearances. In case you have removed the rocker arms for any reason the spring height and the push rod freeness check would lead you nowhere and misguide you.
Dial Gauge Method: In this method the fuel injector is taken out and from the opening a dial gauge is put inside. Then the turning gear is engaged and the engine turned over. The pointer of the dial gauge will move in one direction and then stop and start in opposite direction. The moment the pointer of the dial gauge stops and changes its direction of movement is the TDC of the unit. This method is not normally used in day-to-day practice, but may be used in the calibration of the flywheel if it is not calibrated, or after some repairs
Camshaft Method: The camshaft window of the engine can be opened up and the camshaft inspected. The cam of the engine has a base circle, and acceleration and dwell periods. If the roller of the follower is at the base circle, then the particular valve is closed by spring action. When both the exhaust valve and the inlet valve follower are on the base circle, then the unit is also at TDC. It must be remembered that as a four-stroke engine has two rotations of the crankshaft there is one injection TDC where the injection and the combustion take place. The second time the piston is at TDC is when the exhausting of the flue gases takes place. It is very important to identify the combustion TDC, as tappets have to be adjusted at that point.
Cam Profile
Crankcase Method: In this method the crankcase doors are opened up and the piston is visually checked whether is going up or down. This is the surest method, but a bit cumbersome. It should be used when you have a strong doubt about the other methods.
Valve Spring Method: This is not an independent method but is used in conjunction with the flywheel method. In this method if the flywheel is indicating two units, you can check the springs of both the units. The unit in which the springs are loose is the one at TDC. The caution is that this method is useful for an engine in use. If you have removed the rocker arms during the overhaul and thereafter you want to use this method then it can cause errors.
Push Rod Method: This method is like the spring method and you check that the push rods are free to turn. The unit at TDC will have loose springs. The care that must be taken is that it should be used along with the flywheel method and should be used in a working engine. By a working engine, I mean the engine that was running and has been stopped for tappets adjustment.
Loosen the lock nut of the rocker arm. TAPPET ADJUSTMENT: Now adjust the tappet clearance between the rocker arm & valve stem by tightening or loosing the nut below the lock nut. If tappet clearance is less: I. Valve will open early & close late ii. Air induced through inlet valve may leak out. So less air for combustion. iii. Power will be reduced. iv. Fuel consumption will increase, engine may become unbalanced, exhaust temp. will be very high. v. In worst condition, valve may remain open, resulting in loss of compression pressure, burning of exhaust valve, T/C fouling will increase. If tappet clearance is more: I. Valve will open late & close early. ii. Lesser heat energy to T/C, so reduction in scavenge air & hence power. iii. No proper removal of gases. iv. Hammering of valve stem-may cause damage to valve stem.
Q24) what to check if Engine is not starting on air and fuel? ANS) Engine not starting on Air: * Low air bottle pressure or airline valve may be shut. * Air bottle isolating valve or automatic valve or distributor not functioning. * Control air valves faulty or less control air pressure. * Start air automatic valve jammed. * Turning gear engaged. * Reversing has not taken place completely. * Control valve for fuel or start is not in its end position. * Bursting diaphragm on start airline damaged. * Fuel lever on maneuvering stand not on remote mode. * Auxiliary blower not running or not on ‘auto’ mode. * Emergency stop has activated. * Interlock is operated. *Cylinder air start valve defective or sticky. *Piston not in firing mode.
Engine not starting on fuel: *Less fuel in service tank. * Fuel filter is chocked. * Fuel supply pumps not delivering required pressure. Or fuel pump tripped.
* Fuel level on local maneuvering stand, is not on remote stand. * Fuel rack stuck. * Fuel pump malfunctioning, jammed plunger. * Injector nozzle needle sticking or holes blocked. * Compression pressure is too low due to broken piston ring or exhaust valve not closing properly. * Fuel pump relief valve leaking. * Start air pressure insufficient to turn the engine fast enough.
Q25) WHAT TO CHECK IF ENGINE IS NOT COMING ONLOAD? ANS) * CHECK VOLTAGE OF BUS BAR & INCOMING GENERATOR, BOTH SHOULD BE SAME. * CHECK FREQUENCY OF BUS BAR & INCOMING GENERATOR, BOTH SHOULD BE SAME. * POWER FACTOR IS OK. * SYNCHRONISING PROCEDURE SHOULD BE CORRECT. * ALWAYS BEFORE PARALLELING INCOMING GENERATOR’S PARAMETER SHOULD BE IN OPERATIONAL RANGE.
Q26) WHY IN UMS CLASS SHIPS THE GENERATOR ENGINE IS STARTED AUTOMATICALLY WITHOUT OPENING INDICATOR COCK GIVING A TRIAL START? ANS)IN ENGINE ROOMS, WHICH HAVE WATER MIST FIRE FIGHTING SYSTEM INSTALLED, THIS PROCEDURE IS NOT FOLLOWED BECAUSE WHEN THE ENGINE IS GIVEN A MANUAL KICK WITH OPEN INDICATOR COCKS, SMALL AMOUNT OF SMOKE COMES OUT OF THE HEADS WHICHCAN LEAD TO FALSE FIRE ALARM, RESULTING IN RELEASE OF WATER MIST IN THE SPECIFIED AREA.
Q27) WHAT ALL TRIPS & ALARMS ARE PRESENT IN AUXILIARY ENGINES? ANS)The various trips and alarms are mentioned as follows Alternator bearing low oil level alarm & trip Alternator bearing high temperature lube oil alarm &trip Low sump oil level alarm and trip Lube low oil pressure alarm and trip Reverse current trip
Over speed trip Over load trip High and low frequency trip Jacket cooling water low-pressure alarm
Q28) WHAT ALL PRECAUTIONS SHOULD BE TAKEN TO START AUXILIARY ENGINE AFTER OVERHAUL? ANS) * Turn engine through flywheel for checking any restrictions. *Water tightness to be checked. * Air to be removed from jacket water outlet line. * Priming lube oil pump to run before starting the engine. * Check the lube oil level. * Check the flow of lube oil. * Blow through the engine before starting.
Q29) HOW TO CHANGE PURIFIER IN TO CLARIFIER? ANS)Main Differences: The main difference between a clarifier and a purifier is the presence of a dam ring in the latter. In a purifier, the interface or the line of separation between the oil and water is created using a dam ring. The position of the dam ring plays an important role in the generation of interface and thus in the clarifying process. For example, if the diameter of dam ring is large, the interface moves out towards the periphery and as a result some oil is discharged with water from the water outlet. Also, if the diameter is small, the interface formed will be more inwards and water will be discharged with the oil from the oil outlet. The diameter of holes in the dam rings also plays an important role in the creation of interface and purification process. If the diameter of the holes is more, the interface is formed towards the periphery and oil globules are found with water and sludge. If the diameter is less the oil-water interface moves inwards and water is released with the clean oil discharged.
However, clarifiers do not have a dam ring but have a sealing ring which seals the water outlet. This prevents the impurities and water to remain inside the bowl unless opening the cleansing bowl discharges them automatically or manually. Also, the conical discs in a clarifier usually don’t have feed holes in them but if they do, then a disc without any holes is fitted at the bottom of the stack. Another difference between a clarifier and purifier is that a purifier needs to be filled completely with water for the generation of a seal that prevents the oil to leave from the
water outlet. Whereas a clarifier doe doesn’t sn’t needs to be filled up with water. Purifiers are used for filtering lubricating oil whereas clarifiers are not used for the same unless the oil is completely devoid of water.
Purifiers and Clarifiers differ only in that clarifiers are not set up to remove water. Their design are similar to the point that most purifiers found on board can be converted to use as a clarifier with simple alteration of the gravity disc
Q30) HOW TO SELECT DAMN RING FOR PURIFIER? ANS)From From the monogram provided with manu manual, al, which is drawn with respect to viscosity of oil & which size damn ring to be used. If monogram not there, then a. Chief Engineers experience will come into use. b. Hit & trial method to be used. * First use the largest gravity disc and whether oil is overflowing, if so, then use small size gravity disc and follow this process until oil stops overflowing.
Choosing Gravity Disc
The graph shown above is one typical of one found in a purifier instruction book for selecting appropriate gravity disc size. Shown on the diagram is an example of an oil of sg 0.93 at 0'C. The sg at 15'C for use with this graph is found by projecting alon along g a horizontal line to 15'C. This step would be omitted if the sg at 15'C were already known. A line is then drawn parallel to the pre-drawn drawn sloping lines. Where the drawn sloping line cuts the appropriate oil supply temperature isothermal then This become becomess the selection point for the disc. This is found simply by ascertaining which size band the point lies in.
Q31) WHAT TO CHECK IF PURIFIER IS OVERFLOWING? ANS)
* Size of gravity disc. * High throughput. * Temperature of the oil. * Operating water level in tank. * Sealing water is not present in purifier. * Bowl is not closed properly. * Seal ring is damaged. * By mistake if bowl opening water is feeded. * Increasing the specific gravity of the oil will tend to push the interface outlet and cause overflow from the heavy phase outlet until the equilibrium is restored. Q32) How to stop Aux Engine if not stopping by stop handle? ANS) a. Pull the fuel rack to zero position. b. Operate any trip.
Q33) WHAT ARE ALL TRIPS & ALARMS ARE PRESENT IN PURIFIER? ANS)Typical alarms and shut downs: The following gives a general list of alarms only some of which may be fitted. o o
o
o o o
Back Pressure shutdown- this measures the discharge oil pressure and alarms and initiates a shut down when below a set value Heavy phase overflow. Oil has a much higher viscosity than water. The heavy phase outlet is led to a small catchment tank contain a float. The outlet from the tank is restricted in such a way that water flows freely but oil tends to back up. This initiates an alarm and shut down Bowl not open- this may be done in several ways, typically by a lever switch operated by the discharged sludge hitting a striker plate. The other method is by measuring the motor current, when the bowl opens the bowl speed is dragged down due to friction effects of the discharging sludge and water. The motor current rises until full speed is re-established. This is detected by a current sensing relay Water in oil- This found on modern designs which have a detection probe mounted in the oil discharge High temperature alarm and shut down Low control/seal water pressure. Where control water is supplied via a fixed small header tanks a float switch may be fitted.
Q34) HOW TO CHARGE THE GAS IN REFRIGERATION SYSTEM? ANS)* Close the receiver outlet valve and collect the gas in the receiver.
* Once all gas is collected in receiver then shut the compressor suction valve. • Check the liquid level, if it is below L/3, Charging is reqd. • Check the weight of the refrigerant bottle & keep it upright. • Connect the charging line to the connecting point and keep it loose. • Open the bottle valve slightly and purge the line into the collecting cylinder and then tighten the connection. • Open the charging valve and fully open the bottle valve. • Check the liquid level in the sight glass and make sure no air bubble present in the system. • Close the charging valve and the bottle valve. • Open the receiver outlet valve & start the compressor. • Carry out leakdetection test. • Check the suction pressure & discharge pressure. Q35) WHAT IS PROPERTY OF IDEAL REFRIGERANT? ANS)Required Properties of Ideal Refrigerant: 1) The refrigerant should have low boiling point and low freezing point. 2) It must have low specific heat and high latent heat. Because high specific heat decreases the refrigerating effect per kg of refrigerant and high latent heat at low temperature increases the refrigerating effect per kg of refrigerant. 3) The pressures required to be maintained in the evaporator and condenser should be low enough to reduce the material cost and must be positive to avoid leakage of air into the system. 4) It must have high critical pressure and temperature to avoid large power requirements. 5) It should have low specific volume to reduce the size of the compressor. 6) It must have high thermal conductivity to reduce the area of heat transfer in evaporator and condenser. 7) It should be non-flammable, non-explosive, non-toxic and non-corrosive. 8) It should not have any bad effects on the stored material or food, when any leak develops in the system. 9) It must have high miscibility with lubricating oil and it should not have reacting properly with lubricating oil in the temperature range of the system. 10) It should give high COP in the working temperature range. This is necessary to reduce the running cost of the system. 11) It must be readily available and it must be cheap also.
Important Refrigerants: Properties at -150C (1) Ammonia (NH3)(R-717) Latent heat = 1312.75 kJ/Kg Specific volume = 0.509 m3/kg (2) Dichloro–Difluoro methane (Freon–12) (R-12) [C Cl2 F2] Latent heat = 162 kJ/Kg Specific volume = 0.093 m3/kg (3) Difluoro monochloro methane – or Freon-22 (R-22) [CH Cl F2] Latent heat = 131 kJ/Kg
Specific Volume = 0.15 m3/kg.
Q36) EXPLAIN THE PROPERTY OF LUBRICANT USED IN REFRIGERATION SYSTEM? ANS) For satisfactory performance, all refrigeration lubricants – mineral oil or synthetic – must be compatible with the refrigerant in the system and have the following requirements: 1. Good miscibility and solubility to assist in good oil return to the compressor, where it belongs. 2. Chemical stability to resist chemical reaction with the refrigerant or other materials present in the system. 3. Thermal stability to eliminate excess deposits at compressor hot spots. 4. Low wax content to prevent separation of flocculent wax from the oil mixture at the low temperature points in the system. 5. Low pour point to prevent separated lubricant from congealing and restricting flow. 6. Proper viscosity, even when diluted with refrigerant, to ensure high film strength at elevated operating temperatures and still provide good fluidity under coldest operating conditions. 8. No contamination to prevent scarring of bearing surfaces, plugging of lines or oil ports and general deterioration. Some major compressor manufacturers prefer alkyl
benzene refrigeration oil for some applications with HCFC refrigerant blends such as R-22, R-123 and R-401A.
However, alkyl benzene refrigeration oil with the proper viscosity can be used with most CFC and HCFC refrigerants as well as hydrocarbons and ammonia in most refrigeration and airconditioning applications. The benefits of high-quality alkyl benzene lubricants are high miscibility, low foaming, excellent thermal stability, very low flock points and good compatibility: 1. High miscibility: Miscibility is the ability of the refrigerant and lubricant to stay together as one homogeneous solution. Alkyl benzene has excellent miscibility with CFC and HCFC refrigerants, resulting in the oil and refrigerant remaining as one mixture at a wide range of temperatures and pressures. 2. Low foaming: The low foaming quality of alkyl benzene reduces carryover at compressor startup and subsequent oil loss from the crankcase.
3. Excellent thermal stability: Alkyl benzene can enhance the life of refrigeration systems by providing better thermal stability in the presence of CFC and HCFC refrigerants. It resists change under high temperatures, reducing problems with sludge, acids and copper plating. 4. Very low flock points: The flock point is the highest temperature at which wax-like materials precipitate from the oil in the refrigeration system. Because alkyl benzene is a synthetic lubricant, it contains little or no paraffin or wax, which can plug up parts of a system. This can be very desirable in low-temperature applications. 5. Good compatibility: Alkyl benzene can be blended with mineral oil of the same viscosity. It will not affect motor insulation and is compatible with most elastomers and additives often used to improve lubricity. Preventing contamination problems is extremely critical in the refining and handling of all refrigeration oils. Great care must be used to assure that refrigeration oil is free of moisture and other contaminants. Service technicians must ensure that oil remains clean and dry.
Q37) EXPLAIN THE PROCEDURE OF CHARGING THE OIL IN TO REFRIGERATION PLANT? ANS) Mostly ships have hand p/p provided which develop more pressure than the inside pressure
Q38) WHAT DO WE CHECK IF TEMPERATURE OF ANY ONE ROOM IS NOT COMING DOWN? ANS) 1. IF ROOM DOOR IS NOT CLOSED PROPERLY. 2. PARTICULAR ROOM’S INSULATION IS BAD. 3. PARTICULAR ROOM’S FAN IS NOT RUNNING. 4. EVAPORATOR OF THAT ROOM IS FROSTED. 5. EXPANSION VALVE FOR THAT ROOM IS BLOCKED. 6. SOLENOID IS NOT WORKING FOR THAT ROOM.
Q39) WHAT ALL THINGS TO BE CHECK IF ALL ROOM’S TEMPERATURE IS NOT COMING DOWN? ANS) 1. COMPRESSOR IS NOT RUNNING WELL. 2. PRESENCE OF MOISTURE IN SYSTEM & DRIER IS NOT WORKING PROPERLY DUE TO THIS EXPANSION VALVE OF ALL ROOMS ARE GETTING BLOCKED. 3. LESS REFRIGERANT IN SYSTEM.
Q40) WHAT TO DO IF DOMESTIC REFRIGERATION PLANT IS SHORT CYCLING? ANS)REASONS: * L.P Cut out is defective. * L.P Cut out setting not correct, too low difficult for Cut In. * Lesser gas flow * Less gas in system. * Drier Choked. * Expansion valve filter choked or Expansion valve Malfunction. * Evaporator Choked. * Compressor valves leaking. Actions: a. Check L.P. cut out setting, cut out pressure OK. b. Check flow of gas by seeing sight glass, which should show full flow of refrigerant. c. If no full flow- either less gas or drier chocked, change the drier. d. Check level in receiver, if low, then charges gas. e. Expansion valve filter choked, then clean it. f. Expansion valve malfunctioning- Change it. g. Evaporator choked- Blow-thru evaporator with nitrogen. Q41) HOW WILL YOU OVERHAUL A CENTRIFUGAL PUMP?
ANS) Centrifugal pumps have been used in industry for a hundred and fifty years or more. They are used to convert the energy from the pump driver to kinetic and potential energy into the fluid, via the impeller. They are used aboard ships to circulate seawater and freshwater cooling for the main engine. A ship's engine room contains several different types of pumps including centrifugal pumps. Removal of Pump for Inspection and Maintenance: 1 Isolate pump electrical circuit breaker on main switch board and attach a warning notice. (Do Not Operate-Men at Work). 2. Switch off and lock pump supply at its local supply panel. Attach a warning notice to pump local supply panel. 3. Close suction and discharge valves, chain and lock hand wheels. 4. Open pump suction and discharge pipe drain valves to bilge and when water ceases to flow; crack open the pipes / pump flange joints carefully to ensure that pump has drained off and is safe for opening. 5. Fix a shackle to lifting pad eye above pump and hang chain block; ensuring SWL of block, slings and shackles are satisfactory. 6. Use a center punch to match/mark coupling and casing, then remove the coupling bolts. 7. Disconnect, fix i/d tag and remove motor supply cables; taping over bare ends with insulating tape. 8. Connect shackle and sling to motor eyebolt and lift motor clear of pump using overhead chain block. Lay motor on its side out of harm’s way, protecting machined surfaces on both pump and motor coupling halves against damage. (Cardboard and masking tape is quick and efficient method.) 9. Disconnect all external fittings from pump casing e.g. cooling pipe, pressure gauge, oil reservoirs and air cock. 10. Remove bolting from top cover and remove cover. Scrape off old gasket and check mating surfaces, and renew gasket on assembly. (Light smear of grease on gasket / faces) 11. The pump shaft with impeller can be lifted out of casing. 12. Dismantle the impeller, and remove the wear ring. 13. Remove the gland packing and disregard; replacing it on rebuild. Remember to cut ends of packing at 45° and stagger joints when repacking gland.
Inspection Procedure for Pump and Motor: -
Pump: 1. Impeller, pump shaft and internal volute/casing can now be inspected for erosion, pitting and wear. 2. If required rectify pitting or erosion in the impeller and casing with two-part alloy epoxy putty. (See my article in the Reference section) 3. Check main drive shaft bearings and thrust bearings for wear and replace if required. 4. Check wear ring clearance using feeler gauges; in my day at sea it was general practice is to replace with new rings at major overhaul. 5. Check impeller / shaft key and keyways for damage and undue wear, Unscrew impeller shaft securing nut and check threads are in satisfactory condition; retighten to manufacturers torque settings. 6. Give all parts a good clean removing any dirt/ medium residue before re- assembly using new parts as required. 7. Enter date of overhaul and parts renewed in the pump maintenance record card. Drive Motor 1. Grip motor drive shaft /coupling firmly and check for excess axial and longitudinal movement. Rotate shaft at speed by hand, allowing it to run to a stop whilst listening for excess noise from bearings. Any doubt on either count, the bearings should be replaced. 2. Megger check motor windings to ensure no dampness is present and windings are in good condition. Any suspect readings indicate a full motor strip to check condition of rotor and stator. 3. If these checks are satisfactory, grease bearings as required. Some bearings are now sealed for life and will not require greasing. Procedure to Start the Pump: 1. Unlock and remove chains from inlet/outlet valve wheels and open both valves full. 2. Open air cock and expel air from line and pump while checking for any leaks 3. Turn the shaft coupling and ensure shaft is free to rotate. 4. Reconnect motor. 5. Remove danger notices from pump power supplies and reinstate breakers. 6. Start and record current drawn by the motor under starting and running conditions. Check and record the discharge pressure.
Q42) WHAT IS PURPOSE OF BILGE INJECTION VALVE? ANS) we have been talking about various types of emergency situations on board a ship. Needless to say some of the most dangerous situations arise not due to grounding or collision of ships (though they are risky too) but mainly could be due to those situation, which either involve a fire or flooding. Both these types of emergencies (fire and flooding) involve the use/role of seawater. If there is a fire, seawater is the biggest resource of water available in the sea. Similarly if it involves flooding of the engine room, cargo spaces or any other place on the ship for that matter; you would again require pumping the seawater out of the ship. In both these cases you require pumps.
We have studied a lot about seawater pumps, marine bilge pumps and piping arrangement on ships including various types of valves.
So as you must have noticed, there are two valves in close proximity namely main injection valve and bilge injection valve. Both of them have their own independent controls. The diameter of the bilge injection valve is kept nearly 66% of the main valve diameter, which draws water directly from the sea through the grid. This is a legal requirement that the diameter of this injection valve is at least 2/3 times the main suction, though it can be more also.
Hence the injection valve is an arrangement where the main sea chest can be bypassed in case of emergency so that instead of the sea, water gets drawn from within the ship itself.
There is a strainer attached to the bilge injection valve and the pump used for this valve is normally the largest seawater pump (or pumps) available in the engine room. Hence this valve is used to suck seawater from one of the lowest points in the engine room, which you can also see from the sketch. This basically means that when you need to remove a lot of water from the ship, you simply need to open this valve and run the big pump/s.
REFERENCE: http://www.brighthub.com/engineering/marine/articles/48581.aspx# Checks and Precautions: Emergency situation can arise anytime (that’s why is called emergency) so it would not be a good idea to find out that your valve is stuck due to rust or non-operation. Hence it is a good practice to check for the operation as a matter of routine.
The space near the injection valves should be kept clear of all obstacles since normally one would rush to open the valve in an actual emergency, and hence should be minimal obstacles in the space around the valve.
Not only should the valve be easily approachable and operational, but it also needs to be checked regularly for actual suction and operation. This can be done occasionally by actually running the pump and trying to draw out water from the bilge spaces uses this valve.
The valves should be clearly marked since more often than not, people do get confused in emergency situations and you certainly don’t want to be opening some wrong valve at such a critical time
Q43) BRIDGE INFORMS LOT OF SMOKE COMING FROM FUNNEL. WHAT ALL THINGS WE SHOULD DO? ANS)
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Reduce load on engine. Check purifier operating alright/ reduce throughput to have better purification.
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Drain water from settling & service tank. Check scavenge air temperature & adjust if required. Soot blow the economizer. Ensure, fuel oil end heater outlet temperature proper corresponding to attain viscosity at the point of injection. Check, if any particular Exhaust temperature is higher than others, if so, then stop the engine, Change the injector with a spare overhauled injector. Check all fuel pump timings are correct or not. Dismantle and carry out overhaul of T/C. Send fuel oil for Laboratory analysis.
Reasons: • Improper combustion. • Burning of carbon particles collected at EGE. • Overloading of engine. • Lots of smoke is also seen in scavenge fire. • Exhaust valve is defective. • Fuel valve is defective. • Purifier not working efficiently. • Fuel oil quality is bad.
Q44) FLOODING IN ENGINE ROOM, WHAT WILL BE YOUR ACTION? ANS)
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Inform bridge & Chief engineer. Raise engineer’s call/emergency alarm. Before starting bilge pump note down the position of vessel & time of starting. Other engineers will in between try to locate the hole or burst of pipe and repair. If ingress of water very high, start another pump. Reduce the engine r.p.m. Change over main seawater suction to emergency bilge suction. If level is still coming up try to protect the motor from short-circuiting, If situation is not coming in control, prepare lifeboat for lowering.
Q45) HOW WILL YOU TEST & OVERHAUL THE DEFECTIVE FUEL INJECTOR? ANS)Safety Precautions: * Check whether all tools and spares are available or not. * If so, then start the Stand by generator. * Check all parameters are normal. * Now share the load with the help of synchroscope. * Again check all the parameters are within normal range.
* Put full load on the Stand by generator. * Stop the generator on which work has to be carried out. * Put MEN AT WORK tag. * Shut the air-starting valve, fuel oil inlet & outlet valves and isolates the system. * Let lube oil-priming pump run for half hour after then stop it. * Remove the lock nut of the high-pressure pipe. * Now, remove the high-pressure pipe. * Take out the fuel injector using it tool. * Put it on the testing kit. * Check the lifting pressure, atomization, pressure falling steadily, and dripping of oil. * Now, take out the injector from the testing kit, put in diesel oil & clean it. * Make sure the workshop table should be clean, no rags or jute to be there. * Put the injector on the vice and tighten it. * Loosen the lock nut of the injector. * Now loosen the compression nut to release the spring pressure, and then take out the spring. * Open the cap nut and take out the needle and guide. * Put the parts on the cleaned table. * Check the condition of spring by dropping on the floor plate, it should jump and also check it by tightening in the vice and then releasing. The difference in the length, no cracks to be there. * Check visually needle, there shouldn’t be any scoring marks because it is made of Nitrite material. * Try to insert the needle inside the guide; the needle should on its own weight. * Check the size of injecting holes by using Go or No go gauge. * If go gauge is going then hole size is OK. * If no go gauge going, then it means the size has increased, then nozzle needs to be changed. * Now assemble the injector and do the lifting pressure setting on test kit by adjusting the compression nut. * After this check the injector again for its lifting pressure, atomization, steady fall of pressure and dripping.
Q46) WHAT IS BUMPING CLEARENCE IN AIR COMPRESSOR, HOW TO MEASURE IT & HOW TO ADJUST IT? ANS) The adjustment of Bumping Clearance is a very critical adjustment of the clearance volume. If more the volumetric efficiency of the compressor suffers and if less the unloaded piston may hit the cylinder head and damage both. In this article we discuss the need of this clearance and its adjustment.
What is Bumping Clearance? Bumping clearance as the name signifies is a clearance given so that the piston of the marine reciprocating compressor would not bump into its cylinder head. In new compressors the manufacturers adjust this clearance and the marine engineers are blissfully unaware of its importance. However the ship does not remain new forever and
every machine demands overhauling and that is where the problems start. Even routine jobs like lifting the cylinder head to change the low pressure or first stage valves can change the bumping clearance if the correct thickness gaskets are not used or if the head is over tightened thus squeezing out the gaskets. Many engineers miss this vital adjustment during overhaul of the compressors and efficiency and free air delivery of the compressor suffers. Bumping Clearance Changes over Time The bumping clearance in a new machine is set properly by the manufacturers during construction but over a period of time the clearance changes because of the following reasons:
Wear at the crankpin bearing. The crankpin bearing wears down due to use and this clearance can travel right up to the piston and an unloaded piston can hit the cylinder head. This type of wear can be recognized when the compressor makes impact sounds running unloaded at the starting and stopping operations. This type of wear would also be accompanied by a slow decrease in oil pressure over a period of time. Opening up of cylinder heads. In certain types of reciprocating compressors the cylinder head have to be removed for the changing of the first stage suction and discharge valves. When the cylinder head is put back the correct thickness of the cylinder head gaskets should be used otherwise it would change the bumping clearance. Wear on the main bearings. Over all wear on the main bearings would lower the crankshaft and would thus lower the piston and increase the bumping clearances.
Significance of Bumping Clearance: The bumping clearance must be adjusted properly otherwise there is risk of damage and loss of efficiency. If the bumping clearance were less the volumetric efficiency would increase but there is risk of the piston hitting the cylinder head, especially when the compressor is unloaded during start and stopping.
On the other hand to play safe, the engineer gives few millimeters of extra clearance, the volumetric efficiency of the compressor would decrease, the free air delivery will fall and there will be a fall in pressure. The extra clearance would result in a small volume of air being re-expanded every time causing increase in air temperature, fall in efficiency and overheating of the compressors. This would endanger the ship during maneuvering by sudden loss of propulsion.
How to Check Bumping Clearance: -
The bumping clearance can be checked by the following methods: In case a suitable opening is available the piston can be barred to the top dead centre and then feeler gauges can be put inside and the clearances checked at two three points. The more convenient method is to take lead wire from the engine store and make a small ball based on the expected clearance and put it between the piston and the head from the valve opening. Then the piston is slowly turned to the top dead centre with the help of a Tommy bar. After that the piston is again turned down and the lead wire ball is extracted and the thickness measured with the help of a micrometer. This measurement would give the bumping clearance. The caution, which must be observed in these methods is that, the clearances of the main and the crank pin bearing have not been taken into account. The correct method is thus that after turning the piston to top dead centre the piston connecting rod must be jacked up with the help of a crow bar. It is only after this hidden clearance has been accounted for, will the correct bumping clearance be found.
How to Adjust the Bumping Clearance: The bumping clearance once found to be incorrect would have to be adjusted. The methods of adjusting the bumping clearances are as follows: The cylinder head gaskets can be changed to a different thickness thus altering the bumping clearance. The shims between the foot of the connecting rod and the bottom end bearing can be changed thus changing the bumping clearance. However after adjusting the bumping clearance the clearance should be checked once again to make sure that there is no error and the clearance is within the range as specified by the manufacturers. It must be stressed that compressors are unforgiving and incorrectly maintained compressors have claimed many a lives
Q47) DURING MANEUVERING BURSTING DISC OF AN AIR COMPRESSOR GET DAMAGED. WHAT WILL BE YOUR ACTION? ANS) • • • • • •
Inform the bridge about the problem and give lesser starting air kicks. Start the stand by compressor. Isolate the compressor whose bursting disc is damaged. Cover the motor of affected air compressor to avoid water falling on it. Change the bursting disc, if available onboard. If not available, then let the sea water go into the Engine room bilges, otherwise if Fresh water cooled, then join a flexible hose and put into the expansion tank.
Q48) EXPLAIN THE OVERHAULING PROCEDURE FOR CYLINDER HEAD? ANS)* ENGINE SHUT DOWN. • • • •
STARTING AIR IS SHUT OFF & TURNING GEAR IS ENGAGED. AIR TO EXHAUST VALVE SPRING IS ISOLATED. FUEL OIL TO PARTICULAR UNIT IS ISOLATED. COOLING WATER TO PARTICULAR UNIT IS ISOLATED & DRAINED.
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REMOVE COOLING WATER CONNECTIONS. REMOVE FUEL OIL CONNECTIONS. REMOVE STARTING AIR CONNECTION. REMOVE THE BELLOW PIECE BETWEEN THE EXHAUST VALVE & MANIFOLD. DISCONNECT AIR SPRING CONNECTION TO EXHAUST VALVE. REMOVE HYDRAULIC PIPE CONNECTION & DRAIN PIPE CONNECTION FROM EXHAUST VALVE. CLEAN THE THREADS ON CYLINDER COVER STUDS & CONTACT SURFACES FOR JACKS. LOWER THE TENSIONING JACKS ON TO THE STUDS. CONNECT HYDRAULIC PUMP SNAP CONNECTOR WITH JACK. IN JACK, SCREW ON THE LOCKING RING UNTIL THE PISTON IN JACK GOES DOWN & THEN SLACK BACK ABOUT HALF TURN OTHERWISE THE JACK COULD NOT BE ABLE TO REMOVE FROM THE NUT OF STUD. START THE HYDRAULIC PUMP FOR JACKS & VENT THE AIR FROM JACKS. NOW SHUT THE VENTS & RAISE THE HYDRAULIC PUMP PRESSURE TO 1000 BARS. DUE TO THIS THE CYLINDER HEAD STUDS STRETCH, WHICH ALLOWS NUTS TO BE SLACKENED BACK BY USING A TOMMY BAR. THE JACKS ARE THEN REMOVED & THE CYLINDER HEAD STUD NUTS REMOVED. NOW THE CYLINDER HEAD LIFTING TOOL IS ATTACHED, THE HEAD & WATER GUIDE RING LIFTED USING THE ENGINE ROOM CRANE & LANDED IN A SAFE POSITION ON BLOCKS OF WOODEN PLANK TO PROTECT THE SEATING FACES.
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Q49) EXPLAIN THE PROCEDURE OF OVERHAULING THE PISTON OF LARGE DIIESEL ENGINE. ANS) * AS ABOVE THE CYLINDER HEAD & WATER GUIDING RING ARE REMOVED. •
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BEFORE THE PISTON CAN BE LIFTED & REMOVED FROM CYLINDER LINER , THE WEAR RIDGE AT THE TOP OF THE LINER MUST BE REMOVED. IF THIS IS NOT DONE THEN THE PISTON RINGS WILL JAM AGAINST THE WEAR RIDGE AS THE PISTON IS REMOVED. THIS IS VERY IMPORTANT TO REMOVE THE WEAR RIDGE BY USING A PROPER GRINDING TOOL, IF DUE TO ANY MISTAKE THE LINER GETS DAMAGED AT WEAR RIDGE’S POSITION i.e. WHEN THE PISTON IS AT TDC THIS POSITION IS JUST BELOW THE TOP RING, THE DAMAGE WILL LEAD TO BLOW BY.
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THE PISTON ROD IS NEED TO BE DISCONNECTED FROM THE CROSSHEAD. FOR THIS PISTON IS MOVED TO BDC & TWO JACKS ARE SCREWED ON TO THE THREADS OF THE STUDS SECURING THE PISTON ROD TO THE CROSSHEAD. THE JACKS SHOULD BE POSITIONED DIAGONALLY. ENSURE THAT JACKS ARE SLACKED BACK ABOUT HALF A TURN, SO THAT THEY CAN BE REMOVED AFTER THE NUTS HAVE BEEN LOOSENED. CONNECT THE SNAP CONNECTOR OF HYDRAULIC PUMP TO THE JACK & ENSURE THAT JACK PISTONS ARE AT THE BOTTOM OF THE CYLINDERS. VENT THE AIR FROM THE JACKS USING THE VENTING SCREW& THEN RAISE THE PRESSURE TO 1000 BAR OR RECOMMENDED PRESSURE BY USING THE HYDRAULIC PUMP & SLACK THE NUTS USING TOMMY BAR. AFTER RELIEVING THE PRESSURE ON THE JACKS THE PROCESS IS REPEATED FOR THE OTHER TWO NUTS. BOLT TWO DISTANCE PIECES TO THE PISTON ROD FOOT. THESE PUSH THE STUFFING BOX OUT OF ITS HOUSING, WHEN THE PISTON IS MOVED AT TDC. NOW UNBOLT THE STUFFING BOX. CLEAN OUT THE THREADED HOLES IN THE PISTON CROWN. BOLT ON THE LIFTING TOOL TO THE PISTON & ATTACH ENGINE ROOM CRANE. LIFT THE PISTON FROM THE ENGINE & PLACE IN CRADLE READY FOR CLEANING & EXAMINATION.
FOR BETTER UNDERSTANDING LOG IN: http://www.marinediesels.co.uk/: THEN TO MAINTENANCE & REPAIR: THEN TO REMOVING PISTON FROM SULZER RTA
Q50) AUXILIARY BOILER EXTINGUISHES, WHAT IS YOUR ACTION? ANS)Reasons: • Accept the alarm. • Find out the reason for extinguishing: • If too low water level alarm came, then check pump is developing correct pressure or not, it is working properly. • If tripped on high pressure, let the steam pressure come down. • Fuel oil low-pressure alarm, then check functioning of fuel pump, oil in service tank. • Fuel oil low temperature alarm: then use the heater. • Flame failure trip, then clean flame eye, check the furnace & overhaul the burner. Q51) WHAT IS DYE PENETRATION TEST? WHY IT IS DONE? & HOW IT IS DONE?
ANS) THIS IS THE MOST COMMON METHOD USED TO DETECT CRACKS IN COMPONENTS ON BOARD SHIP. PENETRANT IS SAME PENETRATING OIL USED TO LOOSE A RUSTED NUT & BOLT EXECPT IT CONTAINS A DYE WHICH WILL FIND ITS WAY IN TO THE SMALLEST OF CRACKS, EVEN THOSE INVISIBLE TO THE NAKED EYE. SOME OF THEM ARE FLUORESCENT DYE, WHICH IS THEN USED IN CONJUCTION WITH AN ULTRAVIOLET LIGHT, WHICH MAKES THE CRACKS GLOW GREEN WHEN ORDINARY LIGHTING IS REDUCED. SOME OF THEM ARE DEVELOPER WHICH MAKES THE DYE STAND OUT AS A RED LINE. THIS TYPE USUALLY COMES IN THREE AEROSOLS.
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FIRST IS CLEANER, WHICH IS SPRAYED ON IT. THEN THE COMPONENT IS ALLOWED TO DRY. THEN THE PENETRATING DYE IS SPRAYED ON & AFTER 5 MINUTES THE EXCESS COATING ON SURFACE IS WIPED OFF. THE DEVELOPER IS SPRAYED ON WHICH WILL HIGHLIGHT ANY CRACK PRESENT.
FOR PHOTOS: LOG IN: http://www.marinediesels.info/repairs/crack_detection.htm
Q52) HOW WILL YOU CARRY OUT THE BLOW DOWN OF GAUGE GLASS OF BOILER? ANS)Gauge glass blow down procedure: Gauge glass should be blown before lighting up of boiler, after stopping the boiler and regularly if the level in gauge glass is suspected to be wrong. Cleaning the waterside of gauge glass: * Close the valve S and W as shown in the figure. Now open the cock W and see if the water is coming out of the drain valve D indicating the drain line is clear. Now close the drain valve D and keep the cock W open and see if the water level rises in the gauge glass; this indicates the line to gauge glass is also clear. Repeat the steps two to three times to remove nuds and deposits inside.
Cleaning the steam side of gauge glass: Close both the cocks S and W. Now open the cock S and open the drain valve D and see the steam is coming out. The
drain is opened only for 1-2 seconds only as steam may damage the sealing and service life decreases.
Putting the gauge glass in normal operating position: Close all the valves S, W and the drain valve D. Now open the cock W and let the water fill inside the gauge glass. Now open the cock S and then the level can be seen as the pressure equalizes.
Q53) HOW WILL YOU TEST THE CYLINDER RELIEF VALVE OF ENGINE? ANS)The cylinder relief valve is designed to relieve pressures in excess of 10% to 20%
above normal. A spring holds the valve closed and its lifting pressure is set by an appropriate thickness of packing piece. Only a small amount of lift is permitted and the escaping gases are directed to a safe outlet. The valve and spindle are separate to enable the valve to correctly seat itself after opening. The operation of this device indicates a fault in the engine, which should be discovered and corrected. The valve itself should then be examined at the earliestopportunity.
Pressure testing was carried out on a bench mounted test rig consisting of a high-pressure air compressor, air pressure control valve, and calibrated gauges. The relief valve was bolted to the compressor accumulator flange and the air pressure increased until the valve lifted.
Q54) HOW WILL YOU TIGHT GAUGE GLASS AFTER OVERHAULING?
ANS)
IT SHOULD BE TIGHTED FROM INSIDE TO OUTSIDE ONCE & THEN OUTSIDE TO INSIDE.
11
7
3
10
6
2
1
5
9
8
12
4
THE TIGHTING SHOULD BE DONE ONLY BY HAND TIGHT.
Q55) HOW WILL YOU REMOVE THE BROKEN STUD? ANS) * FIRST DRILL THE BROKEN STUD LITTLE BIT. • • •
THEN USE THREAD EXTRACTOR OF LEFT HAND THREAD FOR MAKING THREAD IN HOLE. NOW PUT THE STUD OF SAME THREAD IN IT BY USING TWO NUTS. ONCE THE STUD IS INSIDE THE THREAD THEN REMOVE THE BROKEN STUD BY USING THE SAME STUD & TWO NUTS.
Q56) WHERE IS POSITION OF UNLOADER IN A/C & REF. COMPRESSOR? ANS) IT IS LOCATED NEAR THE SUCTION VALVE OF COMPRESSOR.
Q57) WHAT ALL CLEARENCES ARE TAKEN IN CENTRIFUGAL PUMP AFTER OVERHAUL? ANS)* CLEARENCE BETWEEN WEAR RING & IMPELLER. • •
CLEARENCE BETWEEN WEAR RING & CASING. CLEARENCE BETWEEN SHAFT & BUSH.
Q58) HOW WILL YOU CARRY OUT BLOW DOWN OF BOILER? ANS) Boiler blow down is done to remove carbon deposits and other impurities from the boiler. Blow down of the boiler is done to remove two types of impurities – scum and bottom deposits. This means that blow down is done either for scum or for bottom blow down. Moreover, the reasons for boiler blow down are:
1.To remove the precipitates formed as a result of chemical addition to the boiler water. 2.To remove solid particles, dirt, foam or oil molecules from the boiler water. This is mainly done by scum valve and the procedure is known as “scumming.” 3.To reduce the density of water by reducing the water level. 4.To remove excess water in case of emergency.
Procedure for Scumming and Bottom Blow Down Below is the procedure for boiler blow down using the blow down valve located at the bottom of the boiler. In order to do scumming, instead of bottom blow down, the scum valve is to be opened.
Steps for blow down procedure are as follows: Kindly refer the diagram to understand the blow down procedure properly. 1.Open the overboard or ship side valve (1) first. 2.Open the blow down valve (2), this valve is a non-return valve. 3.The blow down valve adjacent to the boiler (2) should be opened fully so as to prevent cutting of the valve seat. 4.The rate of blow down is controlled by the valve (3). 5.After blow down close the valve in reverse order. 6. A hot drainpipe even when all valves are closed indicates a leaking blow down valve.
Q59) EXPLAIN CRANKCASE EXPLOSION? HOW IT IS PROTECTED? WHAT IS CRANKCASE RELIEF DOOR? ANS) Crankcase explosions are also the result of high operating temperatures of the engine. The main cause of crankcase explosions is the development of hot spots at various places in the crankcase. Due to the reciprocating motion of the piston the lubricating oil in the crankcase is splashed in the air. Now it is necessary that the flash point of the lubricating oil be maintained at around 200 degree Celsius. If this is not done then there are high chances for the lubricating oil to catch fire. Hot spots are created in the crankcase as a result of: High temperature due to the reciprocating movement of the piston, Increase in bearing temperatures, Sparks entering the crankcase due to leaky piston rings or piston blow past,
Fires in the adjacent scavenge trunks. Now, when these hot spots come in contact with the oil in the crankcase, the oil gets vaporized. When these vaporized particles travel to the cooler part of the crankcase they get condensed into a white mist, which has oil particles properly dispensed in it. The process that takes place is somewhat similar to atomization. This white mist when again travels to the hot spot area, can easily catch fire, which might also lead to an explosion. The fire or the explosion creates immense pressure inside the crankcase and if this pressure crosses the permissible limit, crankcase explosion takes place. The explosion will rupture the crankcase doors and even cause heavy damage to the inside of the engine.
It is a bit difficult to read the early signs of crankcase explosions. This is because the indications are similar to many other emergency situations. But there are few pre-explosion signs that can be read. Crankcase explosion will lead: Sudden increase in the exhaust temperature Sudden increase in the load on the engine Irregular running of the engine Incongruous noise of the engine Smell of the white mist. In case of these indications, engine speed should be brought down immediately and the supply of fuel and air should be stopped. The system should then be allowed to cool down by opening the indicator cocks and turning on the internal cooling system.
Prevention: Preventing the generation of hot spots can do prevention of crankcase explosion. It can also be prevented by the following ways: By providing proper lubrication to the reciprocating parts, thus avoiding high temperatures. Avoiding overloading of the engine Using bearings with white metal material, which prevents rise in temperature. Using oil mist detector in the crankcase with proper visual and audible alarm. Oil mist detectors raise an alarm if the concentration of oil mist rises above the permissible limit. Pressure relief valves should be fixed on the crankcase for the instant release of pressure. They should be periodically pressure tested. Crankcase doors should be made of strong and durable material. Vent pipes shouldn't
be too large and should be checked for any choke up Pressure relief valves should be provided with wire mesh to prevent the release of flames inside the engine room. Safe distance should be kept from the crankcase and the relief valves in case the indications are sighted. In case of indication, the crankcase doors should never be opened till the time the system has totally cooled down. Once the system has cooled down, proper inspection and maintenance should be carried out. Fire extinguishing medium should be kept standby. In many systems, inert gas flooding system is directly connected to the crankcase.
OIL MIST DETECTOR: Lubricating oil is supplied to the main engine under pressure from the main lube-oil pump. It passes through the crankshaft, lubricating and cooling the main and bottom end white metal bearing, returning to the sump. It is also supplied to the crosshead guides and piston rod bearing, from which it cascades down to the main sump. During this activity an oil mist is produced, which is to be expected, however if there is a hot component the oil mist will be increased and vaporize with the real risk of fire and explosion in the engine crankcase. The purpose of the oil mist detector is to detect any increase in the density of the oil mist, setting off an alarm to warn the watch-keeping engineer of potential danger.
Preventive Measures of Crankcase Explosion: Ensure adequate cooling of the engine Ensure proper purification and analysis of lube oil Lube oil filter should be changed over and cleaned as per schedule Ensure proper cylinder lubrication by checking the condition of piston, piston rings and liner through scavenge or exhaust ports Clean scavenge spaces as per schedule and drain scavenge space regularly Maintain stuffing box gland in good condition Be alert and rectify for any abnormal noise in crankcase All safety alarms and trips fitted on engine to be tried out satisfactorily Proper watch on all running gears temperature and pressures to be maintained Blow through all sampling tubes of Oil Mist Detector (OMD) regularly Zero adjustment and sensitivity of OMD to be checked regularly Check for any oil leakage at crankcase relief doors and check for the operation by hand or tool
Check flame trap for cleanliness
Protection against Crankcase Explosion: Oil Mist Detector Warning prior to a crankcase explosion Crankcase relief doors Releases pressure inside crankcase due to primary explosion, prevent rupture of crankcase and entering fresh air into the crankcase. CRANKCASE RELIEF DOOR: As a practical safeguard against explosions, which occur in a crankcase, explosion relief valves or doors are fitted. These valves serve to relieve excessive crankcase pressures and stop flames being emitted from the crankcase. They must also be self closing to stop the return of atmospheric air to the crankcase. Various designs and arrangements of these valves exist where, on large slow-speed diesels, two door type valves may be fitted to each crankcase or, on a medium-speed diesel, one valve may be used. One design of explosion relief valve is shown in Figure. A light spring holds the valve closed against its seat and a seal ring completes the joint.
A deflector is fitted on the outside of the engine to safeguard personnel from the out flowing gases, and inside the engine, over the valve opening, an oil wetted gauze acts as a flame trap to stop any flames leaving the crankcase. After operation the valve will close automatically under the action of the spring.
The Crankcase relief doors are also fitted to prevent any damage to the crankcase and ingress of fresh air inside the crankcase. The crankcase doors are spring-loaded valves, which lift up in case there is any rise of pressure inside the crankcase. Once the pressure is released they re-seat to prevent any ingress of fresh air. This helps especially in case of any ingress of air that can lead to a secondary explosion followed by a lot of surge and damage to the crankcase. The opening pressure and sizes of the valves are specified by different classification societies, depending on the volume of the crankcase. The number of doors to be present
also depends on the bore of the cylinder.
Q60) EXPLAIN FUNCTION OF OIL MIST DETECTOR? ANS) The Oil mist detector takes continuous samples from the main engine crankcase and check whether the sample concentrations of mist are well below the level at which a crankcase explosion can take place. The oil mist is drawn into the instrument with the help of small fan, which takes suction from each crankcase through sampling tubes provided on each crankcase. The oil mist detector consists of a small rotator with which it takes sample from one cylinder at a time and the rotator then turns to the next after approximately 4 seconds. The sample from the rotator goes to the measured cell and the reference cell takes sample from rest of the crankcase to evaluate the difference in oil mist. An overall mist density of the crankcase is also measured by comparing the samples with the fresh air once every rotation of the sampling valve is done. A beam of light from a common lamp is reflected through mirrors and output is measured from a photocell.
Under normal conditions the output from the reference and measured contact is same and hence no deflection is measured. However, a deflection in the output gives an alarm indication and the valve rotator stops at position to know which chamber has high mist concentration. Some engines are even fitted with slowdown alarms so that when the oil mist alarms rings, the engine automatically slows down to prevent crankcase explosion.
Q61) HOW THE TESTING OF CRANKCASE RELIEF DOOR IS CARRIED OUT? ANS)* THE MAIN TESTING OF CRANKCASE RELIEF DOOR IS CARRIED OUT AT SHORE. * BUT THEN ALSO SOME OF THINGS TO BE INSPECTED DURING CRANKCASE INSPECTION: 1. Check crank case explosion relief door wire mesh (should be wet), spring tension, and sealing ring condition. 2. Check the proper functioning of spring of valve by inserting stud in it. 3. Visual condition of valve.
Q62) WHAT IS SPARK EROSION CHECK IN CRANKCASE INSPECTION? ANS)Spark Erosion Checks: Spark erosion is caused by voltage discharged between the main bearings and their respective journals. This voltage originates from the development of galvanic action between the ship’s steel hull and the propeller shaft, with the seawater acting as an electrolyte. This is then transferred to the main crankshaft where, due to dissimilar metals, erosion can occur between the white metaled main bearing and its journal. Spark erosion can only occur if the current is not grounded. The checks consist of a visual check for white metal fragments around the main bearings and respective journals and checking for any electric current between the main bearing white metal and journal. This should be carried out using a micro-amp current meter or similar device for measuring small amperages and voltages. This should read no more than 50mV; any higher than this indicating that shaft grounding is not working. Grounding is carried out by fitting a cathodic protection system to the main propeller drive shaft, consisting of a set of slip rings on the shaft and carbon pick-up brushes. The brushes are wired and grounded to a good earth on the ships structure close by the slip rings. Both components should be checked regularly for wear; especially if a currentis picked up between main bearings and journal during crankcase inspection. A drawing of one type of cathodic protection is shown below. The oil film acts as a dielectric, so the puncture voltage in the bearing depends on the thickness of the oil film. Remember that as the oil temperature rises, its viscosity decreases, and similarly as the load increases, oil film thickness decreases. Therefore as well as adequate grounding, the temperature and pressure of the oil must be maintained to provide the dielectric effect. In the early stages of spark erosion, slightly roughened pitted areas are acceptable. However, if this is allowed to continue, the roughness will escalate with the small erosions picking up the white metal, hence the silvery white appearance around the main bearing/journal.
Q63) EXPLAIN WORKING OF GEAR PUMP? ANS)A gear pump uses the meshing of gears to pump fluid by displacement.[1] They are one of the most common types of pumps for hydraulic fluid power applications. Gear pumps are also widely used in chemical installations to pump fluid with a certain viscosity. There are two main variations; external gear pumps which use two external spur gears, and internal gear pumps which use an external and an internal spur gear. Gear pumps are positive displacement (or fixed displacement), meaning they pump a constant amount of fluid for each revolution. Some gear pumps are designed to function as either a motor or a pump.
As the gears rotate they separate on the intake side of the pump, creating a void and suction, which is filled by fluid.The .The fluid is carried by the gears to the discharge side of the pump, where the meshing of the gears displaces the fluid. The mechanical clearances are small— small in the order of 10 μm. The tight clearances, along with the speed of rotation, effectively prevent the fluid from leaking backwards. The rigid design of the gears and houses allow for very high pressures and the ability to pump highly viscous fluids. Many variations exist, including; helical and herringbone gear sets (instead of spur gears), lobe shaped rotors similar to Roots Blowers (commonly used as superchargers), superchargers and mechanical designs that allow the stacking of pumps. The most common variations are shown below (the drive gear is shown blue and the idler is shown purple).
Suction and pressure ports need to interface where the gears mesh (shown as dim gray lines in the internal pump images). Some internal gear pumps have an additional, crescent shaped seal (shown above, right).
Generally used in: diesel oil, crude oil, lubes oil & sludge etc.
External gear pumps are similar in pumping action to internal gear pumps in that two gears come into and out of mesh to produce flow. However, the external gear pump uses two identical gears rotating against each other :a motor drives one gear and it in turn drives the other gear. A shaft supports each gear with bearings on both sides of the gear. 1. As the gears come out of mesh, they create expanding volume on the inlet side of the pump. Liquid flows into the cavity and is trapped by the gear teeth as they rotate. 2. Liquid travels around the interior of the casing in the pockets between the teeth and the casing -- it does not pass between the gears. 3. Finally, the meshing of the gears forces liquid through the outlet port under pressure. Because the gears are supported on both sides, external gear pumps are quiet running and are routinely used for high-pressure applications such as hydraulic applications. With no overhung bearing loads, the rotor shaft can't deflect and cause premature wear.
Q64) EXPLAIN WORKING OF CENTRIFUGAL PUMP? ANS) Centrifugal pump principles and working procedure A pump is a machine used to raise liquids from a low point to a high point. In a centrifugal pump liquid enters the centre or eye of the impeller and flows radially out between the vanes, its velocity being increased by the impeller rotation. A diffuser or volute is then used to convert most of the kinetic energy in the liquid into pressure. The arrangement of a centrifugal pump is shown diagrammatically in figure below
Fig: Centrifugal pumping operation A vertical, single stage, single entry, centrifugal pump for general marine duties is shown in Figure here. The mainframe and casing, together with a motor support bracket, house the pumping element assembly. The pumping element is made up of a top cover, a pump shaft, an impeller, a bearing bush and a sealing arrangement around the shaft. The sealing arrangement may be a packed gland or a mechanical seal and the bearing lubrication system will vary according to the type of seal. Replaceable wear rings are fitted to the impeller and the casing. The motor support bracket has two large apertures to provide access to the pumping element, and a coupling spacer is fitted between the motor and pump shaft to enable the removal of the pumping element without disturbing the motor.
Fig: Single entry centrifugal pump
A vertical multi-stage single-entry centrifugal pump used for deep-well cargo pumping is shown in Figure below. This can be considered as a series of centrifugal pumps arranged to supply one another in series and thus progressively increase the discharge pressure. The pump drive is located outside the tank and can be electric, hydraulic or any appropriate means suitable for the location.
A diffuser is fitted to high-pressure centrifugal pumps. This is a ring fixed to the casing, around the impeller, in which there are passages formed by vanes. The passages widen out in the direction of liquid flow and act to convert the kinetic energy of the liquid into pressure energy. Hydraulic balance arrangements are also usual. Some of the high-pressure discharge liquid is directed against a drum or piston arrangement to balance the discharge liquid pressure on the impeller and thus maintain it in an equilibrium position. Centrifugal pumps, while being suitable for most general marine duties, are not self-priming
and require some means of removing air from the suction pipeline and filling it with liquid. Where the liquid to be pumped is at a level higher than the pump, opening an air cock near the pump suction will enable the air to be forced out as the pipeline fills up under the action of gravity. If the pump is below sea water level, and seawater priming is permissible in the system, then opening a seawater injection valve and the air cock on the pump will effect priming. Alternatively an air-pumping unit can be provided to individual pumps or as a central priming system connected to several pumps. The water ring or liquid ring primer can be arranged as an individual unit mounted on the pump and driven by it, or as a motor driven unit mounted separately and serving several pumps. The primer consists of an elliptical casing in which a vaned rotor revolves. The rotor may be separate from the hub and provide the air inlet and discharge ports as shown in Figure down. Alternatively another design has the rotor and hub as one piece with ports on the cover. The rotor vanes revolve and force a ring of liquid to take up the elliptical shape of the casing. The water ring, being elliptical, advances and recedes from the central hub, causing a pumping action to occur. The suction piping system is connected to the air inlet ports and the suction line is thus primed by the removal of air. The air removed from the system is discharged to atmosphere. A reservoir of water is provided to replenish the water ring when necessary.
Fig: Water-ring primer
When starting a centrifugal pump the suction valve is opened and the discharge valve left shut: then the motor is started and the priming unit will prime the suction line. Once the pump is primed the delivery valve can be slowly opened and the quantity of liquid can be regulated by opening or closing the delivery valve. When stopping the pump the delivery valve is closed and the motor stopped. Regular maintenance on the machine will involve attention to lubrication of the shaft bearing and ensuring that the shaft seal or gland is not leaking liquid. Unsatisfactory operation or loss of performance may require minor or major overhauls. Common faults, such as no discharge, may be a result of valves in the system being shut, suction strainers
blocked or other faults occurring in the priming system. Air leaks in the suction piping, a choked impeller or too tight a shaft gland can all lead to poor performance. When dismantling the pump to remove the pumping element any priming pipes or cooling water supply pipes must be disconnected. Modern pumps have a coupling spacer, which can be removed to enable the pumping element to be withdrawn without disturbing the motor: the impeller and shaft can then be readily separated for examination. The shaft-bearing bush together with the casing and impeller wear rings should be examined for wear. Q65) Why centrifugal pump is not self –priming? ANS) This is because of its churning effect it is unable to remove air positively, as mass of air is relatively zero.
Q66) What is Hot well & why it is kept heated? ANS) Hot Well recollects the steam after the work is done and it is condensed. Boiler water tank is known as the hot well because boiler feed pump takes suction from the hot well and gives it to the boiler through feed check valve. It can be called by three different names, they are: Hot well - because the water collected is hot Cascade tank - because it collects the water from the condenser Observation tank - because it is used for observe for any oil or dirt entering the system If any traces of oil are found in the system, it indicates that there is a crack in the steam heating line in side the fuel oil tanks. A sight glass is placed to observe the traces of oil or dirt present in the system. If oil is present in the system then it forms a coating in tubes of the boiler, which may lead to lesser heat transfer to the water in the boiler.
Water is kept heated to avoid oxidation of feed water & also to avoid thermal stress of boiler.
Q67) HOW TO MEASURE MAIN BEARING CLEARENCE OF 2-STROKE DIESEL ENGINE? ANS) * MAINBEARING CLEARENCES ON A 2 STROKE CROSSHEAD ENGINE ARE MEASURED USING A SET OF RETRACTABLE FEELERS SOMETIMES REFFERED TO AS “SWEDISH FEELERS” •
THE CLEARENCE IS MEASURED AT THE TOP OF THE BEARING, & TO OBTAIN ACCESS. THE ENGINE IS FIRST TURNED SO THAT THE CRANKWEBS ARE HORIZONTAL.
• • •
•
BY SITTING ON THE CRANKWEB, SWEDISH FEELERS CAN BE SLID DOWN THE GAP BETWEEN WEB & BEARING. THE CLEARENCE CAN BE MEASURED BY EXTENDING THE FEELERS IN TO THE GAP BETWEEN JOURNAL & BEARING. THE FEELERS SHOULD BE FULLY RETRACTED BEFORE ATTEMPTING TO REMOVE THEM; IF THEY ARE NOT, THERE IS A CHANCE OF BREAKING A FEELER IN THE CLEARENCE GAP, MEANING THE BEARING WILL HAVE TO BE LIFTED. MODERN BEARINGS ARE USUALLY OF THINWALL TYPE. THE CLEARENCE ON THESE BEARINGS IS NON ADJUSTABLE & THE BEARING IS CHANGED WHEN THE CLEARENCE HAS REACHED A MAXIMUM.
FOR BETTER UNDERSTANDING WITH PICTURES REFER:http://www.marinediesels.info/repairs/main_bearing_clearance.htm
Q68) EXPLAIN MARPOL? ANS) I. MARPOL ANNEXES The MARPOL Convention includes 6 technical Annexes. Annexes I and II, dealing with oil and bulk noxious liquid substances respectively, are mandatory, in the sense that ratification of the Convention is impossible without ratification of these Annexes. Annexes III, IV, V and VI, dealing respectively with harmful substances in packaged forms, sewage, garbage and air pollution are optional. The Convention also has two Protocols, dealing respectively with reports of incidents involving harmful substances and arbitration. Entry into force is as follows: MARPOL 73/78 2 October 1983 (international) Annex I: 2 October 1983 (international) Annex II: 2 October 1983 (international) Annex III: 1 July 1992 (international) Annex IV: 27 September 2003 (international) Annex V: 31 December 1988 (international) Annex VI: 19 sept 2005 The Annexes can be summarized as follows: Annex I - Oil Oil mixtures, distillates, gasoline, jet fuels, etc. Annex II - Noxious liquid substances Mainly chemicals including acids, alcohols, castor oil, hydrogen peroxide, pentane, etc. Also citric juice, glycerin, milk, molasses, wine, etc. Annex III - Harmful substances in packaged form Includes freight containers, portable tanks, road and rail tank wagons, etc. Annex IV - Sewage Wastes from toilets, drainage from medical premises, drainage from spaces containing live
animals, etc. Annex V - Garbage Plastic bags, synthetic ropes, food wastes, paper products, glass, metal, crockery, packaging material, synthetic fishing nets, etc. Annex VI - Air Pollution
Annex I - Oil Except where otherwise stated, these regulations apply to all tankers of 50 gross tons (about 30 meters in length) and above and other ships of 400 gross tons (about 40 meters) and above. A complete ban on operational discharges of oil from ships except under the following conditions: For All Ships The rate at which oil may be discharged must not exceed 30 liters permile traveled by the ship; The oil content of any bilge water discharged must be below 15 parts per million; Ship must be more than 12 miles from nearest land; and Ship must have in operation an approved oil discharge monitoring and control system, oily water separating equipment or oil filtering equipment. For Tankers No discharge of any oil whatsoever must be made from the cargo spaces of a tanker within 50 miles of the nearest land; The total quantity of oil which a new tanker may discharge in any ballast voyage must not exceed 1/30,000 of the total cargo carrying capacity of the vessel. For existing tankers the limit is 1/15,000 of the cargo capacity. Instantaneous rate at which oil may be discharged must not exceed 30 liters per mile traveled by the ship Small vessels (less than 150 GRT/35m) not covered above No oil or waste oil discharge permitted. Dispose of waste oil and oily bilge water in approved shore facilities Transfer to waste barge if available For guidance on marina operations see the NSW EPA's brochure The definition of oil includes petroleum in any form including crude oil, fuel oil, sludge, oil refuse and refined products (other than petro-chemicals). ‘Nearest land’ is defined as the baseline used to establish the territorial sea. However, the Convention makes a special case for the Great Barrier Reef where nearest land means a line shown between a series of co-ordinates on the outer edge of the reef. All distances relating to discharge prohibitions are measured from these lines. The discharge of oil is completely forbidden in certain ‘special areas’ where the threat to the marine environment is especially great. These include the Mediterranean Sea, the Black Sea,
the Baltic Sea and some areas in the Middle East. Parties to the Convention are obliged to provide adequate facilities for the reception of residues and oily mixtures at oil loading terminals, repair ports, etc.
Annex II - Noxious Liquid Substances This section contains detailed requirements for discharge criteria and measures for the control of pollution by noxious liquid substances carried in bulk. Full details of this Annex is in Appendix The substances are divided into four categories which are graded A to D according to the hazard they present to marine resources, human health or amenities. ·As with Section I there are requirements for the discharge of residues only into reception facilities unless various conditions, depending on the category of the substance are complied with. ·Even stricter restrictions apply in the Baltic Sea and Black Sea.
Annex III - Harmful Substances in Packaged Form This section applies to all ships carrying harmful substances in packaged forms, or in freight containers, portable tanks or road and rail tank wagons. ·It requires the issuing of detailed requirements on packaging, marking, labeling, documentation, stowage, quantity limitations, exceptions and notifications, for preventing or minimizing pollution by harmful substances. ·To help implement this requirement the International Maritime Dangerous Goods Code is being revised to cover pollution aspects.
Annex IV - Sewage Under Annex IV of MARPOL, it is proposed that the discharge of sewage from ships should be controlled in all coastal areas in a manner similar to that of garbage. Australia has already signed and adopted the Annex. The following vessels are required to fit holding tanks and ancillary pollution control equipment: New vessels of 400 gross registered tonnes and over. New vessels certified to carry more than 15 persons. Existing vessels of 400 gross registered tonnes and over (to be fitted within 10 years). Existing vessels certified to carry more than 15 persons (to be fittedwithin 10 years). Sewage is defined as: Drainage and other wastes from any form of toilets and urinals; Drainage from medical premises (dispensary, sick bay, etc) via wash basins, wash tubs and scuppers located in such premises; Drainage from spaces containing live animals; or Other wastewaters when mixed with the drainages defined above.
Discharge of sewage Ships are not permitted to discharge sewage within three miles of the nearest land unless they have in operation an approved treatment plant. Between three and twelve miles from land sewage must be comminuted and disinfected before discharge.
Annex V - Garbage As far as garbage is concerned, specific minimum distances have been set for the disposal of the principal types of garbage. Perhaps most important feature of this section is the complete prohibition placed on the disposal of plastics, including synthetic ropes and fishing nets into the sea. Category of Garbage Plastics, including synthetic ropes, synthetic fishing nets, plastic garbage bags and incinerator ashes from plastic products Dunnage, lining and packing materials which will float Food wastes and all other garbage Garbage that has been ground or comminuted to particles less than 25mm Annex VI – Air Pollution Annex VI deals with air pollution and sets limits on sulphur oxide and nitrogen oxide emissions from ships. Provisions include using low sulphur fuel and associated record keeping requirements. Air pollutant category
Discharge conditions
Ozone-depleting substances Nitrogen Oxides
Discharge Prohibited. Operation of diesel engines >130kW prohibited unless engine is certified to m
Sulphur Oxides
Sulphur content of fuel not to exceed 4.5%.
Incinerators
Incinerators installed after 1 January 2000 must be certified to meet prescrib
Fishing Vessels Fishing vessels must make every effort to retrieve all lost or damaged fishing gear. Lost fishing gear should be reported to the Australian Rescue Co-ordination Centre (RCC) in Canberra. This can easily be done via a Coast Radio Station. If, while engaged in deepwater trawling a net fouls a submarine cable and the net has to be sacrificed, the skipper should anchor a buoy on the spot to assist in the later recovery of the net
Great Barrier Reef Under MARPOL, no discharge of any type is permitted in the area of Great Barrier Reef. In some cases this can be as much as 150 nautical miles from the Queensland coast. Where discharges are prohibited within a certain distance from the land these distances are measured from the outer edge of the reef.
Q69) EXPLAIN IN DETAILS ABOUT SEWAGE, MARPOL ANNEX 4? ANS) Regulations for the prevention of pollution by sewage from ships I.Discharge regulations according to Annex IV, MARPOL 73/78 A) Application according to Regulation 2: - Ships of 400 GT and above - Ships of less than 400 GT, which are certified to carry more than 15 persons B) Mandatory equipment according to Regulations 9 and 10: - Sewage treatment plant of a type approved by the Administration in compliance with IMOCriteria - Comminuting and disinfecting system approved by the Administration fitted with facilities forthe temporary storage of sewage when the ship is less than 3 nm from the nearest land, or - Holding tank of a capacity to the satisfaction of the administration, having regard to theOperation of the ship, the number on persons on board, and provided with a means to indicatevisually the amount of its contents The flanges for discharge connections must have the dimensions specified in Regulation 10, Annex IV, MARPOL 73/78. C) Discharge requirements according to Regulation 11: Under the provisions of Regulation 11, Para. 1, Annex IV MARPOL 73/78, the discharge ofSewage into the sea is prohibited, except when the following requirements are met:
Discharge ofsewage from treatment plants Regulation 11, Para. 1, no. 2comminuted and disinfectedsewage Regulation 11, Para. 1, no. 1untreated sewage Regulation 11, para. 1, no. 1- test results of the treatment Plant are laid down in the Ship’s International SewagePollution PreventionCertificate - Effluent does not producevisible floating solids nor cause discoloration of thesurrounding water - At a distance of more than3 nm from the nearest land II.Special regulations for the Baltic Sea area under the provisions of the Helsinki Convention A) Application and discharge regulations under Art. 1d, Para 1, MARPOL- (In the Baltic Sea area, the discharge requirements according to Regulation 11, Para. 1, Annex IV MARPOL 73/78 also apply to German pleasure craft equipped with toilet holding tanks (seepoint II.B): Under the provisions of the above Regulation, sewage stored in holding tanks is not allowed tobe discharged at a distance of less than 12 nm from the nearest land. When using chemical toilets, care should be taken to use chemicals which do not pollute themarine environment. Discharges of such sewage are subject to Regulation 11, Para. 1, Annex IV, MARPOL 73/78, according to which any discharge of sewage into the sea is prohibited,except when it has been treated in an approved sewage treatment plant, or comminuted anddisinfected using an approved system. Therefore, any discharge of sewage from chemical toiletson board pleasure craft is prohibited; such sewage has to be kept on board in holding tanks until it can be discharged to a reception facility. B) Mandatory equipment under Art. 6b, Para. 1, (Ship Safety Ordinance), BGBl I, p. 3013, 3023, last amended by Art. 2 of the second ordinance to amend environmental regulations in shipping, 9 April 2008 BGBl. I p. 701) - German ships including pleasure craft - ships of other Baltic Sea stateswhich navigate the German Baltic Sea waters (territorial sea and EEZ) have to be equipped withtoilet holding tanks if they have toilets on board (ships not referred to in Regulation 2, Annex IV,MARPOL = ships of less than 400 gross tonnage which are not certified to carry more than 15persons). The required shipboard facilities are subject to HELCOM’s Guidelines for Installation of Toilet Retention Systems and Standard Connections for Sewage on BoardExisting Fishing Vessels, Working Vessels and Pleasure Craft, HELCOM Recommendation 22/1 of 21 March 2001 (As an alternative to fixed retention systems on board, portable toilets or portable retentionSystems may be used provided that they are emptied into shore side reception facilities. Exemptions from the carriage requirement under Art. 6b, para. 3, - Ships built prior to 1 Jan. 1980 - Ships built between 1 Jan. 1980 and 1 Jan. 2003
a) Whose hull length and beam is less than 11.50 m and 3.80 m, respectively, or b) Which have been issued by Bundesamt für Seeschifffahrt und Hydrographie with acertificate of exemption from the carriage requirement. III.Special regulations applying to navigable maritime waterways* A) Application and discharge regulations under Art. 1d, para 3, MARPOL- Allwatercraft including pleasure craft, which have a toilet, equipped with a retention system The discharge of sewage on navigable maritime waterways* is prohibited. Exceptions aredischarges from sewage treatment plants according to Regulation 11, para. 1, no. 2, Annex IV,MARPOL 73/78. * Navigable maritime waterways according to Art. 1, para. 1, p. 3, German Traffic Regulations for Navigable Maritime Waterways of 22 Oct. 1998 (BGBl. I, p. 3209, 1999 I p. 193), last amended by Art. 1 of the Ordinance dated 28 June 2006 (BGBl. I, p. 1417). Amendments to MARPOL 73/78 - Annex IV
The revised MARPOL Annex IV containing regulations for the prevention of pollution by sewage from ships was approved by the MEPC in 2000 and can now be formally adopted following the entry into force of the optional Annex in September 2003, with a proposed entry into force date of 1 August 2005.
Annex IV contains a set of regulations regarding discharge of sewage into the sea, ships' equipment and systems for the control of sewage discharge, provision of facilities at ports and terminals for the reception of sewage, and requirements for survey and certification. It includes a model International Sewage Pollution Prevention Certificate to be issued by national shipping administrations to ships under their jurisdiction.
The revised draft Annex will apply to new ships engaged in international voyages, of 400 gross tonnage and above or which are certified to carry more than 15 persons. Existing ships will be required to comply with the provisions of the revised Annex IV five years after the date of its entry into force. Once in force, the Annex will require ships to be equipped with either a sewage treatment plant or a sewage comminuting and disinfecting system or a sewage-holding tank.
The discharge of sewage into the sea will be prohibited, except when the ship has in operation an approved sewage treatment plant; or is discharging comminuted and disinfected sewage using an approved system at a distance of more than three nautical miles from the nearest land; or is discharging sewage which is not comminuted or disinfected at a distance of more than 12 nautical miles from the nearest land.
Q70) EXPLAIN THE REGULATION FOR SEWAGE HOLDING TANKS? ANS) Applies to all ships that are: 1.400 gross tons or more, and 2.Less than 400 gross tons but certified to carry more than 15 persons. * A holding tank which is in accordance with the requirement developed by the Classification Society, which should include the amount of fluid, used to transport waste to the holding tank, the number of persons carried and the type of voyage the ship will be employed. * The device is installed in accordance with the society’s electrical standards.
* The piping and installation are in accord with good marine practice and the standards of the Classification Society, and * A pipeline for the discharge of sewage to a shore side reception facility is properly installed. * Be installed as far away as possible from heat sources that can accelerate the growth of bacteria. * Be adequately vented to ensure that there are sufficient changes of air to remove any methane gases that may build up. * Shall have vents that are located away from any accommodation and work spaces and shall be screened to prevent the entry of insects and to act as a flame barrier should gases build up in the tank. * The design of the tank and its associated equipment (pumps, piping and water supply) shall be sufficient to ensure the tanks can be completely discharged and flushed clean.
Q71) EXPLAIN RISE OF FLOOR? ANS) Rise of Floor: - The bottom shell of ship is sometimes sloped up from the keel to the bilge to facilitate drainage. The rise of floor is very small. Q72) DEFINE FREEBOARD & REVERSE BOUYANCY? ANS)Freeboard:-It is the distance from the waterline to the top of the deck plating at the side of the deck amidships. Reserve Buoyancy:- It is the potential buoyancy of a ship and depends upon the intact, watertight volume above the waterline. When a mass is added to ship, or buoyancy is lost due to bilging, the reserve buoyancy is converted into buoyancy by increasing the draught. If the loss in buoyancy exceeds the reserve buoyancy the vessel will sink.
Q73) why tankers have less freeboard? ANS)Oil tankers have lesser area of hatch openings when compared to bulk and containers. So the structural strength is more and safer, hence allowed for lesser freeboard Q74) WHAT IS STABILITY OF SHIP? HOW A STABLE SHIP COMES TO UPRIGHT POSITION IF HEELED BY EXTERNAL FORCES? ANS)Ship stability can be defined in simple terms as its characteristics or tendency to return to its original state or upright state, when an external force is applied on or removed from the ship. A ship is at equilibrium when the weight of the ship acting down through centre of gravity is equal to the up thrust force of water acting through centre of buoyancy and when both of these forces are in same vertical line.
B is center of buoyancy and G is center of gravity
A ship will come to its upright position or will become stable, when an external force is applied and removed, if the centre of gravity remains in the same position well below metacentric height of the ship. When ship is inclined, centre of buoyancy shifts from B to B1, which creates a movement and the righting lever returns the ship to its original position and makes it stable. M is metacenter and GZ is righting lever A ship is seaworthy if it fulfills two important stability criteria- Intact and Damage stability.
Intact and damage stability are very important factors that govern the overall stability of the ship. Q75) WHAT IS METACENTER & METACENTRIC HEIGHT? ANS)Metacenter: Top: upward thrust of buoyancy (B) and downward thrust of gravity (G) allow a stable ship to right itself when heeled Bottom: with a metacenter (M) below gravity, forces of gravity and buoyancy are further apart and will cause an unstable ship to capsize when heeled
The metacenter had to be determined which is a point where an imaginary vertical line (through the center of buoyancy) intersects another imaginary vertical line (through a new centre of buoyancy) created after the ship is displaced, or tilted, in the water. The center of buoyancy in a floating ship is the point in which all the body parts exactly balance each other and make each other float. In other words, the metacenter remains directly above the center of buoyancy regardless of the tilt of the floating ship. When a sship hip tilts, one side displaces more water than the other side, and the center of buoyancy moves and is no longer directly under the center of gravity; but regardless of the amount of the tilt, the center of buoyancy remains directly below the metacenter. If the metacenter is above the center of gravity, buoyancy restores stability when the ship tilts. If the metacenter is below the center of gravity, the boat is unstable and capsizes. METACENTRIC HEIGHT: - The distance from the centre of gravity of a ship to the metacentre;; it is considered positive if the metacentre lies aabove bove centre of gravity
Ship Stability diagram showing centre of gravity (G), centre of buoyancy (B), and metacentre (M) with ship upright and heeled over to one side. Note that for small angles, G and M are fixed, while B moves as the ship heels, while for big angles both B and M are moving.
The metacentric height is a measurement of the initial static stability of a floating body. It is calculated as the distance between the centre of gravity of a ship and its metacentre (GM). A larger metacentric height implies greater initial stability against overturning. Metacentric height also has implication on the natural period of rolling of a hull, with very large metacentric heights being associated with shorter periods of roll, which are uncomfortable for passengers. Hence, a sufficiently high but not excessively high metacentric height is considered ideal for passenger ships.
Q76) what is tender and stiff ship? ANS) Tender Ship: - The ship with a small Metacentric height has a small righting lever at any angle & will roll easily is said to be tender ship. In tender ship, in this centre of gravity lies below the transverse metacentre. The GM is more than GZ. & these kinds of ship are more stable. Stiff Ship: - The ship with a large Metacentric height has a large righting lever at any angle & has considerable resistance to rolling. A stiff ship is very uncomfortable. In it the Centre of Gravity lies above the transverse metacentre. Q77) WHAT IS FREE SURFACE EFFECT & HOW IT IS REDUCED CONSTRUCTIONALLY? ANS)Free Surface Effect: - It has a lot to do with the stability of a ship. A ship that has taken in a lot of water will also experience this kind of phenomenon that will make it unstable. Ships carrying liquid cargo, or Tankers, have to be designed so as to minimize the effects of free liquid surface. Water ballast, fuel oil, fresh water, lubrication oil, and other liquid carried in the ship can also contribute to the free surface effect.
The drawing shows a cross section through the midship of a tanker ship. If there is some dynamic force that makes a ship tilt to one side, notice how the oil in the tank finds its own level el and tends to shift more towards the tilting side. The center of gravity of the oil in the tank will also shift. If the ship has enough buoyancy, it is able to right itself. However, if the tilt is too big, the shift in the center of gravity of the oi oill may become too big. Instead of righting the ship, the buoyancy force on the ship may even turn the ship in the same direction of tilt, and the ship rotates and overturns.
What can be done to minimize the free surface effect?
The ship is fitted with compartments so that there are several tanks instead of one big tank. Even though the same quantity of oil is carried, notice how the oil behaves. The center of gravity of individual oil tanks will also shift, but the summation of aall ll the centers of gravities
does not shift the center of gravity of the ship that significantly as before. Another way to minimize the free surface effect is to fill the tanks nearly full. In this case there is less room for the liquid to move about freely. This method may be a bit difficult to control for tanks carrying consumables like fuel oil, domestic water, and potable water. The shape of the tanks can also be built to ensure stability, but in most cases, ships are built for maximum storage capacity and the rectangular cross sectional shape is most feasible. The tanks in a Tanker are built in compartments for this purpose. The sides of the tanks also serve to protect the ship from complete flooding should some damage to its hull occur. REFER:-http://www.freemarine.com/i8freesurface.htm
Q78) EXPLAIN THE PURPOSE & LOCATION OF COLLISION BULKHEAD? ANS)Purpose: Avoids flooding of ship in case of damage to bows. Location: Location is such that it is not so much forward as to get damaged on impact, Neither it should be too far aft so that compartment flooded forward causes extensive trim by head. As a rule located at minimum distance to get maximum space for cargo. Minimum at 1/20 of ships length from forward perpendicular The collision bulkhead is continuous to upper most continuous deck The collision bulkhead is 20% stronger than other bulkheads Collision bulkhead is 5 to 8 percent of ships length from forward. Q79) WHAT IS BULKHEAD & EXPLAIN DIFFERENT TYPES OF BULKHEAD? ANS)There are three basic types of bulkhead, watertight, non-watertight and tank. Different types of bulkheads are designed to carry out different functions. The watertight bulkhead several important ones; i. It divides the ship into watertight compartments giving a buoyancy reserve in the event of hull being breached. The number of compartments is governed by regulation and type of vessel ii. Cargo separation iii. They restrict the passage of flame iv. Increased transverse strength, in effect they act like ends of a box
v. Longitudinal deck girders and deck longitudinal are supported by transverse watertight bulkheads, which act as pillars
The number of bulkheads depends upon the length of the ship and the pos position ition of the machinery. There must be a collision bulkhead positioned at least 1/20th of the distance from the forward perpendicular. This must be continuous to the uppermost continuous deck. The stern tube must be enclosed in a watertight compartment form formed ed by the stern frame and the after peak bulkhead which may terminate at the first continuous deck above the waterline. The engine room must be contained between two watertight bulkheads one of which may be the after peak bulkhead. Each main hold watertightt bulkhead must extend to the uppermost continuous deck unless the freeboard is measured from the second deck in which case the bulkhead can extend to the second deck. A watertight bulkhead is formed from plates attached to the shell, deck and tank top by means of welding. The bulkheads are designed to withstand a full headwater pressure and because of this the thickness of the plating at the bottom ofthe bulkhead may be greater than that at the top. Vertical stiffeners are positioned 760mm apart except were wer corrugated
bulkheads are used.
Watertight bulkheads must be tested with a hose at a pressure of 200 Kn/m2 . The test being carried out from the side on which the stiffeners are fitted and the bulkhead must remain watertight. Watertightbulkheads, which h are penetrated by pipes, cables etc. must be provided with suitable glands that prevent the passage of water. Bulkhead definitions Class A Are divisions forming bulkheads and decks that; Constructed of steel or equivalent
Suitably stiffened Prevent passage of smoke and flame to the end of one hour standard fire test Insulated using non-combustible material so that average temperature on exposed side does not rise above 140oC and point temperature above 180oC. The time the bulkhead complies with this governs its class
A-60 60min
A-30 30Min
A-15 15Min
A-0 0Min Class B These are divisions formed by bulkheads, decks, ceilings and lining Prevent passage of flame for first half hour of standard fire test Insulated so average exposed side temperature does not rise more than 139oC above original and no single point rises more than 225oC above original. The time the bulkhead complies with this governs its class
B-15 15Min
B-0 0Min Constructed of non-combustible material and all materials entering the construction are similarly non-combustible except where permitted Class C These are divisions constructed of approved non-combustible materials. Combustible veneers are allowed were they meet other criteria Main vertical zones Divided by Class A bulkheads and not exceeding 40m in length a. Flat Bulkhead b. Corrugated Bulkhead c. Longitudinal Bulkhead d. Transverse Bulkhead. e. Watertight Bulkhead f. Non-Watertight Bulkhead g. Fire Class A Bulkhead h. Fire Class B Bulkhead i. Fire Class C Bulkhead j. Collision Bulkhead. k. Insulated bulkhead
Q80) EXPLAIN CORRUGATED BULKHEAD? ANS)Corrugated Bulkheads: - These are bulkheads, which do not have, steel stiffeners. Like in containers, the plate itself is corrugated to provide adequate stiffness. Largely used in bulk carrier constructions. Corrugated watertight bulkheads: - The use of corrugations orswedgesina plate instead of welded stiffeners produces as strongastructure with a reductioninweight. The troughs are vertical on transverse bulkheads but onlongitudinal bulkheads they must be horizontal in order to add to the longitudinal strength of theship. The corrugations orswedgesare made in the platingstrakesprior to fabrication of thecomplete bulkhead. As a consequence, the strakes run vertically and the platingmust be of uniform thickness and adequate to support the
greater loads at the bottom of the bulkhead. Thisgreater thickness of plate offsets to some extent the savingin weight through not addingstiffenersto the bulkhead. The edges of the corrugated bulkhead, which join to the shell plating,may have a stiffened flat plate fitted to increase transverse strength and simplifyfittingthebulkhead to the shell. Onhigh bulkheads with vertical corrugations, diaphragm plates are fitted across the troughs. This prevents any possible collapse of the corrugations. A watertight floor is fitted in the double bottom directly below everymain transverse bulkhead.Where a watertight bulkheadis penetrated, e.g. by pipe work, a watertight closure around thepenetrationmust be ensured bya collar fully welded to the pipe and the bulkhead.
CORRUGATED BULKHEAD
PLAIN BULKHEAD
Q81) WHAT ARE DIFFERENT METHODS OF REDUCING THE ROLLI ROLLING NG OF A SHIP? SKETCH THE ATTACHMENT OF BILGE KEEL. WHAT ENSURES SHIP SIDE WILL NOT BE DAMAGED IF BILGE KEEL SUFFERS DAMAGE? ANS) Bilge keel: - A bilge keel is a long fin of metal, often in a "V" shape, welded along the length of the ship at the turn of the bilge. Antiroll tanks: - tanks within the vessel fitted with baffles intended to slow the rate of water transfer from the port side of the tank to the starboard side. The tank is designed such that a larger amount of water is trapped on the higher side of the vessel. This is intended to have an effect completely opposite to that of the free surface effect. Outriggers: - Rolling is reduced either by the force required to submerge buoyant floats or by hydrodynamic foils. Paravanes: - employed by slow moving vessels (such as fishing vessels) to incr increase ease stability.
Active systems: - Active stability systems are defined by the need to input energy to the system in the form of a pump, hydraulic piston, or electric actuator. These systems include stabilizer fins attached to the side of the vessel or tanks in which fluid is pumped around to counteract the motion of the vessel. Stabilizer fins: - Active fin stabilizers are normally used to reduce the roll that a vessel experiences while under way or, more recently, while at rest. The fins extend beyond the hull of the vessel below the waterline and alter their angle of attack depending upon heel angle and rate-of-roll of the vessel. They operate similar to airplane ailerons. Cruise ships and yachts frequently use this type of stabilizer system. Gyroscopic internal stabilizers
Attachment: Bilge keels, particularly on steel vessels, are "lightly welded" along a portion of the vessels length. This allows the bilge keel to be deformed or detached in case of impact without risking the vessels hull. Typically, short sections will be welded, with gaps between. The bilge keel will be attached to a backing strip - a strip of metal, which prevents the bilge keel from propagating cracks into the hull when damaged. Most ships are fitted with some form of bilge keel the prime function of which is to help damp the rolling motion of the vessel. Other relatively minor advantages of the bilge keel are protection for the bilge on grounding, and increased longitudinal strength at the bilge. The damping action provided by the bilge keep is relatively small but effective, and virtually without cost after the construction of the ship. It is carefully positioned on the ship so as to avoid excessive drag when the ship is underway; and to achieve a minimum drag; various positions of the bilge keel may be tested on the ship model used to predict power requirements. This bilge keel then generally runs over the midship portion of the hull, often perpendicular to the turn of the bilge. There are many forms of bilge keel construction, and some quite elaborate arrangements have been adopted in an attempt to improve the damping performance whilst reducing any drag. Care is required in the design of the bilge keel, for although it would not be considered as a critical strength member of the hull structure, the region of its attachment is fairly highly stressed owing to its distance from the neutral axis. Cracks have originated in the bilge keel and propagated into the bilge plate causing failure of the main structure.
Proper Placement: Bilge keels should be situated so they will not strike the wharf or another vessel when tying alongside. The bilge keels should also not extend below the baseline of the vessel so as not to be damaged if the vessel runs aground. The only exception to this is seen on vessels that are designed to be loaded/unloaded while aground, in this case the bilge keels are backed with more structure tructure to help support the vessel (a feature on some sailboats, were the vessels prominent bilge keels will self self-supported supported the boat when beached). The bilge keel itself should be aligned with the vessels flow lines, to minimize drag.
Q82) How much length bilge keel extends to? ANS) It is half of the length of the ship. Starting from midship to fore & aft equally distance.
Q83) DRAW MIDSHIP SECTION OF OIL TANKER? ANS)
xxx Misalignment Cross-tie in centre tank
Stress concentrationXXX concentration
Cross-tie tie in wing tank Stress concentration XXX
Misalignment
Q84) DRAW MIDSHIP SECTION FOR A BULK CARRIER?
Q85) WHAT IS A MARGIN LINE? ANS).It is the imaginary line, which is drawn 75mm below the uppermost continuous deck. It denotes the limit, up to which can be flooded/ loaded without sinking. For a ship which has a continuous bulkhead deck, the margin line is to be taken as a line drawn not less than 76 mm be below low the upper surface of the bulkhead deck at side, except that where there is a variation in the thickness of the bulkhead deck at side the upper surface of the deck should be taken at the least thickness of deck at side above the beam. If desired however,, the upper surface of the deck may be taken at the mean thickness of the
deck at side above the beam as calculated for the whole length of the deck, provided that the thickness is no greater than the least thickness plus 50 mm. See figure 2.1.2.1 a) and 2.1.2.1
b). Q86) EXPLAIN ANGLE OF LOLL? ANS)It is the angle at which the ship with initial negative Metacentric height will lie at rest in still water. If the ship is further inclined to an angle less than angle of loll, the ship will sink. When a ship with ne gative initial me tacentric height is incli ned to a small angle, the ri ghting lever is ne gative, resulti ng in a capsizing mo ment. This effect is shown i n Figure 24.1(a) and i t can be seen that the ship will te nd to he el still further.
At a large angle o f he el the centre o f buoyanc y will have move d furthe rout the low side and the force of buoyanc y can no longer be considered toac t vertically upwards though M, the initial me tacentre. If, by he eling stillfurthe r, the centre of buoyancy can move out far e nou gh to lie verticallyunder G the centre of gravity, as in Figure 24.1(b), the righting lever andthus the ri ghting moment, will be zero.
The angle of he el at which this occurs is referre d to as the angle of lollandm a y b e d e f i n e d a s t h e a n g le t o w h i c h a s h i p w i t h n e g a t i v e i n i t i a l metacentri c height will lie at re st in still water. If the ship should now be incli ned to an angle greater than th e angle of lo ll, as shown i n Figure 24.1(c), the righ ting lever will be positive, giving a m o m e n t t o r e t u r n t h e s h i p t o t h e a n g le o f lo l l. Q87) WHAT IS PLIMSOLL MARKING? ANS) Mark painted on both sides of merchant ships to indicate the maximum point they are allowed to sink to when loaded, depending on the specific gravity of water which varies according to season and place. This mark is accompanied by a circle bisected by a horizontal
line and letters indicating the ship's registration society. Plimsoll mark was made compulsory in 1876 in UK, and is named after Samuel Plimsoll (1824-98), a member of parliament who campaigned for better and safer workconditions for sailors. Also called Plimsoll line. The original "Plimsoll Mark" was a circle with a horizontal line through it to show the maximum draft of a ship. Additional marks have been added over the years, allowing for different water densities and expected sea conditions. Letters may also appear to the sides of the mark indicating the classification society that has surveyed the vessel's load line. The initials used include AB for the American Bureau of Shipping, LR for Lloyd's Register, GL for Germanischer Lloyd, BV for Bureau VERITAS, IR for the Indian Register of Shipping, RI for the Registro Italiano Navale and NV for Det Norske VERITAS. These letters should be approximately 115 millimeters in height and 75 millimeters in width.[6] The Load Line Length is referred to during and following load line calculations. The letters on the Load line marks have the following meanings: TF – Tropical Fresh Water F – Fresh Water T – Tropical Seawater S – Summer Temperate Seawater W – Winter Temperate Seawater WNA – Winter North Atlantic Fresh water is considered to have a density of 1000 kg/m³ and seawater 1025 kg/m³. Fresh watermarks make allowance for the fact that the ship will float deeper in fresh water than salt water. A ship loaded to her Fresh Water mark in fresh water will float at her Summer Mark once she has passed into seawater. Similarly if loaded to her Tropical Fresh water mark she will float at her Tropical Mark once she passes in to sea water. The summer load line is the primary load line and it is from this mark that all other marks are derived. The position of the summer load line is calculated from the Load Line Rules and depends on many factors such as length of ship, type of ship, type and number of superstructures, amount of sheer, bow height and so on. The horizontal line through the circle of the Plimsoll mark is at the same level as the summer load line. The winter load line is one forty-eighth of the summer load draft below the summer load line. The Tropical load line is one forty-eighth of the summer load draft above the summer load line. The Fresh Water load line is an amount equal to centimeters above the summer load line where is the displacementin metric tones at the summer load draft and T is the metric tones per centimeter immersion at that draft. In any case where cannot be ascertained the fresh water load line is at the same level as the tropical load line. The position of the Tropical Fresh load line relative to the tropical load line is found in the same way as the fresh water load line is to the summer load line. The Winter North Atlantic load line is used by vessels not exceeding 100 meters in length when in certain areas of the North Atlantic Ocean during the winter period. When assigned it is 50 millimeters below the winter mark.
Timber load line marks Certain vessels are assigned Timber Freeboards but before these can be assigned certain additional conditions have to be met. One of these conditions is that the vessel must have a forecastle of at least 0.07 the length of the vessel and of not less than standard height, which is 1.8 meters for a vessel 75 meters or less in length and 2.3 meters for a vessel 125 meters or more in length with intermediate heights for intermediate lengths. A poop or raised quarterdeck is also required if the length is less than 100 meters. The letter L prefixes the load line marks to indicate a timber load line. Except for the Timber Winter North Atlantic freeboard the other freeboards are less than the standard freeboards. This allows these ships to carry additional timber as deck cargo, but with the facility to jettison this cargo. The letters on the Timber Load line marks have the following meanings: LTF – Timber Tropical Fresh Water LF – Timber Fresh Water LT – Timber Tropical Seawater LS – Timber Summer Seawater LW – Timber Winter Seawater LWNA –Timber Winter North Atlantic The Summer Timber load line is arrived at from the appropriate tables in the Load Line Rules.
The Winter Timber load line is one thirty-sixth of the Summer Timber load draft below the Summer Timber load line. The Tropical Timber load line is one forty-eighth of the Summer Timber load draft above the summer timber load line. The Timber Fresh and the Tropical Timber Fresh load lines are calculated in a similar way to the Fresh Water and Tropical Fresh water load lines except that the displacement used in the formula is that of the vessel at her Summer Timber load draft. If this cannot be ascertained then these marks will be one forty-eighth of the Timber Summer draft above the Timber Summer and Timber Tropical marks respectively. The Timber Winter North Atlantic load line is at the same level as the Winter North Atlantic load line.
Q88) what is block coefficient. If we say that block coefficient of one ship is 0.9 and 0ther 0.95. What does it mean? ANS)Block Coefficient: - It is the ratio of volume of displacement to the product of the length, breadth & draught. Cb = Volume of displacement / (L x B x d) When Block coefficient is more, it means Volume of displacement is more.
Q89) Regulations for pumping out ER bilges in Special areas and outside special areas.
ANS)Pumping out ER Bilges outside special area: As per Marpol Annex I, Regulation 15. Any discharge into the sea of oily or oily mixtures from ships of 400 GRT & above shall be prohibited except when all the following conditions are satisfied: 1. The ship should be proceeding enroute from Point A to point B. 2. The oily mixture is processed through an oil filtering equipment. 3. The oily content of the effluent without dilution does not exceed more than 15ppm. 4. The oily mixture does not originate from cargo pump room bilges on oil tankers. 5. The oily mixture, in case of oil tankers, is not mixed with oil cargo residues. Pumping out ER Bilges inside special area: 1. The ship should be proceeding enroute from Point A to Point B. 2. The oily mixture is processed through an Oil filtering Equipment approved by the
Administration. 3. The oil content of the effluent without dilution does not exceed more than 15ppm. 4. The oily mixture does not originate from Cargo pump room bilges on oil tankers. 5. The oily mixture in case of oil tankers is not mixed with oil cargo residues. 6. Any discharge into sea of oil or oily mixtures from any ship shall be prohibited in Antarctic area.
Q90) Name special areas. ANS)As Per MARPOL Annex 1, Regulation 1, the special areas are: 1. Mediterranean Sea 2. Baltic sea 3. Black sea 4. Red Sea 5. Gulf area 6. Gulf of Aden area 7. Antarctic area. 8. North West European Waters 9. Oman area of the Arabian Sea.
Q91)Regulations for pumping out p/p room bilges. ANS)As per MARPOL Annex 1, Regulation 34. Outside Special area. 1. The tanker is not within a special area. 2. The tanker is more than 50 nautical miles away from the nearest land. 3. The tanker is proceeding enroute from Point A to point B. 4. The instantaneous rate of discharge of oil content does not exceed 30litres/ nautical miles. 5. The total quantity of oil discharged into the sea does not exceed 1/30000 of the total quantity of the particular cargo. 6. The tanker has in operation an Oil Discharge Monitoring and Control System & slop tank
arrangement approved by the Administration.
Inside Special Area Any discharge into the sea of oil or oily mixture from the cargo area of an oil tanker shall be prohibited while in special area.
Q92) Explain the procedure to pump out ER Bilge step by step. ANS) a. Inform Chief Engineer. b. Note down the V/L Position from the bridge. c. Take the sounding of the bilge tank. d. Check the 15ppm alarm for its proper working. e. Open the overboard valve, open seawater valve & bilge pump inlet and outlet valve. f. Note down the time of starting. g. Start the bilge pump & fill the OWS with seawater. Let the OWS run on seawater for 10-15 minutes. h. Slowly close the seawater inlet valve & start opening the outlet valve of the bilge tank.
Q93) SOPEP? Purpose. ANS) SOPEP: - Shipboard Oil Pollution Emergency Plan As per MARPOL Annex 1, Regulation 37: Every oil tanker of 150GRT and above and every ship other than oil tanker of 400GRT & above shall carry onboard a SOPEP approved by the administration. The SOPEP consists of: 1. The procedure to be followed by Master & other person having charge of the ship to report an Oil Pollution incident. 2. The list of authorities or persons to be contacted in event of Oil Pollution incident. 3. A detailed description of the action to be taken immediately by persons onboard to reduce or control the discharge of oil. 4. The procedures & point of contact on the ship for coordinating ship board action with national & local authorities. Q94) HOW GARBAGE IS DISPOSED OFF? ANS) As per MARPOL Annex V, Regulation for the prevention of pollution by Garbage from ship. 1. The disposal into the sea of all plastics, plastic garbage bags and incinerator ashes from plastic products, which may contain toxic or heavy metal residues, is prohibited. 2. The disposal of garbage i.e., Dunn age, lining & packing materials to be made 25 Nautical miles away from the nearest land. 3. Disposal of food wastes and all other garbage including paper products, rags, glass, metal to be made 12 Nautical miles away from the nearest land. 4. Disposal of food wastes can be permitted if it has passed through a comminuter or grinder; distance is more than 3 Nautical miles from the nearest land. Such comminuted or
ground garbage shall be capable of passing through a screen with openings no greater than 25mm. Q95) What chapter of Solas refers to Bulk carriers, Chemical tankers, ISM code, and ISPS code? ANS) Bulk Carrier: -SOLAS Chapter 12: - Additional Safety Requirement for Bulk Carriers Chemical Tankers: - SOLAS Chapter 7 Carriage of Dangerous goods. ISM Code: - SOLAS Chapter 9 Management for the safe operation of ship. ISPS Code: - SOLAS Chapter 11-2 Special Measures to enhance maritime security.
Q96) HOW THE TESTING OF EMERGENCY GENERATOR IS CARRIED OUT? ANS)Emergency generator on ship provides power in case the main generators of the ship fails and creates a “dead or blackout condition”. According to general requirement, at least two modes of starting an emergency generator should be available. The two modes should be – battery start and hydraulic or pneumatic start. The Port state control (PSC) might detain a ship or provide some time to correct any kind of deficiency found if the second mode of starting is not operating. Testing of Emergency Generator: The testing of ship’s emergency generator is done every week (as part of weekly checks) by running it unloaded to check if it starts on battery mode. The hydraulic start is done every month to ensure that it is working fine. Also every month automatic start of generator is also done to check its automatic operation and to see whether it comes on load.
Procedure for Battery Start: -
1 Go to the emergency generator room and find the panel for emergency generator. 2 Put the switch on the test mode from automatic mode. The generator will start automatically but will not come on load. 3 Check voltage and frequency in the meter. 4 Keep the generator running for 10-15 min and check the exhaust temp and other parameters. 5 Check the sump level. 6 For stopping the generator, put the switch in manual and then stop the generator.
Procedure for Hydraulic Start: 1 Out the switch in manual mode as stated above and check the pressure gauge for sufficient oil pressure. 2 Open the valve from accumulator to generator.
3 Push the spring-loaded valve and the generator should start. 4 Check voltage and frequency. 5 Keep the generator running for 10-15 min and check the exhaust temp and other parameters. 6 Check the sump level 7 For stopping, use the manual stop button from the panel. 8 After stopping the generator, pressurize the hydraulic accumulator to desired pressure.
9 Close the valve from accumulator to generator. Procedure for Automatic Start: 1 For automatic start, we know that there is a breaker, which connects Emergency Switch Board (ESB) and Main Switch Board (MSB); and there is also an interlock provided due to which the emergency generator and Main power of the ship cannot be supplied together.
2 Therefore, we simulate by opening the breaker from the tie line, which can be done from the MSB or the ESB panel. 3 After opening the breaker, the emergency generator starts automatically with the help of batteries and will supply essential power to machinery and pumps connected to ESB. 4 For stopping the generator, the breaker is closed again and due to the interlock the generator becomes off load. 5 Now again put the switch to manual mode to stop the generator. 6 Press stop and the generator will stop.
Q97) Requirements for emergency generating sets? ANS)Requirements for emergency generating sets involve starting in cold condition and starting energy-storing devices. The Convention contains the following in the regulations: Emergency generating sets shall be capable of being readily started at a temperature of 0°C. If this is impracticable, or if lower temperatures are likely to be encountered,
provision shall be made for the maintenance of heating arrangements. Each emergency generating set arranged to be automatically started shall be equipped with starting devices approved by the Administration with a stored energy capability of at least three consecutive starts. A second source of energy shall be provided for an additional three starts within 30 min unless manual starting can be demonstrated to be effective. The stored energy shall be maintained at all times, as follows: Electrical and hydraulic starting systems shall be maintained from the emergency switchboard; Compressed air starting systems may be maintained by the main or auxiliary compressed air receivers through a suitable non-return valve or by an emergency air compressor which, if electrically driven, is supplied from the emergency switchboard; All of these starting, charging and energy-storing devices shall be located in the emergency generator space; […]. This does not preclude the supply to the air receiver of the emergency generating set from the main or auxiliary compressed air system through the non-return valve fitted in the emergency generator space. Where automatic starting is not required, manual starting is permissible, such as manual cranking, inertia starters, manually charged hydraulic accumulators, or powder charge cartridges, where they can be demonstrated as being effective. When manual starting is not practicable, the requirements of paragraphs 2 and 3 shall be complied with except that starting may be manually initiated. The section on electrical installations sets out all the requirements concerning a ship's power supply. Clearly, Regulation 44 provides requirements for the starting systems of emergency generating sets. SOLAS Regulations II-1/42 and II-1/43 address emergency source of electrical power inpassenger ships and cargo ships respectively. Q98) TO WHAT ALL SYSTEMS THE EMERGENCY GENERATOR SUPPLIES POWER? ANS) In case of the failure of the main power generation system on the ship, an emergency power system or a standby system is also present. The emergency power supply ensures that the essential machinery and system continues to operate the ship. Batteries can supply emergency power or an emergency generator or even both systems can be used. Rating of the emergency power supply should be made in such a way that it provides supply to the essential systems of the ship such as: a) Steering gear system b) Emergency bilge and fire p/p c) Watertight doors.
d) Fire fighting system. e) Ships navigation lights and emergency lights. f) Communication and alarm system. Emergency generator is normally located outside the machinery space of the ship. This is done mainly to avoid those emergency situations wherein access to the engine room is not possible. A switchboard in the emergency generator room supplies power to different essential machinery.
Q99) Markings on Lifeboat and life raft? ANS) As per LSA Code book Chapter 4. Marking on Lifeboat: a. Name of Ship b. Port of Registry c. IMO Number d. Lifeboat dimension e. Carrying Capacity f. Maker Name g. Serial number Marking on Life raft: a. Name of Ship.
b. Port of Registry c. IMO Number d. Carrying Capacity e. Maker Name f. Serial Number g. Date of last servicing.
Q100) TYPES OF LIFEBOAT? ANS)A lifeboat must carry all the equipments described under SOLAS and LSA codes, which are passed for the survival at sea. This includes rations, fresh water, first aid, compass, distress-signaling equipments like rocket etc. A ship must carry one rescue boat for the rescuing purpose, along with other lifeboats. One of the lifeboats can be designated as a rescue boat, if more than two or more lifeboats are present onboard a ship.
Types of Lifeboat: There are three types of lifeboats used on merchant vessels: Open Lifeboat: As the name suggests, the open lifeboat has no roof and is normally propelled by manual power by using hand-propelled ores. Compression ignition engine may also be provided for the propulsion purpose. However, open lifeboats are becoming obsolete now because of stringent safety norms, but one may find them on older ship.
The open lifeboat doesn’t help much in rain or bad weather and the possibility of water ingress in the highest. Closed lifeboat:
Closed lifeboats are the most popular lifeboats that are used on ships, for they are enclosed which saves the crew from seawater, strong wind and rough weather. Moreover, the water tight integrity is higher in this type of lifeboat and it can also get upright on its own if toppled over by waves. Closed lifeboats are further classified as – Partially enclosed and fully enclosed lifeboats.
Free fall lifeboat: Free fall lifeboat is similar to an enclosed lifeboat but the process of launching is entirely different. They are aerodynamic in nature and thus the boat can penetrate the water without damaging the body when launched from the ship. The free fall lifeboat is located at the aft of the ship, which provides a maximum clear area for free fall.
Q101) Types of Lifeboat Release Mechanisms & SOLAS Requirements for Lifeboats? ANS) There are different types of lifeboats used on board a ship on the basis of the type of ship and other special requirements. Not all the lifeboats have the same type of releasing mechanisms, for the launching of a lifeboat depends on several other factors. In this article we will take a look at the main types of lifeboat releasing mechanisms and also learn about the SOLAS requirements for lifeboats. Types of lifeboat releases: On load and off load release. There are two types of lifeboat releasing mechanisms- on load and off load. These mechanisms release the boat from the davit, which is attached to a wire or fall by means of a hook. By releasing the hook the lifeboat can be set free to propel away from the ship. Off load mechanism: The off load mechanism releases the boat after the load of the boat is transferred to water or the boat has been lowered fully into the sea. When the boat touches the surface of water, the load on the fall and hence the hook releases and due to its mechanism the hook detaches from the fall. If the detachment dose not takes place, any of the crewmembers can remove the hook from the fall. Most of the times the offload mechanism is manually disengaged in case of malfunction; however, in case of fire, it is dangerous to go out and release the hook.
On load mechanism: On load mechanism can release the lifeboat from the wire, with the ship above the water level and with all the crewmembers inside the boat. The load will be still on the fall, as the boat would not have touched the water. Normally the height of about 1 m is kept for the on load release, so that the fall is smooth without damaging the boat and harming the crew inside. A lever is provided inside the boat to operate this mechanism. As the lever is operated from inside, it is safe to free the boat without going of the out lifeboat, when there is a fire on ship.
Free Fall lifeboat release: In Free fall lifeboat, the launching mechanism is similar to on load release. The only difference is that the free fall lifeboat is not lowered till 1m above water level, it is launched from the stowed position by operating a lever located inside the boat, which releases the boat from rest of the davit, and boat slides through the tilted ramp into the water.
SOLAS and LSA code Requirements for lifeboat: -The size, number and the capacity of the lifeboat for a merchant vessel is decided by the type of the ship and number of ship’s crew, but it should not be less then 7.3 m in length and minimum two lifeboats are provided on both side of the ship (port and starboard). -The requirement for lifeboat of a cargo ship with 20,000 GT is that the boat must be capable of launching when the ship is heading with a speed of 5 knots. -The lifeboat must carry all the equipments described under SOLAS, which can be used in survival at sea. It includes rations, fresh water, first aid, compass, distress-signaling equipments like rocket etc. -The ship must carry one rescue boat for rescue purpose along with other lifeboats. One lifeboat can be designated as a rescue boat if more then onelifeboat is present onboard ship. -The gravity davits must be hold and slide down the lifeboat even when the ship is heeled to an angle of 15 degree on either side. Ropes are used to hold the lifeboat in stowed position with cradle. These ropes are called gripes. -The wires, which lift or lower the lifeboat are known as falls and the speed of the lifeboat descent should not be more then 36m/ min which is controlled by means of centrifugal brakes.
-The hoisting time for the boat launching appliance should not be less then 0.3 m/sec with the boat loaded to its full capacity. -The Lifeboat must be painted in international bright orange color with the ship’s call sign printed on it. -The lifeboat station must be easily accessible for all the crewmembers in all circumstances. Safety awareness posters and launching procedures must be posted at lifeboat station. -Regular drills must be carried out to ensure that the ship’s crewmembers are capable of launching the boat with minimal time during real emergency.
Q102) Types of brakes on lifeboat? ANS) 1. Centrifugal brake 2. Dead man Handle
Q103) what is the function of limit switch in lifeboat davit system? ANS) to stop lifeboat winch motor power, when we heave up life boat, so we prevent damages of our machinery with safety. ALSO FOR AVOIDING UNLOADING OF MOTOR. Q104) WHAT IS SPECIALLITY OF TANKER LIFEBOATS? ANS)Tankers are required to carry fireproof lifeboats, tested to survive a flaming oil or petroleum product spill from the tanker. Fire protection of such boats is provided by insulation and sprinkler system, which has pipe system on top, through which water is pumped and sprayed to cool the surface. This system, while prone to engine failure, allows fireproof lifeboats to be built of fiberglass and not only metal. The boat should be fully enclosed type.
Q105) EXPLAIN DECK FOAM FOR FIRE FIGHTING SYSTEM? ANS)Deck foam for fire extinguishing: -Foam for fire protection purposes is an aggregate of air-filled bubbles formed from aqueous solutions, and is lower in density than the lightest flammable liquids. It is mainly used to form a coherent floating blanket on flammable and combustible liquids to prevent or to extinguish fires by excluding air and cooling the fuel. It also pre-vents re-ignition by suppressing formation of flammable vapors. It has the property of adhering to surfaces, providing a degree of exposure protection from adjacent fires. Foam is used as a fire prevention, control, or extinguishing agent for flammable liquid in tanks or processing areas. Foam solution for these hazards may be supplied by fixed systems or portable foam generating systems. Foam Types: -The principal use of foam is to extinguish burning flammable or combustible liquid spills or tank fires by developing a coherent coolant blanket. Foam is the only permanent extinguishing agent used for fires of this type. Its application allows fire fighters
to extinguish fires progressively. A foam blanket covering a liquid surface is capable of preventing vapor transmission for some time, depending on its stability and thickness. Fuel spills may be rendered safe by foam blanketing. The blanket may be removed after a suitable period of time. Foam is used to diminish or halt the generation of flammable vapors from non-burning liquids or solids, and to cut off access to air for combustion. The water content of foam cools and diminishes oxygen by steam displacement. Foam is also used to fill cavities or enclosures where toxic or flammable gases may collect. Foam solutions are conductive and therefore not recommended to be used for electrical fires. Foam CONCENTRATE Types 1. Protein foam concentrate. It is diluted with water to form 3% to 6% solutions depending on the type and, in general, it is only used for crude oil fires. 2. Fluor protein foam concentrate is very similar to protein foam concentrates. It may also deposit a vaporization preventing film on the surface of a liquid fuel. It is diluted with water to form 3% to 6% solutions depending on the type, and is used for crude oil or refined oil products where a higher degree of protection is preferred. 3. Special ‘alcohol type’ foam concentrate forms a foam that has an insoluble barrier in the bubble structure which resists breakdown at the interface of the fuel and foam blanket. It is used for fighting fires in water solution and certain flammable or combustible liquids and solvents that are destructive to regular foam. Mainly used for protection onboard chemical tankers. 4. Synthetic foam concentrate includes: AFFF and medium and high expansion foam concentrates are used to produce foam or foam-to-solution volume ratios from 20:1 to approx. 1000:1 and are used for local protection and engine room hi-ex systems. SOLAS RULES: -For ships carrying chemicals or oils in bulk, SOLAS/IMO require a fixed deck foam system for extinguishing fires on deck or in tanks. In principle, the systems required are identical; however, for chemical tankers, IMO type 2 and 3, the foam system is considerably larger than for crude oil tankers, due to the higher risk of fire in chemicals. Design Figures Oil Tankers: - The foam system capacity shall be a minimum of the largest of the entire cargo tank deck covered with 0.6-l/ m2/min. or 6.0 l/m2/min. for the largest cargo tank. Chemical Tankers: - The foam system capacity shall be a minimum of the largest of the entire cargo tank deck covered with 2.0 l/m2/min. or 20 l/m2/min. for the largest cargo tank. SystemDescription: -All foam systems, consist of a water supply, foam liquid storage, a proportioning device and a distribution system. The water supply pump(s) provide(s) a certain capacity of seawater to the deck foam system, and is/are supplied by the ship’s fire pumps. The foam liquid is stored in a tank. The tank must be complete with vent, contents gauge, and access manhole. The foam is delivered via a high-pressure foam liquid pump to the automatic foam liquid proportionate, which will accurately proportionate foam liquid at 3% to 6% to the seawater flow, irrespective of flow rate or pressure. For satisfactory operation of the proportionator, foam liquid must be supplied with a
minimum pressure of at least 10 meters head higher than the inlet water pressure under all load conditions. The electrically driven foam liquid pump is provided for this purpose. Foam solution is supplied to the deck monitors and hand lines by the deck main fitted with isolating valves. Each monitor is isolated from the main supply pipe by means of butterfly valves, which are normally closed. Four portable foam-making branch pipes are provided. Each branch pipe has a solution rate of 400 l/min.
Q106) AT WHAT INTERVALS THE TESTING & INSPECTION OF FIRE FIGHTING SYSTEM IS TO BE DONE? ANS) Weekly inspections shall be carried out to ensure that: a. All public address systems and general alarm systems are functioning properly; and b. Breathing apparatus cylinders do not present leakages. Monthly inspections shall be carried out to ensure that: a. All fireman's outfits, fire extinguishers, fire hydrants, hose and nozzles are in place, properly arranged, and are in proper condition; b. All fixed fire-fighting system stop valves are in the proper open or closed position, dry pipe sprinkler systems have appropriate pressures as indicated by gauges; c. Sprinkler system pressure tanks have correct levels of water as indicated by glass gauges; d. All sprinkler system pumps automatically operate on reduction of pressure in the systems; e. All fire pumps are operated; and f. All fixed fire-extinguishing installation using extinguishinggases is free from leakage. Quarterly inspections shall be carried out to ensure that: a. All automatic alarms for the sprinkler systems are tested using the test valves for each section; b. The international shore connection is in proper condition according to the specifications of the FSS Code; c. Lockers providing storage for fire-fighting equipment contain proper inventory and equipment is in proper condition; d. All fire doors and fire dampers are tested for local operation; and e.All CO2 bottle connections for cable operating system clips shall be checked for tightness on fixed fire-extinguishing installations. Annual inspections shall be carried out to ensure that: a. All portable fire extinguishers are checked for proper location, charging pressure, and condition according to the ship’s fire plan; b. Fire detection systems are tested for proper operation, as appropriate; c. All fire doors and dampers are tested for remote operation; d. All foam-water and water-spray fixed fire-fighting systems are tested for operation; e. All accessible components of fixed fire-fighting systems are visually inspected for proper condition; f. All fire pumps, including sprinkler system pumps, are flow tested for proper pressures and flows; g. All hydrants are tested for operation;
h. All antifreeze systems are tested for proper solutions; i. Sprinkler system connections from the ship's fire main are tested for operation; j. All fire hoses are hydrostatically tested; k. All Self-contained breathing apparatus (including SCBA’s on lifeboats) should be checked for external condition and air recharging systems checked for air quality; * Every two years, portable fire extinguishers and SCBA’s cylinders shall be checked by a service agent or facility certified by the manufacturer to perform this type of work and accepted by the Recognized Organization issuing the pertinent safety certificate[§]. Every other year, these checks shall be carried out either by a service agent or facility (certified and accepted§) or by a deck or engine officer trained and assigned to this duty. * Halon installations of fire–extinguishing systems on board ships, which keel was laid or at a similar stage of construction on or after October 1994, are prohibited. Moreover, full-scale tests of Halon fire-extinguishing systems on board ships are prohibited since January 1992 in accordance with Resolution A.719 (17)/2(b). However, an annual leakage test shall be carried out, MSC/Circ.600. The Chief Engineer can carry out this test if provided with the proper equipment and training. Two-year service 1. At least once every two years, the following inspections and tests shall be carried out: a.CO2 Fixed System contents shall be verified at least every two years. b.Air shall be blown through the piping of extinguishing gas systems. 2. The blow test (item 9.1(b)) shall be carried out by a service agent or facility certified by the manufacturer to perform this test and accepted by the Recognized Organization issuing the pertinent safety certificate. Three-year service .1. Periodical controls of foam concentrates stored on board .2. The first periodical control of fixed foam fire-extinguishing system and foam concentrates stored on board shall be performed after a period of 3 years (from the original installation date), after that, every year. A record of the age of the foam concentrates and of subsequent control should be kept on board readily available for inspection. Periodical controls or analysis will be performed by an independent or manufacturer’s laboratory, which is accepted by the Recognized Organization issuing the pertinent safety certificate. Tests, controls or analysis of foam will be performed as per MSC/Circ.582, MSC/Circ. 670 and MSC/Circ.798. Five-year service
.1. Hydrostatic testing for all SCBA's cylinders (*) .2. Hydrostatic testing for all SCBA's cylinders shall be carried out by a servicing facility or agent certified by the manufacturer to perform this type of work and accepted by the Recognized Organization issuing the pertinent safety certificate. Test certificates must be provided and kept on board for inspections. Test date and pressure must be stamped or tagged on each cylinder. This test shall not be carried on board. Ten-year Service 1At least once every ten years, the following inspections and tests should be carried out: a.Control valves of fixed fire-fighting systems shall be internally inspected. b.Hydrostatic Pressure Test of Portable Fire Extinguishers 2. Hydrostatic Testing for all Portable Fire Extinguishers and internal inspection of control valves of the fixed fire-fighting systems shall be carried out by a servicing facility or agent certified by the manufacturer to perform this type of work and accepted by the Recognized Organization issuing the pertinent safety certificate. 3. Portable Fire Extinguishers Test certificates must be provided and kept on board for inspections. Test date and pressure must be tagged on each bottle. This test shall not be carried on board. Q107) WHAT TO DO INCASE OF PURIFIER ROOM FIRE? ANS) A purifier room is one of the most probable places in the engine room to catch fire. Purifier room fire has been the reason for several major accidents on various ships in the past. In this article we will learn about everything related to purifier room fires. As we all know, for a fire to happen, three things are needed and in the purifier room all these things are present. These three things are – fuel oil which is present in abundant (lubricating oil in lube oil separator and fuel oil or diesel oil in fuel oil separator), air for combustion, and a heat source such as extremely hot oil, electrical short circuit etc. When all these things are present together and lie within the flammable limit, a fire can take place.
Therefore, if a spray of oil takes place through a leaking pipe over a hot surface or over an electrical point, a fire can immediately take place.
Prevention of Purifier Fire The following points are to be followed in order to prevent purifier room fire: 1) All the pipes leading to the separator are to be double sheathed; the reason for this is that if inner pipe leaks, then it will not spray all over the place but instead it will leak into outer pipe. 2) Drip trays should be provided below the purifier or separator, so that in case of oil spill the oil will not flow and spread in the purifier room and contact with any hot material and catch fire. 3) All the pipes with flanges or connections are to be covered with anti spill tapes which can prevent spill from the flanges in case of a leakage. 4) Fire fighting system such as water mist and CO2 system should be installed. 5) Quick closing valves and remote stopping of pumps and purifier should be provided. 6) Fire detection and alarm system are to be provided so that quick action can be taken. How to fight purifier room fire
A small purifier fire can be easily stopped with the help of small fire extinguisher. In case of a bigger fire, the following steps should be taken: 1) 2) 3)
As soon as fire alarm is sounded, call the chief engineer and locate the fire.
Close the quick closing valves from which the oil is leaking.
Stop the transfer pump.
4) Both transfer and quick closing valves can be closed from remote location like ship control center or from the engine control room.
5) Stop all the motors and electrical equipments, which can be stopped from emergency stop button outside the purifier room.
6) The fire can be stopped with the help of fire extinguisher.
7) In case of a big fire, close the air supply pump and exhaust from the purifier room.
8 )The fire can be stopped by releasing water mist system if present on the ship.
9) Entry in the purifier room is made putting on the fire fighter suit, along with self contained breathing apparatus (SCBA) and fire hose.
10) The fire can be extinguished with the help of spraying water.
11) In case the fire is still not extinguished then the chief engineer will decide about using the carbon dioxide bottles for fighting fire.
12) When these bottles are to be used, there should not be any person present inside the Purifier space as Co2 can cause suffocation due to displacement of air and the person involved may die.
Q108) Types of foams? ANS) a. Low Expansion Foam b. Medium Expansion Foam c. High Expansion foam
Q109) EXPLAIN SPRINKLER SYSTEM OF SHIP? ANS) Sprinkler systems Must be fitted to passenger ships carrying less than 36 passengers in the accommodation spaces and other areas considered necessary be the administration. For passenger ships carrying greater than 36 passengers it must be fitted to accommodation spaces, corridors, and stairwells wells and to control stations (the latter may be served by an alternative system to prevent damage). The system must be of an approved type. See below for full requirements. Generally takes the form of a wet pipe (line continuously flooded) on to which are connected a number of sprinkler head. These heads consist of a valve held shut by a high expansion fluid filled quartzoid bulb. A small air space is incorporated.
When a fire occurs in an adjacent area to this bulb the fluid expands until the air space is filled, increasing internal pressure causes the bulb to fracture. The size of the air gap determines the temperature at which this failure occurs. The valve plug falls out and a jet of water exits, striking the spray generator where it is then distribu distributed ted evenly over the surrounding area. In acting this way only the area of the fire is deluged and damage is minimized.
Water is supplied from an air pressurized water tank (thus the system functions without electrical power), this water is fresh water to minimize damage. The tank is half filled with water and the rest is compressed air at pressure sufficient to ensure that all the water is delivered to the highest sprinkler at sprinkler head working pressure. Once this source of water is exhausted, a pressure sure switch detects falling main pressure. This activates a sea water supply pump. A valve is fitted on the system to allow proper testing of this function. After seawater has entered the system proper flushing with fresh water is required to prevent corrosion A shore connection may be connected to the system to allow function during dry-dock dry High Pressure Water spray system A similar but essentially different system exists for the supply of water under pressure to dry pipes onto which sprinkler heads are ffitted. itted. These sprinkler heads do not have the bulb and valve arrangement. Instead when an area is to be served a relevant isolation valves is opened. The fundamental difference between this and the sprinkler system is that human intervention is required, whereas ereas the sprinkler system is required to be fully automated. Commonly a cross connection via a non non-return return valve exists able to deliver to the water from the high pressure spray system to the sprinkler system
When an isolation valve is opened pressure in the line falls and the seawater pump is started. The air vessel is there to prevent cycling of the pump due to slight water leakage. The fresh water pump is there for flushing and initial filling of wet pipe only. Regulations Taken from SOLAS 1974 Regulat Regulation II/2A Regulation 12 Automatic sprinkler, fire detection and fire alarm systems 1.1 Any required automatic sprinkler, fire detection and fire alarm system shall be capable of immediate operation at all times and no action by the crew shall be necessary to set it in operation. It shall be of the wet pipe type but small exposed sections ma may y be of the dry pipe type where in the opinion ofthe Administration this is a necessary precaution. Any parts of the system, which may be subjected to freezing temperatures in service, shall be suitably protected against freezing. It shall be kept charged at the necessary pressure and shall have provision for a continuous supply of water as required in this regulation. 1.2 Each section of sprinklers shall include means for giving a visual and audible alarm signal automatically at one or more indicating uni units ts whenever any sprinkler comes into operation. Such alarm systems shall be such as to indicate if any fault occurs in the system.
Such units shall indicate in which section served by the system fire has occurred and shall be centralized on the navigation bridge and in addition, visible and audible alarms from the unit shall be located in a position other than on the navigation bridge, so as to ensure that the indication of fire is immediately received by the crew.
2.1 Sprinklers shall be grouped into separate sections, each of which shall contain not more than 200 sprinklers. In passenger ships any section of sprinklers shall not serve more than two decks and shall not be situated in more than one main vertical zone. However, the Administration may permit such a section of sprinklers to serve more than two decks or be situated in more than one main vertical zone, if it is satisfied that the protection of the ship against fire will not thereby be reduced.
2.2 Each section of sprinklers shall be capable of being isolated by one stop valve only. The stop valve in each section shall be readily accessible and its location shall be clearly and permanently indicated. Any unauthorized person shall provide means to prevent the operation of the stop valves.
2.3A gauge indicating the pressure in the system shall be provided at each section stop valve and at a central station.
2.4 The sprinklers shall be resistant to corrosion by marine atmosphere. In accommodation and service spaces the sprinklers shall come into operation within the temperature range from 68АC to 79АC, except that in locations such as drying rooms, where high ambient temperatures might be expected, the operating temperature may be increased by not more than 30АC above the maximum deck head temperature. 2.5 A list or plan shall be displayed at each indicating unit showing the spaces covered and thelocation of the zone in respect of each section. Suitable instructions for testing and maintenance shall be available.
3 Sprinklers shall be placed in an overhead position and spaced in a suitable pattern to maintain an average application rate of not less than 5 l/m2/min over the nominal area covered by the sprinklers. However, the Administration may permit the use of sprinklers providing such an alternative amount of water suitably distributed as has been shown to the satisfaction of the Administration to be not less effective.
4.1 A pressure tank having a volume equal to at least twice that of the charge of water specified in this subparagraph shall be provided. The tank shall contain a standing charge of fresh water, equivalent to the amount of water which would be discharged in one minute by the pump referred to in paragraph 5.2, and the arrangements shall provide for maintaining an air pressure in the tank such as to ensure that where the standing charge of fresh water in the tank has been used the pressure will be not less than the working pressure of the sprinkler, plus the pressure exerted by a head of water measured from the bottom of the tank to the highest sprinkler in the system. Suitable means of replenishing the air under pressure and of replenishing the fresh water charge in the tank shall be provided. A glass gauge shall be provided to indicate the correct level of the water in the tank.
4.2 Means shall be provided to prevent the passage of seawater into the tank.
5.1 An independent power pump shall be provided solely for the purpose of continuing automatically the discharge of water from the sprinklers. The pump shall be brought into
action automatically by the pressure drop in the system before the standing fresh water charge in the pressure tank is completely exhausted.
5.2 The pump and the piping system shall be capable of maintaining the necessary pressure at the level of the highest sprinkler to ensure a continuous output of water sufficient for the simultaneous coverage of a minimum area of 280 m2 at the application rate specified in paragraph 3.
5.3 The pumpshall have fitted on the delivery side a test valve with a short open-ended discharge pipe. The effective area through the valve and pipe shall be adequate to permit the release of the required pump output while maintaining the pressure in the system specified in paragraph 4.1.
5.4 The sea inlet to the pump shall wherever possible be in the space containing the pump and shall be so arranged that when the ship is afloat it will not be necessary to shut off the supply of seawater to the pump for any purpose other than the inspection or repair of the pump.
6 The sprinkler pump and tank shall be situated in a position reasonably remote from any machinery space of category A and shall not be situated in any space required to be protected by the sprinkler system.
7.1 In passenger ships there shall be not less than two sources of power supply for the seawater pump and automatic alarm and detection system. Where the sources of power for the pump are electrical, these shall be a main generator and an emergency source of power. One supply for the pump shall be taken from the main switchboard, and one from the emergency switchboard by separate feeders reserved solely for that purpose. The feeders shall be so arranged as to avoid galleys, machinery spaces and other enclosed spaces of high fire risk except in so far as it is necessary to reach the appropriate switchboards, and shall be run to an automatic changeover switch situated near the sprinkler pump. This switch shall permit the supply of power from the main switchboard so long as a supply is available there from, and be so designed that upon failure of that supply it will automatically change over to the supply from the emergency switchboard. The switches on the main switchboard and the emergency switchboard shall be clearly labeled and normally kept closed. No other switch shall be permitted in the feeders concerned. One of the sources of power supply for the alarm and detection system shall be an emergency source. Where one of the sources of power for the pump is an internal combustion engine it shall, in addition to complying with the provisions of paragraph 6, be so situated that a fire in any protected space will not affect the air supply to the machinery.
7.2 In cargo ships there shall not be less than two sources of power supply for the seawater pump and automatic alarm and detection system. If the pump is electrically driven it shall be connected to the main source of electrical power, which shall be capable of being supplied by at least two generators. The feedersshall be so arranged as to avoid galleys, machinery spaces and other enclosed spaces of high fire risk except in so far as it is necessary to reach the appropriate for the alarm and detection system shall be an emergency source. Where one of the sources of power for the pump is an internal combustion engine it shall, in addition to complying with the provisions of paragraph 6, be so situated that a fire in any protected space will not affect the air supply to the machinery.
8 The sprinkler system shall have a connection from the ship's fire main by way of a lockable screw-down non-return valve at the connection which will prevent a backflow from the sprinkler system to the fire main.
9.1 A test valve shall be provided for testing the automatic alarm for each section of sprinklers by a discharge of water equivalent to the operation of one sprinkler. The test valve for each section shall be situated near the stop valve for that section.
9.2 Means shall be provided for testing the automatic operation of the pump on reduction of pressure in the system.
9.3 Switches shall be provided at one of the indicating positions referred to in paragraph 1.2 which will enable the alarm and the indicators for each section of sprinklers to be tested.
10 Spare sprinkler heads shall be provided for each section of sprinklers to the satisfaction of the Administration.
Q110) HOW SPRINKLER SYSTEM IS TESTED? ANS) Testing procedure: a. Close the section isolating valve, this will raise an alarm indicating zone isolation. b. Now, open the test valve, if no water comes out, then it means the NR valve placed after the section-isolating valve is not leaking. c. Since, the section after the NR valve remains pressurized, opening of the drain valve will cause the water pressure in the section line to decrease. A pressure switch sensor senses the decreased pressure & raises an alarm. d. Now, close the drain valve, open the section isolating stop valve. To check the flow switch, open the flow test switch to activate an alarm. e. All the above alarms will be indicated on the navigation bridge, E/room as well as in the Fire Control Room. The alarm will also indicate the particular zone from where it has risen. f. If all the alarm conditions are satisfied, close all the testing valves, open the sectionisolating valve, purge the sprinkler line by air and again keep the line pressurized. Check from the pressure gauge, that proper pressure has been maintained or not.
Q111) What Chemicals used in DCP extinguisher? ANS) Sodium bicarbonate & Magnesium striate Q112) what are the requirements of a Fixed CO2 Fire Fighting Installation? ANS)The System must give 40% saturation of the Compartment to be filled. 85% of the CO2 charge must be discharged into the Compartment within the first two minutes.
Q113) why should the boiler not be blown down on finding oil contamination? ANS) The boiler should not be blown down, as this will cover all heating surfaces with oil i.e. insulating the tubes, heating surfaces.
Q114) what must the capability of Gravity Davits be with regards heel of ship? ANS)The Davits must be able to lower the Lifeboats when the Ship is heeled to 15° on either side.
Q115) what is the duration and range of a 136L Trolley Foam Extinguisher? ANS) The duration of a 136L Foam Trolley Extinguisher is 15 minutes approximately with a range of around 18m.
Q116) Maintenance on Co2 system? ANS) Check the hinges of the CO2 Room door & grease it. Check the pressure gauge. Check the condition of the blower. Check all lightings are properly working. If Manual pull cables operate the remote release controls, they should be checked to verify the cables & corner pulleys are in good condition and freely move and do not require an excessive amount of travel to activate the system. Check the weight of the CO2 Bottles. The discharge piping & nozzles should be tested to verify that they are not blocked. The test should be performed by isolating the discharge piping from the system & flowing Dry air or nitrogen from test cylinder or through any other suitable means. The hydrostatic test of all the cylinders should be done once in 10 years at least. The alarm to be tested. The CO2 Lines should be blown through with service air. Q117) what testing and maintenance is done regarding Soda Acid and Foam Extinguishers? ANS) The extinguisher containers are pressure vessels, therefore require testing. Containers are initially tested to 25 bar every year for five years and thereafter at four yearly intervals to 20 bars. On Soda Type Extinguishers 20% of contents should be discharged per year and replenished with Foam Type 50%. Where practical the operating mechanism of portable extinguishers should be examined
every three months. Q118) How is a Life raft Launched? ANS)A Life raft is simply launched by releasing it from its lashings, a painter is secured to the Ship and the Life raft container is thrown over the side. Inflation takes place automatically, the container bursting open and the Life raft floats clear. A pressurized cylinder of CO2 is used to inflate the raft. Life rafts must normally be boarded from water level, dry if possible. Q119) What action would you take in the event of Fire breaking out in the Machinery Space? ANS) If a Fire breaks out, the alarm should be raised and the Bridge informed immediately. If the Ship is in Port, the Local Fire Authority should be called. If possible, an attempt should be made to extinguish or limit the fire by any means possible (a Fire in its first few minutes can usually be readily extinguished). Ventilation fans should be stopped (should stop automatically on activation of fire alarm). Openings to the space should be sealed to reduce the supply of air to the fire and to prevent it spreading. Any fuel lines feeding the fire or threatened by it should be isolated. If practicable, combustible materials adjacent to the Fire should be removed. After the Fire has been extinguished, precautions should be taken against spontaneous reignition. Personnel, unless wearing breathing apparatus, should not re-enter a space in which a fire has occurred before it has been fully ventilated. Q120) where would you expect to find a Dry Powder Extinguisher? ANS)It is usually located near Electrical Equipment in the Machinery Space and elsewhere on the Ship.
Q121) why fire line fitted with relief valve and drain valve? ANS)Relief valve: - Relief valve is provided if pumps are capable of developing the pressure exceeding the design pressure of water service pipes, hydrants & hoses. It assists to avoid any overpressure to develop in any part of the fire main. The fire line is fitted with relief valve to prevent the damage to pipe in case, the V/L is fighting fire with the help of shore while in dry-dock. Drain Valve: - Drain valve is fitted to drain the fire line when not in use & also prevent the damage to pipe due to icing, while V/L is operating in Sub-zero temperature area.
Q122) Purpose of isolating valve and where situated? ANS) An isolating valve is fitted to separate the section of fire main within machinery space
containing main fire pumps from the rest of fire main. Generally Situated in the Fire station
Q123) HOW ENTRY IS MADE AFTER EXTINGUISHING FIRE VIA CO2 IN A SPACE? ANS)SAFE USE OF CO2 FIRE EXTINGUISHING SYSTEMS 2.1 It is recommended that in the event of any fire breaking out onboard, including one that requires the fixed CO2 system to be activated, the nearest Coastguard to your position is informed as soon as practicable. 2.2 Carbon dioxide (CO2), a compound of carbon and oxygen, is a colorless gas with a slightly astringent smell causing coughing to occur when inhaled; at high concentrations it is acutely toxic. As it is about 50% heavier than air, it will form a blanket over a fire and smother it. 2.3 To obtain “total flooding” of an engine room, a CO2 concentration of about 35% by volume or more is required to be obtained within 2 minutes. This will reduce the oxygen content of the air in the space to less than 15% to extinguish the fire. At this CO2 concentration human life cannot be supported. 2.4 It is therefore essential that personnel leavethe space as soon as the CO2 warning alarm sounds. CO2 should not be discharged into a space until all those within have left and a full head count has been taken. 2.5 Before a space is filled with CO2 it is essential that the compartment ventilation flaps are properly closed and sealed, ventilation fan emergency stops and all fuel and hydraulic oil remote quick closing valves are operated. 2.6 Whilst safe navigation is always a priority, in the event of a serious machinery space fire it is imperative that all machinery within the affected space, e.g. main engine(s) and generator(s), are shut down to prevent fuel and/or oil feeding the fire. 2.7 Masters, skippers and crew should be fully competent with the remote and local operation of the fixed CO2 fire extinguishing system. 2.8 Masters, skippers and crew should be fully competent with the operation of the remote controls for the isolation of fuel oil, hydraulic oil and ventilation systems from the space. 2.9 Masters, skippers and crew should be fully competent with the maintenance of the fixed CO2 fire extinguishing system. 2.10 Typically, it takes about 15–20 seconds after release of CO2 before the concentration within the space reaches a dangerous level. 2.11 Personnel inadvertently caught in the space when the CO2 is released are
recommended to hold their breathand leave the space immediately. 3. SAFETY PRECAUTIONS AFTER CO2 RELEASE 3.1 It is strongly recommended that expert advice should be obtained from ashore before ventilation of the space or any attempt at re-entry is made. The nearest Coastguard to your position may be contacted who will assist in trying to obtain this advice. Unless specifically requested, the Coastguard as a request for on-scene fire-fighting assistance will not interpret this. 3.2 Immediately after activation of the CO2 system checks should be carried out to ensure that the gas has been correctly released from the cylinders. This can be achieved by feeling the CO2 cylinders, which should be cold to the touch, and visually checking the individual cylinder release valves to ensure they are in the open position. 3.3 Crew should keep well clear of the ventilation flaps to prevent the inhalation of noxious gases. 3.4 Ventilation of the space should not be resumed until it has been definitely established that the fire has been extinguished. This is likely to take several hours. Monitoring the fire boundary to confirm that temperatures are falling, especially in way of the seat of the fire if this is known, may be useful in this regard. Applying controlled amounts of water to the boundaries, by whatever means, tosee if any steam is given off can also be good indicator of the temperature inside the space. 3.5 Entry into a space that has contained CO2 should only be attempted by trained personnel wearing breathing apparatus with safety lines attached and sufficient back up immediately available should difficulties arise. 3.6 In the event that breathing apparatus is not carried onboard and it is really impossible to wait for assistance from ashore, to avoid asphyxiation to personnel, entry should only be attempted when the space has been thoroughly ventilatedwith clean air. This can be achieved by using mechanical or natural means, with more time given for natural ventilation, to remove all residues of CO2 and toxic gases from the fire. 3.7 The number of persons entering the space should limited to those who actually need to be there. An attendant should be detailed to remain at the entrance to the space whilst it is occupied. 3.8 An agreed and tested system of communication shouldbe established between any person entering the space and the attendant at the entrance. 3.9 Should an emergency occur to the personnel within the space, under no circumstances should the attendant enter the space before help has arrived and the situation has been evaluated to ensure the safety of those entering the space to undertake the rescue. 3.10 Ventilation should continue throughout the period that the space is occupied and during temporary breaks.
3.11 In the event that the ventilation system fails any personnel in the space should leave immediately. 3.12 Protection methods, other than a clean source of air, such as smoke filters on an ordinary gas mask, should not be used, as these will not protect the user against the effects of CO2. 3.13 If a space is suspected to be deficient in oxygen a smoke hood will offer no respiratory protection and must not be used for entry. 4. ADDITIONAL RECOMMENDATIONS 4.1 Ensure clear instructions for operating CO2 fixed fire-extinguishing systems are displayed near the remote operating controls, distribution control valves and the gas cylinders. 4.2 Ensure remote controls for fuel oil and hydraulic pumps, quick closing fuel oil valves and closing devices for ventilators, emergency stops for ventilation fans and CO2 fixed fire fighting systems are clearly marked, regularly tested and maintained in good working order. 4.3 Audible and visual CO2 alarms within the machinery spaces, for warning personnel within the spaces that the CO2 fire extinguishing system is about to be operated, should be automatically activated when opening the door of the CO2 release valves control cabinet(s). These alarms should be regularly tested, maintained in good working order and the crew familiar with them.
Q124) EXPLAIN THE SOLAS REGULATION FOR INSTALLATION OF C02 FIXED FIRE FIGHTING SYSTEM? ANS)SOLAS Regulations: CO2 usage on ships has to abide by few safety regulations, as on ship there are lives at stake and measure to fight accidents are few .The main regulations are: * If the CO2 system is installed in the cargo spaces, the quantity of CO2 available should be sufficient enough to give at least a minimum of 30% of the total volume of the largest space that is protected by the CO2 system. * If the CO2 system is installed in machinery spaces, the quantity of CO2 available should be sufficient to give at least a volume equal to either of the following: a) 40% of the total volume of the largest machinery spaces that is protected by the CO2 system. (The volume should exclude that part of the casing where the horizontal area of the casing is 40% or less then the horizontal area of the space taken into consideration and measured midway, between tank top and lowest part of casing) b) 35% of the total volume of the largest machinery spaces that are protected by the CO2
system including the area covered by the casing. It is also a requirement that 85% of the required quantity of gas should be released into the spaces within two minutes of evacuating the fire-affectedspace.
Q125) EXPLAIN ABOUT THE CONSTRUCTION OF CO2 BOTTLES? ANS)Construction of CO2 bottles for fixed fire fighting system: It is imperative that the CO2 bottles are strong and sturdy due to the high internal pressure they are going to withstand. For this reason, the bottles are made from solid drawn steel and are also hydraulically tested up to 228 bars prior to installation. CO2 is retained inside the cylinder in the liquid form under pressure. A siphon tube is provided inside the bottle to ensure that the liquid CO2 is discharged from the bottle or else it would evaporate from the surface, giving a very slow discharge rate and taking away the latent heat would probably cause the remaining CO2 in the bottle to freeze.
Q126) EXPLAIN THE SAFETY FEATURES OF CO2 SYSTEM? ANS)Safety Features: Some special features are provided to the system in order to increase the safety level and also to make operation smooth. The control cabinet doors are installed with a special signaling system. Whenever a person opens the door of the control cabinet in order to operate the CO2 system, an alarm is sounded automatically. This is done to signal crewmembers of CO2 flooding on ship. This is also an indication to leave the fire-affected place and assemble at the muster station. A master valve is also provided on the main pipe going to the machinery or cargo spaces, in order to stop the CO2 supply in case of accidental release.
Q127) WHAT ALL CHECKS TO BE DONE ON TOTAL CO2 FLOODING SYSTEM? ANS)Checks on the system Pipes leading to the spaces should regularly be blown with air to ensure that they are not blocked. The level in the Co2 bottles should be checked on regular basis. If in a particular check, the difference is 10% of the total volume, the bottle should be replaced as soon as possible. Sensors should be checked periodically. Cabinet door alarms should also be checked on regular interval of time.
All the piping’s and connections at the CO2 bottles should be checked regularly.
Q128) EXPLAIN THE CONSTRUCTION & WORKING OF TOTAL FLOODING SYSTEM? ANS)CO2 High Pressure Fire Extinguishing System Characteristics • Suitable for extinguishing in closed spaces like engine rooms, auxiliary rooms, cargo holds, etc. • Extinguish the fire within a short time and leave no residue after extinguishing: shutdown time after a fire willbe reduced to a minimum • Suitable for extinguishing fires in combustible liquids, gases and electrical equipment, and for extinguishingsmoldering fires in wood, paper, textiles, etc. •Installed as a total flooding central bank system inclusive a number of distributions • Normally installed with pneumatic release, but can also be supplied with mechanical, electrical, and manual release. Constructions: The CO2 system consists of one or more pressure cylinders containing the extinguishing agent CO2. The cylinders are connected via a common manifold. From the main manifold, the extinguishing agent is led through distribution valves to the protected spaces. The valve construction, cylinder size, and cylinder pressure, combined with the computercalculated pipe and nozzle dimensioning, ensures that the extinguishing agent is distributed in correct quantities and within the prescribed time. The release is activated pneumatically, electrically and/or mechanically. Pressure-operated cylinder valves offer the possibility of connecting CO2 cylinders in groups operated pneumatically from one or more release cabinets equipped with CO2 gas cylinders. The release cabinets are equipped with pilot valves for use in opening cylinders and distribution valves by pipe connections. For pneumatic operation, the built-in actuator is used for each cylinder valve. These are connected to the othercylinder valves in the group via series-connected, flexible highpressure hoses. CO2Cylinders: The cylinders are delivered as 67.5-litre steel cylinders filled with 45 kg of CO2, or alternatively as 80-litre steel cylinders filled with 53.6 kg of CO2. To enable remote control and quick release, the cylinders are supplied with pressure operated quick opening valves, which also offer the possibility of manual operation. The valve construction secures against damaging overpressure in the cylinder, as the valve has a built-in bursting disc, activated at a nominal pressure of 190 bars. CO2room: The cylinders are normally stored in a separate, well-ventilated and insulated room, where thetemperature is kept between 0° and 40°C. The room must have free access to open air. The room should have a minimum clear height of 2.4 m to provide adequate space for the mounting of manifolds and weighing beams for check weighing of the cylinders. CheckingEquipment. The cylinders can be checked by a weighing device or liquid level measurement. SpecialEquipment: To reduce the installation time in CO2 rooms onboard ships, cylinder arrangements mounted in racks consisting of up to 100 pieces of 45/53.6 kg cylinders,
complete with manifold and fixing equipment, can be supplied. CO2 Extinguishing System: release System ThePressureControlledCylinderValve. All release systems are based on the unique pressure operated cylinder valve. This valve is used in all systems in which pressure cylinders (CO2and N2) form a part. CO2 cylinders, with contents of up to 60 kg discharge, can be released within one minute. Valve housings and internal parts are made of brass or stainless steel, with tightening materials of neoprene or copper. The valve is constructed as a combined pressure operated quick opening valve with hand wheel for manual opening. The valve is designed with a unique function that enables the user to perform a real check ofthe valve function. By opening the control valve for releasing the cylinders while leaving the distribution valve closed, the manifold will be pressurized. It can then be proved that each valve is opened. By closing the control valve, the release piping system will be relieved and the cylinder valves will close. Some classes and authorities require this function. PneumaticreleaseSystem. Total flooding systems require groups of cylinders to be released simultaneously. For this purpose, pneumatically operated cylinder valves are used in conjunction with the pilotpressure from the master release box containing control cylinder(s) (CO2 or N2), two control valves, a pressuregauge, and one or two door switches. As an option, the system can be supplied with a pneumatic time delay device to delay the opening of the mainvalve. Manually opening the cylinder valve and then operating the two local control valves can make emergency release from the CO2 room. FOR DIAGRAM: http://www.danfoss-semco.com/media/CO2_High_Pressure_Systems.pdf
Q129) EXPLAIN INTERNATIONAL SHORE CONNECTION? ANS)The international shore connection is a universal hose connection that is to be provided on all ships as per the SOLAS requirement. The purpose of the International Shore Connection is to keep a standby hose attachment to get a connection from shore or from other ships in case there is a total failure of pumps onboard. While using International Shore Connection the seawater is supplied at a pre-decided pressure and is connected to ship’s fire main. This coupling is generally kept on the bridge of a ship so that in case of an emergency it is readily available and used. As per SOLAS, ships above 500 tons gross tonnage and upwards must have at least one international shore connection. The international shore connection has a standard size and is same for all the countries and ships
Basic Requirements for International Shore Connection The connection should be made up of steel or other suitable material and shall be designed for 1.0 N/mm2 services. The flange should have flat surface on one side and other side should be permanently connected or attached to a coupling, which can be easily fitted to ships hydrant and hose connection. The connection should be kept onboard with a ready gasket of material, which can handle a pressure of 1.0 N/mm2 together with four 16mm bolts, 50 mm in length and eight washers so that the connection can be readily used in case of an emergency situation.
Q130) Purpose of ISM code? ANS)ISM Code: - As per SOLAS Chapter IX. Management for the Safe Operation of Ship. ISM is International Safety Management Code for safe operation of ships & for pollution prevention as adopted. Purpose of this code is to provide an international standard for safe management and operation of ships and for pollution prevention. The objective is to ensure safety at sea, prevention of human injury or loss of life & avoidance of damage to the environment, in particular to marine environment and to property. Q131) what certificate issued for ISM code? ANS) DOC- Document of Compliance: - Valid for 5 years SMC- Safety Management Certificate: -Valid for 5 Years Interim DOC: - Valid for 12 months. Interim SMC: - Valid for 6 months Q132) what certificate you appearing for? ANS) Officer in-charge of an engineering watch at Operational Level. Q133) Which Imo publication gives you the guidelines for watch keeping? ANS) STCW’95
Q134) what is CAS? ANS) CAS- Condition Assessment Scheme Tanker type 1: - Oil Tankers above 20000 DWT, not having segregated ballast tank (SBT) Tanker Type 2: - Oil tankers above 20000 DWT have SBT. Type 1 tankers have already been phased out by 2005. CAS Applies to only Type 2 tankers. Which are to be phased out in segregated manner by April 2015. CAS is a method of checking structural integrity of ship, & its certification by regular inspection by authority. Authorities carry on the said inspections annually. Q135) Alarms and trips of boiler and IG system? ANS)Alarms in IG System: a. Scrubber High Level b. Scrubber low level c. Deck seal High level d. Deck seal low level e. High O2 Content f. High blower casing temp. g. Low lube oil pressure alarm. Trips in IG System: a. High Casing Temp. Trip b. Low lube oil pressure trip. c. Low/ no flow scrubber water d. Low / no flow deck seal water. e. High boiler pressure trip. f. Low boiler pressure trip. Alarms in Boiler: a. Low water level Alarm b. Too low water level alarm. c. High water level alarm d. High fuel oil temp. Alarm. e. Low fuel oil temp. Alarm f. Low boiler pressure alarm. Trips in Boiler: a. Low Low-level water trip b. High boiler pressure trip. c. Flame failure d. Low fuel oil pressure
Q136) VARIOUS ALARMS & TRIPS IN COPT SYSTEM? ANS) a) Lube oil Low-pressure alarm & trip.
(b) Lube oil High temperature alarm. (c) Over speed trip (d) High back pressure alarm & trips. (e) High discharge pressure alarm & trip. (f) Steam inlet low-pressure trip. (g) Rotor axial movement trip. (h) I.G. system abnormal trip. (i) Pump bearing high temperature trip. (j) Intermediate shaft bearing high temperature trip. (k) Casing overheat trip. (l) Emergency trip. Q137). What entries should be done for bunkers in oil record book? ANS) Date and time of start & stop of bunkering. Position of vessel. Quantity of bunker taken. Bunker taken in which tank Any internal fuel transfer did while bunkering. Q138) What are the entries made in Oil record book? ANS) As per MARPOL Annex 1 Regulation 17: - Regulation for the prevention of pollution by oil: - Entries done in Oil Record book are: a. Ballasting or cleaning of fuel oil tanks. b. Discharge of dirty ballast or cleaning water from fuel oil tanks. c. Collection & disposal of oil residues, sludge & bilge oil. d. Bunkering of fuel or bulk lubricating oil. e. Any failure of the Oil Filtering Equipment. f. Date & time of the operation. Q139) what is COW? ANS)COW: - Crude Oil Washing As per MARPOL Annex 1, Regulation 33: -Regulation for the prevention of pollution by oil. Every crude oil tanker of 20000 Dwt and above shall be fitted with cargo tank cleaning system using crude oil washing. The purpose of COW is to reduce accumulation of sludge in tanks & reduce the amount of carry over cargo. During operation of COW, tanks must have oxygen content less than 8 % and under positive IG Pressure. The advantage of COW is that tank remains clean & ROB cargo is less & hence increases cargo carrying capacity. Q140) what are the safety on Engine room Overhead Crane? ANS) * Overload trip. * Limit switch at fore & aft side. * Limit switch port & starboard movement. * Switch button have non-metallic body.
* Emergency stop. Q141) what was NRT & GRT of your ship and definitions? ANS) NRT: - Net Registered Tonnage It is the tonnage obtained by deduction from the Gross Tonnage, the tonnage of spaces, which are reqd. for the safe working of ship: (a) Master’s Accommodation (b) Crew Accommodation and allowance for provision stores. (c) Wheel House, Chartroom, and Navigation Aids room (d) Space for safety equipment & batteries. GRT: - Gross Registered Tonnage The Gross Registered Tonnage is found by adding to the under deck Tonnage, the tonnage of all enclosed spaces between the upper & the second deck. Q142) Emergency Generator- Location & services supplied? ANS)Location: - Should be on the uppermost continuous deck outside from the engine room but not located at the forward collision bulkhead. Services Supplied: (a) For a period of 3 Hrs at Emergency lighting at every muster & embarkation station. (b) For a period of 18 hrs at:(i) In all service & accommodation alleyways, stairways & exits, personal lift cars & personnel lift trunks. (ii) In the machinery spaces & main generating stations including their control positions. (iii) In all control stations, machinery control rooms, and at each main & emergency switchboard. (iv) At all stowage positions. (v) At the steering gear. (vi) At the fire pump & in all cargo pump rooms. (vii) The navigational lights. (viii) VHF & MF Radio installation. (ix) The ship earth radio station. (x) At all internal communication equipment (xi) The fire detection & fire alarm system. (xii) Intermittent operation of the daylight signaling lamp & all integral signals that are required in an emergency. Q143) Lifeboat lowering procedure? ANS) Minimum of 5 persons are required to lower the L/B. One person goes inside the L/B and passes the end of toggle painter and plugs the drain. Check all lifeline and falls are clear of L/B. Make fast the other end of toggle painter on a strong point forward of the ship. Remove forward and aft gripes and both person stand by for passing bowing tackle and tracings pendant. Remove harbor safety pin. Make sure the ship’s side is free of everything; no water or garbage is there.
Now, one-person lift’s the dead mans handle slowly which releases the brake. The boat along with cradle side’s downward till it comes to the embarkation deck. By pulling tracings pendant, bring it alongside the embarkation deck. Persons embark inside the boat. Now, tracings pendant is removed and the whole load comes on falls. Now, boat is further lowered with dead man’s handle. As soon as the boat comes around 1meter above the seawater, it can be released
Q144) what are the lifeboat equipments? ANS) Sufficient buoyant oars 2-boat hook. 2 Buckets 6 Hand Flares 2 Rocket parachutes 2 smoke signals. EPIRB SART Food Ration. 1 knife and 3 tin openers. Hand Pump Tow line Anti-sea sickness tablets 1 set of fishing tackles. Waterproof torch Daylight signaling lamp. Radar reflector First Aid Kit Tools Compass Sea Anchor 1 Whistle Portable fire extinguisher Thermal Protective aid
Q145) what is the difference between flame arrester and flame screen? ANS) Flame Arrester will not let the fire to come out from inside. Flame Screen will not let the fire to come in from outside. Q146) WHAT IS REQUIREMENT FOR CO2 STORAGE ROOM? ANS)Carbon dioxide storage rooms The following requirements are applicable only for the storage rooms for fire-extinguishing media of fixed gas fire-extinguishing systems:
1)The storage room should be used for no other purposes; 2) If the storage space is located below deck, it should be located no more than one deck below the open deck and should be directly accessible by a stairway or ladder from the open deck; 3)Spaces which are located below deck or spaces where access from the open deck is not provided, should be fitted with a mechanical ventilation system designed to take exhaust air from the bottom of the space and should be sized to provide at least 6 air changes per hour; and 4)Access doors should open outwards, and bulkheads and decks including doors and other means of closing any opening therein, which form the boundaries between such rooms and adjacent enclosed spaces, should be gas tight. Q147) WHAT ALL MAINTENANCE SHOULD BE CARRIED OUT ON CO2 FIXED FIRE FIGHTING INSTALLATIONS? ANS) FIXED HIGH PRESSURE CO2 FIRE EXTINGUISHING Installations: * CO2 bottles of fixed CO2 fire extinguishing installation shall be hydraulically tested 20 years after the date on which the bottles were put into use, and every 5 years thereafter. * The quantity of the medium in the CO2 bottles should be checked once every 4 years. This may be carried out in batches of 25% of the CO2 bottles annually, or 50% of the CO2 bottles biennially or in accordance with the ship’s maintenance so long as every CO2 bottle is checked once every 4 years. * All stop valves should be checked monthly to ensure that they are in their proper open or closed position. * The installation should be checked monthly for leakage. * All CO2 bottle connections for cable operating clips should be checked for tightness every 3 months. * All control valves should be inspected annually, and internally inspected every 5 years. • Air should be blown through the piping of the installation annually. Q148) WHAT ALL MAINTENANCE SHOULD BE CARRIED OUT ON PORTABLE FIRE FIGHTING EXTINGUISHER? ANS)PORTABLE FIRE EXTINGUISHERS: * Portable fire extinguishers are to be examined by a competent person annually. * Each portable fire extinguisher is to be provided with a label indicating that it has been examined and the date of the examination, or the date of next examination. * Containers of permanently pressurized portable fire extinguishers and propellant bottles / containers of non-pressurized portable fire extinguishers shall be hydraulically pressure
tested as follows: a. Powder extinguishers every 10 years b. CO2 extinguishers every 10 years c. Other extinguishers every 10 years Q149) HOW WATER & MUDS ARE DRAINED OUT FROM CHAIN LOCKER? ANS) The chain moves through the chain pipe and the hawse pipe as the anchor is raised or lowered. The chain pipe connects the chain locker to the deck and the hawse pipe runs from the deck through the hull of the ship. When recovering the anchor, the anchor and chain are washed off with a fire hose to remove mud, marine organisms, and other debris picked up during anchoring. Seawater from the fire hose is directed either through the hawse pipe or directly over the side onto the chain while recovering the anchor. The top of the chain pipe has a canvas sleeve to keep water from entering the chain locker through the chain pipe. Under rare circumstances, like heavy weather, rain or green water (seawater that comes over the bow during heavy weather) gets under the chain pipe canvas cover and into the chain locker. A diagram of a typical chain locker is provided in Figure 2. Any fluid that accumulates in the chain locker sump is removed by either drainage eductor for discharge directly overboard or by draining the chain locker effluent into the bilge. As the fluid in the chain locker sump is being drained for overboard discharge, the locker is sprayed with firemain water to flush out sediment, mud, or silt. An eductor is a pumping device that uses a high velocity jet of seawater from the firemain system to create a suction to remove the accumulated liquids and solids.
Q150) what are the main components of the hull? ANS) The main components are the framing or skeleton to which the platting or skin is attached. The backbone of the skeleton is the keel to which the frames or ribs are connected. Deck beams are fitted between the side frames across or athwart the hull and are fastened to it by brackets. The frames are shaped to the hull lines and the deck beams are given a slight curve or beam round. Q151) WHAT IS SHEER STRAKE & WHAT IS ITS IMPORTANCE? ANS)This is the uppermost strake of side plating which meets the upper deck. Because when the vessel is subjected to bending the forces alternative from tension to compression (see Chapter 4) and the sheer strake is subjected to maximum compressive and tensile stresses. Hence it plays an important part in contributing to the strength of the hull. The upper edge, which is contoured to the sheer line, must be smooth and contain no ‘notches’. Q152) EXPLAIN CORRUGATED WITH HELP OF DIAGRAM? ANS) Corrugated Type: As discussed above a lot of extra strengthening is needed to be added to a plain bulkhead to withstand hydrostatic pressure. By using a corrugated bulkhead the strength is inherently formed in the construction, this results in a large reduction in weight. The troughs in the bulkhead on a transverse bulkhead run vertically as shown below To add additional strengthening on high bulkheads, diaphragm plates are fitted to prevent the corrugations collapsing in on them. Additionally, the floors in the double bottom structure below the main watertight bulkheads must all be watertight. Any penetrating pipe work through a watertight bulkhead must be fully welded into the bulkhead.
Q153) WHAT IS STRINGER? ANS)The stiffener used to strengthening the sides surface (hull) of the ship is called stringers. Without using stringers the hull shape of the ships does not formed.
Q154) Regulation regarding air pollution? ANS)MARPOL Annex VI:- Regulation for the prevention of pollution by air from ships. Regulation 12:- Ozone depleting Substance Any deliberate emissions of Ozone depleting substance shall be prohibited. Deliberate emissions include emissions occurring in the course of maintaining, servicing, repairing or disposing of systems or equipments. New installations, which contain ozone-depleting substance, shall be prohibited on all ships, except that new installations containing HCFCs are permitted until January 2020. The substances & equipment containing such substances shall be delivered to appropriate reception facilities when removed from ships. Regulation 13:- Nitrogen Oxide (NOx) This regulation applies to the diesel engine with a power output of more than 130 KW, which is installed on a ship constructed on or after 1st January’2000. & to diesel engines with a power output of more than 130 KW which has undergone major conversion on or after 1st January’2000. This regulation does not apply to emergency diesel engine, engines installed in lifeboats & any device intended to be used solely in case of emergency. Regulation 14:- Sulphur Oxide (Sox) The sulphur content of any fuel used on board ships shall not exceed 4.5% m/m. In SECA Area the sulphur content should not exceed 1.5% m/m. If in SECA area fuel used is having sulphur content more than 1.5% m/m, then exhaust gas cleaning system to be provided to limit emission of Sox to 6.0g Sox /Kw-h or less. Regulation 15: - Volatile Organic Compound Regulation 16: - Shipboard Incineration Q155) WHAT IS DOC? ANS)DOCUMENT OF COMPLIANCE: (1) A Company owning or operating a ship to which this Regulation applies shall hold a Document of Compliance. (2) The document of compliance shall be issued by the Authority to a Company that complies with the requirements of Chapter IX of SOLAS and the ISM Code. (3) The Document of Compliance shall be issued for a period not exceeding five years. (4) The document of compliance shall only be issued following verification that the Safety Management System of the company complies with the requirements of the ISM Code and determination of objective evidence proving that:
(a) A Safety Management System has been effectively implemented; and (b) The Safety Management System has been in operation for at least three months; and (c) A Safety Management System has been in operation for at least three months on board at least one ship of each type operated by the company. (5) The document of compliance shall be subject to annual verification within three months before or after the anniversary date to confirm the effective functioning of the Safety Management System. (6) The Authority may delegate the evaluation of evidence of compliance with the ISM Code to the Safety Officer or to an organization recognized by the Authority as being capable of carrying out such evaluation, or the marine administration of another contracting government. (7) The Authority may withdraw the document of compliance if the annual verification is not requested or if there is evidence of major non-compliance with the ISM Code. (8) The master of a vessel to which this Regulation applies shall keep on board a copy of the Document of Compliance and shall, when requested, produce it for verification. (9) The Authority may issue an interim document of compliance, valid for not more than twelve months, to facilitate the initial implementation of the ISM Code, where a company is newly established, or where a new ship type has been added to an existing document of compliance, provided that the Company has fully demonstrated that it has a Safety Management System that meets the requirements of the ISM Code.
Q156) WHAT IS SMC? ANS) SAFETY MANAGEMENT CERTIFICATE: (1) The Safety Officer shall issue a Safety Management Certificate to each ship to which this Regulation applies, following an initial verification of compliance with the requirements of the ISM Code, to ensure that the company and its shipboard management system operate in accordance with the approved safety-management system. (2) The verification referred to in sub-section (1) shall include: (a) The verification that the document of compliance for the company responsible for the operation of the ship is applicable to that particular type of ship; and (b) An assessment of the shipboard Safety Management System to ensure that it complies with the requirements of the ISM Code and that it is implemented and has been functioning for at least three months aboard the ship. (3) The Safety Management Certificate shall be issued for a period not exceeding five years. (4) The Safety Officer may delegate the evaluation of evidence of: (a) Compliance with the ISM Code; and (b) Maintenance of a Safety -Management System, to an organization recognized by the Authority as being capable of carrying out such evaluation, or the marine administration of another Contracting Government.
(5) The Safety Management Certificate shall be subject to at least one intermediate verification to confirm the effective functioning of the safety management system and that any modifications carried out since the previous verification comply with the requirements of the ISM Code. (6) The Safety Officer may withdraw the Safety Management Certificate if there is evidence of major non-compliance with the approved Safety-Management System. (7) The master of a vessel to which this Regulation apply shall keep on board the original Safety Management Certificate and shall, whenrequested, produce it for verification. (8) The Safety Officer may issue an interim Safety Management Certificate, valid or not more than six months, to new ships on delivery, or where a company takes on responsibility for the management of a ship which is new to the company, provided that – (a) The company has fully demonstrated that it has a Safety Management System that meets the requirements of the ISM Code; and (b) The document of compliance is relevant to the ship; and (c) The master and senior officers are familiar with the Safety Management System and the arrangements for its implementation; and (d) The company has provided essential information and instructions to the master before sailing; and (e) The company has provided relevant information on the safety management system in the working language or languages understoodby the ship's personnel; and (f) The company plans to audit the ship within t
Q157) WHAT ALL CHECKS DOES PSC INSPECTOR ON SHIP MAKE? ANS) • Is the ISM Code applicable to the ship? • Is ISM certification on board? • Are certificates and particulars in order? • Is there a Company safety and environmental protection policy and are the appropriate crew members familiar with it? • Is the Safety Management documentation readily available on board? • Is the relevant documentation on the SMS in a working language or a language understood by the ship’s crew? • Can senior officers identify the Company responsible for the operation of the ship and does this correspond with the entity specified on the ISM certificates? • Can senior officers identify the “designated person“? • Are procedures in place for establishing and maintaining contact with shore management in case of emergency? • Are programs for drills and exercises to prepare for emergency actions available on board? • How have new crew members been made familiar with their duties and are there instructions available which are essential prior to sailing ? • Can the Master provide documented proof of his responsibility and authority, which should include his overriding authority?
• Does the ship has a routine maintenance and is there records available? • Have non-conformities, accidents, incidents and hazardous situations been reported to the Company and has timely corrective actions been taken by the Company? • Are there procedures in place to maintain the relevant documentation? • Are there procedures in place intended to internal audits and have internal audits been carried out? (PSC Officer, normally, does not examine the contents of non-conformities resulting from internal audits). • If detainable deficiencies and/or many deficiencies are detected, the PSC officer will use his professional judgment to decide if thismeans a failure of the Safety Management System.
Q158) EXPLAIN MAJOR NON-CONFORMITY? ANS)Major non-conformity means an identifiable deviation, which poses a serious threat to crewmembers or to the ship or is a serious risk to the environment and requires immediate action. In addition, the lack of effective and systematic implementation of an ISM requirement is considered as major non-conformity. The ship should correct all the following major non-conformities prior to departure: • The ISM certificates are not on board. • The Company mentioned on the DoC is not the same as the Company mentioned on the SMC. • The Safety Management documentation is not on board. • Safety information is not in the working language or in the language understood by the crew. • Senior officers are unable to identify the operator and designated person. (nocommunication ship/shore). • There is no procedure to contact the Company in emergency situations. • Drills have not been carried out according to the program. • New crew-members are not familiar with their duties (within the SMS). • Master’s overriding authority is not documented and Master is unaware of his authority. • No records of maintenance kept or no evidence of maintenance has • No records of maintenance kept or no evidence of maintenance has been carried out as indicated in the records. Q159) WHAT ARE ISM & WHAT ALL CERTIFICATES SHIP SHOULD HAVE IN ACCORDANCE WITH ISM CODE? ANS)International Safety Management (“ISM”) Code means the International Management Code for the Safe Operation of Ships and for Pollution Prevention. Ships should have ISM certification on board, in accordance with the ISM Code: copy of the Document of Compliance (“DoC”) issued to the Company and the safety Management Certificate (“SMC”) issued to the ship. The SMC is not valid unless the operating Company holds a valid DoC for that ship. The type of ship indicated on the SMC should be the same as indicated on the
DoC. The Company’s particulars indicated on the DoC and the SMC should be the same.
Q160) WHAT IS CLEARGROUND? ANS)If “clear grounds” are detected, the ship will be subject to a more detailed inspection. Clear grounds include missing or inaccurate ISM certification or detainable deficiencies in other areas. Many non-detainable deficiencies may also be an evidence of a deficient management system. Q161) WHAT IS CONFORMITY? ANS) An observed situation where objective evidence indicates the non-fulfillment of a specified requirement of the ISM Code or the Company's SMS. This deviation or the identified lack of a plan or instruction for a key shipboard operation. Could endanger the safety of people, the ship its cargo and the environment.
Q162) Emergency Fire pump-Location, Capacity & how to check performance? ANS) Location of Emergency Fire pumps: - The space containing the pump should not be contiguous to the boundaries of machinery space or those spaces containing main fire pumps. Normally located at: Steering Gear Compartment, Aft of Collision Bulkhead, Shaft Tunnel, and Forward part of ship. Capacity: - Shall have capacity not less than 25 m3/hr & pump should be able to deliver water at following pressure with two hydrants opens: Passenger Ship above 4000 GRT: -4 bar Passenger ship below 4000 GRT: -3 bar Cargo ship above 6000 GRT: -2.7 Bar Cargo ship below 6000 GRT: -2.5 bars The throw at the top most deck should not be fewer 12 meters. Q163) WHAT IS GARBOARD STRAKE? ANS) A strake is part of the shell of the hull of a boat or ship, which, in conjunction with the other strakes, keeps the sea out and the vessel afloat. It is a strip of planking in a wooden vessel or of plating in a metal one, running longitudinally along the vessel's side, bottom or the turn of the bilge, usually from one end of the vessel to the other. GARBOARD STRAKE: -Strake adjacent to the keel on each side of the ship is called Garboard strake.
Q164) How to calibrate Oxygen Analyzer?
ANS) a. SPAN Gas: - SPAN gas consists of 99.99% Nitrogen. As per it the O2 analyzer should show 0.01% oxygen. b. The analyzer is kept in fresh air where it should show 20.97% oxygen. Q165) EEBD/SCBA checks and operation? ANS)Checks on SCBA: -self-contained breathing apparatus: a. Examine all tubing for any cracks, cuts or any damage. b. Examine inhalation/ exhalation valve and facemask is clear, clean & dry. c. Open cylinder valve, listen for audible leaks(with positive pressure sets) d. Check whether correct pressure is maintained inside the cylinder. e.To check actual cylinder air pressure & that there are no leaks in the system. Open the cylinder valve & read the pressure registered on the gauge, compare with full pressure marked on the cylinder. Close the valve & observe the pressure gauge. Pressure should not drop more than 10 bars in 1 min. f. Check correct operation of the audible warning whistle. When 80% of Oxygen is consumed whistle should blow automatically telling wearer that only 20%( 10 mins) of air is left inside. g. Tightness of facemask& wearer’s face is checked for effective tightness of the seal. h. Pressure gauge to be checked for proper working. i. Cylinder valve should operate freely Q166) what is given in SOLAS Chapter 4, 5 & 11-1? ANS)SOLAS Chapter 4 refers to Radio communication. In this chapter International Navtex, Sea Area A1, A2, A3 & A4, GMDSS, Digital selective Calling is defined. SOLAS Chapter 5 refers to Safety of Navigation. This chapter tells about Voyage Date Recorders, Navigation Bridge visibility, steering gear testing & drills. SOLAS Chapter 11-1 refers to Special measures taken to enhance maritime safety. In this chapter, it is told about Ships Identification Number, Continuous Synopsis Record. Q167) DRAW EXPANSION BELLOW?
ANS) An expansion piece is fitted in a pipeline, which is subject to considerable temperature variations. One type consists of a bellows arrangement, which will permit movement in several directions and absorb vibration. The fitting must be selected according to the variation in system temperatures and installed to permit the expansion and contraction required in the system.
Q168) WHAT IS MUD BOX & WHAT IS ITS PURPOSE? ANS)Mud boxes: Mud boxes are fitted into the machinery space bilge suction piping. The mud box is a coarse strainer with a straight tailpipe down to the bilge. To enable the internal perforated plate to be cleaned when necessary, the lid of the mud box is easily removed without disconnecting any pipe work.
Q169) why emergency bilge suction is BELL MOUTHED? ANS)The bell end or foot should provide an inlet area of about one-and-a-half times the pipe area. It should also be a sufficient distance from the bottom plating and nearby structure to provide a free suction area, again about one-and-a-half times the pipe area. Q170) WHAT IS STEAM TRAP & WHAT IS ITS PURPOSE? ANS)A steam trap does as its name implies and permits only the passage of condensed steam. It operates automatically and is situated in steam drain lines. Various designs are available utilizing mechanical floats which, when floating in condensate, will enable the condensate to discharge. Other designs employ various types of thermostat to operate the valve, which discharges the condensate.
Q171) where u will find information on code on ship? ANS) On Navigational Bridge. Q172) WHAT IS OBSERVATION? ANS)Observation: An observation means a statement of fact made during a safety management audit and substantiated by objective evidence. The company/ship is not liable to provide evidence of the corrective action taken for an Observation. Q173) How aft peak tank is sealed from stern tube? ANS)The propeller enters the shaft outside from the ship, acting as its barrier. In case of water-cooled Stern Tube, Gland packing is used to prevent water ingress inside. But incase of Lignum vitae bearing, some water is allowed to go. In case of Oil cooled Stern tube, the rubber seals fitted with springs are used. Q174) WHAT ALL PRECAUTIONS SHOULD BE TAKEN DURING BUNKERING? ANS) 1) Sawdust is a great absorbent and hence ample amount of sawdust should be kept in
sacks on deck so that if any leakage takes place during the bunkering procedure, it can be easily controlled by putting sawdust on it. 2) Proper means of communication with the use of hand held radio sets or other means should be established between the ships crew and the staff at the bunkering installation to avoid misunderstandings. 3) The scuppers should be closed to make sure that no oil goes overboard. 4) Drips trays should be closed off. 5) The bunkering lines should be properly checked and fuel tank valves should be carefully checked before commencing bunkering. 6) Valves not in operation should be effectively sealed off. 7) A sounding of all the ship tanks should be done before starting the bunkering operation. 8) Sounding equipment should be checked properly before the bunkering starts. 9) A marker to indicate the filling up of a particular tank should be used. 10) Port authorities should be immediately contacted in case of a major oil spill. 11) There should be no damage to the hose and it should be of a sufficient length. The couplings should also be checked for any damage. 12) High level alarms of bunker tanks should be properly checked for their functioning. 13) The SOPEP lockers should be checked whether they have sufficient supplies. 14) Oil absorbing apparatus like oil absorbing pads should be kept at important areas to reduce any oil leaks. 15) Make sure the bunkering plans are agreed upon by all officers onboard the ship. 16) Discuss the procedures to be undertaken in case of an emergency with the supplier. 17) A proper system of signals for communication should be established between the shipboard crew and suppliers. 18) Fire extinguishers and other fire fighting apparatus should be readily available.
Q175) How u measure rudder drops and purpose? ANS) Rudder drop is measured by Trammel Gauge. Purpose: - To know about the rudder jumping.
Q176) what is regulation 13G and 13H? ANS) For information of all Ship Owners, Operators and Charters of single hull oil tankers The 50th session of the IMO Marine Environment Protection Committee (MEPC 50) held on December 1 and 4, 2003 has adopted amendments to MARPOL 73/78 Annex 1 Regulation 13G and introduced a new Regulation 13H together with amendments to the Condition Assessment Scheme (CAS). These amendments should be deemed to have been accepted by 04-10-2004 and the new Regulation will enter into force on 05-04-2005. Prevention of Accidental Oil Pollution - Measures for existing Oil Tankers: Amendments to MARPOL 73/78, Annex I, Regulation 13G: 1. Category 1 oil tankers are to be phased-out by 2005 2. Category 2 and 3 oil tankers will be gradually phased-out from 2005 to 2010 as per their delivery date. 3. Category 2 and 3 oil tanker of 15 years and over is to be subjected to the Condition Assessment Scheme (CAS) 4. Category 2 and 3 tankers which are provided with either double bottom or double sides are permitted to trade beyond their phase-out date until 25 years of age, subject to acceptance by the flag administration. 5. The amendments introduce a new CAS regime for Category 2 and 3 tankers of 15 years and older by requiring a CAS survey to be held at the first intermediate or renewal survey after April 5, 2005. 6. Provided that a satisfactory CAS survey is held before the phase-out date, Category 2 and 3 tankers can trade until they reach 25 years of age, or their anniversary date of delivery in 2015, whichever occurs first.
MARPOL 73/78 Annex 1 Regulation 13H This new Regulation prohibits the carriage, as cargo, of heavy grade oil by Category 2 or 3 tankers of 5000 tonnes deadweight and above after April 5, 2005. All tankers of less than 5000 tonnes deadweight but more than 600 tonnes deadweight are to be provided with double bottoms and double sides by 2008. The Flag Administration may allow carriage of heavy grade oil as cargo beyond the above dates subject to certain conditions being complied with, for example ships on domestic voyages, floating storage units operating in areas under a flag administrations jurisdiction and certain oil densities being transported by tankers that have been subjected to satisfactory CAS surveys. Right to deny entry Both Regulations 13G and 13H contain provisions to permit a Port State to deny entry into their ports and offshore terminals of all Category 2 or 3 tankers trading beyond 2010 and those carrying heavy grade oil as cargo. CAS The Condition Assessment Scheme (CAS) was amended by modifying its application to include Category 3 tankers age 15 years and older and tankers carrying heavy grade oil as cargo. Provisions were included in the certification requirements of CAS to cater for the time required by the flag administration to review the final report and issue a Statement of Compliance
Definitions Category 1: So-called pre-MARPOL single hull oil tankers, being crude oil tankers of 20000 tons deadweight and above and oil product carriers of 30000 tons deadweight and above having no segregated ballast tanks in protective locations (SBT / PL). These are the most vulnerable and oldest tankers. Generally constructed before 1982. Category 2: corresponds to MARPOL single hull tankers, being of the same size as category 1, but which are equipped with SBT / PL. Generally constructed between 1982 and 1996. Category 3: corresponds to single hull oil tankers below the size limits of categories 1 and 2 but above 5000 tons deadweight. These smaller tankers often operate in regional traffic. Heavy grade oi1 means any of the following: (a) Crude oils having a density higher than 900 kg/m3 (b) Fuel oils having either a density higher than 900 kg/m3 at 150 Kinematic viscosity higher than 180 mm2 /s at 50 C (c) Bitumen, tar and their emulsions. Q177) what happens if allowed rudder drop is not kept? ANS) The bearings on which rudder weight is coming will wear down fastly. Q178) WHAT IS TRANSOME POST?
C or a
ANS)
A transom ransom is, at its simplest definition, the back part of a boat or a ship. Transoms come in many shapes and have different functions based on the size and type of boat. Types Transoms are sometimes just the back end of the boat; they can be curved or flat and the bottom edge of the transom is usually at or just above the waterline. Function On smaller ships and boats with outboard motors, the transom is used to attach the motor to the boat. Wires, cables and the power supply go through the transom.
Significance Larger boats often use the transom to advertise the name of the boat, and a transom stern increases the amount of deck space available for the boat. Boats with outboard motors need a transom to attach the motor to the boat. Benefits A transom stern in a larger ship reduces the overall construction cost for the ship; a traditional convex stern costs more and can restrict deck space. Identification Its flat, squarish shape can recognize a transom on larger ships, such as shipping boats and some cruise ships.
Q179) WHAT IS STREN FRAME? ANS) Stern frame: A large casting attached to the after end of the keel, incorporating the rudder gudgeons and propeller post in single single-screw ships
Sternpost: The vertical part of the stern frame to which the rudder is attached Q180) DRAW STIFFNER? ANS)
Q181) WHAT IS ISGOTT? ANS)ISGOTT: -International Safety Guide for Oil Tankers and Terminals. Q182) ENTRY PROCEDURE IN PUMP ROOM? ANS)Entry Procedures: It is strongly recommended that a formalized permit system is employed to control pump room entry, regardless ofWhether or not a fixed gas detection system is in use, and that clear procedures are established with regard toundertaking pre-entry checks. In addition to detailing pre-entry checks, procedures should advocate the use of personnel gas monitors for thoseentering the space. Arrangements should be established to enable effective communication to be maintained at all times betweenpersonnel within the pump room and those outside. Regular communication checks should be made at pre-agreedintervals and failure to respond should be cause to raise the alarm. A communications system should provide links between the pump room and the navigation bridge, engine room andcargo control room. In addition, audible and visual repeaters for essential alarm systems, such as the general alarm,should be provided within the pump room. The frequency of pump room entry for routine inspection purposes during cargo operations should be criticallyreviewed with a view to minimizing personnel exposure. Q183) SAFETIES ON TANKER SHIPS? ANS) * Restriction of Smoking, other Burning activities and Naked Lights. * Prohibition of Using Fire except in Designated Areas and Control of Potential Ignition Sources * Standards for Use of Private Electric Appliances and other Portable Electrical Equipment * No Wiring without Permission * Closing Portholes and doors * Control of personnel in cargo tank deck areas * Attention to Visitors * Precautions when storing Spontaneously Combustible Materials: - Materials, which may cause spontaneous combustion (saw dust, oily rags, especially oil of vegetable origin, etc) must be stored in a well ventilated area to prevent the accumulation of flammable gases. They are liable to ignite without the external application of heat, as a result of gradual heating within the material produced by oxidation. * Precautions against Sparks from Funnel
Q184) PROCEDURE FOR OPERATING CO2 FLOODING SYSTEM IN EVENT OF FIRE?
ANS) In case of a major engine room fire on merchant ships, CO2 fixed fire extinguishing system is the most common method used for extinguishing fire. The chief engineer of the ship is responsible for operating the system, after taking all precautionary measures. There have been several cases in the past; wherein the engine room crew has been killed not because of the fire but because of suffocation after CO2 was released in the engine room. Suffocation of the crew combined with re-ignition of fire due to lack of air tight engine room has resulted in gruesome condition as after using CO2 no more firefighting method is available (CO2 system can be used only once). The CO2 operator in-charge i.e. Chief engineer (or 2nd engineer in C/E’s absence) has to be extremely careful when it comes to following procedure to avoid fire or any casualty. Following steps are to be followed without fail for extinguishing major find in engine room. 1. On outbreak of fire, the fire alarm will sound and bridge officer will know the location of fire. If the fire is big enough to fight with portable extinguishers, all crew should be gathered in muster station for head count. 2. Inform wheelhouse about the situation of the fire and the chief engineer should take decision in consent with the master to flood the engine room with CO2 to extinguish fire. 3. Emergency generator should be started, as CO2 flooding requires all machineries including auxiliary power generator to be stopped. 4. Reduce ship speed and stop the main engine at safe location. Captain should inform the nearest coastal authority if the ship is inside a coastal zone. 5. Open the Cabinet of CO2 operating system in the fire station with the Key provided nearby in glass case. This will give an audible CO2 Alarm in the engine room. 6. Some systems and machinery like engine room blowers and fans etc. will trip with opening of CO2 cabinet. Counter checks all the tripped system for surety. 7. Make sure there no one is left inside the engine room by repeating the head count. 8. Operate all remote closing switches for quick closing valve, funnel flaps, fire flaps, engine room pumps and machinery, watertight doors etc. 9. Air condition unit of ECR should be stopped. 10. Close all the entrance doors of the engine room and make sure the room is airtight. 11. Operate the control and master valve in the CO2 cabinet. This will sound another alarm and after 60 seconds time delay CO2 will be released for fire extinguishing. 12. If there is need to enter the engine room for rescuing a person (which must be avoided, SCBA sets and life lines should be used). Safety of personnel should be of the highest priority during such incidences. Q185) WHAT IS DUCT KEEL?
ANS)
Q186) How to measure propeller drop? ANS) Propeller drop is measured with Poker Gauge.
Q187) WHAT IS FLARE? ANS)Flares: There are three types of flare carried on board ships — red hand held, orange smoke and parachute. These are designed for day or night use and are used to attract attention of other boat or passing aircraft. Flares must be regularly inspected (expiry date three years from manufacture) and stowed in a readily accessible position in a watertight container away from heat. Again it is vital that all crew know the correct safety precautions and firing procedures. Operating instructions might differ depending on the manufacturer. Instructions must be read and carefully followed. Effective ranges of flares in conditions of good visibility are: At night • Parachute flare — 25 to 35 nautical miles. • Hand flare — five to 10 nautical miles. By day • Orange smoke — very limited, up to 1.4 nautical miles, better from air. • Red (hand and parachute) — may attract attention by day. • Only flares that are within the manufacturer's expiry date can be considered as part of the safety equipment complement for your boat. • You can dispose of flares that have passed the manufacturer's expiry date at these flare disposal locations. • There are severe penalties for misuse of flares and any offender may also face the costs of labour undertaken, risk incurred, or loss sustained in consequence of the signals. Q188) Limits of NOx & SO x and why they are not applicable to boilers? What are the precautionary & prevention measure to reduce? What are the certificates concerning this? ANS) Limits of NOx: a. 17.0 g/Kw-h when n less than 130 rpm. b. 45.0 x n -0.2 g/Kw-h when is 130 or more but less than 2000 rpm c. 9.8 g/Kw-h when n is 2000 rpm or more. Limits of Sox: Outside SECA the Sox content in fuel oil should not be more than 4.5 %. Inside SECA the Sox content in fuel oil should not be more than 1.5 %. If the fuel oil taken in SECA is having more than 1/5 % Sox content, then Exhaust Gas Cleaning system be fitted to reduce the total emission of sulphur oxides from ship, including both auxiliary and main propulsion engines to 6.0 g Sox / Kw-hor less. Compliance: - Compliance with the provisions of Annex VI is determined by periodic inspections and surveys. Upon passing the surveys, the ship is issued an “International Air Pollution Prevention Certificate”, which is valid for up to 5 years. Under the “NOx Technical Code”, the ship operator (not the engine manufacturer) is responsible for in-use compliance.
Q189) EXPLAIN ALL MARPOL ANNEXS?
ANS)Annex I - Prevention of Pollution by Oil Annex I allows for specific discharges of oil from tankers only when certain conditions are met. In addition, the maximum quantity of oil permitted to be discharged on a ballast voyage of oil tankers is limited and applies equally to both persistent and non-persistent oils. Annex I also defines "special areas" which are considered to be so vulnerable to pollution by oil that oil discharges within them have been completely prohibited, with minor and well defined exceptions. Annex I entered into force internationally on 2 October 1983 and for Australia on 14 January 1988. On 15 October 2004 MEPC adopted a revised version of Annex I, which entered into force both internationally and for Australia on 1 January 2007. The revised Annex I incorporates the various amendments adopted since MARPOL entered into force in 1983, including the phasing-in of double hull requirements for oil tankers. It also separates the construction and equipment provisions from the operational requirements and makes clear the distinctions between the requirements for new ships and those for existing ships. Annex II - Prevention of Pollution by Noxious Liquid Substances in Bulk Annex II details discharge criteria and measures for the control of pollution by noxious liquid substances carried in bulk. Annex II regulates the discharge of the residues of about 250 substances. The discharge of their residues is allowed only to reception facilities unless certain concentrations and conditions (which vary with the category of substances) are complied with. No discharge of residues containing noxious substances is permitted within 12 nautical miles of the nearest land. More stringent restrictions apply to special areas. Annex II entered into force internationally on 6 April 1987 and for Australia on 14 January 1988. On 15 October 2004 MEPC adopted a revised version of Annex II, which entered into force both internationally and for Australia on 1 January 2007. The revised Annex II includes a new four-category categorization system for noxious and liquid substances. In addition, improvements in ship technology, such as efficient stripping techniques, have made possible significantly lower permitted discharge levels of certain products. Annex III - Prevention of Pollution by Harmful Substances Carried by Sea in Packaged Forms Annex III contains general requirements for the issuing of detailed standards on packing, marking, labeling, documentation, stowage, quantitylimitations, exceptions and notifications for preventing pollution by harmful substances. Annex III entered into force internationally on 1 July 1992 and for Australia on 10 January 1995. Annex IV - Prevention of Pollution by Sewage from Ships Annex IV deals with the discharge of sewage into the sea, ships' equipment and systems for the control of sewage discharge, the provision of facilities at ports and terminals for the reception of sewage, and requirements for survey and certification. It is generally considered that on the high seas, the oceans are capable of assimilating and dealing with raw sewage through natural bacterial action and therefore the regulations in Annex IV of MARPOL prohibit ships from discharging sewage within a specified distance of the nearest land, unless they have in operation an approved treatment plant. Annex IV entered into force internationally on 27 September 2003 and for Australia on 27 May 2004. A revised Annex IV was adopted on 1 April 2004 and entered into force on 1 August 2005.
Annex V - Prevention of Pollution by Garbage from Ships Annex V deals with different types of garbage and specifies the distances from land and the manner in which they may be disposed of. The requirements are much stricter in a number of special areas. The Annex imposes a complete ban on the dumping into the sea of all forms of plastic. Annex V entered into force internationally on 31 December 1988 and for Australia on 14 November 1990. Annex VI - Prevention of Air Pollution from Ships The Annex sets limits on the emissions of nitrogen oxides (NOx) from marine diesel engines, requires ships to avoid using fuel with sulphur content exceeding 4.5% by mass, prohibits deliberate emissions of ozone depleting substances, and prohibits the incineration of certain products on board ships. Furthermore, if a ship is within a sulphur oxides (SOx) Emission Control Area, it has to use a fuel with a sulphur content not exceeding 1.5% by mass, or an exhaust gas cleaning system or any other approved apparatus to limit SOx emissions. From 1 January 2012, the global sulphur cap shall be 3.5% and is scheduled to decrease to 0.5% from 1 January 2020. However, the 2020 decrease is subject to a feasibility review to be completed by the IMO no later than 2018, which shall consider among other issues, the availability of compliant fuel. The sulphur limit in SOx Emission Control Areas shall be 1.0% from 1 July 2010 and shall decrease to 0.1% from 1 January 2015. Reductions in NOx emissions from marine engines also form part of the revised Annex VI. Q190) EXPLAIN THE REGULATION FOR SEWAGE HOLDING TANK? ANS)Regulation 11.1.1 of the revised Annex IV of MARPOL 73/78 requires that untreated sewage, which may be discharged at more than 12 nautical miles from the nearest land, should not be discharged instantaneously but at a moderate rate of discharge when the ship is en route and proceeding at a speed not less than 4 knots, while the rate should be approved by the Administration based upon standards developed by the Organization. This Recommendation provides the standard and guidance for the approval and calculation of a moderate rate of discharge. 1.2 A moderate rate of discharge applies to the discharge of untreated sewage that has been stored in holding tanks. 1.3 This standard does not incorporate the dilution of sewage with water or greywater into calculations of the discharge rate. Therefore the rate is a conservative estimate and it is recognized that discharges of sewage in accordance with this standard will present a higher level of protection to the marine environment due to mixing prior to the actual discharge in addition to the mixing action of the ship’s wake. The maximum permissible discharge rate is 1/200,000 (or one 200,000th part) of swept volume as follows: DRmax = 0.00926 V D B Where: DRmax is maximum permissible discharge rate (m3/h) V is ship’s average speed (knots) over the period D is Draft (m) B is Breadth (m)
3.2 The maximum permissible discharge rate specified in 3.1 refers to the average rate as calculated over any 24 hour period, or the period of discharge if that is less, and may be exceeded by no more that 20% when measured on an hourly basis. Before undertaking a sewage discharge in accordance with this standard, the crew member responsible for sewage operations should ensure that the ship is en route, is more than 12 nautical miles from the nearest land and the navigation speed is consistent with the discharge rate that has been approved by the Administration. Ships with high discharge requirements are encouraged to keep notes of calculations of the actual discharges to demonstrate compliance with the approved rate. Q191) what all things are written in BDN (Bunker Delivery Note)? ANS)a. Name of Barge/Port b. Position of vessel. c. Delivery date d. IMO number e. Gross tonnage of Vessel f. Vessel name g. Time of starting h. Time of stopping i. Product name & code j. Viscosity at 50 Degree C k. Density @ 15°C l. Water Content % V/V m. Flash Point ° C n. Sulphur Content % m/m o. Pour Point °C p. Quantity taken @ 35°C
Q192) EXPLAIN REVISED MARPOL REGULATION 5 FOR GARBAGE? ANS)Revised MARPOL Annex V text approved: The MEPC approved, with a view to adoption at its next session, amendments to revise and update MARPOL Annex V Regulations for the prevention of pollution by garbage from ships, following a comprehensive review of this Annex. The main changes include the updating of definitions; the inclusion of a new requirement specifying that discharge of all garbage into the sea is prohibited, except as expressly provided otherwise (the discharges permitted in certain circumstances include food wastes, cargo residues and water used for washing deck and external surfaces containing cleaning agents or additives which are not harmful to the marine environment); expansion of the requirements for placards and garbage management plans to fixed and floating platforms engaged in exploration and exploitation of the sea-bed; and the proposed addition of discharge requirements covering animal carcasses. Q193) WHAT ALL IMO CERTIFICATES SHOULD ALL SHIP HAVE?
ANS) 1. International Tonnage Certificate1A 2. International Load Line Certificate2A 3. International Load Line Exemption Certificate3A 4. Intact Stability Booklet1B 5. Damage Control Plans and Booklets2B 6. Minimum Safe Manning Document4A 7. Fire Safety Training Manual3B 8. Fire Control Plan/Booklet4B 9. On board Training and Drills Record1C 10. Fire Safety Operational Booklet5B 11. Certificates for Masters, Officers or Ratings6B 12. International Oil Pollution Prevention Certificate5A 13. Oil Record Book2C 14. Shipboard Oil Pollution Emergency Plan7B 15. International Sewage Pollution Prevention Certificate 6A 16. Garbage Management Plan8B 17. Garbage Record Book3C 18. Voyage Data Recorder System – Certificate of Compliance7A 19. Cargo Securing Manual9B 20. Document of Compliance8A 21. Safety Management Certificate9A 22. International Ship Security Certificate (or Interim)10A 23. Ship Security Plan and Associated Records10B 24. Continuous Synopsis Record4C 25. Noise Survey Report
Q194) WHAT CERTIFICATES PASSENGER SHIP NEEDS TO CARRY? ANS) * Passenger Ship Safety Certificate/Exemption Certificate11A * Special Trade Passenger Ship Safety Certificate12A * Special Trade Passenger Ship Space Certificate13A * Search and Rescue Co-operation Plan11B * List of Operational Limitations12B * Decision Support System for Masters13B Q195) WHAT CERTIFICATES CARGO SHIP SHOULD CARRY? ANS) * Cargo Ship Safety Construction Certificate14A * Cargo Ship Safety Equipment Certificate15A * Cargo Ship Safety Radio Certificate16A * Cargo Ship Safety Certificate17A * Exemption Certificate18A * Document of Authorization for the Carriage of Grain19A
* Certificate of Insurance or Other Financial Security inrespect of Civil Liabilities for Oil Pollution Damage20A * Enhanced Survey Report File6C * Record of Oil Discharge Monitoring and Control * System for the last Ballast Voyage7C * Cargo Information8C * Bulk Carrier Booklet14B * Dedicated Clean Ballast Tank Operation Manual15B * Crude Oil Washing Operation and Equipment Manual16B * Condition Assessment Scheme Statement of Compliance, CAS Final Report and Review Record17B * Hydrostatically Balanced Loading Operational Manual18B * Oil Discharge Monitoring and Control Operational Manual19B * Subdivision and Stability Information20B
Q196) WHAT CERTIFICATES TO BE CARRIRED BY A SHIP CARRYING NOXIOUS LIQUID CHEMICAL IN BULK? ANS) * International Pollution Prevention Certificate for theCarriage of Noxious Liquid Substances in Bulk21A * Cargo Record Book9C * Procedures and Arrangements Manual21B * Shipboard Marine Pollution Emergency Plan forNoxious Liquid Substances22B Q197) WHAT CERTIFICATE ANY CHEMICAL TANKERS SHOULD HAVE? ANS) Certificate of Fitness for the Carriageof Dangerous Chemicals in Bulk22A Q198) EXPLAIN THE REGULATIONS FOR GARBAGE DISPOSAL? ANS) Under Annex V of the Convention, garbage includes all kinds of food, domestic and operational waste, excluding fresh fish, generated during the normal operation of the vessel and liable to be disposed of continuously or periodically. Annex V totally prohibits of the disposal of plastics anywhere into the sea, and severely restricts discharges of other garbage from ships into coastal waters and "Special Areas". The Annex also obliges Governments to ensure the provision of reception facilities at ports and terminals for the reception of garbage. The special areas established under Annex V are: • The Mediterranean Sea • The Baltic Sea Area • The Black Sea area • The Red Sea Area • The Gulfs area
The North Sea The Wider Caribbean Region and Antarctic Area These are areas, which have particular problems because of heavy maritime traffic or low water exchange caused by the land-locked nature of the sea concerned. • • •
The regulation makes it clear that port State control officers can inspect a foreign-flagged vessel "where there are clear grounds for believing that the master or crew are not familiar with essential shipboard procedures relating to the prevention of pollution by garbage". All ships of 400 gross tonnages and above and every ship certified to carry 15 persons or more, and every fixed or floating platform engaged in exploration and exploitation of the seabed to provide a Garbage Record Book and to record all disposal and incineration operations. The date, time, position of ship, description of the garbage and the estimated amount incinerated or discharged must be logged and signed. The Garbage Record Book must be kept for a period of two years after the date of the last entry. Thisregulation does not in itself impose stricter requirements - but it makes it easier to check that the regulations on garbage are being adhered to as it means ship personnel must keep track of the garbage and what happens to it. It may also prove an advantage to a ship when local officials are checking the origin of dumped garbage - if ship personnel can adequately account for all their garbage, they are unlikely to be wrongly penalized for dumping garbage when they have not done so. All ships of 400 gross tonnage and above and every ship certified to carry 15 persons or more will have to carry a Garbage Management Plan, to include written procedures for collecting, storing, processing and disposing of garbage, including the use of equipment on board. The Garbage Management Plan should designate the person responsible for carrying out the plan and should be in the working language of the crew. The regulation also requires every ship of 12 meters or more in length to display placards notifying passengers and crew of the disposal requirements of the regulation; the placards should be in the official language of the ship's flag State and also in English or French for ships traveling to other States' ports or offshore terminals.
Q199) EXPLAIN SOLAS? ANS) The International Convention for the Safety of Life at Sea (SOLAS) is one of the oldest conventions of its kind. The first version was adopted in 1914 following the sinking of the R.M.S. "TITANIC" with the loss of more than 1500 lives. Since then, there have been four more versions of SOLAS – 1929, 1948, 1960, and the present SOLAS 1974 version, which entered into force in 1980. Parts of the Convention apply to every ship, including small pleasure craft. A Protocol of 1978 (SOLAS Protocol 1978) dealing with safety matters relating to tankers was adopted by the International Conference on Tanker Safety and Pollution Prevention, and came into force in 1981. Over the last 20 years there have been several amendments to both treaty documents. These amendments are not just to correct the spelling! Since 1974 the amendments have added extra chapters to SOLAS, for GMDSS, ISM, etc., and in 1988 a new SOLAS Protocol replaced the Protocol of 1978.
As SOLAS is an agreement between Governments who 'undertake to give effect to the provisions of the present Convention and the annex thereto', it is ultimately the flag State under which a yacht is registered who is responsible for interpretations and implementation of the Regulations. Yacht owners should always contact their national maritime administrations for guidance and relevant national rules and regulations. We shall concern ourselves with a look at the consolidated text of the annex to the 1974 SOLAS Convention and the 1988 Protocol, which is divided into 12 chapters. Each chapter contains Regulations, and the numbering of these Regulations starts again with each chapter. Some chapters have more than one part, and in this case the Regulation numbers run on through the different parts. CHAPTER I: General provisions. Chapter I, Part A – Application, definitions, etc. Unless expressly provided otherwise, SOLAS applies only to ships engaged on an ‘international voyage’ – which is defined as ‘a voyage from a country to which the present Convention applies to a port outside such country, or conversely’. (Note that it is ‘expressly provided otherwise’ in chapter V. The first part of each chapter gives the details of which types of ship the chapter will apply). A ‘passenger’ is defined as ‘every person other than: (i) the master and the members of the crew or other persons employed or engaged in any capacity on board a ship on the business of that ship; and (ii) a child under one year of age.’ A ‘passenger ship’ is a ship, which carries more than twelve passengers. A ‘cargo ship’ is any ship, which is not a passenger ship. The regulations, unless expressly provided otherwise, do not apply to: i. Ships of war and troopships. ii. Cargo ships of less than 500 gross tons. iii. Ships not propelled by mechanical means. iv. Wooden ships of primitive build. v. Pleasure yachts not engaged in trade. vi. Fishing vessels. Although ‘pleasure yacht’ is not defined, it follows that if a pleasure yacht is ‘engaged in trade’ it is – for the purposes of SOLAS – a ‘cargo ship, and if more than 500 gross tons then the regulations apply. Regulation 5 provides for Administrations (the Government of the State whose flag the ship is entitled to fly) to allow any alternative fitting, material, appliance or apparatus to be fitted or carried, or any other provision to be made in a particular ship, if it is satisfied by trial thereof or otherwise that the alternative is at least as effective as that required by the regulations. This gives Administrations fairly wide powers to accept equivalents, although they are required to pass particulars of the substitution, together with a report on any trials, to the IMO for them to circulate to other Contracting Governments. Chapter 1, Part B: Surveys and Certificates. This section (Regulations 6 – 20) deals with Safety Certificates - who inspects, the types of Certificates issued, the duration, and measures to be taken in the case that deficiencies are found. The inspections and surveys are to be carried out by officers of the Administration, or surveyors nominated by them. In either case, the Administration assumes full responsibility for the certificates. Until recently, cargo ships were always issued with 3 separate safety certificates, unlike passenger ships which were issued with a single Passenger Ship Safety Certificate which
was valid for 12 months. This was because the different Cargo Ship Safety Certificates had different duration’s – one year for the Radio Certificate, two for the Equipment Certificate and five years for the Construction Certificate. Administrations may now issue a single Cargo Ship Safety Certificate, valid for up to 5 years, but like the separate certificates (which still may be issued) subject to various intermediate survey requirements. The surveys are the same whether 3 separate certificates or the single certificate is issued. Cargo Ship Safety Radio Certificate – issued after survey of the radio equipment and installation (including any used in life saving appliances). Valid up to 5 years, but subject to annual surveys. Supplemented by a Record of Equipment. Cargo Ship Safety Equipment Certificate – issued after survey of the life saving appliances and arrangements, navigation equipment, fire safety systems and appliances, fire control plans, embarkation of pilots, and nautical publications. Lights, shapes and sound signals are also included in this survey for the purpose of ensuring that they comply fully with the requirements of SOLAS and the International Regulations for Preventing Collisions at Sea (COLREGS). Valid up to 5 years, but subject to annualsurvey, and a periodical survey (more thorough than an annual survey) in place of the second or third annual survey. Supplemented by a Record of Equipment. Cargo Ship Safety Construction Certificate – issues after survey of hull, machinery and equipment, including the arrangements, materials and scantlings of the structure, machinery, steering gear, control systems, electrical installation and other equipment. Valid up to 5 years, but subject to annual surveys, and an intermediate survey in place of the second or third annual survey. When an exemption is granted to a ship, an Exemption Certificate is issued in addition to the Safety Certificate(s). All Safety Certificates cease to be valid on change of flag. Regulation 19 authorizes officers duly appointed by Governments to control visiting ships (Port State Control), the circumstances under which ships may be detained, and points out that all possible efforts shall be made to avoid a ship being unduly detained or delayed. Ships which are unduly detained or delayed shall be entitled to compensation for any loss or damage suffered. Chapter 1, Part C: Casualties. This part contains only Regulation 21, which obliges Administrations to conduct investigations of any casualty when it judges that it may assist in determining any changes in the regulations. CHAPTER II-1 Construction – Structure, subdivision and stability, machinery and electrical installations Chapter II-1, Part A – General. Like all the chapters, this starts with more detail of ships to which the chapter applies. Chapter II-1, unless expressly provided otherwise, applies to ships built on or after 1 July 1986. Ships built before need to comply with the earlier version of SOLAS 1974. In this chapter the expression ‘all ships’ means ships constructed before, on, or after 1 July 1986. The expression is re-defined in each chapter. Administrations may exempt individual or classes of ships from any requirements which may be unreasonable or unnecessary, given the sheltered nature of voyages by ships which do not proceed more than 20 miles from land. There are good definitions in this part, including ‘permeability of a space’ which is the percentage of that space which can be occupied by water, measured only to the height of the ‘margin line’, which is a line drawn at least 76mm below the upper surface of the bulkhead deck at side. The ‘bulkhead deck’ is the uppermost deck up to which the transverse watertight bulkheads are carried.
Chapter II-1, Part A1: Structure of Ships. Regulation 3-1 of this part requires ships shall be designed, constructed and maintained in compliance to the rules of a classification society (or equivalent national standards). The rest deals with corrosion prevention of seawater ballast tanks, safe access to tanker bows, and emergency towing arrangements on tankers. Chapter II-1, Part B: Subdivision and stability. This part deals with floodable lengths in passenger ships, permeability in passenger ships, lengths of compartments, stability of passenger ships in damaged condition and similar subjects – all with formulae for the computation of criterion of service numeral, which determines the factor of subdivision. Watertight bulkheads, double bottoms, watertight doors, openings in shell plating, bilge pumping arrangements, stability information, damage control plans, and related subjects are covered. Cargo ships require a watertight collision bulkhead located at a distance from the forward perpendicular of not less than 5% of the length of the ship. This would normally be 5% of the ships length back from the bow at the waterline, and no doors or openings (apart from a single pipe protected with valve) are allowed to penetrate this bulkhead. Cargo ships built on or after 1 February 1992 are required to have a double bottom extending from the collision bulkhead to the afterpeak bulkhead, as far as this is practicable and compatible with the design and proper working of the ship. Chapter II-1, Part B-1: Subdivision and damage stability of cargo ships. This part applies to cargo ships over 100m built on or after 1 February 1992, and between 80m and 100m if built on or after 1 July 1998. The regulations are intended to provide ships with a minimum standard of subdivision, and deals with the calculation of the required subdivision index R, the attained subdivision index A (this not to be less than R), calculation of the factors pi (the probability that only the compartment or group of compartments under consideration may be flooded, disregarding any horizontal subdivision) and si, (the probability of survival after flooding those compartments, including the effects of any horizontal subdivision). Related regulations deal with permeability, stability information, openings in watertight bulkheads and external openings in cargo ships. Chapter II-1, Part C: Machinery installations. This part applies to passenger ships and cargo ships. It deals fully with the safety and reliability of machinery. Some points from this part: • It requires Administrations to ‘give special consideration to the reliability of single essential propulsion components’. • Main Propulsion is to be retained (or restored) in the event of a breakdown of one of the essential auxiliaries. • Means to be provided to ensure that the machinery can be brought into operation from the dead ship condition without external aid. • Engines with cylinder diameter of 200mm or a crankcase volume of 0.6m3 to have crankcase explosion relief valves. • Stopping times, ship headings and distances on trials, performance with only one engine etc. to be recorded and available on board. • Main steering gear to put the rudder from 35deg on side to 30deg on other side in 28 seconds whilst running ahead at maximum service speed. • Auxiliary steering gear to put the rudder from 15deg on side to 15deg on the other in 1 minute whilst running ahead at half speed. • Indicators for propeller speed and direction to be fitted on the bridge (and engine control room if the ship is built on or after 1 July 1998).
At least 2 means of communication (one being an engine-room telegraph) to be provided between Navigation Bridge and engine control room. Chapter II-1, Part D: Electrical installations. This part gives quite general descriptions of much of the installation, and great detail about emergency lighting, emergency power sources, times emergency equipment is required to operate, transitional source of emergency power (to operate between shut down of main power and start of emergency genset), precautions against shock and other electrical hazards, and type and use of cables. As examples: • Administrations are required to ensure the uniformity of electrical installations, and referred to the publications of the International Electotechnical Commission, especially Publication 92 – Electrical Installations in Ships. • The main source of electrical power is to be at least two gensets, and any one should be able to run the ship. • Emergency source of power and emergency switchboard to be provided, and to be located above the uppermost continuous deck, remote from the main power and switchboard and from the engine room boundaries, and with ready access to the open deck. • Emergency source of power, which can be either a genset or batteries, to supply power for given minimum times to emergency services including emergency lighting, navigation lights, radio equipment, navigation equipment, fire detection and alarm, fire pump, emergency bilge pump. Chapter II-1, Part E: Additional requirements for periodically unattended machinery spaces. The arrangements provided shall be such as to ensure that the safety of the ship in all sailing conditions, including maneuvering, is equivalent to that of a ship with manned machinery spaces. Engines of 2,250 kW and above or having cylinders of more than 300mm bore shall be provided with crankcase oil mist detectors or engine bearing temperature monitors or equivalent devices. Increased requirements apply to bilge pumping, engine controls, communications, alarm systems, automatic machinery shutdown, and generator operation including load shedding to ensure the integrity of power for essential services. CHAPTER II-2 Construction: Fire protection, fire detection and fire extinction. Chapter II-2, Part A – General. Unless expressly provided otherwise, this chapter applies to ships built on or after 1 July 1998. Ships built before need to comply with earlier versions of SOLAS. ‘All ships’ means ships built before or after that date. The basic principals, which are applied –depending on the type of ship –, are: • Division of the ship into main vertical zones, and separation of accommodation spaces, by thermal and structural boundaries. • Restricted use of combustible materials. • Detection, containment and extinction of any fire in the zone of origin. • Protection of means of escapes or access for fire fighting. • Ready availability of fire fighting appliances. • Minimization of possibility of ignition of flammable cargo vapour. Requirements are detailed and provide exact details of equipment and specifications. Chapter II-2, Part B: Fire safety measures for passenger ships. Full details of bulkheads and fire test requirements, escape routes, ventilation systems, and fixed fire fighting systems – for passenger ships. Chapter II-2, Part C: Fire safety measures for cargo ships. As above, but for cargo ships. With restricted use of combustible materials. •
Chapter II-2, Part D: Fire safety measures for tankers. As may be imagined, a very detailed chapter. CHAPTER III: Life-saving appliances and arrangements. Chapter III, Part A – General. This chapter applies to ships built on or after 1 July 1998. ‘All ships’ means ships built before, on or after that date. Ships built prior to that date need to conform to earlier versions of SOLAS, and phase into the latest requirements as and when equipment is replaced. There are good definitions in this section, including ‘Length’, ‘Moulded depth’, and ‘Novel life-saving appliance or arrangement’. Chapter III, Part B: Requirements for ships and life-saving appliances. SECTION I – PASSENGER SHIPS AND CARGO SHIPS. The paragraph dealing with Radio life-saving appliances (the requirement to carry VHF radio and Radar transponders) applies to passenger ships, cargo ships over 500GT, and to a slightly lesser extent all cargo ships between 300GT and 500GT. As well as detailing the various appliances to be carried, sections dealing with Muster lists, Abandon ship drill procedures, Emergency training and drills, Fire drills, On-board training and instructions, Operational readiness, Servicing and maintenance of life-saving appliances and related issues give a very good (and easy to understand) overview of the types of systems which should be in place on board. Taking section I as basic requirements for all ships, sections II, III and IV give the additional requirements for passenger ships (II), cargo ships (III), and section IV requires life-saving appliances to comply with the requirements of ‘the Code’ – which is the International LifeSaving Appliance (LSA) Code adopted by the Maritime Safety Committee of the IMO by resolution MSC.48 (66). It is the responsibility of the ship to fit equipment approved by the flag State Administration, and the responsibility of the Administration to ensure that they only approve equipment, which meets the standards set out in ‘the Code’. SECTION V – MISCELLANEOUS This is a very useful part which gives the format for the compilation of the Training manual and on-board training aids, Instructions for on-board maintenance, and the Muster List and emergency instructions. CHAPTER IV: Radio communications. This chapter deals with the Global Maritime Distress and Safety System (GMDSS) and is in three parts: Chapter IV, Part A – General. The requirements of this chapter apply to passenger ships and cargo ships of 300 GT and upwards. There was a phase-in period for ships built before February 1995, but this has now passed, and since February 1999 all of these ships have needed to comply fully with this chapter. Whilst other chapters give various degrees of latitude to Administrations to accept equivalents or allow exemptions, it is noted here that ‘Contracting Governments consider it highly desirable not to deviate from the requirements of this chapter’. Any partial or conditional exemptions which may be granted to individual ships needs to be reported to IMO together with the reasons for granting the exemption. The four Sea Areas are defined, A1 (VHF coverage), A2 (MF coverage), A3 (INMARSAT coverage) and A4 (an area outside the other 3). The actual Functional Requirements are summarized in simple and positive language – ‘Every ship, while at sea, shall be capableof transmitting ship-to-shore distress alerts by at least two separate and independent means, each using a different Radio communication serviceof receiving shore-to ship distress alertsand so on. Chapter IV, Part B: Undertakings by Contracting Governments.
This deals with the undertaking from Contracting Governments to make available shorebased facilities for space and terrestrial Radio communication services, providing service by Satellite, VHF, MF and HF as may be appropriate. Chapter IV, Part C :Ship requirements. These 14 pages give the detail of the equipment to be carried and service provided on board so the ship can comply with the Functional Requirements as set out in Part A. The concise and (in general) non-technical descriptions of Equipment, Power sources, Watches to be maintained, Maintenance requirements and Certification of personnel, are – apart from being the prime regulations - a valuable introduction to the whole system of GMDSS to yachtsmen who may be considering fitting GMDSS as a ‘voluntary fit’. CHAPTER V: Safety of Navigation. This chapter, unless otherwise expressly provided for in this chapter, applies to all ships on all voyages, except ships of war and ships solely navigating the Great Lakes of North America and their connecting and tributary waters. SOME PARTS OF THIS CHAPTER THEREFORE APPLY TO ‘PLEASURE YACHTS’ OF ANY SIZE. The various express provisions within this chapter which effectively exempt certain types or sizes of ships (including yachts) from compliance to some of the Regulations in this chapter take a number of different forms and need to be read with great care. Some of the Regulations apply to ‘every ship to which Chapter I of SOLAS applies’ – that meaning they apply to passenger ships, and cargo ships over 500GT, engaged on international voyages (so other ships do not need to comply). Other descriptions used to either include or exclude ships from particular Regulations include: • Ships of less than 150 gross tonnage. • Ships of 150 gross tonnages and upwards. • All ships of over 150 gross tonnage, when engaged on international voyages. • On every passenger ship to which chapter I applies. • Ships engaged on voyages in the course of which pilots are likely to be employed, • All ships which, in accordance with the present Convention, are required to carry radio installations. • Ships of not less than 45m in length. • And lots more. Apart from the need to comply with fairly obvious requirements, there are some perhaps less well-known requirements, which apply to ALL yachts. Some requirements (well known and not so well known), which apply, to ALL YACHTS are: • The Master of every ship is bound to report Danger Messages (e.g. meeting dangerous ice, derelict, or other direct danger to navigation, or tropical storm, etc.). •
The Master of a ship at sea which is in a position to be able to provide assistance, on receiving a signal from any source that persons are in distress at sea, is bound to proceed with all speed to their assistance (Note – this Regulation 10 goes on to provide that in special circumstances, if the master considers it unreasonable or unnecessary to proceed to their assistance he must log the reasons and inform search and rescue services accordingly.)
•
The Master shall not be constrained by the ship-owner, charterer or any other person from taking any decision, which, in the professional judgment of the Master, is necessary for safe navigation, in particular in severe weather and in heavy seas.
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The Contracting Governments undertake, each for its national ships, to maintain, or, if it is necessary, to adopt, measures for the purpose of ensuring that, from the point
of view of safety of life at sea, all ships shall be sufficiently and efficiently manned. (Note – in a footnote attention is drawn to the Principals of safe manning adopted by IMO by resolution A.890 (21) and to IMO Maritime Safety Committee Circular 242 on single-handed voyages.) Ships to which chapter I of SOLAS apply are required to carry a Safe Manning Document.) •
Ships engaged on voyages in the course of which pilots are likely to be employed shall be provided with pilot transfer arrangements. (Note – their follows 4 pages with the detail of the required arrangements.)
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Within 12 hours before departure, the ship’s steering gear is to be checked and tested by the ship’s crew. Administrations may waive this requirement for ships which regularly engage on short voyages, in which case they should be done at least once a week. Dates of checks and tests to be logged.
All ships shall carry adequate and up-to-date charts, sailing directions, lists of lights, notices to mariners, tide tables, and all other nautical publications necessary for the intended voyage. CHAPTER VI (Carriage of cargoes) and Chapter VII (Carriage of dangerous goods) deal with their titled subjects, and have almost no relation to yachts – although they do both apply to cargo ships of less than 500GT. CHAPTER VIII deals with nuclear ships. The relevant Nuclear Passenger Ship Safety Certificate and Nuclear Cargo Ship Safety Certificate are valid for one year. CHAPTER IX Management for the safe operation of ships. This chapter brings into effect the requirement for the owner or manager of the ship (the ‘Company) and the ship, to comply with the IMO International Safety Management (ISM) Code and to be issued with a Document of Compliance (DOC) by the Administration after satisfactory audit. The ship, which must carry a copy of the DOC, is issued with a Safety Management Certificate after the Administration verify that the Company and its shipboard management operate in accordance with the approved safety-management plan. These regulations already apply to passenger ships and tankers, and come into force for cargo ships of 500GT and upwards on 1st July 2002. Note also that Resolution 3 of the 1994 Conference of Contracting Governments to the International Convention for the Safety Of Life At Sea strongly urges Governments to implement as far as practicable the ISM Code for cargo ships of 150GT and over, and requests Governments to inform IMO of the action they have taken to implement the ISM Code for those smaller ships. CHAPTER X Safety measures for high-speed craft. High Speed Craft – as defined in this chapter and operating no more than 4 or 8 hours (depending if passenger or cargo craft) from a place of refuge – conforming to the IMO HighSpeed Craft (HSC) Code ‘in its entirety’ shall be deemed to have complied with the requirements of chapters I to IV and regulation V/12 of SOLAS. The HSC Code is an alternative to SOLAS in those areas, and drafted to be more suitable for High Speed Craft, which operate in coastal waters and rely on shore based maintenance. The one and a half pages of this chapter in SOLAS only give effect to the use of the HSC Code. The actual Code is a booklet – separately available from IMO –, which gives all the detail. CHAPTER XI Special measures to enhance maritime safety. This is a general ‘tidying up’ exercise dealing with Authorization of recognized organizations, Enhanced surveys (bulk carriers and oil tankers), and Port State Control. There is one Regulation, which may apply to yachts, and that is the requirement for all cargo •
ships (that includes pleasure yachts engaged in trade) of 300 GT and upwards to be provided with an IMO identification number. CHAPTER XII Additional safety measures for bulk carriers. Additional requirements relating to damage stability and structural strength of bulk carriers. Q200) WHAT IS ISM? ANS) ISM is the short form of International Safety Management, initiated by IMO. ISM code means International Safety management code for safe operation ships & for pollution prevention. Solas chapter 9 outlined ISM procedures.Human error & poor management cause majority of accidents and injury. ISM is organized mainly to reduce this error. ISM is meant for standard of safety & operation of ships and for pollution prevention. Become mandatory for all vessels after 1 JULY 2002 ISM Consists of 13 clauses: i) General objective, application, functional requirement ii) Safety & environmental policy & SMS iii) Company responsibility iv) Designated person v) Masters responsibility vi) Resources & personnel vii) Developments of plans for shipboard operation viii) Emergency preparedness ix) Report & analysis on non conformities, accidents & hazardous occurrence x) Maintenance of ship equipment xi) Documentation xii) Company verification, review & evaluation xiii) Certification, verification & control
What are the benefits gained from ISM ? Safety consciousness Safety culture Greater confidence
Favorable insurance premium Cost saving
Purpose Of ISM code & international requirements To provide an international standard for the safe management and operation of ships and for prevention of pollution. Main objectives are to ensure safety at sea, prevention of human injury or loss of life, and avoidance of damage to the environment. The new chapter IX to SOLAS 1974, Management for the Safe Operation of Ships requires compliance of Passenger Vessels and high speed Passenger Craft over 500 GRT by 1 July 1998. Oil Tankers, Cargo high-speed craft, Chemical Tankers, Gas Carriers and Bulk Carriers to comply by 1 July 1998. Other Cargo ships and mobile Offshore drilling rigs of over 500 GRT to comply by 1 July 2002.The MSA will be responsible for the system audit, issue and renewal of ISM Convention Certificates and the periodic verification. Certification: The application of the code will lead to the issue of two certificates: The Document Of Compliance (DOC) i) will be issued to the company following a successful audit of the shore side aspects of the Safety Management System ii) evidence required that the system as been in operation on at least one type of ship in the companies fleet for a period of three months. iii) Specific to ship types at time of audit iv) valid for 5 years v) subject to annual verification (within 3 months of anniversary date)
The Safety Management Certificate (SMC) i) issued to each ship following audit ii) evidence that SMS has been in operation for 3 months prior to audit iii) valid DOC required iv) valid for 5 years Subject to one verification between the second an third anniversaries with a provision for more frequent audits if necessary. This is more likely in the early days of ISM Code implementation. Temporary certification- A 12month valid DOC may be issued to a newly
formed company or a company acquiring a new type of vessel as long as they have a SMS meeting the minimum requirements of the ISM code and can demonstrate plan for full compliance. A six-month valid SMC may be issued to a new building or when a company takes of the responsibilities for the running of a vessel. Safety Management System Safety Management objectives of the company: 1. Provide for safe working practices and a safe working environment 2. Establish safeguards against possible risks 3. Continuously improve safety management skills of personnel ashore and aboard ships,
A Safety Management system (SMS) meeting the requirements of the ISM code requires a company to document its management procedures and record its actions to ensure that conditions, activities and tasks that affect safety and the environment are properly planned, organized, executed and checked. A SMS is developed and implemented by people and clearly defines responsibilities, authorities and lines of communication. A SMS allows a company to measure its performance against set criteria hence identifying areas that can be improved. The increase in Safety Management skills improves morale and can lead to a reduction in costs due to an increase in efficiency and a reduction in claims The safety management system should ensure; i) compliance with mandatory rules and regulations ii) applicable codes and guidelines both statutory and organizational are taken into account. iii) Promulgation and understanding of company and statutory regulations and guidelines. (It is the task of a visiting surveyor to test the general knowledge of company and statutory regulations and instructions) The functional requirements for a safety management system; 1. A safety and environmental policy 2. Instructions and procedures to ensure that safe operation of the vessel in compliance with relevant international and flag state legislation 3. Defined levels of authority and communication between shore and ship personnel 4. Procedures for reporting accidents and non-conformities with the code 5. Procedures for responding to emergency situations (drills etc)
6. Procedures for internal audits and management reviews 7. A system is in place for the on board generation of plans and instructions for key shipboard operations. These tasks may be divided into two categories: a) Special operations-those where errors only become apparent after a hazardous situation or accident has occurred. E.g. ensuring watertight integrity, navigational safety (chart corrections, passage planning), maintenance operations, bunker operations b) Critical shipboard operations- where an error will immediately cause an accident or a situation that could threaten personnel, environment or vessel. e.g. navigation in confined waters, operation in heavy weather, bunker or oil transfers, cargo operations on tankers. Safety and environmental protection policy: The company should establish a safety and environmental protection policy, which describes how objectives listed above will be achieved. The company should ensure that the policy is implemented and maintained at all levels of the organization both ship based as well as shore based. The ISM guideline is in the Chapter IX of SOLAS. It is mandatory for all vessels after 1st July 2002. There are two parts in ISM i) Part-A: Implementation. ii) Part-B: Certification and Verification
Part-A: 1. General, objective, application, functional requirements 2. Safety & environment protection policy. 3. Company responsibility & authority. 4. DPA. 5. Master responsibility and Authority. 6. Resource & personnel. 7. Development of plan for shipboard operation. 8. Emergency preparedness. 9. Report & analysis on non-conformities, accidents & hazardous occurrence 10. Maintenance of ship equipments 11. Documentation. 12. Company verification, review and Evolution.
Part-B: 13. Certification and periodical verification 14. Interim certification. 15. Verification. 16. Form of certification.
Objective of ISM: 1. Safety at sea. 2. Prevention of human injury or loss of life. 3. Avoidance of damage to the environment & to the property. Certificate under ISM: 1) Document of compliance (DOC). 2) Safety management certificate (SMC). DOC: Issued to company, which comply with the requirement of ISM. SMC: Issued to the ship. Which company shipboard management operate in accordance with the SMS. Issuing authority of DOC & SMC: Flag state administration or authorized classification societies on their behalf. SMS - Safety management system enabling the company personal to effectively implement company safety & environment protection policy.
DPA means Designated Person Ashore. A person who is provides a link between the company & the ship. He has a direct assess to the highest level of management. Duties of DPA: 1. Monitoring the safety & pollution prevention aspect of ship & to ensure adequate resources & shore base support for ship. 2. A person or persons who has direct access to the highest levels of management providing a link between the company and those on board. The responsibility and authority of the designated person is to provide for the safe operation of the vessels. He should monitor the safety and pollution prevention aspects of the operation of each vessel and ensure their are adequate shore side resources and support Master responsibilities Master responsibilities are to implement the SMS on board ship. 1) Implement of safety & environment protection policy. 2) Motivation of crew in observing the policy. 3) Issue order & instruction.
4) Review SMS & report.
Resources and Personnel: 1. The company should ensure that the Master is suitably qualified and fully conversant with the SMS. They should also ensure that the ship is correctly manned. 2. The company should ensure that there is adequate familiarization with safety and protection of the environment for new personnel. They should ensure that the personnel have an adequate understanding of the relevant rules, regulations, guidelines and codes. 3. Training is to be provided where necessary. Relevant information for the SMS should be promulgated and be written in an easy to understand method. Development of plans for shipboard operations: 1. The company should establish procedures for the generation of shipboard plans and instructions with regard to the prevention of pollution and that these should be generated by qualified personnel
Emergency Preparedness: The company should establish procedures for the response actions to potential emergency situations. Programmes for drill should be established and measures taken to ensure that the company's organization can respond to hazards and accidents. Reports and analysis of non-conformities, accidents and hazardous occurrences The company should ensure there is a procedure for the reporting and analysis of accidents, hazardous occurrences and non-conformities, and for the corrective action. Maintenance of the ship and equipment The company is to ensure that the vessel is properly maintained. Procedures within the SMS should be in place to identify, record and plan for repair defects. A system of preventive maintenance should be in operation. Regular inspections integrated with the ships operational maintenance routine should take place to ensure that the vessel is in compliance with relevant regulations.
Documentation 1. The company should establish and maintain procedures for the control of all documentation relevant to the SMS. This should include; 1. Valid documents are available at all relevant locations 2. Changes to documents are reviewed and approved to authorized personnel
3. Obsolete documents are promptly removed All documents, carried in a company approved relevant form, should be present on board
Company verification, review and evaluation 1. The company should carry out periodic audits to verify that safety and pollution prevention's are complying with SMS. The audits and corrective actions should be carried out as per laid down procedures. 2. Personnel carrying out the audits should be independent of the areas that they are carrying out the audit unless size of the company is such that this is impractical. 3. Deficiencies or defects found should be brought to the attention of the personnel in that section and the management team so effective corrective action can be carried out
Certification, verification and control The following documentation is issued by whichever administration, complying with ISM, is relevant to the shipping company: 1. A DOC is issued to all company's who can demonstrate that they have complied with the code should be held. A copy of the DOC should be held on board to allow the Master to produce it to the relevant authorities is required. 2. An SMC is issue to the ship following verification that the ship and company comply with the requirements of SMS. Future verification that compliance with SMS should be carried out by the administration.
Requirements on board ship 1. Proof that the vessel is being maintained in a satisfactory condition at all times, and not only at the time of surveys-objective evidence in the form of no overdue surveys, no overdue recommendations from port or flag state inspections and that planned maintenance is being carried out and records kept. 2. Applicable codes and guidelines are being taken into consideration when operating the vessel. Vessels staff must be able to demonstrate that operations are carried out in a controlled manner utilizing information contained in these codes, guidelines and standards. 3. That emergency situations have been identified and drills are conducted to ensure the vessel and company are ready to respond to emergency situations. The master is expected to be fully conversant with Company safety management system. Officers and crew would be expected to be familiar with the parts of the system relevant to their safety responsibilities as well as a thorough understanding of their operational
responsibilities- auditors will ensure compliance. Examples of the type of documentation the auditor will wish to see to verify compliance with the ISM are as follows; Log books Safety and management meeting minutes and follow up actions Medical log Company circular letters Planned maintenance records Records of verification Records of masters review of the system Records of internal audits and follow up Records of chart corrections Class quarterly listings Records of passage planning Oil record books Garbage logs Company manual and forms
Pollution prevention and OPA 90 Tied into the ISM code are the requirements to meet OPA90 to wit a Federal Response Plan. Each company that trades in US coastal waters must have in place a suitable response plan. They must have a designated person resident in the United States ready to act as consultant. There is an IMO regulation which is equivalent to OPA90. A company must be in possession of a valid DOC to trade, and it must be able to clearly demonstrate its ability to respond to situations such as oil spillage. Non conformity (NC) An observed situation where objective evidence indicate the non-fulfillment of a specified requirement. Non-conformance report (NCR) raised by department managers. Any one can inform his superior of a non-conformance.
DCR means Document Change Request. It is a recommendation for change/correction of company SMS documents.
Q201) What is IG System Requirement. Why IG System not used on ships which are less than 20000 dwt? ANS) Every oil tanker of 20000 DWT or above should be provided with an IG System. IG System is not used on ship which are less than 20000Dwt because COW is not applicable to ship which are lesser than 20000 DWT. Q202) EXPLAIN ISPS? ANS) ISPS: Chapter XI of SOLAS describes ISPS regulations. ISPS code means International ship & port facilities security code, enforced in July 2004. There are two parts in it: 1) maritime safety & 2) maritime security There are 19 chapters in ISPS: a. General b. Definition c. Application d. Responsibilities of contacting government e. Declaration of security f. Obligation of company g. Ship security h. Ship security assessment i. Ship security plan j. Record k. Company security officer l. Ship security officer m. Training, drill and exercise n. Port facility security o. Port facility security assessment p. Port security plan q. Port facility security officer r. Training, drill and exercise at port s. Verification and certification for ships OBJECTIVE: 2) International connection to detect security threats. 3) Provide adequate guideline against breach of security There are three levels in ISPS:
LEVEL-1: Background level of threat that is normal operating condition. Maintaining minimum appropriate protective security measure at all time. LEVEL-2: Heightened threat but no defined target. Maintain additional protective security measure for period of time. LEVEL-3: High level of threat against a specific target. Further high level of security measure maintained for a limited period of time.
SECURITY MEASURE: Level -1 1) Adequate deck & over side lighting. 2) Crew member should be issued photo identification. 3) Access on & off the vessel should be control & all person identify. 4) Access to certain area of the vessel to be limited with key control. 5) Unused room or space should be kept locked. 6) Periodic inspection/patrol should be made a regular interval. Level -2 In addition to level -1 1) Occasional search should be made at random interval. 2) Access of all visitors to the vessel should strictly control. 3) Close security to be paid on deliveries and stores. 4) Baggage should not be unattended. 5) Check should make on seal on container & other cargo. 6) No person other than crew member should be allowed on bridge or E/R. 7) Maintain close liaison with shore concerned. 8) All crewmembers should be reminded of bomb alert security of the vessel. Level-3 In addition to level 1 & 2: 1) Limiting access to a single & controlled access. 2) Granting access only to those responding to the security incident. 3) Carry out full or partial search of the ship. 4) Suspending cargo-handling operation. 5) Tighten security patrol of the vessel. 6) Crew member should be briefed on seriousness of the situation.
RESTRICTED AREA: 1) Navigation room 2) Radio room 3) Engine room 4) Steering room
5) Emergency generator area 6) Bow thruster 7) Fire control room 8) Crew accommodation area 9) Ventilation, air conditioning equipment room, 10) Similar key area which is essential to safe operation of ship. SSO means Ship Security Officer (person accountable to master, designated by company. CSO means Company Security Officer. PFSO means Port Facility Security 0fficer. SSP means Ship Security Plan. MAR SEC means Maritime Security.
Q203) Meaning of Panting & Pounding? ANS)Panting: - As the waves pass along the ship they cause fluctuations in water pressure, which tend to create an in- and- out movement of the shell plating. The effect is mostly found to be greatest at the ends of the ship, particularly at the fore end. Such effect is termed as Panting. Pounding: - When a ship meets heavy weather and commences heaving and pitching, the rise of the fore end of the ship occasionally synchronizes with the trough of the wave. The fore end then emerges from the water and re-enters with a tremendous slamming effect known as pounding. Q204) What are the regulation regarding use of Low Expansion Foam system on deck? ANS) The ratio of low expansion foam system used on deck should not have ratio more than 1:12. Q205) EXPLAIN THE PRINCIPLE OF REFRIGERATION? ANS)The principle of refrigeration is to remove heat from one area (i.e. inside your fridge) and locate it to another area (i.e. outside of your fridge). Air is not brought in from the outside of the fridge the heat is absorbed by the evaporator inside the fridge which has refrigerant inside it, this refrigerant at low pressure is at low temperature inside the evaporator so the heat from the product inside the fridge is absorbed by the evaporator (as heat always transfers from the hotter object to the colder object) which has a fan to circulate the air around the fridge. Then the refrigerant is pushed around the pipe work by the compressor to the condenser where the refrigerant is hot from the heat out of the fridge, because the outside air will be lower than that of the pressurized refrigerant the heat is absorbed by the ambient air which
leaves the refrigerant cooler and lower pressure so when its back into the evaporator it can absorb more heat and expel it into the ambient air. There are 5 main components in a normal refrigeration system like on your fridge:Compressor Condenser Expansion Device or Capillary tube Evaporator Thermostat The compressor compresses the refrigerant gas. This raises the refrigerant's pressure and temperature, so the heat-exchanging coils outside the refrigerator allow the refrigerant to dissipate the heat of pressurization. As it cools, the refrigerant condenses into liquid form and flows through the expansion valve. When it flows through the expansion valve, the liquid refrigerant is allowed to move from a high-pressure zone to a low-pressure zone, so it expands and evaporates. In evaporating, it absorbs heat, making it cold. The coils inside the refrigerator allow the refrigerant to absorb heat, making the inside of the refrigerator cold. The cycle then repeats.
