Wire Rope Inspection and Examination

By A. Noble & Son Ltd. Courtesy of Casar

. W!y must "ire ropes be inspected and examined# &. W!at is Inspection' "!at is Examination# (. W!en must "ire ropes be inspected# ). W!en must "ire ropes be examined# *. Sur+ey for remo+al criteria ,. W!ere must "ire ropes be inspected or examined# .. /iscard number of "ire brea0s 1. Rope examination procedure 1. 1.& 1.( 1.) 1.* 1., 1.. E2uipment Locatin% of "ire brea0s /etermination of t!e rope diameter 3easurin% rope lay C!ec0in% t!e stability of t!e rope C!an%es in rope structure Inspectin% s!ea+es and drums $a%e & $a%e ( $a%e ) $a%e ) $a%e , $a%e $a%e & $a%e ( $a%e ( $a%e ( $a%e * $a%e , $a%e 1 $a%e 1 $a%e 1 $a%e &-

4. Electro5ma%netic "ire rope examination

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Why must wire ropes be inspected and examined? Wire ropes are consumable items "it! a limited life. /urin% ser+ice t!e p!ysical properties of a "ire rope "ill c!an%e. At t!e commencement of ser+ice' t!e indi+idual "ires and strands settle into position and t!e rope brea0in% stren%t! increases. After reac!in% a maximum it decreases rapidly 67i%. 8. 9!is decrease in brea0in% stren%t! is caused by t!e pro%ressi+e loss of t!e metallic cross5section due to abrasion and corrosion' by "ire brea0s and by c!an%es in t!e structure of t!e rope. A c!ain represents a series con5 nection of load bearin% elements.

If only one lin0 in t!e c!ain brea0s' t!e "!ole liftin% de+ice "ill fail completely. A "ire rope represents a parallel connection of load bearin% elements and conse2uently it can still be oper5 ated safely after one or more "ire brea0s. :enerally' t!ere is a steady rate of increase in t!e number of "ire brea0s durin% t!e life of t!e rope. 7i%. ( s!o"s t!e increasin% num5 ber of "ire brea0s as a function of t!e number of cycles in a bendin% fati%ue test. ;ne of t!e ob<ecti+es of inspectin% and examinin% a "ire rope is to super+ise t!e normal process of deterioration so t!at t!e rope can be remo+ed from ser+ice before becomin% a !a=ard to safety. Anot!er benefit of t!e

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inspection and examination procedures is to detect unexpected dama%e or corrosion. Inspections and examinations' properly carried out' ensure t!e discard of a rope before failure. In addition' precautions can be ta0en to a+oid a recurrence of dama%e or excessi+e "ear to future ropes. 1. What is Inspection, what is Examination? An inspection is a careful and critical assessment of t!e rope and fittin%s carried out "it!out dismantlin%.

An examination is a careful and critical assessment of t!e rope and fittin%s carried out by a competent person. 9!is s!ould include' "!ere necessary' a +isual assess5 ment of t!e internal condition of t!e rope' supplemented by ot!er means suc! as measurement and non5destructi+e testin%. In order for end fittin%s to be examined properly t!ey may need to be dismantled.

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2. When must wire ropes be inspected? Wire ropes s!ould be inspected at t!e start of eac! s!ift' "or0 period or more fre2uently' dependin% upon past experience. >sually t!is inspection "ill be carried out by t!e operator of t!e indi+idual piece of e2uipment or possibly by a member of t!e "or0 force spe5 cially appointed. 9!e inspection s!ould be a +isual assessment of t!e condition of as muc! of t!e rope len%t! as possi5 ble' includin% t!e points of at5 tac!ment to t!e e2uipment. W!en a rope !as been remo+ed from e2uipment and later fitted to t!e same or different e2uipment' it s!ould be inspected after fittin% but before resumin% ser+ice.

If at any time a c!an%e in t!e rope condition is suspected it s!ould be reported immediately and t!e e2uipment ta0en out of ser+ice until t!e rope !as been examined by a competent person. As a result of t!is examination it may be prudent to re+ie" and amend t!e scope and fre2uency of t!e in5 spections. 3. When must wire ropes be examined? 9!e 7actories Act 4, Section &,' 9!e Construction 6Liftin% ;perations8 Re%ulations No. *1 and t!e ;ffs!ore Installations 6;perational Safety' ?ealt! and Welfare8 Re%ulations 4., No. - 4 all re2uire a t!orou%! rope examination at least once in e+ery period of six mont!s.

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9!e S!ipbuildin% and S!ip repairin% Re%ulations 4,re2uires a t!orou%! examination e+ery t!ree mont!s or mont!ly after t!e first bro0en "ire !as been disco+ered. ;ne of t!e statutory re%ulations listed abo+e "ill apply to t!e location and type of rope usin% e2uipment bein% examined. It is t!e responsibility of t!e indi+idual to institute and maintain a pro%ram of periodic examination "!ic! satisfies t!e re2uirements of t!e appropriate re%ulations and t!e specific operatin% conditions of t!e e2uipment. Examination s!ould be carried out at re%ular inter+als. 9!e inter+als s!ould be sc!eduled so t!at any dama%e "ill be detected early. Accordin% to BS ,*.- examina5 tions s!ould be carried out @at re%ular inter+als' t!e fre2uency of "!ic! "ill be influenced by t!e follo"in%A a8 b8 c8 d8 e8 f8 Statutory re2uirements 9ype of appliance andBor desi%n of t!e system ;perational en+ironmental conditions 3et!od and fre2uency of operation 3anufacturerCs recommend5 ations Results of pre+ious inspec5 tions and examinations

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Experience "it! pre+ious ropes on t!e appliance or systemD

/urin% t!e first fe" "ee0s after t!e installation of a ne" rope t!e daily inspection can be used to monitor performance as t!e rope mi%!t !a+e been fitted incorrectly or t!e type of rope mi%!t not be suited to t!e e2uipment. 9!e inter+als bet"een t!e examin5 ations s!ould also be reduced after t!e first bro0en "ire or ot!er dama%e !as been detected. If t!e rope !as been o+erloaded or if non5+isible dama%e is suspect5 ed' t!e inter+als bet"een exami5 nations s!ould be reduced ac5 cordin%ly. 3oreo+er' t!e examinations s!ould be carried out "!en a rope is put bac0 into ser+ice after lon% periods of standin%. If a liftin% de+ice !as been dis5 mantled and re5assembled' t!e rope must be examined before it is allo"ed to operate a%ain.

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4. Survey o remova! criteria A "ire rope must be remo+ed if one or more of t!e follo"in% crite5 ria can be satisfiedA 8 Bro0en "ires. A "ire rope must be discarded if t!e permissible number of "ire brea0s is reac!ed or exceeded. It must also be replaced "!en local concentrations of "ire brea0s occur. C!apter . co+ers in detail t!e sub5 <ect of t!e permissible number of "ire brea0s accordin% to Britis! Standard ,*.- and t!e statutory re2uirements. &8 Reduction in diameter. Reduction in diameter can be caused by abrasion' corrosion or a local failure of t!e rope core. Accordin% to BS ,*.- a "ire rope s!ould be discarded @"!en t!e rope diameter any"!ere is reduced to 4- E of t!e nominal diameter in t!e case of six and ei%!t strand ropesD. Considerin% t!e fact t!at a rope is allo"ed to !a+e an o+ersi=e of ) E "!en ne"' t!is fi%ure "ould allo" for a diameter reduction of ) E' "!ic! seems to be excessi+e. 7or multi5strand ropes BS ,*.recommends a detailed examina5 tion @if t!e rope diameter falls to 4. E of t!e nominal' or rises to -* E of t!e nominalD' because @discard may be necessaryD.

(8 Corrosion. Corrosion may be external or in5 ternal' %eneral or locali=ed. Ac5 cordin% to BS ,*.-' a "ire rope s!ould be discarded @"!en t!e surface of t!e "ires is se+erely rou%!ened or pitted' or if t!e "ires are slac0 "it!in t!e strands due to "asta%eD. )8 Rope deformation a8 Wa+iness 67i%. )a8. 9!is deformation' "!ile it may not necessarily affect t!e stren%t! of t!e rope' can transmit pulsation and produce une+en rope "ear. W!en t!e rope is laid on a le+el surface under no load' t!e maximum !ei%!t of t!e @"a+eD s!ould not be %reater t!an t!e nominal rope diameter F B(' ot!er"ise t!e rope s!ould be remo+ed from ser+ice. b8 Birdca%e 6Bas0et /eformation8 A birdca%e 67i%. )b8 de+elops "!en t!e outer layer of strands be5 comes lon%er t!an t!e inner layer or layers. 9!e condition may occur as a result of incorrect fit5 tin%' ti%!t s!ea+es' s!oc0 loadin%' incorrect use of a s"i+el or t!e application of a !ea+y load to a ne" rope before t!e strands !a+e settled into position. Ropes "it! a birdca%e s!ould be discarded. c8 Loop 7ormations. Wires or %roups of "ires may form a line of loops parallel to t!e axis of t!e rope 67i%. *a8. 9!is deformation is often caused by

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s!oc0 loadin%. Loop formations are a <ustification for discard. d8 Loose Wires. W!ere loose outer "ires 67i%. *b8 are found "it!out any ad<acent mec!anical dama%e' t!e most li0ely cause "ill be corrosion and t!e rope s!ould be remo+ed from ser+ice. W!ere loose "ires !a+e been caused by mec!anical dama%e' a full examination "ill decide if t!e rope can remain in use.

e8 Nodes 67i%. *c8. A node is a local increase in rope diameter "it! t!e core easily +isible bet"een se+eral co+erin% strands. It can be caused by s!oc0 loadin% or' in t!e case of fibre main core ropes' by t!e absorption of moisture. A node is a <ustification for discard.

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f8 9!innin% of t!e rope 67i%. ,a8. 9!innin% is a reduction in t!e diameter of t!e rope o+er a s!ort len%t!. It is often associated "it! older fibre cored ropes usually in areas of sustained !ea+y loads o+er s!ea+es. 9!e disinte%ration and loss of t!e core can allo" one of t!e co+erin% strands to ta0e t!e place of t!e core. W!en t!is condition occurs in ropes "it! IWRC t!e distortion "ill most often be in t!e +icinity of t!e

termination a"ay from drum. 9!e most li0ely cause is rope rotation "!ic! !as allo"ed t!e rope to unlay' resultin% in t!e o+erload and reduction in diameter or failure of t!e IWRC. %8 3isplaced ;uter Wires. 3isplaced outer "ires are "ires forced out of position alon% t!e line of t!e rope to form small flat5 tened loops. 9!is can be caused by bad drum spoolin% or by t!e rope bein% dra"n across a s!arp

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ed%e. Lan%s lay ropes are often "orst affected. 3isplaced outer "ires are a <ustification for dis5 card. !8 Gin0s 67i%. ,b8 /eformation caused by a loop in a rope bein% ti%!tened "!en t!e rope cannot rotate about its axis to release t!e tor2ue. 9!e ti%!t bend or 0in0 t!us formed can result in a serious loss of stren%t! due to un5

balance in t!e lay len%t!s. Ropes "it! 0in0s must be discarded. i8 7lat areas 67i%. ,c8. A flattenin% can be caused by bendin% t!e rope se+erely o+er t!e rim of a S!ea+e or any s!arp ob<ect "it! t!e "ires on t!e inside of t!e bend bein% forced out of position. Ropes "it! flat areas s!ould be discarded.

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*8 /ama%e caused by !eat. ?eatin% rope "ires to approxim5 ately (-- C and o+er' "ill lead to considerable reduction in tensile stren%t! of t!e "ires 67i%. .8. Wire ropes "!ic! !a+e been sub<ected to excessi+e !eat must be discarded. ". Where must wire ropes be inspected or examined? /urin% an inspection or a periodic examination by a competent person' t!e full len%t! of t!e rope s!ould be c!ec0ed. 9!e follo"in% areas may re2uire more detailed attentionA a8 Rope =ones "it! t!e !i%!est number of cycles. /urin% normal day to day operations some

sections of a rope len%t! "ill suffer a %reater number of bends o+er s!ea+es and drums t!an ot!ers. It is in t!ese areas "!ere t!e %reatest number of fati%ue "ire brea0s can be expected. b8 $ic05up points. W!en a liftin% de+ice pic0s up or releases a load "it! t!e same sections of rope re%ularly in contact "it! s!ea+es and drums' t!ose sections of t!e rope are sub<ected to increased stress. c8 End fittin%s. At' or closely ad<a5 cent to terminal fittin%s' t!e elas5 ticity of t!e rope is restricted and t!e %eometry @fro=enD. /ependin% upon t!e type of fit5 tin%' t!ere "ill be additional pres5 sure on t!e rope and t!e section close to t!e area of contact be5
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t"een rope and fittin% is often t!e focal point for increased stress caused by +ibration. 9!e dan%er of corrosion is also increased by t!e retention of moisture in t!e area of contact bet"een rope and fittin%. d8 E2ualisin% S!ea+es. Ropes "!ic! are often considered to be stationary around E2ualisin% S!ea+es can be sub<ected to !i%! numbers of bend cycles caused by t!e une+en spoolin% of t"o drums' by s"in%in% loads or by fre2uency +ibrations. As t!e rope mi%!t ne+er lea+e t!e E2ualisin% S!ea+e' moisture can be trapped in t!e area of contact bet"een rope and S!ea+e and cause corrosion. e8 Hones of maximum "ear on drums. $ic05up points and cross5 o+er points on t!e drum are sub5 <ected to increased "ear and t!erefore re2uire special attention. 3isplaced and bro0en "ires caused by scrubbin% can be ex5 pected at cross5o+er points. 9!e dama%e can be se+ere "!ere t!e fleet an%le is excessi+e. Wit! multiple layer spoolin%' t!e first layer of rope on t!e drum s!ould be ti%!tly "ound to pro5 +ide a firm base for subse2uent layers. 9!is applies in particular to plain drums and parallel %roo+ed drums' e.%. Lebus. Slac0 "indin% or lateral mo+ement bet"een turns of rope "ill affect t!e spoolin% of subse2uent layers and can cause dama%e.

9!e point "!ere t!e rope is s2uee=ed bet"een t!e drum flan%e and t!e pre+ious turn as it rises to commence t!e next layer' is an area of accelerated "ear and s!ould be %i+en special attention. f8 S!ea+es. S!ea+es s!ould be examined for %eneral condition and tested for freedom of mo+e5 ment. >sin% a %roo+e %au%e t!e tread radius can be measured. 9!e radius of t!e %roo+es s!ould be e2ual to t!e nominal rope di5 ameter plus F , E to F - E. >ndersi=e %roo+es "ill seriously reduce t!e ser+ice life of t!e rope due to t!e effects of crus!in%. ;+ersi=e %roo+es reduce t!e ser+5 ice life due to premature fati%ue caused by insufficient support in t!e %roo+e area. W!ere t!e rope surface pattern is imprinted into t!e S!ea+e tread' t!e S!ea+e s!ould be replaced. %8 Rope sections "or0in% in a !ostile en+ironment. ?i%! temper5 ature can considerably reduce t!e brea0in% load of a "ire rope. 9emperatures of up to &*- C "ill not affect t!e tensile stren%t! of t!e "ire' but temperatures of only *- C can cause leac!in% of t!e rope lubricant. 9!e conse2uent se+ere "ire to "ire friction "ill result in a mar0ed reduction of rope per5 formance. 9!e exposure of rope to c!emical action can %reatly in5 crease t!e effect of corrosion.

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In eac! of t!e areas "!ere "ire brea0s or ot!er defects are found' t!e number and description alon% "it! t!e location' must be recorded. #. $iscard number o wire brea%s 9!e Construction 6Liftin% ;pe5 rations8 Re%ulations re2uires a rope to be replaced "!en t!e number of bro0en "ires reac!es * E of t!e total number of "ires in t!e rope in - x d. 9!e 7actories Act' 9!e S!ipbuild5 in% and S!ip5repairin% Re%ula5 tions and t!e ;ffs!ore Installa5 tions Re%ulations do not specify a particular number of bro0en "ires for discard and lea+es t!is decision to t!e discretion of t!e examiner. 9!e ?ealt! and Safety at Wor0 Act re2uires t!e pro+ision and maintenance of plant and systems of "or0 t!at are' so far as is reasonably practical' safe and "it!out ris0s to !ealt!. 9!e table on $a%e &* s!o"s t!e recommended number of discard "ire brea0s for CASAR special "ire ropes. 7or t!e number of discard "ire brea0s in ot!er types of multi5strand ropes t!e user is ad+ised to contact t!e rope manu5 facturer. /ependin% on t!e 7actor of Safety' t!e assessment of bro0en "ires in , and 1 strand ropes

"or0in% o+er steel s!ea+es is di5 +ided into t"o %roupsA 7actor of Safety less t!an * I * E of t!e number of outer strand "ires excludin% 7iller "ires. 7actor of Safety %reater t!an * I - E of t!e number of outer strand "ires excludin% 7iller "ires. W!en bro0en "ires are detected' t!e number and position' alon% "it! t!e examinerJs opinion of t!e %eneral rope condition' "ill decide "!et!er or not t!e rope s!ould be discarded. If local concentrations or %roups of bro0en "ires are found' t!e rope s!ould be discarded "!enA a8 9!ree or more bro0en "ires are found in t!e close proximity of t!e termination' b8 9!ree or more bro0en "ires are found in one strand or c8 7i+e bro0en "ires are found bet"een t"o ad<acent strands "it!in a len%t! of - x rope diameter. If t!e number of bro0en "ires does not <ustify discard' t!e position and number of all bro0en "ires found must be recorded in t!e rope examination Lo% Boo0. W!en bro0en "ires are found in close proximity to a permanent termination' suc! as a "!ite metal or resin secured soc0et and t!e %eneral condition of t!e remainder of t!e rope is acceptable' it may be decided to cut t!e rope and re5

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ma0e t!e termination. In suc! cases it is recommend t!at t!e soc0et is submitted for N./.9. and !eat treatment. Care must be ta0en to ensure sufficient turns of @deadD rope remain on t!e drum after t!e termination !as been re5 made. &. 'ope examination procedure (.1 E)uipment In order to carry out a proper inspection' t!e follo"in% tools s!ould be a+ailableA A list of t!e discard criteria 6t!is manual8 Rope caliper or +ernier %au%e Steel tape $iece of "!ite c!al0 Wax pencil 6dar0 coloured8 Roll of addin% mac!ine paper S!eet of typin% carbon paper Scre"dri+er 3a%nifyin% %lass $encil Roll of mar0in% tape 9"o sets of %roo+e %au%es $iece of cleanin% clot! Wire brus! $air of %lo+es Noteboo0 or an inspection form 9!e pre+ious inspection records

(.2. *ocatin+ o wire brea%s Identification of "ire brea0s can be by +isual and p!ysical exam5 ination or by t!e use of electroma%netic e2uipment 6see section 48. 9!e first step in "ire rope exam5 ination is to find t!e rope section "it! t!e %reatest concentration of "ire brea0s. 9!is is normally done by first +isually inspectin% t!e full len%t! of t!e rope. In some cases it can be !elpful to spool t!e rope slo"ly t!rou%! t!e !and. Special attention !as to be paid and stron% protecti+e %lo+es must be "orn. A piece of "ood !eld on t!e sur5 face of a mo+in% rope "ill be de5 flected by t!e protrudin% ends of bro0en "ires. In t!e same "ay' a soft cotton or similar type clot! !eld a%ainst a mo+in% rope "ill be cau%!t by protrudin% ends and t!us detect t!e bro0en "ires. Smoot! synt!etic material is less suitable for t!is purpose. 9!e detection of bro0en "ires in t!e strand +alleys can be difficult. 9!e use of a scraper or piece of s!aped "ood "ill !elp clean out t!e +alleys. 9!e use of a "ire brus! on a dirty' !ea+ily lubri5 cated rope can loosen' but not al"ays remo+e' old lubricant and t!e brus! may !a+e to be cleaned fre2uently "it! a sol+ent. W!ere sol+ents are used to clean t!e rope surface' t!ey s!ould be used sparin%ly and t!e rope sec5
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tion s!ould be t!orou%!ly lubri5 cated after"ards. A li%!t lubricatin% oil used "it! a "ire brus! is preferred for softenin% old lubricant "!ic! can t!en be "iped off "it! a clot!. W!en t!e "orst affected sections of rope !a+e been found' t!eir boundaries s!ould be mar0ed by c!al0 or tape for furt!er examination. A %au%e s!ould be set to a len%t! of - x d. 9!is can no" be mo+ed "it!in t!e boundaries to locate t!e section "it! t!e maximum number of "ire brea0s. 9!e brea0s in - x d s!ould be count5 ed and entered in t!e records.

Wit! t!in ropes' +alley brea0s can be detected by stron%ly flexin% t!e unloaded rope 67i%. 18.

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(.3. $etermination o the rope diameter 9!e rope diameter s!ould be measured on receipt for conformi5 ty "it! t!e specification. Britis! Standard 6BS (-&A 41.' Stranded steel "ire ropes' $art . Clause *. 8 allo"s for a tolerance of K E to F) E of t!e nominal rope dia5 meter. 9!e %enerally accepted met!od of measurin% rope diameter for com5 pliance "it! t!e Standard is to use a caliper "it! <a"s broad enou%! to co+er not less t!an t"o ad<acent strands. 9!e measurements must be ta0en on a strai%!t portion of rope at t"o points at least metre apart. At eac! point t"o diameters at ri%!t an%les s!ould be measured. 9!e a+era%e of t!e four measurements is t!e actual diameter. After t!e rope !as made t!e first fe" cycles under lo" load' t!e rope diameter s!ould be measured at se+eral points. 9!e a+era%e +alue of all t!e measurements at eac! point must be recorded and "ill form t!e basis of comparison for all future measurements. 9!e measurement of t!e rope di5 ameter is an essential part of all inspections and examinations. It ensures t!e maximum diameter reduction does not exceed t!e re5 commended fi%ure. As stated in *.&. Britis! Standard ,*.- re5 commends t!at a "ire rope s!ould be discarded "!en t!e diameter of

t!e rope is reduced to 4- E of t!e nominal diameter. A comparison of t!e measured data "it! t!e recorded pre+ious +alues can detect an abnormal rate of reduction in diameter. Coupled "it! assessment of pre+ious rope examination data' t!e probable date of rope rene"al can be predicted. If "e examine t!e cross5section of a six5strand "ire rope' "e "ill find t!at measurin% t!e t!ic0ness of t!e rope o+er t!e cro"ns 67i%. 4a8 "ill produce a !i%!er +alue t!an measurin% it o+er t!e +alleys 67i%. 4b8. 9!e actual diameter of t!e rope is defined as t!e diameter of t!e circumscribin% circle. W!en usin% a con+entional cali5 per' "ire ropes "it! an e+en num5 ber of outer strands 6four' six' ei%!t' ten' and multi5strand8 ropes must be measured from cro"n to cro"n. 9!e ad+anta%e of a proper "ire rope caliper "it! measurin% plates is t!at e+en if t!e measurement is carried out @incorrectlyD' ad<acent cro"ns are al"ays included' so t!at t!e actual diameter is determined at any section 67i%. -8. 3easurin% t!e diameter of "ire ropes "it! an une+en number of outer strands 6t!ree' fi+e' se+en' or nine strand ropes8 is more complicatedA a cro"n on t!e one side of t!e "ire rope al"ays !as a +alley as a counterpart on t!e ot!er side of t!e "ire rope. A con+entional caliper' t!erefore'
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!as to be applied dia%onally to t!e axis of t!e rope' so t!at at any time a cro"n ad<acent to a +alley is co+ered. A%ain a "ire rope caliper "it! measurin% plates is definitely to be preferred as it al"ays includes strand cro"ns. In all cases durin% periodic ex5 aminations "!ere t!e measure5 ments are to be recorded' t!e rope s!ould be measured as already described. W!ere t!e @roundnessD is bein% c!ec0ed to detect potential faults' t"o diameters' one at ri%!t an%les to t!e ot!er can be ta0en and noted in t!e records. 9!e entry into t!e records mi%!t read @Rope diameterA &-.)B&-.* mmD.

(.4 ,easurin+ rope !ay After a rope !as been fitted to t!e appliance' its len%t! cannot be measured a%ain accurately "it!out a %reat deal of trouble. 9!e purpose of measurin% t!e len%t! of lay is to detect any increase in t!e rope len%t! "!ic! may !a+e been caused by corrosion' core deterioration or rope rotation 6unlayin%8. Wit! a ne" rope t!e "ires and strands s!ould be allo"ed to settle into t!eir permanent position. Six or se+en liftin% cycles "it! a li%!t to medium load are recommended before measurin% t!e lay of t!e rope. 9o minimise error' t!e

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measurement s!ould be made o+er four lays and t!e len%t! di+ided by four to find t!e a+era%e lay len%t!. ;n ei%!t strand ropes t!e ei%!t' sixteent!' t"enty5fourt! and t!irty5second strands must be mar0ed. >sin% a strai%!t len%t! of t!e rope and "it! t!e rope under no load' first mar0 any strand on t!e cro"n "it! a piece of c!al0. 9!is strand no" becomes @cro"n =eroD. Excludin% t!is strand' count t!e next ei%!t strands and mar0 t!e ei%!t! strand "it! c!al0. Exclude t!e ei%!t! strand and repeat t!is procedure a furt!er t"o times. 9!e measured len%t!

bet"een t!e outer c!al0 mar0s is t!en di+ided by four to %i+e t!e lay len%t!. As a rou%! c!ec0 on t!e o+erall accuracy of t!e c!al0 mar0in%' t!e len%t! of lay for ei%!t strand ropes is approximately ,.&* 5 ,.* x t!e diameter of t!e rope. e.%. usin% a lay len%t! of ,.* x rope diameter' four lay len%t!s of a (& mm diameter rope "ill be (& mm x ,.* x ) I 1(& mm. An alternati+e met!od of meas5 urin% t!e rope lay is to secure t!e free end of t!e roll of addin% mac!ine paper to t!e rope "it! ad!esi+e tape. 9!e paper is rolled
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out o+er t!e rope and simultane5 ously t!e "ax pencil is dra"n o+er t!e paper' pro+idin% a clear print of t!e outer "ires of t!e rope. 9!e finis!ed print can be filed for comparison "it! later measurements. A t!ird met!od is to "rap typin% carbon papers round t!e rope under t!e roll of paper. By rub5 bin% alon% t!e paper "it! a piece of cardboard' t!e carbon mar0in% on t!e underside of t!e paper can be confined to t!e tops of t!e strand cro"ns. (." -hec%in+ the stabi!ity o the rope A rope in %ood condition "ill !a+e all strands ti%!tly laid. A scre"dri+er inserted bet"een strands "!en t"isted s!ould meet "it! stiff resistance. If t!e scre"dri+er can be t"isted bet"een different pairs of strands "it!out muc! resistance' a full examination s!ould be carried out. 9!e uns0illed use of a scre"dri+er or 3arlin Spi0e to examine t!e rope core can cause serious dam5 a%e to t!e rope. (.# -han+es in rope structure In addition to t!e examination areas detailed in section )' defor5 mation caused at any point in t!e main "or0in% area can mo+e alon% t!e rope. Wa+iness' and in particular' birdca%e can be mo+ed

alon% t!e rope by t!e action of t!e s!ea+es. A de%ree of slac0ness in t!e outer co+er of a multi5 strand rope may not be sufficient to form an immediate birdca%e. ?o"e+er' slac0ness can be @s2uee=edD alon% t!e rope. Wit! t!e normal len%t! of rope out any slac0ness in t!e outer co+er "ill usually be found at t!e end termination or "!ere t!e rope meets t!e drum. (.& Inspectin+ sheaves and drums Remar0s in t!is section are in5 tended to apply e2ually to s!ea+es and drums. A ti%!t %roo+e in a S!ea+e or drum "ill sub<ect t!e rope to enormous radial pressure. Rapid deterioration and premature "ire failure' particularly in t!e +alleys bet"een strands' can be expected 67i%. 'A8. ;n t!e ot!er !and a "ide %roo+e "ill not pro+ide essential support to a rope under load. ;+al s!aped deformation is produced resultin% in une+en distribution of t!e load bet"een indi+idual "ires "it! conse2uent early failure 67i%. 'C8. S!ea+es can be c!ec0ed "it! %au%es "!ic! are a+ailable on t!e open mar0et. 9!e use of specially made circular templates is pre5 ferred. 9!e recommend si=e for a S!ea+e %au%e is t!e nominal rope diame5 ter F , E to F - E 67i%. ' B8. In order to establis! t!e si=e of a
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S!ea+e %roo+e' templates for t!e si=es abo+e and belo" t!e recom5 mended si=e "ill be re2uired. 9!e sides and tread of s!ea+es "!ic! !a+e been in use for some time' are often !ea+ily coated "it! old lubricant' some of "!ic! may first !a+e to be remo+ed "it! a scraper. By insertin% t!e template as far as possible and dra"in% it t!rou%! t!e remainin% lubricant' t!e fit of t!e template relati+e to

Attention s!ould also be %i+en to t!e flan%es of t!e s!ea+es. Ab5 sence of lubricant' scratc!in% or unexpected "ear on one side "ill indicate 6a8 misali%nment of t!e S!ea+e and 6b8 t!e dan%er of tor2ue bein% induced into t!e rope due to t!e rope rollin% do"n t!e flan%e into t!e tread. 9!e tread s!ould be cleaned and carefully examined for any si%n of rid%in% or imprintin%. In t!e case

t!e S!ea+e tread can be assessed. 9!e correct template s!ould be in contact "it! t!e S!ea+e tread for about (- . If t!e template only touc!es t!e side flan%es' t!e %roo5 +e is too ti%!t. If t!e template touc!es only t!e bottom part of t!e tread' t!e %roo+e is too "ide.

of imprintin% "it! t!e rope profile t!e rope in ser+ice may !a+e caused t!e dama%e and is unli0ely to be seriously affected. A re5 placement rope "ill not fit exactly into t!e imprint and "ill suffer serious dama%e durin% t!e early part of its ser+ice.

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W!en a rope c!an%e is made' t!e s!ea+es s!ould be c!ec0ed for eccentricity and t!e bearin% for "ear and free runnin%.

may be imminent. Specific "or0in% conditions !o"e+er' may lead to internal "ire brea0s and to internal loss of metallic area. It may be surprisin% to learn t!at t!is applies in particular to ropes "!ic!' for safety reasons' are operated "it! lar%e diameter s!ea+es and !i%! factors of safety.

.. E!ectro/ ma+netic wire rope examination After a period in ser+ice surface "ear andBor a number of "ire brea0s "ill indicate t!e rope con5 dition !as deteriorated and discard

/ynamically loaded ropes or ropes "!ic! are sub<ected to tor2ue "!en "or0in%' can suffer from internal "ire brea0s caused by o+erstrained interior rope ele5 ments. In addition' "!en t!e ree+5 in% system includes s!ea+es lined
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"it! plastic or all plastic s!ea+es' t!ese s!ea+es offer more elastic support t!an steel s!ea+es. 9!e pressure bet"een outer "ires and t!e S!ea+e %roo+es can be reduced to suc! an extent t!at "it! some rope constructions t!e first "ire brea0s "ill occur' not on t!e surface' but "it!in t!e rope. In all t!ese cases Electro5ma%netic testin% "ill allo" nondestructi+e examination and appraisal of t!e ropeCs internal condition. Electro5ma%netic testin% e2uip5 ment a+ailable on t!e mar0et al5 lo"s' dependin% on indi+idual desi%n' indication or continuous recordin% of localised dama%e suc! as sin%le bro0en "ires' brea0s of strands' soldered and "elded <oints as "ell as "ire pit5 tin% and e+en detection of reduced metallic area caused by corrosion and abrasion o+er t!e "!ole rope len%t!. 9!e data are plotted as a function of t!e rope len%t!' "!ic! is con5 tinually measured eit!er durin% t!e inspection or' if a recordin% is done' durin% t!e follo"in% analy5 sis. In t!is "ay e+ery si%nal on t!e recordin% can unmista0ably be related to a =one on t!e rope. 9!is met!od allo"s a more precise +isual inspection of t!ose sections of t!e rope "!ic! s!o"ed excep5 tional inconsistencies durin% t!e Electro5ma%netic inspection. 7ur5 t!ermore' recordin% t!e data du5 rin% re%ular Electro5ma%netic inspections ma0es it possible to compare t!e results "it! pre+ious
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recordin%s. In t!is "ay t!e ad5 +ance of t!e deterioration of t!e rope can be ascertained. Electro5ma%netic testin% e2uip5 ment for "ire ropes "as already bein% de+eloped at t!e be%innin% of t!e &-t! century. ;nly +ery fe" specialists could use t!e e2uip5 ment properly but o+er t!e past fe" years t!e use of t!ese instru5 ments !as been %reatly impro+ed so t!at t!ey are no" at t!e com5 mand of a muc! "ider ran%e of users. It is li0ely t!at "it!in a fe" years t!ere "ill be e2uipment on offer "!ic! not only records measured data but also' 6by means of a micro computer8' "ill process t!e data "it! re%ard to amplitude and fre2uency. In t!is "ay t!e e2uip5 ment "ill pro+ide t!e examiner "it! data suc! as fre2uency cur+es and t!e accurate assess5 ment of t!e reduction in brea0in% stren%t!. At t!e moment instruments are bein% de+eloped "!ic!' apart from t!e data mentioned abo+e' can also record t!e rope diameter and t!e lay len%t! of t!e rope. 9!is "ill enable t!em to re%ister out5of5roundness of t!e rope diameter' cor0scre" li0e deform5 ations or c!an%es of t!e lay len%t!s alon% t!e rope len%t!. 7or inspection' a test !ead is clamped around t!e rope. 9!en t!e "!ole len%t! of t!e rope is pulled t!rou%! t!e test !ead. If t!is is not possible' as in t!e case

of suspended ropes of Rope5"ays' t!e test !ead is dra"n alon% t!e "ire rope. /urin% t!is procedure all test data are transmitted +ia cable or radio to an amplifier. 9!e test data are indicated eit!er opti5 cally or acoustically' recorded on ma%netic tape or represented %rap!ically durin% t!e test. An Electro5ma%netic test instrument is s!o"n in 7i%. ).

cellotape t!ese "ires can be secured in t!e strand +alleys. At t!e be%innin% of t!e recordin% strip c!art t!e examiner "ill obtain reference data indicatin% t!e si=e of t!e amplitudes of t!e test "ires.

Calibration of t!e testin% e2uip5 ment re2uires %reat care. A re5 commended met!od of c!ec0in% t!e function and accuracy of t!e e2uipment is to attac! len%t!s of "ire' !a+in% diameters e2ual to t!e lar%est and smallest si=es in t!e rope' alon% t!e first metres of rope len%t!. By means of
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7i%. *a illustrates a typical dia5 %ram of a rope section "it! "ire brea0s. 7i%. *b s!o"s t!e re5 cordin% of a rope section affected by corrosion. Selectin% t!e suitable test instru5 ment' competent !andlin% and t!e correct interpretation of t!e data re2uire a lot of experience and expert 0no"led%e. Larious uni+ersities' test institutes as "ell as commercial firms' render Elec5 tro5ma%netic inspection of "ire ropes as a ser+ice. 9!e discard numbers of "ire brea0s specified in t!e Standards refer solely to external "ire brea0s. Appraisin% t!e condition of t!e "ire rope "it! re%ard to internal "ire brea0s is t!erefore left to t!e inspector. It "ould be ad+isable to discard a "ire rope

"!en t!e total number of external and internal "ire brea0s' added to%et!er' reac!es t!e discard number of "ire brea0s specified in t!e Standards. Electro5ma%netic tests cannot' and must not' totally replace +isual inspections. Met' t!ey pro+ide +aluable additional information on t!e conditions of "ire ropes and must be re%arded as a useful addition to t!e +isual inspection.

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