®
Wire Rope Inspection and Examination
Wire Rope Inspection and Examination by Dipl.-Ing. Roland Verreet Verreet and William Lindsay 1. 2. 3. 4. 5. 6. 7. 8. 8.1 8.2 8.2 8.3 8.3 8.4 8.4 8.5 8.5 8.6 8.6 8.7 8.7 9.
Why must wi wire ro ropes be in inspected an and ex examined? ............ page Wha What is is In Inspe spectio tion, wh what is is Ex Examin minatio tion? .... ....... ...... .... .... .... .... .... .... .... .... page Whe When mus must wire ire rop ropes be ins inspected ted? .... ...... .... .... .... .... .... .... .... .... ........ ...... .... .... page Whe When mus must wire ire rop ropes be examin mined? .... ...... .... .... .... .... .... .... .... .... .... ........ ...... .... page Surv Survey ey for for remo remova vall crit criter eria ia .... ...... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .. page page Wher Where e must must wire wire rope ropes s be insp inspec ecte ted d or exam examin ined ed? ? .... ...... .... .... .... .. page page Disc Discar ard d num numbe berr of of wir wire e bre break aks s .... ...... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... page page Rope Rope exam examin inat atio ion n proc proced edur ure e .... ...... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... page page Equipm Equipment ent... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ... page page Loca Locati ting ng of wire wire break breaks s .... ...... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... page page Dete Determi rmina nati tion on of of the the rope rope dia diame mete terr .... ...... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... page page Meas Measur urin ing g rope rope lay lay .... ...... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... page page Chec Checki king ng the the sta stabi bili lity ty of of the the rope rope .... ...... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .. page page Chan Change ges s in rope rope str struc uctu ture re .... ...... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .. page page Insp Inspec ecti ting ng shea sheave ves s and dru drums ms .... ...... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .. page page Elec Electr troo-ma magn gnet etic ic wir wire e rope rope exa exami mina nati tion... on..... .... .... .... .... .... .... .... .... .... .... .... .... page page
2 3 4 4 6 10 12 13 13 13 15 17 18 18 18 20
FOREWORD
In the UK two Codes of Practice deal with the Inspection and Examination of steel wire ropes, B.S.7121: Part 1 1989 „Safe use of Cranes“ and B.S. 6570 : 1986 „The selection, care and maintenance of steel wire ropes“. B.S. 7121 deals specifically with cranes, much of the information it contains relating to ropes has been taken from B.S.6570. However, B.S.7121 does have additional useful information about the discard criteria to be applied when assessing assessing the the condition condition of a rope. B.S.6570 is a comprehensive Code of Practice and gives information on the selection, care, maintenance, inspection and examination of general purpose ropes. R. Verreet & W. W. Lindsay, Wire Rope Inspection and Examination, 1996
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Wire Rope Inspection and Examination by Dipl.-Ing. Roland Verreet Verreet and William Lindsay 1. 2. 3. 4. 5. 6. 7. 8. 8.1 8.2 8.2 8.3 8.3 8.4 8.4 8.5 8.5 8.6 8.6 8.7 8.7 9.
Why must wi wire ro ropes be in inspected an and ex examined? ............ page Wha What is is In Inspe spectio tion, wh what is is Ex Examin minatio tion? .... ....... ...... .... .... .... .... .... .... .... .... page Whe When mus must wire ire rop ropes be ins inspected ted? .... ...... .... .... .... .... .... .... .... .... ........ ...... .... .... page Whe When mus must wire ire rop ropes be examin mined? .... ...... .... .... .... .... .... .... .... .... .... ........ ...... .... page Surv Survey ey for for remo remova vall crit criter eria ia .... ...... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .. page page Wher Where e must must wire wire rope ropes s be insp inspec ecte ted d or exam examin ined ed? ? .... ...... .... .... .... .. page page Disc Discar ard d num numbe berr of of wir wire e bre break aks s .... ...... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... page page Rope Rope exam examin inat atio ion n proc proced edur ure e .... ...... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... page page Equipm Equipment ent... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ... page page Loca Locati ting ng of wire wire break breaks s .... ...... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... page page Dete Determi rmina nati tion on of of the the rope rope dia diame mete terr .... ...... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... page page Meas Measur urin ing g rope rope lay lay .... ...... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... page page Chec Checki king ng the the sta stabi bili lity ty of of the the rope rope .... ...... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .. page page Chan Change ges s in rope rope str struc uctu ture re .... ...... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .. page page Insp Inspec ecti ting ng shea sheave ves s and dru drums ms .... ...... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .... .. page page Elec Electr troo-ma magn gnet etic ic wir wire e rope rope exa exami mina nati tion... on..... .... .... .... .... .... .... .... .... .... .... .... .... page page
2 3 4 4 6 10 12 13 13 13 15 17 18 18 18 20
FOREWORD
In the UK two Codes of Practice deal with the Inspection and Examination of steel wire ropes, B.S.7121: Part 1 1989 „Safe use of Cranes“ and B.S. 6570 : 1986 „The selection, care and maintenance of steel wire ropes“. B.S. 7121 deals specifically with cranes, much of the information it contains relating to ropes has been taken from B.S.6570. However, B.S.7121 does have additional useful information about the discard criteria to be applied when assessing assessing the the condition condition of a rope. B.S.6570 is a comprehensive Code of Practice and gives information on the selection, care, maintenance, inspection and examination of general purpose ropes. R. Verreet & W. W. Lindsay, Wire Rope Inspection and Examination, 1996
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1. Why Why mus mustt wir wire e rop ropes es be inspected and examined?
and by changes in the structure of the rope.
Wire ropes are consumable items with a limited life. During service the physical properties of a wire rope will change. At the commencement of service, the individual wires and strands settle into position and the rope breaking strength increases. After reaching a maximum it decreases rapidly (Fig. 1). Th T h i s d e c r e a s e i n b r e a k i n g strength is caused by the progressive loss of the metallic cross-section due to abrasion and corrosion, by wire breaks
A chain represents a series connection of load bearing elements. If only one link in the chain breaks, the whole lifting device will fail completely. A wire rope represents a parallel connection of load bearing elements and consequently it can still be operated safely after one or more wire breaks. Generally, there is a steady rate of increase in the number of wire breaks during the life of the rope. rope. Fig. 3 shows the increasing num ber of wire breaks as a function of the number of cycles in a bending fatigue test.
] % [ d a o l g n i k a e r b l a u t c a
100
~100% 0 0
discard number of cylces
break [%]
Fig. 1 2
R. Verreet & W. W. Lindsay, Wire Rope Inspection and Examination, 1996
One of the objectives of inspecting and examining a wire rope is to supervise the normal process of deterioration so that the rope can be removed from service before becoming a hazard to safety. Another benefit of the inspection and examination procedures is to detect unexpected damage or corrosion. Inspections and examinations, properly carried out, ensure the discard of a rope before failure. In addition, precautions can be taken to avoid a recurrence of damage or excessive wear to future ropes.
chain, one element broken
2. What is Inspection, what is Examination?
An inspection is a careful and critical assessment of the rope and fittings carried out without dismantling. An examination is a careful and critical assessment of the rope and fittings carried out by a competent person. This should include, where necessary, a visual assessment of the internal condition of the rope, supplemented by other means such as measurement and non destructive testing. In order for end fittings to be examined properly they may need to be dismantled.
rope, one element broken
Fig. 2 R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
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3. When must wire ropes be inspected?
When a rope has been removed from equipment and later fitted to the same or different equipment, it should be inspected after Wire ropes should be inspected at fitting but before resuming servthe start of each shift, work pe- ice. riod or more frequently, depending upon past experience. Usu- If at any time a change in the rope ally this inspection will be carried condition is suspected, it should out by the operator of the indi- be reported immediately and the vidual piece of equipment or pos- equipment taken out of service sibly by a member of the work until the rope has been examined force specially appointed. by a competent person. As a result of this examination it may be The inspection should be a visual prudent to review and amend the assessment of the condition of as scope and frequency of the inmuch of the rope length as possi- spections. ble, including the points of attachment to the equipment.
] – [ d x 0 3 n o s e r i w n e k o r b f o r e b m u n
30 D/d = 20 load proportional to minimum breaking load
25
20
tensile strength 200 kp/mm 2 load 111 % 15
tensile strength 180 kp/mm 2 load 100 % 10
5
0 0
30.000
60.000
number of cycles
90.000
120.000
[–]
Fig. 3 4
R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
4. When must wire ropes be examined?
a) b) c)
The Factories Act 1961 Section 26, The Construction (Lifting Operations) Regulations No. 1581 and the Offshore Installations (Operational Safety, Health and Welfare) Regulations 1976 No. 1019 all require a thorough rope examination at least once in every period of six months. The Shipbuilding and Ship-repairing Regulations 1960 requires a thorough examination every three months or monthly after the first broken wire has been discovered.
d) e) f) g)
statutory requirements type of appliance and/or design of the system operational environmental conditions method and frequency of operation manufacturer’s recommendations results of previous inspections and examinations experience with previous ropes on the appliance or system”
During the first few weeks after the installation of a new rope the daily inspection can be used to monitor performance as the rope might have been fitted incorrectly or the type of rope might not be suited to the equipment.
One of the statutory regulations listed above will apply to the location and type of rope using equipment being examined. The intervals between the examiIt is the responsibility of the indi- nations should also be reduced vidual to institute and maintain a after the first broken wire or programme of periodic examina- other damage has been detected. tion which satisfies the requirements of the appropriate regula- If the rope has been overloaded or tions and the specific operating if non- visible damage is suspected, the intervals between exconditions of the equipment. Examination should be carried aminations should be reduced out at regular intervals. The in- accordingly. tervals should be scheduled so that any damage will be detected early.
Moreover, the examinations should be carried out when the rope is put back into service after long periods of standstill.
According to B.S. 6570 examinations should be carried out “at regular intervals, the frequency If a lifting device has been disof which will be influenced by the mantled and re assembled, the following: rope must be examined before it is allowed to operate again. R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
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5. Survey of removal criteria
falls to 97% of the nominal, or rises to 105% of the nominal”, because “discard may be necessary”.
A wire rope must be removed if one or more of the following crite- 3) Corrosion. ria can be satisfied: Corrosion may be external or in1) Broken wires. ternal, general or localized. According to BS 6570, a wire rope A wire rope must be discarded if should be discarded “when the the permissible number of wire surface of the wires is severely breaks is reached or exceeded. It roughened or pitted, or if the must also be replaced when local wires are slack within the concentrations of wire breaks oc- strands due to wastage”. cur. 4) Rope deformation Chapter 7 covers in detail the subject of the permissible num- a) Waviness (Fig. 4a). This defor ber of wire breaks according to mation, while it may not necesBritish Standard 6570 and the sarily affect the strength of the statutory requirements. rope, can transmit pulsation and produce uneven rope wear. When 2) Reduction in diameter. the rope is laid on a level surface under no load, the maximum Reduction in diameter can be height of the “wave” should not caused by abrasion, corrosion or be greater than the nominal rope a local failure of the rope core. diameter + 1/3, otherwise the According to B.S. 6570 a wire rope should be removed from rope should be discarded „when service. the rope diameter anywhere is re- b) Birdcage (Basket Deformation) duced to 90% of the nominal di- A birdcage (Fig. 4b) develops ameter in the case of six and when the outer layer of strands eight strand ropes“. Considering be comes longer than the inner the fact that a rope is allowed to layer or layers. The condition have an oversize of 4% when new, may occur as a result of incorrect this figure would allow for a di- fitting, tight sheaves, shock loadameter reduction of 14%, which ing, incorrect use of a swivel or seems to be excessive. the application of a heavy load to a new rope before the strands For multi- strand ropes B.S. have settled into position. Ropes 6570 recommends a detailed ex- with a birdcage should be disamination “if the rope diameter carded. 6
R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
c) Loop Formations. Wires or groups of wires may form a line of loops parallel to the axis of the rope (Fig. 5a). This deformation is often caused by shock- loading. Loop formations are a justification for discard. d) Loose Wires. Where loose outer wires (Fig. 5b) are found without any adjacent mechanical damage, the most likely cause will be corrosion and the rope should be removed from service. Where
loose wires have been caused by mechanical damage, a full examination will decide if the rope can remain in use. e) Nodes (Fig. 5c). A node is a local increase in rope diameter with the core easily visible between several covering strands. It can be caused by shock loading or, in the case of fibre main core ropes, by the absorption of moisture. A node is a justification for discard.
a
b
Fig. 4 R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
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f) Thinning of the rope (Fig. 6a). Thinning is a reduction in the diameter of the rope over a short length. It is often associated with older fibre cored ropes usually in areas of sustained heavy loads over sheaves. The disintegration and loss of the core can allow one of the covering strands to take the place of the core. When this condition occurs in ropes with IWRC the distortion will most of-
ten be in the vicinity of the termination away from drum. The most likely cause is rope rotation which has allowed the rope to unlay, resulting in the overload and reduction in diameter or failure of the IWRC. g) Misplaced Outer Wires. Misplaced outer wires are wires forced out of position along the line of the rope to form small flat-
a b
c Fig. 5 8
R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
tened loops. This can be caused by bad drum spooling or by the rope being drawn across a sharp edge. Langs lay ropes are often worst affected. Misplaced outer wires are a justification for discard. h) Kinks (Fig. 6b). Deformation caused by a loop in a rope being tightened when the rope cannot rotate about its axis to release the
torque. The tight bend or kink thus formed can result in a serious loss of strength due to un balance in the lay lengths. Ropes with kinks must be discarded. i) Flat areas (Fig. 6c). A flattening can be caused by bending the rope severely over the rim of a sheave or any sharp object with the wires on the inside of the bend being forced out of position.
a
b
c
Fig. 6 R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
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220
]
200
2
m 180 m / p k 160 [ h t 140 g n e r t 120 s e l i 100 s n e t 80 60 0
100
200
300
temperature
Fig. 7
Ropes with flat areas should be discarded. 5) Damage caused by heat. Heating rope wires to approximately 300 C and over will lead to considerable reduction in tensile strength of the wires (Fig.7). Wire ropes which have been sub jected to excessive heat must be discarded. °
500
400
600
700
[ C] °
should be checked. The following areas may require more detailed attention: a) Rope zones with the highest number of cycles. During normal day to day operations some sections of a rope length will suffer a greater number of bends over sheaves and drums than others. It is in these areas where the greatest number of fatigue wire breaks can be expected.
6. Where must wire ropes be inspected or examined?
b) Pick- up points. When a lifting device picks up or releases a load with the same sections of rope During an inspection or a peri- regularly in contact with sheaves odic examination by a competent and drums, those sections of the person, the full length of the rope rope are subjected to increased 10
R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
stress.
the fleet angle is excessive.
c) End fittings. At, or closely adja- With multiple layer spooling, the cent to, terminal fittings the elas- first layer of rope on the drum ticity of the rope is restricted and should be tightly wound to prothe geometry “frozen”. vide a firm base for subsequent layers. This applies in particular Depending upon the type of fit- to plain drums and parallel ting, there will be additional pres- grooved drums, e. g. Lebus. Slack sure on the rope and the section winding or lateral movement beclose to the area of contact be- tween turns of rope will affect the tween rope and fitting is often the spooling of subsequent layers focal point for increased stress and can cause damage. caused by vibration. The poi nt where the rop e is The danger of corrosion is also squeezed between the drum increased by the retention of flange and the previous turn as it moisture in the area of contact rises to commence the next layer, between rope and fitting. is an area of accelerated wear and should be given special attention. d) Equalising sheaves. Ropes which are often considered to be f) Sheaves. Sheaves should be exstationary around equalising amined for general condition and sheaves can be subjected to high tested for freedom of movement. numbers of bend cycles caused Using a groove gauge the tread by the uneven spooling of two radius can be measured. drums, by swinging loads or by frequency vibrations. As the rope The radius of the grooves should might never leave the equalising be equal to the nominal rope disheave, moisture can be trapped ameter plus + 6% to + 10%. in the area of contact between rope and sheave and cause corro- Undersize grooves will seriously sion. reduce the service life of the rope due to the effects of crushing. e) Zones of maximum wear on Oversize grooves reduce the servdrums. Pick- up points and ice life due to premature fatigue cross- over points on the drum caused by insufficient support in are subjected to increased wear the groove area. and therefore require special attention. Misplaced and broken Where the rope surface pattern is wires caused by scrubbing can be imprinted into the sheave tread, expected at cross- over points. the sheave should be replaced. The damage can be severe where R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
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g) Rope sections working in a hostile environment. High temperature can considerably reduce the breaking load of a wire rope. Temperatures of up to 250 C will not affect the tensile strength of the wire, but temperatures of only 50 C can cause leaching of the rope lubricant. °
°
The consequent severe wire to wire friction will result in a marked reduction of rope performance. The exposure of rope to chemical action can greatly increase the effect of corrosion. In each of the areas where wire breaks or other defects are found, the number and description along with the location, must be recorded.
7. Discard number of wire breaks
The Health and Safety at Work Act requires the provision and maintenance of plant and systems of work that are, so far as is reasonably practical, safe and without risks to health. The table on Page 25 shows the recommended number of discard wire breaks for CASAR special wire ropes. For the number of discard wire breaks in other types of multi-strand ropes the user is advised to contact the rope manufacturer. Depending on the factor of safety, the assessment of broken wires in 6 and 8 strand ropes working over steel sheaves is divided into two groups : 1) Factor of safety less than 5 : 5% of the number of outer strand wires excluding Filler wires.
2) Factor of safety greater than 5 : 10% of the number of outer The Construction (Lifting Ope- strand wires excluding Filler rations) Regulations requires a wires. rope to be replaced when the number of broken wires reaches When broken wires are detected, 5% of the total number of wires in the number and position, along the rope in 10 x d. with the examiner’s opinion of the general rope condition, will The Factories Act, The Shipbuild- decide whether or not the rope ing and Ship-repairing Regula- should be discarded. tions and the Offshore Installations Regulations do not specify a If local concentrations or groups particular number of broken of broken wires are found, the wires for discard and leaves this rope should be discarded when: decision to the discretion of the examiner. 12
R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
a) three or more broken wires are should be available: found in the close proximity of the termination, a list of the discard criteria (this manual) b) three or more broken wires are a rope caliper or vernier gauge found in one strand or a steel tape a piece of white chalk c) five broken wires are found be- a wax pencil (dark coloured) tween two adjacent strands a roll of adding machine paper within a length of 10 x rope a sheet of typing carbon paper diameter. a screwdriver a magnifying glass If the number of broken wires a pencil does not justify discard, the posi- a roll of marking tape tion and number of all broken two sets of groove gauges wires found must be recorded in a piece of cleaning cloth the rope examination Log Book. a wire brush a pair of gloves When broken wires are found in a note book or an inspection form close proximity to a permanent the previous inspection records termination, such as a white metal or resin secured socket and the general condition of the re8.2 Locating of wire breaks mainder of the rope is acceptable, it may be decided to cut the rope and re make the termination. In Identification of wire breaks can such cases it is recommend that be by visual and physical examithe socket is submitted for N.D.T. nation or by the use of electromaand heat treatment. Care must gnetical equipment (see sec be taken to ensure sufficient tion 9). turns of “dead” rope remain on the drum after the termination The first step in wire rope examihas been remade. nation is to find the rope section with the greatest concentration of wire breaks. This is normally 8. Rope examination done by first visually inspecting procedure the full length of the rope.
8.1 Equipment In order to carry out a proper inspection, the following tools
In some cases it can be helpful to spool the rope slowly through the hand. Special attention has to be paid and strong protective gloves must be worn.
R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
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A piece of wood held on the surface of a moving rope will be deflected by the protuding ends of broken wires. In the same way, a soft cotton or similar type cloth held against a moving rope will be caught by protruding ends and thus detect the broken wires. Smooth synthetic material is less suitable for this purpose. The detection of broken wires in the strand valleys can be difficult. The use of a scraper or piece of shaped wood will help clean out the valleys. The use of a wire brush on a dirty, heavily lubricated rope can loosen, but not
always remove, old lubricant and the brush may have to be cleaned frequently with a solvent. Where solvents are used to clean the rope surface, they should be used sparingly and the rope section should be thoroughly lubricated afterwards. A light lubricating oil used with a wire brush is preferred for softening old lubricant which can then be wiped off with a cloth. When the worst affected sections of rope have been found, their boundaries should be marked by chalk or tape for further examination.
Fig. 8 14
R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
A gauge should be set to a length of 10 x d. This can now be moved within the boundaries to locate the section with the maximum number of wire breaks. The breaks in 10 x d should be counted and entered in the records.
ured at several points. The average value of all the measurements at each point must be recorded and will form the basis of comparison for all future measurements.
The measurement of the rope di With thin ropes, valley breaks ameter is an essential part of all can be detected by strongly flex- inspections and examinations. It ing the unloaded rope (Fig. 8). ensures the maximum diameter reduction does not exceed the recommended figure. As stated in 5.2. British Standard 6570 re8.3 Determination of the rope diameter commends that a wire rope should be discarded when the diameter of the rope is reduced to The rope diameter should be 90% of the nominal diameter. measured on receipt for conformity with the specification. British A comparison of the measured Standard (B.S. 302:1987, Stran- data with the recorded previous ded steel wire ropes, Part 1. values can detect an abnormal Clause 5.1) allows for a tolerance rate of reduction in diameter. of - 1% to + 4% of the nominal Coupled with assessment of prerope diameter. vious rope examination data, the probable date of rope renewal can The generally accepted method of be predicted. measuring rope diameter for compliance with the Standard is If we examine the cross-section of to use a caliper with jaws broad a six-strand wire rope, we will enough to cover not less than two find that measuring the thickadjacent strands. The measure- ness of the rope over the crowns ments must be taken on a (Fig. 9a) will produce a higher vastraight portion of rope at two lue than measuring it over the points at least 1 metre apart. At valleys (Fig. 9b). The actual diameach point two diameters at right eter of the rope is defined as the angles should be measured. The diameter of the circumscribing average of the four measure- circle. ments is the actual diameter. When using a conventional ca After the rope has made the first liper, wire ropes with an even few cycles under low load, the number of outer strands (four-, rope diameter should be meas- six-, eight-, ten-, and multiR. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
15
strand) ropes must be measured from crown to crown. The advantage of a proper wire rope caliper with measuring plates is that even if the measurement is carried out “incorrectly”, adjacent crowns are always included, so that the actual diameter is determined at any section (Fig. 10).
conventional caliper, therefore, has to be applied diagonally to the axis of the rope, so that at any time a crown adjacent to a valley is covered. Again a wire rope caliper with measuring plates is definitely to be preferred as it al ways includes strand crowns.
In all cases during periodic exMeasuring the diameter of wire aminations where the measureropes with an uneven number of ments are to be recorded, the outer strands (three-, five-, se- rope should be measured as al ven, or nine-strand ropes) is mo- ready described. Where the re complicated: a crown on the „roundness“ is being checked to one side of the wire rope always detect potential faults, two diamhas a valley as a counterpart on eters, one at right angles to the the other side of the wire rope. A other can be taken and noted in
20,00 mm
a
18,30 mm
b Fig. 9 16
R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
the records. The entry into the wires and strands should be alrecords might read „Rope diam- lowed to settle into their permaeter : 20.4/20.5mm“. nent position. Six or seven lifting cycles with a light to medium load are recommended before 8.4 Measuring rope lay measuring the lay of the rope. To minimise error, the measurement should be made over four lays After a rope has been fitted to the and the length divided by four to appliance, its length cannot be find the average lay length. measured again accurately without a great deal of trouble. The On eight strand ropes the eight, purpose of measuring the length sixteenth, twentyfourth and of lay is to detect any increase in thirtysecond strands must be the rope length which may have marked. Using a straight length been caused by corrosion, core of the rope and with the rope undeterioration or rope rotation der no load, first mark any strand (unlaying). With a new rope the on the crown with a piece of chalk: this strand now becomes “crown zero”. Excluding this strand, count the next eight strands and mark the eighth strand with chalk. Exclude the eighth strand and repeat this procedure a further two times. The measured length between the outer chalk marks is then divided by four to give the lay length. As a rough check on the overall accuracy of the chalk marking, the length of lay for eight strand ropes is approximaFig. 10 R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
17
tely between 6.25 and 6.5 x the diameter of the rope e.g. using a lay length of 6.5 x rope diameter, four lay lengths of a 32mm diameter rope will be 32mm x 6.5 x 4 = 832mm. An alternative method of measuring the rope lay is to secure the free end of the roll of adding machine paper to the rope with adhesive tape. The paper is rolled out over the rope and simultaneously the wax pencil is drawn over the paper, providing a clear print of the outer wires of the rope. The finished print can be filed for comparison with later measurements. A third method is to wrap typing carbon papers round the rope under the roll of paper. By rub bing along the paper with a piece of cardboard, the carbon marking on the underside of the paper can be confined to the tops of the strand crowns.
8.5 Checking the stability of the rope
A rope in good condition will have all strands tightly laid. A screwdriver inserted between strands when twisted, should meet with stiff resistance. If the screwdriver can be twisted between different pairs of strands without much resistance, a full examination should be carried out. 18
The unskilled use of a screwdriver or Marlin Spike to examine the rope core can cause serious damage to the rope.
8.6 Changes in rope structure
In addition to the examination areas detailed in section 4, deformation caused at any point in the main working area can move along the rope. Waviness, and in particular, a birdcage can be moved along the rope by the action of the sheaves. A degree of slackness in the outer cover of a multi- strand rope may not be sufficient to form an immediate birdcage. However, slackness can be “squeezed” along the rope. With the normal length of rope out any slackness in the outer cover will usually be found at the end termination or where the rope meets the drum.
8.7 Inspecting sheaves and drums
Remarks in this section are intended to apply equally to sheaves and drums. A tight groove in a sheave or drum will subject the rope to enormous radial pressure. Rapid deterioration and premature wire failure, particularly in the valleys
R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
between strands, can be expected (Fig. 11, A). On the other hand a wide groove will not provide essential support to a rope under load. Oval shaped deformation is produced resulting in uneven distribution of the load between individual wires with consequent early failure (Fig. 11, C). Sheaves can be checked with gauges which are available on the open market. The use of specially made circular templates is preferred.
order to establish the size of a sheave groove, templates for the sizes above and below the recommended size will be required. The sides and tread of sheaves which have been in use for some time are often heavily coated with old lubricant, some of which may first have to be removed with a scraper. By inserting the template as far as possible and drawing it through the remaining lu bricant, the fit of the template relative to the sheave tread can be assessed.
The correct template should be in The recommend size for a sheave contact with the sheave tread for gauge is the nominal rope diam- about 130 . If the template only eter + 6% to +10% (Fig. 11, B). In touches the side flanges, the °
d r a c s i d l i t n u ] – [ s e l c y c f o r e b m u n
A
B
C
max. % 6 + r e t e = m a r i e t d e e m p a o r i d l e a n v i o m o r o g n
A
B
C
optimum Fig. 11
groove diameter
R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
19
groove is too tight. If the template replacement rope will not fit extouches only the bottom part of actly into the imprint and will the tread, the groove is too wide. suffer serious damage during the early part of its service. Attention should also be given to the flanges of the sheaves. Ab- When a rope change is made, the sence of lubricant, scratching or sheaves should be checked for unexpected wear on one side will eccentricity and the bearing for indicate (a) misalignment of the wear and free running. sheave and (b) the danger of torque being induced into the rope due to the rope rolling down 9. Electro-magnetic the flange into the tread. wire rope examination The tread should be cleaned and carefully examined for any sign of ridging or imprinting. In the case of imprinting with the rope profile the rope in service may have caused the damage and is unlikely to be seriously affected. A
After a period in service surface wear and/or a number of wire breaks will indicate the rope condition has deteriorated and discard may be imminent. Specific working conditions however, may
Point of contact
Fig. 12 20
Fig. 13 R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
lead to internal wire breaks and to internal loss of metallic area. It may be surprising to learn that this applies in particular to ropes which, for safety reasons, are operated with large diameter sheaves and high factors of safety. Dynamically loaded ropes or ropes which are subjected to torque when working, can suffer from internal wire breaks caused by overstrained interior rope elements. In addition, when the ree ving system includes sheaves lined with plastic or all plastic sheaves, these sheaves offer more elastic support than steel sheaves. The pressure between outer wires and the sheave grooves can be reduced to such an extent that with some rope constructions the first wire breaks will occur, not on the surface, but within the rope. In all these cases electro- magnetic testing will allow non-destructive examination and appraisal of the rope’s internal condition.
The data are plotted as a function of the rope length, which is continually measured either during the inspection or, if a recording is done, during the following analysis. In this way every signal on the recording can unmistakably be related to a zone on the rope. This method allows a more precise visual inspection of those sections of the rope which showed exceptional inconsistencies during the electro-magnetic inspection. Furthermore, recording the data during regular elec tro-magnetic inspections makes it possible to compare the results with previous recordings. In this way the advance of the deterioration of the rope can be ascertained.
Electro-magnetic testing equipment for wire ropes was already being developed at the beginning of the 20th century. Only very few specialists could use the equipment properly but over the past few years the use of these instruments has been greatly improved so that they are now at the comElectro-magnetic testing equip- mand of a much wider range of ment available on the market al- users. lows - depending on individual design - indication or continuous It is likely that within a few years recording of localised damage there will be equipment on offer such as single broken wires, which not only records measured breaks of strands, soldered and data but also - by means of a mi welded joints as well as wire pit- cro computer - will process the ting and even detection of re- data with regard to amplitude duced metallic area caused by and frequency. In this way the corrosion and abrasion over the equipment will provide the exam whole rope length. iner with data such as frequency R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
21
curves and the accurate assess- wire rope. During this procedure ment of the reduction in breaking all test data are transmitted via strength. cable or radio to an amplifier. The test data are indicated either op At the moment instruments are tically or acoustically, recorded bei ng de velop ed which , apart on magnetic tape or represented from the data mentioned above, graphically during the test. An can also record the rope diameter electro-magnetic test instrument and the lay length of the rope. is shown in Fig. 14. This will enable them to register out-of-roundness of the rope di- Calibration of the testing equipameter, corkscrew-like deforma- ment requires great care. A retions or changes of the lay commended method of checking lengths along the rope length. the function and accuracy of the equipment is to attach lengths of For inspection a test head is wire, having diameters equal to clamped around the rope. Then the largest and smallest sizes in the whole length of the rope is the rope, along the first metres of pulled through the test head. If rope length. By means of sellothis is not possible, as in the case tape these wires can be secured of suspended ropes of rope ways, in the strand valleys. At the bethe test head is drawn along the ginning of the recording strip
Fig. 14 22
R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
chart the examiner will obtain reference data indicating the size of the amplitudes of the test wires. Fig. 15a illustrates a typical diagram of a rope section with wire breaks. Fig. 15b shows the recording of a rope section affected by corrosion. Selecting the suitable test instrument, competent handling and the correct interpretation of the data require a lot of experience and expert knowledge. Various universities, test institutes as well as commercial firms, render electro-magnetic inspection of wire ropes as a service.
The discard numb ers of wi re breaks specified in the Standards refer solely to external wire breaks. Appraising the condition of the wire rope with regard to internal wire breaks is therefore left to the inspector; he would be well advised to discard a wire rope when the total number of external and internal wire breaks, added together, reaches the discard number of wire breaks specified in the Standards. Electro-magnetic tests can not, and must not, totally replace visual inspections. Yet, they pro vide valuable additional information on the conditions of wire ropes and must be regarded as a useful addition to the visual inspection.
a
b
Fig. 15 R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
23
®
machine:
application:
type of rope:
left hand lay
right hand lay
nominal diameter [mm]:
regular lay
langs lay
tensile strength [N/mm2 ]:
ungalvanized
galvanized
type of end fitting:
rope length [m]:
working hours to date:
date of installation:
location measured
no. of broken wires on 10 x d
allowed no.:
final evaluation
24
abrasion
corrosion
diameter/ ø-reduction mm/%
other
*
*
eff. Ø of new rope
**
date/ signature
* description, e.g. no, little, etc.
R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996 ** comments, e.g. description of a rope deformation
®
Discard Number of Wire Breaks according to the criteria of BS 6570 s 5 : k s k : a 5 e n e a a r r n s h a b t b r e * h r e e r r e r i t s i t i w * t o s w s s r e a c i s g d e d f f w r a t e o r o n n w f l n o i n g t f t r r a t r y e r y e r a o a h t a t t t b a c e e s g r s s b f e i i f l b r f m * e l l s e a m a r d i l f t e b i f s e o u u s w f r e o t t n f m f n i u r o c e c e o d n o n u e a a d c g g o n r r r r i f i p b e t l t r a r a s n t o c a c t o c a h c a a m m i e e t t t a s s l o u v p v i o o a a n c p a s t f d f i a n i r d
* up to approx. 40 mm Ø, 1770 N/mm2
0,653
0,90
0,77
245
112
4
8
0,748
0,86
0,79
280
126
4
8
0,710
0,91
0,84
358
126
4
22
0,608
0,92
0,87
319
152
10
20
0,661
0,87
0,86
327
208
10
20
0,688
0,86
0,84
344
260
12
24
0,660
0,89
0,86
303
152
10
20
0,730
0,85
0,84
311
208
10
20
0,755
0,85
0,84
307
205
10
20
0,650
0,89
0,86
303
152
10
20
0,755
0,85
0,84
307
205
10
20
0,660
0,90
0,88
119
56
3
6
0,655
0,90
0,90
145
72
3
6
0,627
0,90
0,82
319
152
10
20
0,663
0,85
0,83
180
126
5
10
0,566
0,90
0,86
126
126
5
10
0,477
0,94
0,85
96
96
5
10
0,684
0,86
0,84
140
140
7
14
R. & W. Lindsay, ** Verreet up to approx. 40 mm ØWire Rope Inspection and Examination, 1996
25
Additional CASAR literature CASAR CD-ROM
•
All e U rh e
b er -
s t
c a a d
The first CASAR CD-ROM is an interactive tool with the intention to inform the user about wire ropes. It offers many detailed information referring to:
c e n a
n d a
u n d
L e i s t u n
o b r
g s s c h u t z
m r
r e c
f o r
h t e
e
c i l
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b
b u
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h a l t
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,
n
e i n
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a
V e
c
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r
i
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p
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! K
u
h
d
technical features • end connections • handling
d e
installation • maintenance • inspection
•
•
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a
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U
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A
m r o
f r e p d r o
r u n g S e n d u n g l l A
c e r n i s t h C g i r o y p
,
•
®
Wire Rope End Connections
®
Handling, Installation and Maintenance of Steel Wire Ropes
r v i e l
f ä
®
®
26
i
r
The rotation characteristics of steel wire ropes
TECHNICAL DOCUMENTATION
n
i
The CD-ROM is available at no cost. For Macintosh and Windows.
®
e
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Which rope for my crane?
R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
The CASAR product line
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R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
27
®
Calculated aggregate breaking load
28
Nominal diameter
Metallic area
Weight
mm
mm2
kg/%m
Minimum breaking load
with tensile strength of wire
1770 N/mm2 (180 kp/mm2) kN
t
1960 N/mm2 (200 kp/mm2) kN
1770 N/mm2 (180 kp/mm2)
t
kN
t
1960 N/mm2 (200 kp/mm2) kN
t
7 8 9
25,0 32,8 40,8
22,5 29,5 36,7
44,2 58,1 72,2
4,51 5,92 7,37
49,0 64,3 80,0
4,99 6,56 8,16
34,1 44,5 55,4
3,47 4,53 5,63
37,8 49,3 61,3
3,86 5,03 6,26
10 11 12
51,7 62,2 73,9
46,5 56,0 66,5
91,5 110,2 130,9
9,33 11,23 13,34
101,3 122,0 144,9
10,33 12,44 14,78
69,2 83,1 99,9
7,04 8,45 10,16
76,6 92,1 110,7
7,82 9,39 11,29
13 14 15
86,9 100,4 116,0
78,2 90,4 104,4
153,7 177,7 205,3
15,68 18,13 20,94
170,2 196,8 227,4
17,36 20,07 23,19
117,3 135,9 156,3
11,92 13,83 15,89
129,8 150,5 173,0
13,25 15,36 17,66
16 17 18
132,3 147,8 165,5
119,0 133,0 149,0
234,1 261,5 293,0
23,87 26,67 29,88
259,3 289,6 324,4
26,44 29,53 33,08
178,1 200,1 222,6
18,11 20,35 22,64
197,2 221,6 246,5
20,12 22,61 25,15
19 20 21
186,6 205,0 226,7
167,9 184,5 204,0
330,3 362,9 401,2
33,68 37,00 40,91
365,7 401,8 444,3
37,30 40,98 45,30
250,9 277,7 306,3
25,52 28,24 31,15
277,8 307,5 339,2
28,35 31,38 34,61
22 23 24
250,0 271,2 296,0
225,0 244,1 266,4
442,5 480,0 523,8
45,12 48,94 53,42
490,0 531,5 580,1
49,96 54,20 59,15
337,0 366,5 400,5
34,27 37,28 40,73
373,2 405,9 443,5
38,08 41,42 45,26
25 26 27
319,9 347,0 372,9
287,9 312,3 335,6
566,2 614,2 660,0
57,74 62,63 67,30
627,0 680,2 730,9
63,94 69,36 74,53
431,9 469,2 508,3
43,93 47,71 51,69
478,3 519,5 562,9
48,81 53,01 57,44
28 29 30
402,1 432,5 464,7
361,9 389,2 418,3
711,7 765,5 822,6
72,57 78,06 83,88
788,1 847,7 910,9
80,36 86,44 92,89
548,8 585,8 627,1
55,81 59,57 63,77
607,7 648,6 694,4
62,01 66,19 70,85
32 34 36
526,4 591,2 661,5
473,7 532,1 595,3
931,7 1046,4 1170,8
95,00 106,71 119,39
1031,7 1158,8 1296,5
105,20 118,16 132,21
710,5 803,9 906,1
72,25 81,75 92,15
786,7 890,2 1003,4
80,28 90,84 102,39
38 40 42
742,5 818,1 902,7
668,3 736,3 812,4
1314,2 1448,0 1597,8
134,01 147,66 162,93
1455,3 1603,5 1769,3
148,40 163,51 180,42
1005,5 1111,9 1234,1
102,26 113,08 125,50
1113,5 1231,3 1366,6
113,62 125,64 139,44
44 46 48
994,4 1083,6 1186,5
895,0 975,3 1067,8
1760,1 1918,0 2100,1
179,48 195,58 214,15
1949,1 2123,9 2325,5
198,75 2 16,58 237,14
1352,7 1473,9 1608,1
137,56 149,89 163,53
1497,9 1632,1 1780,7
152,85 166,54 181,70
50 52 54
1286,3 1391,7 1501,4
1157,7 1252,5 1351,2
2276,8 2463,3 2657,4
232,17 251,18 270,98
2521,2 2727,7 2942,7
257,09 278,15 300,07
1740,0 1832,5 1976,4
176,94 186,35 200,99
1926,7 2029,2 2188,5
196,61 207,06 223,32
56 58 60
1610,3 1727,4 1848,6
1449,3 1554,7 1663,7
2850,3 3057,5 3272,0
290,65 311,78 333,65
3156,3 3385,7 3623,3
321,85 345,25 369,47
2141,3 2285,4 2455,9
217,76 232,42 249,75
2371,1 2530,8 2719,5
241,95 258,24 277,50
62 64 66
1973,9 2103,3 2236,8
1776,5 1893,0 2013,1
3493,8 3722,8 3959,1
356,27 379,62 403,72
3868,8 4122,5 4384,1
394,51 420,37 447,06
2623,1 2799,3 2978,8
266,76 284,67 302,93
2904,7 3099,8 3298,5
296,40 316,31 336,59
68 70 72
2374,4 2516,2 2662,0
2137,0 2264,5 2395,8
4202,7 4453,6 4711,7
428,56 454,14 480,46
4653,9 4931,7 5217,5
474,56 502,89 532,04
3173,9 3336,5 3545,6
322,77 339,31 360,57
3514,6 3694,7 3926,2
358,64 377,01 400,64
R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
®
Calculated aggregate breaking load Nominal diameter
Metallic area
Weight
mm
mm2
10 11 12
Minimum breaking load
with tensile strength of wire
1770 N/mm2 (180 kp/mm2)
1960 N/mm2 (200 kp/mm2)
2160 N/mm2 (220 kp/mm2)
1770 N/mm2 (180 kp/mm2)
1960 N/mm2 (200 kp/mm2)
2160 N/mm2 (220 kp/mm2)
kg/%m
kN
t
kN
t
kN
kN
t
kN
t
kN
t
56,9 69,0 82,0
49,0 59,3 70,5
100,8 122,1 145,1
10,28 12,45 14,79
111,6 135,2 160,7
11,38 13,79 16,38
123,0 149,0 177,0
12,54 15,19 18,05
81,9 99,5 118,2
8,33 10,12 12,10
89,6 108,8 130,8
9,14 11,11 13,30
97,4 118,4 139,9
9,86 11,98 14,16
13 14 15
95,4 110,4 126,8
82,1 94,9 109,1
168,9 195,4 224,5
17,22 19,93 22,89
187,0 216,4 248,6
19,07 22,06 25,35
206,1 238,5 274,0
21,02 24,32 27,94
139,0 161,7 184,5
14,14 16,50 18,80
152,7 179,1 204,0
15,60 18,30 20,80
165,4 190,9 219,5
16,73 19,31 22,21
16 17 18
146,2 163,5 186,2
125,7 140,6 160,1
258,8 289,4 329,5
26,39 29,51 33,60
286,6 320,5 364,9
29,22 32,68 37,21
315,8 353,2 402,1
32,20 36,02 41,01
209,4 235,9 266,9
21,29 23,99 27,15
230,6 257,9 293,9
23,50 26,32 30,00
249,1 280,6 317,5
25,20 28,39 32,13
19 20 21
205,6 227,5 249,1
176,8 195,6 214,2
363,8 402,6 440,9
37,10 41,06 44,96
402,9 445,9 488,3
41,08 45,47 49,79
444,0 491,4 538,1
45,28 50,11 54,87
297,1 329,3 362,3
30,30 33,49 36,84
329,0 362,2 396,1
33,50 36,90 40,20
352,8 391,7 430,9
35,70 39,64 43,60
22 23 24
276,0 303,3 327,1
237,3 260,9 281,3
488,5 536,9 578,9
49,81 54,75 59,03
540,9 594,5 641,1
55,16 60,62 65,37
596,1 655,2 706,5
60,78 66,81 72,04
398,5 431,5 474,3
40,60 43,88 48,30
441,4 471,8 524,3
45,00 48,14 53,50
472,0 513,2 564,1
47,76 51,94 57,08
25 26 27
357,6 382,0 410,5
307,6 328,5 353,0
633,0 676,1 726,5
64,55 68,94 74,08
701,0 748,6 804,5
71,48 76,34 82,03
772,5 825,0 886,6
78,78 84,13 90,41
512,8 555,0 598,3
52,30 56,60 60,85
567,9 614,9 654,2
57,90 62,70 66,75
609,4 657,4 711,7
61,67 66,52 72,02
28 29 30
447,3 472,3 505,4
384,6 406,2 434,7
791,7 835,9 894,6
80,73 85,24 91,23
876,6 925,7 990,6
89,39 94,39 101,02
966,1 1020,1 1091,7
98,51 104,02 111,33
643,7 690,2 738,1
65,60 70,19 75,30
712,9 754,6 817,4
72,70 77,00 83,40
765,6 821,0 877,9
77,47 83,07 88,84
32 34 36
582,7 655,9 735,7
501,1 564,0 632,7
1031,3 1160,9 1302,1
105,16 118,38 132,78
1142,0 1285,5 1441,9
116,45 131,08 147,03
1258,5 1416,7 1589,0
128,33 144,46 162,04
843,4 950,8 1070,0
85,74 96,69 109,10
930,0 1045,0 1185,0
94,90 106,60 120,90
1002,8 1130.9 1262,3
101,48 114,44 127,74
38 40 42
823,3 910,5 1004,2
708,1 783,1 863,6
1457,3 1611,7 1777,5
148,60 164,34 181,25
1613,7 1784,7 1968,3
164,55 181,98 200,71
1778,4 1966,8 2169,1
181,34 200,55 221,19
1191,0 1360,0 1455,0
121,50 138,00 147,97
1319,0 1462,0 1611,2
134,50 149,10 164,41
1412,2 1560,4 1667,4
142,90 157,90 169,83
44 46 48
1098,4 1198,3 1317,2
944,6 1030,6 1132,7
1944,1 198,24 2121,0 216,29 2331,4 237,73
2152,8 2348,7 2581,6
219,53 239,50 263,25
2372,5 2588,4 2845,0
241,93 263,94 290,11
1596,0 1748,0 1908,4
162,80 178,30 194,30
1767,0 1935,0 2113,3
180,20 197,40 215,64
1823,7 1989,7 2187,0
185,75 202,65 222,75
t
Further diameters upon request.
R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
29
®
Calculated aggregate breaking load
30
Nominal diameter
Metallic area
Weight
mm
mm2
kg/%m
8 9 10
30,8 39,5 48,3
28,3 36,3 44,4
11 12 13
60,0 69,9 81,1
14 15 16
Minimum breaking load
with tensile strength of wire
1770 N/mm2 (180 kp/mm2) kN
1960 N/mm2 (200 kp/mm2)
t
kN
t
54,5 69,9 85,4
5,56 7,12 8,71
60,3 77,4 94,6
6,15 7,89 9,65
55,2 64,3 74,6
106,3 123,7 143,6
10,84 12,62 14,64
117,7 137,0 159,0
93,9 109,4 123,9
86,4 100,7 114,0
166,2 193,7 219,3
16,95 19,75 22,37
17 18 19
139,5 156,1 177,5
128,4 143,7 163,3
247,0 276,4 314,2
20 21 22
195,8 217,3 237,6
180,2 199,9 218,6
23 24 25
258,6 280,3 302,0
26 27 28
1770 N/mm2 (180 kp/mm2) kN
1960 N/mm2 (200 kp/mm2)
t
kN
t
47,2 60,0 74,0
4,80 6,10 7,53
52,3 66,4 82,0
5,34 6,78 8,37
12,00 13,97 16,22
88,5 106,6 125,5
9,00 10,84 12,76
98,0 118,0 138,9
10,00 12,05 14,18
184,1 214,5 242,9
18,77 21,87 24,77
144,6 166,3 189,0
14,71 16,91 19,22
160,1 184,1 209,3
16,34 18,79 21,36
25,18 28,18 32,04
273,5 306,0 347,9
27,89 31,21 35,48
211,5 239,8 264,5
21,51 24,38 26,90
234,2 265,5 292,9
23,90 27,09 29,89
346,6 384,6 420,6
35,34 39,22 42,89
383,8 425,9 465,7
39,14 43,43 47,49
295,3 324,2 356,2
30,03 32,97 36,23
327,0 359,0 394,5
33,36 36,63 40,25
237,9 257,9 277,8
457,6 496,1 534,5
46,67 50,59 54,51
506,8 549,4 591,9
51,68 56,02 60,36
386,8 423,4 464,3
39,34 43,06 47,22
428,3 468,9 514,2
43,71 47,84 52,47
326,8 353,2 375,9
300,6 324,9 345,8
578,4 625,1 665,3
58,98 63,75 67,84
640,4 692,2 736,7
65,31 70,59 75,12
504,7 535,8 576,2
51,32 54,49 58,59
558,8 593,3 638,0
57,03 60,54 65,10
29 30 31
407,7 435,8 464,3
375,1 400,9 427,1
721,6 771,4 821,8
73,59 78,66 83,80
799,1 854,2 910,0
81,48 87,10 92,79
618,0 666,3 708,3
62,85 67,76 72,03
684,3 737,8 784,3
69,83 75,28 80,03
32 33 34
495,4 526,4 556,8
455,8 484,3 512,3
876,9 931,7 985,5
89,42 95,01 100,50
971,1 1031,7 1091,3
99,02 105,21 111,29
756,7 809,6 853,7
76,95 82,33 86,82
837,9 896,5 945,3
85,50 91,48 96,46
35 36 38
585,9 626,5 705,1
539,1 576,4 648,7
1037,1 1108,9 1248,0
105,76 113,08 127,26
1148,4 1227,9 1382,0
117,11 125,21 140,92
905,8 952,4 1071,1
92,12 96,86 108,92
1003,0 1054,7 1186,0
102,35 107,62 121,02
40 42 44
779,4 859,3 942,5
717,0 790,6 867,1
1379,5 1521,0 1668,2
140,67 155,10 170,11
1527,6 1684,3 1847,3
155,77 171,75 188,37
1181,1 1308,5 1430,1
120,11 133,06 145,44
1307,9 133,46 1448,9 147,85 1583,7 1691,60
46 48 50
1031,5 1123,1 1212,7
949,0 1033,3 1115,7
1825,8 1987,9 2146,5
1 86,18 2 02,71 2 18,88
2 021,8 2 201,3 2 376,9
2 06,17 2 24,47 2 42,38
1556,7 1692,8 1850,7
158,31 172,15 188,21
1723,8 1874,5 2049,4
175,90 191,27 209,12
52 54 56
1309,7 1410,5 1508,1
1204,9 1297,7 1387,4
2318,2 2496,7 2669,3
2 36,39 2 54,59 2 72,19
2 567,0 2 764,7 2 955,9
2 61,76 2 81,92 3 01,41
2013,7 2175,3 2344,8
204,78 221,22 238,45
2229,9 2408,8 2596,5
227,54 245,80 264,94
58 60 62
1581,2 1707,4 1845,1
1454,7 1570,8 1697,5
2798,7 3022,1 3265,9
2 85,39 3 08,17 3 33,03
3 099,1 3 346,5 3 616,4
3 16,02 3 41,25 3 68,77
2508,9 2621,5 2815,8
255,14 266,59 286,35
2778,2 2902,9 3118,0
283,49 296,21 318,17
64 66 68
1966,1 2090,9 2183,5
1808,8 1923,6 2008,8
3480,0 3700,9 3864,8
3 54,86 3 77,38 3 94,10
3 853,5 4 098,1 4 279,6
3 92,95 4 17,89 4 36,40
3000,1 3198,3 3357,6
305,10 325,25 341,45
3322,1 3541,6 3718,0
338,99 361,39 379,39
70 72
2352,0 2488,3
2163,8 2289,3
4163,0 4404,3
4 24,51 4 49,12
4 609,9 4 877,1
4 70,08 4 97,33
3552,7 3751,7
361,29 381,53
3934,1 4154,4
401,44 423,92
R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
Acknowledgement The authors and the publisher are pleased to acknowledge the valuable help received from Mr. M. J. McEntee, C. Eng., F. I. Mech. E., F. I. Plant E., H. M. Principal Specialist Inspector (Engineering).
Readers Comments For reasons of space, this booklet can only deal with general aspects of wire rope inspection and examination. However, the publisher and the authors are always pleased to give their opinions on specific problems. For future editions of this booklet, the authors look forward to receiving readers’ suggestions for improvements or general comments.
These should be addressed to:
Wire Rope Technology Dipl.-Ing. Roland Verreet Grünenthaler Straße 40a 52072 Aachen Germany Telephone + 49 241 - 17 31 47 Fax + 49 241 - 1 29 82 e-mail
[email protected] or William Lindsay Wire Rope Consultancy 10 Poplar Drive Lenzie, Glasgow, G66 4DN UK Telephone 041-776 1696
R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996
31
This brochure is published by Casar Drahtseilwerk Saar GmbH, manufacturers of the famous
®
Setting, Layout and Production: PR GmbH Werbeagentur und Verlag, Grünenthaler Stra ße 40a, 52072 Aachen, Germany © 1989/1998 Casar Drahtseilwerk Saar GmbH
The material presented in this publication has been prepared in accordance with recognized engineering principles and is for general information only. This information should not be used without first securing competent advice with respect to its suitability for any given application. The publication of the material contained herein is not intended as a representation or war ranty of the part of Casar Drahtseilwerk Saar GmbH or the authors that this information is suitable for any general or particular use or of freedom from infringements of any patent or patents. Anyone making use of this information assumes all liability arising from such use. Permission to reproduce or quote any portion of this book as editorial reference is hereby granted. When making such reproductions or quotations, the title and the author of this publication must be mentioned.
32
R. Verreet & W. Lindsay, Wire Rope Inspection and Examination, 1996