drilling operations - shaw's ent · riser tensioner lines present a tough application for wire...

Product Selection

Blue Strand API 9A Standard 6x19 Class

Conventional, tried & tested lines in regular sizes and tensile grades.See page 12

DYFORM® 6Drilling lines typically utilise Dyform Bristar 6 constructions which offersprotection for the core and improved abrasion resistance on draw works,greater cross sectional stability and excellent fatigue capabilities.See page 14 & 15

Riser Tensioner LinesRiser Tensioner Lines present a tough application for wire rope, repetitive high load bending over sheaves requiring aflexible solution with exceptional bend fatigue properties and resistance to wear & abrasion.

DYFORM® 6Dyform Bristar 6 ropes for riser tensioner applications aredesigned to give characteristics which enhance fatigueperformance. The ‘compacting’ process facilitates excellentresistance to wear on the sheaves and drums.See page 14 & 15

Drilling Operations

Drilling LinesDrilling lines present a tough application for wire rope, repetitive high load bending over sheaves requiring a flexible solutionwith exceptional bend fatigue properties and resistance to wear & abrasion.

06

Handling OperationsDeck Handling

BRIDON Oil and Gas

Endurance DYFORM® 34LR

Endurance Dyform 34LR multi-strand ropes are recommended fordemanding lift operations offering high strength, low rotation construction. The Dyform construction ensures accurate diameter tolerances for multi-layer coiling and suitable for single or multi-part reeving.See page 20

Endurance DYFORM® 8PI

Dyform 8PI ropes are impregnated with plastic providing a cushion withinthe rope that increases fatigue life and internal protection, whilst maintainhigh strength, crush resistance and low stretch.See page 21

Products

12

Blue Strand 6x19 Class to API steel core (Metric)

Rope diameter

262832363840444852

2.703.144.105.185.786.407.749.2210.8

1.812.112.763.483.884.305.206.207.26

4264946458179101010122014501700

43.450.465.783.392.8103124148173

47.955.572.591.8102113137163191

47254771590410101120135016101890

48.155.872.992.2103114138164193

53.061.480.3102113126152181212

52060378799711101230149017702080

53.061.580.2102113125152180212

58.467.788.4112125138167199234

31.336.347.459.966.874.089.5107125

7.08.211131517202428

17221432045653762783210821376

1271582363363964626137981015

30435246058264871886910341214

0.4700.5460.7130.9021.001.111.351.601.88

In air 1770 grade 1960 grade 2160 grade Ordinary

mm kg/m lb/ft kN Tonnes 2000lbs kN Tonnes 2000

lbs kN Tonnes 2000lbs MN Mlbs N.m lbs.ft mm2 in2

Approximatemass Minimum breaking force (Fmin) Axial

stiffness@20% load

Torquegenerated@20% load

Metalliccrosssection

Blue Strand 6x19 Class to API steel core (Imperial)

Rope diameter

25.428.631.834.938.141.344.547.650.8

111/811/413/811/215/813/417/82

2.753.484.305.196.197.268.429.6611.0

1.852.342.893.494.164.885.666.497.39

3995036177438801020118013501530

40.751.362.975.789.7104120138156

44.856.569.383.598.9115133152172

46057871185410101170136015501760

46.958.972.587.1103119139158179

51.764.979.995.9113131153174198

50663678294311101300150017101930

51.664.879.796.1113133153174197

56.871.487.8106125146169192217

29.837.846.856.367.178.891.4105119

6.78.511131518212427

16423131741753967684610331252

121171233308397499624762923

29036745454765276588710171159

0.4490.5690.7040.8481.011.191.381.581.80

In air IPS EIPS EEIPS Ordinary

mmin kg/m lb/ft kN Tonnes 2000lbs kN Tonnes 2000



stiffness@20% load



Figures quoted within published tables represent our standard products.Bridon specialise in the development of products to suit your individual needs, please contact us directly and we will be pleased to develop aspecification to match your requirements.

BRIDON Oil and Gas

13

Products

Blue Strand 6x36 Class steel core (Metric)

Rope diameter

38404448525660

5.916.547.929.4211.112.814.7

3.974.395.326.337.478.609.88

910101012201450170019802270

92.8103124148173202231

102113137163191222255

1010112013501610189021902510

103114138164193223256

113126152181212246282

1110123014901770208024102770

113125152180212246282

125138167199234271311

697793110129150172

16172125293439

5376278321082137617172108

396462613798101512661555

6647368911060124414431656

1.031.141.381.641.932.242.57

In air 1770 grade 1960 grade 2160 grade Ordinary

Blue Strand 6x36 Class steel core (Imperial)

mm kg/m lb/ft kN Tonnes 2000lbs kN Tonnes 2000



stiffness@20% load



Rope diameter

38.141.344.547.650.857.263.566.769.976.282.688.995.3102

11/215/813/417/8221/421/225/823/4331/431/233/44

6.197.268.429.6611.013.917.319.120.824.729.033.838.744.0

4.164.885.666.497.399.3511.612.814.016.619.522.726.029.8

88010201180135015301910

89.7104120138156195

98.9115133152172215

10101170136015501760220029503240353041604830552062706340

103119139158179224301330360424493563639647

113131153174198247331364397467543620705712

111013001500171019302420

113133153174197247

125146169192217272

698295108123156193213234278326378434498

16182124283543485362738598112

53967684610331252176026233026345444385585687083659054

397499624762923129819342231254732724119506661686676

66878490910421187150218552046224826713138363541784786

1.041.211.411.621.842.332.883.173.484.144.865.646.487.42

In air IPS EIPS EEIPS Ordinary

mmin kg/m lb/ft kN Tonnes 2000lbs kN Tonnes 2000



stiffness@20% load




BRIDON Oil and Gas

Products

14

DYFORM®

6x19 Class for Drilling Lines

Ropediameter

mm in kg/m lb/ft kN Tonnes 2000lbs MN Mlbs N.m lbs.ft N.m lbs.ft mm2 in2

In air

Approximate mass Minimum breakingforce (Fmin)

EIPS/1960 grade Ordinary Lang’s

Axial stiffness@20% load

Torque generated @20% load Metalliccrosssection

25.428.631.834.938.141.344.547.650.854.057.263.569.976.2

111/811/413/811/215/813/417/8221/821/421/223/43

2.843.604.455.366.397.518.719.9711.412.814.417.721.525.5

1.912.422.993.604.295.045.856.707.638.629.6711.914.417.2

5146528059701156135915771805205523232606321237624471

52.466.482.198.9118138161184210237266327383456

57.773.290.5109130153177203231261293361423502

344454657891106121138156175215261310

810121517202427313539485970

1802573534676087749691185144117312057281436294701

133190261345448571714874106312761517207526763467

n/an/an/an/an/an/an/an/an/an/an/an/an/an/a

n/an/an/an/an/an/an/an/an/an/an/an/an/an/a

33442452463175288410261174133815121696209025333010

0.5180.6570.8120.9791.171.371.591.822.072.342.633.243.934.67


BRIDON Oil and Gas

Products

15

DYFORM®

6x37 Class for Riser Tensioner Lines

Ropediameter

mm in kg/m lb/ft kN Tonnes 2000lbs MN Mlbs kN.m lbs.ft mm2 in2

In air

Approximate mass Minimum breakingforce (Fmin)

IPS/1770 grade Lang’s lay

Axial stiffness@20% load

Torque generated @20% load Metalliccrosssection

4444.547.64850.852545657.260.363.56466.769.973.076.2

13/417/8

2

21/8

21/423/821/2

25/823/427/83

8.628.7910.110.311.512.013.014.014.516.217.918.219.821.723.725.8

5.795.916.786.897.728.098.729.389.7710.912.112.213.314.615.917.4

1456148617041733194120342194235923702639292629723229354638674214

148152174177198207224240242269298303329361394430

164167191195218228246265266296329334363398434473

103105121123138144156167174194215219238261285310

23242728313235383944484953596470

1.41.41.81.82.12.32.62.93.03.54.14.14.75.46.27.0

1030106213041337158517001904212421772558298730583462398445385161

1004102411741194133814021512162616931885209021232306253327623010

1.561.591.821.852.072.172.342.522.622.923.243.293.573.934.284.67


BRIDON Oil and Gas

Products

20


BRIDON Oil and Gas

Diameter

mm

EIPS / 1960 grade

Minimum breaking force (Fmin)

EEIPS / 2160 grade @20% load

Axialstiffness

Torque generated @20% load Metallic

crosssectionLang’sOrdinary

mm2kg/m kN tonnes kN tonnes MN N.mN.m

Approx.nominal lengthmass

101112131415161718192021222324252627282930323435363840

4244464850

0.500.610.720.850.981.131.281.451.621.812.002.212.422.652.883.133.383.653.924.214.505.125.786.136.487.228.00

8.829.6810.611.512.5

92.111113315618120723626629833336840644648753157662367272277582993910601124118913251468

16181776194121132293

9.3911.413.515.918.421.124.027.130.433.937.641.445.449.754.158.763.568.573.679.084.595.7108115121135150

165181198215234

96.7117139163190218248279313349387426468511557604654705758813870990

9.911.914.216.719.322.225.228.531.935.639.443.547.752.156.861.666.671.977.382.988.7101

5.87.08.39.71113151719212325283033363942454852596770758392

101111122133144

1.52.02.53.24.05.06.07.28.6101214161820232629323640485863688194

109125143162183

3.34.45.77.39.111141619232731354046525865738190108130142154181211

245281321365413

58708498114131149168188210232256281307335363393424456489523595672712753839930

10251125123013391453

Dyform 34x7

Dyform 34x19

Endurance DYFORM® 34LR & 34LRPI

Products

21

DYFORM® 8PI


Ropediameter

mm in kg/m lb/ft kN Tonnes 2000lbs

kN Tonnes 2000lbs

mm2 in2

In air

Approximatemass

EIPS/1960 grade 2160 grade Ordinary Lang’s

Axialstiffness

@20% load

Torque generated@20% loadMinimum breaking force (Fmin) Metallic

crosssection

1617181919.1202222.22425.4262828.63031.8323434.9363838.1404244464850

3/4

7/8

1

11/8

11/4

13/8

11/2

1.201.361.521.701.721.882.282.322.713.043.183.693.854.234.764.825.445.736.106.796.837.538.309.119.9510.811.8

0.810.911.021.141.151.261.531.561.822.042.142.482.592.843.203.243.653.854.104.564.595.065.586.126.697.287.90

22625528631832235342743550856959669172179489290310201074114312741280141115561708186620322205

23.026.029.132.532.836.043.544.351.858.060.870.573.580.990.992.1104110117130131144159174190207225

25.428.632.135.836.139.648.048.857.163.967.077.781.089.2100101115121128143144159175192210228248

23626729933333636944645553159562372375483093394410661123119513321339147616271786195221252306

24.127.230.533.934.33845.546.354.260.763.673.776.984.695.196.3109115122136136150166182199217235

26.529.933.637.437.841.450.151.159.766.870.081.284.793.2105106120126134150150166183201219239259

1415171919212626313436424448545562656977788594103113123134

3.13.53.94.34.44.85.85.96.97.78.19.4101112121415161717192123252830

5161728586991311351712022172712893333974054855255766786837909151052120213661544

3745536263739710012614916020021324629329835838742550050458367577688610071138

657893109111127169174219260279349371429511520624675741871878101611761352154517561985

485868808294125128162192206257274316376384460498546642647749867997113912951463

1371541731931952142582633083453614194374815405476176506927717758549421034113012301335

0.2120.2390.2680.2990.3020.3310.4010.4080.4770.5340.5600.6490.6770.7450.8370.8480.9571.011.071.201.201.321.461.601.751.912.07

MN Mlbs N.m lbs.ft N.m lbs.ft

BRIDON Oil and Gas

Steel Rope Technical Information

30 BRIDON Oil and Gas

Recommended Handling Procedures

This section provides recommendations and information on thecorrect installation and handling of Drilling Lines, to ensureoptimum working lives are achieved.

In general all reputable Wire rope producers now manufactureDrilling-Lines to very precise regulations and within high qualitycontrol procedures.

As a result of this, it is a proven fact that the majority ofunnecessary drilling line wear, damage and premature discardproblems arise from incorrect handling and treatment of therope in service.

With the Drilling Lines now becoming much larger in diameterand often longer in length, making them significantly heavier,the potential for damage is proportionally greater. Therefore itbecomes increasingly essential that these ropes are handledcorrectly in order to operate safely and optimise the ropeworking life.

Rope Storage

Unwrap and examine the rope immediately after delivery to site,(whether it’s at the on-shore base warehouse, or out on the rig)to confirm everything is in order.

Check its diameter, it’sidentification and conditionand to verify that it is fully inaccordance with yourrequirement, as per thepurchase order andspecification and importantlythe details shown on theCertificates and documents.

Select a clean and well ventilated, dry location for storage,where it is not likely to be affected by chemical fumes, steam ofcorrosive agents.

Mount the reel on timbers or suitable frame to ensure that the ropedoes not make direct contact with the ground and if stored forextended periods of time ensure the reel in rotated periodically toprevent the migration of lubricants from the rope.

Installation

Prior to installation of the rope (drill-line), ensure that:

A. The drill-line storage reel is properly mounted and free torotate.

B. The reel is correctly positioned, so that the drill-line willspool off correctly, in the same direction the fast-line willspool onto the draw-work’s drum, i.e. Over-wind to over-wind, or under-wind to under-wind.

C. Prior to reeving the drill-line, the following components andequipment must be inspected, to ensure they arecompatible with and won’t damage the new drill-line that isto be installed.

i), All sheave groove root profiles are to be gauged, to ensurethat they are within acceptable tolerances (as per picturesleft). Ideally the groove profile should measure 7.5% abovethe nominal diameter of the rope.

ii), All sheave grooves areto be checked thoroughly,to ensure that there are norope (drill-line) tread wearpatterns, indentations orscoring in them.

iii), All sheave bearingsmust be checked foradjustment, so they arefree to rotate efficientlyand with the minimum oftractive effort.

Check to ensure that there is no excessive side-movement,(wobble) which would cause sheave groove enlargementand the accompanying premature sheave bearing failure,and undoubtedly contribute to premature drill-line discard.

D. The Travelling Block should be positioned so it is aligned aswell as possible with the Crown Cluster Block’s sheaves. Itshould also be “hung off” and secured to preventmovement, which is essential to ensure that no turn isinduced in the rope during installation. On most operationalrigs, the travelling-block is hung-off in the derrick , stillattached to its guide dolly, so the sheave alignment of bothblocks will be good.

E. The Draw-works drum and it’s flanges need to be inspectedto make sure all grooves are in good condition and that theyare still compatible with the drill-line size.

(Note: The groove radius and pitch should be checked andmeasured prior to ordering the new line and the detailsadvised to the rope supplier, to ensure the rope supplied issuitable for the system).

F. The drum flanges, wear and kick-plates should be checked toensure they are in good condition. (As damage and adversewear to them can damage the drill-line).

G. The Travelling block must be hung off and secured to preventmovement whilst the new Drill line is being reeved.

If any component in the reeving configuration is worn, ordamaged, to the extent where it might damage the drill-line,then it should be repaired in situ or changed out prior to reevingthe new drill-line.

To leave it in this condition and continue operating, will not onlycause premature drill-line discard, but also constitute an unsafeworking operation.

Drilling Lines

P

O

BBRRIIDDOONN

WRONG

Sheave groove toonarrow

Sheave groove toowide

Sheave groovecorrectlysupporting therope for 33% ofits circumference

WRONG

RIGHT


31BRIDON Oil and Gas

Rope Installation

Installation of the new drilling Line is usually undertaken bypulling it through the reeve-up system with the old rope. API9B, recommends that the two ropes be connected by means ofwhat they call a “swivel stringing grip”, (which is also known asa snake, a Chinese finger, or a sock). This can be a satisfactoryprocedure with the smaller drill-lines with minimum number offalls. But preferably without a swivel in the reeving hook-up.

(A swivel should never ever be used with Flattened Strand or anyother Langs Lay rope.)

In the case of the much larger diameter drilling lines and multi-fallsystems, where the tensions in reeving are much higher, then the useof a stringing grip, or similar, is not a practical or safe way toproceed. The common practice is to directly connect one line to theother. (Splicing is the preferred and safest method).

The prime objective during reeving of the new line is to ensurethat no turn is introduced into the new line, either from the oldline or by the system.

The possible imposition of rope turn can be checked byattaching a flag or marker at the connection point of the newdrill-line and then observed during installation. If any twist isseen to be induced into the rope, then this should be let outbefore the rope is attached to the drawworks.

Ideally the rope should then be wound onto the Draw-work’sdrum at the recommended minimum required fast-line tension ,possibly by using a pinch-roller type drill-line tensioner. Thisrope tension should be applied until the drill-line has the weightof the travelling assembly on it.

The manufacturers recommended minimum number of deadwraps on the Drawworks drum, should where possible becomplied with, as any additional or an excessive number ofdead wraps, especially any wraps without sufficient tension onthem, could lead to rope slackness on the drum with probablerope crushing damage.

On Rigs with Crown Mounted Compensators, it is recommendedthat the cylinders be extended, prior to winding the line on to thedraw-work’s drum. This ensures that the excessive amount ofdrill-line that is required for CMC operation when the cylinders areextended, is taken up in the falls between the crown and travellingblocks as the drill-line is wound onto the drum under tension.

On some draw-works the fast-line’s exit-hole through the drumflange to the clamp may not allow the rope to enter if it has beenserved (seized). In such a case it is essential to fuse all the wiresand strands at the rope end, by weld, to ensure that nothingmoves when the serving (seizings) are removed.

Once installed, the rope system should then be lifted andlowered under average working tensions for several cycles,until the rope has bedded in.

Slipping and Cutting

It is essential that before the rope is cut it is securely bound, onboth sides of the cut. Failure to properly bind the rope will allowrelative movement of the components of the rope – wires andstrand – which can cause constructional unbalance andsubsequent distortion of the rope in the working rope system.

Distortions or disturbance of the strands within the rope, will resultin uneven distribution of the load applied and also surface wear.

A condition, that will effect the working life of the rope.

The binding/seizing itself should be of soft or annealed wire orstrand (of approximately 0.125” in diameter), wound tightlyaround the rope at both sides of the cutting position, using a‘Serving Mallet’ or a ‘Marlin Spike’.

Alternatively a clamp of suitable design, such as a spare draw-work’s drum anchor clamp is ideal for serving (seizing) the drill-line prior to cutting and fusing it

For conventional 6 strand preformed ropes the serving (seizing)length, should be no less than twice the diameter of the ropebeing cut. However in Triangular (Flattened) Strand or otherLangs Lay ropes, then two servings (seizings) on either side ofthe cut would be preferred.

The calculated length of rope to be slipped is critical to ensurethat the rope is subject to even wear as the rope progressesthrough the reeving system. Therefore this length must bemeasured as accurately as possible, to avoid the rope beingpositioned at repeat critical wear positions in the system.

An inaccurate measurement and cut of say half of a singledrum wrap, could cause a slip and cut to be inaccurate enoughto cause critical wear-spots to move to repeat positions duringthe slip and cut.

It is of course of paramount importance, after the slip and cut iscompleted, that the drill-line is wound onto the drawworks at therecommended tension using a pinch-roller type drill-line tensioneruntil the weight of the travelling assembly is on the drill-line.

One Important Thing To Remember

The main issue that normally dictates/necessitates the need fordrill-line handling, whether it’s to do a slip and cut, or to changeout a complete drill-line, is the actual rope condition in terms ofwear and damage.

Ton.Miles is a conventional method, based upon experience, ofcalculating the amount of work done by the rope and to thendetermine the service life of the rope through a slip and cutprogramme. However it must be emphasised that Ton.Miles is ageneral guide only and should not be used as the sole criteriafor assessing the rope condition, as continual visual monitoringis also essential.

If the visual condition of the drill-line, indicates that the drill-lineis showing excess wear and/or damage, or is encroaching on,equal to, or exceeding that described as discard criteriaaccording to ISO 4309, then it should take precedence overTon.Mileage as the discard criteria.

Failure to slip and cut, if this sort of excessive drill-line wearoccurs, ahead of the scheduled ton-mileage slip and cut,normally results in extremely long slip and cuts in the future andprobably an unsafe working condition.

It should be noted, If the rope regularly appears in goodcondition at the programmed time for slip and cut, and that thisgood condition can be further confirmed by the Manufacturer,then the Ton.Mile Slip and Cut programme may be extended toincrease the rope’s service life.

The above recommendations are offered as a guidance to thehandling of Drilling Lines during installation and service. It isessential that the Drilling Line is at all times correctly handled,inspected and slipped through the system, to ensure a safeworking operation and an optimum working rope life

For further information please contact Bridon direct.


32

Any assembly of steel wires spun into a helical formationeither as a strand or wire rope, when subjected to a tensileload, can extend in three separate phases, depending onthe magnitude of the applied load.

There are also other factors which produce rope extensionwhich are very small and can normally be ignored.

Phase 1 - Initial or Permanent Constructional Extension

At the commencement of loading a new rope, extension iscreated by the bedding down of the assembled wires with acorresponding reduction in overall diameter. This reductionin diameter creates an excess length of wire which isaccommodated by a lengthening of the helical lay. Whensufficiently large bearing areas have been generated onadjacent wires to withstand the circumferential compressiveloads, this mechanically created extension ceases and theextension in Phase 2 commences. The Initial Extension ofany rope cannot be accurately determined by calculationand has no elastic properties.

The practical value of this characteristic depends uponmany factors, the most important being the type andconstruction of rope, the range of loads and the numberand frequency of the cycles of operation. It is not possibleto quote exact values for the various constructions of ropein use, but the following approximate values may beemployed to give reasonably accurate results.

The above figures are for guidance purposes. More precisefigures are available upon request.

Phase 2 - Elastic Extension

Following Phase 1, the rope extends in a manner whichcomplies approximately with Hookes Law (stress isproportional to strain) until the Limit of Proportionality orElastic Limit is reached.

It is important to note that wire ropes do not possess aYoung’s Modulus of Elasticity, but an ‘apparent’ Modulus ofElasticity can be determined between two fixed loads.

The Modulus of Elasticity also varies with different ropeconstructions, but generally increases as the cross-sectional area of steel increases. By using the valuesgiven, it is possible to make a reasonable estimate ofelastic extension, but if greater accuracy is required it isadvisable to carry out a modulus test on an actual sampleof the rope.

Elastic Extension =

W = load applied (kN)

L = rope length (m)

EA = axial stiffness MN

Phase 3 - Permanent Extension

The permanent, non-elastic extension of the steel causedby tensile loads exceeding the yield point of the material.

If the load exceeds the Limit of Proportionality, the rate ofextension will accelerate as the load is increased, until aloading is reached at which continuous extension willcommence, causing the wire rope to fracture without anyfurther increase of load.

Thermal Expansion and Contraction

The coefficient of linear expansion (∝) of steel wire rope is0.0000125 = (12.5 x10-6) per oC and therefore the changein length of 1 metre of rope produced by a temperaturechange of t oC would be;

Change in length ∆| = ∝ |o t

where:

∝ = coefficient of linear expansion

|o = original length of rope (m)

t = temperature change (oC)

The change will be an increase in length if the temperaturerises and a decrease in length if the temperature falls.

Extension due to Rotation

The elongation caused by a free rope end being allowed to rotate.

Extension due to Wear

The elongation due to inter-wire wear which reduces thecross-sectional area of steel and produces extraconstructional extension.

Example: What will be the total elongation of a 200 metre length of 38mm diameter Blue Strand 6x36 wire rope with an axial stiffness of 69MN, at a tension of 202 kNand with an increase in temperature of 20oC.

Permanent Constructional Extension = 0.25% of

rope length = 500mm

Elastic Extension = = = 585mm

Thermal Expansion = ∆| = ∝ |o t = 0.0000125 x 200,000 x 20 = 50mm

Therefore total extension = 500 + 585 + 50 = 1135mm

Properties of Extension of Steel Wire Ropes

WL (mm)EA

WLEA

202 x 20069

% of rope length

Fibre Core Steel CoreLightly loaded 0.25 0.125Factor of safety about 8:1Normally loaded 0.50 0.25Factor of safety about 5:1Heavily loaded 0.75 0.50Factor of safety about 3:1Heavily loaded Up to 2.00 Up to 1.00with many bends and/or deflections

BRIDON Oil and Gas


33

In addition to bending stresses experienced by wire ropesoperating over sheaves or pulleys, ropes are also subjectedto radial pressure as they make contact with the sheave.This pressure sets up shearing stresses in the wires,distorts the rope’s structure and affects the rate of wear ofthe sheave grooves. When a rope passes over a sheave,the load on the sheave results from the tension in the ropeand the angle of rope contact. It is independent of thediameter of the sheave.

Load on bearing =

Assuming that the rope is supported in a well fitting groove,then the pressure between the rope and the groove isdependent upon the rope tension and diameter but isindependent of the arc of contact.

Pressure, P =

P = pressure (kg/cm2)

T = rope tension (kg)

D = diameter of sheave or drum (cm)

d = diameter of rope (cm)

Maximum Permissible Pressures

It should be emphasised that this method of estimation ofpressure assumes that the area of contact of the rope inthe groove is on the full rope diameter, whereas in fact onlythe crowns of the outer wires are actually in contact with thegroove. The local pressures at these contact points may beas high as 5 times those calculated and therefore thevalues given above cannot be related to the compressivestrength of the groove material.

If the pressure is high, the compressive strength of thematerial in the groove may be insufficient to preventexcessive wear and indentation and this in turn will damagethe outer wires of the rope and effect its working life. Aswith bending stresses, stresses due to radial pressureincrease as the diameter of the sheave decreases.Although high bending stresses generally call for the use offlexible rope constructions having relatively small diameterouter wires, these have less ability to withstand heavypressures than do the larger wires in the less flexibleconstructions. If the calculated pressures are too high forthe particular material chosen for the sheaves or drums orindentations are being experienced, consideration shouldbe given to an increase in sheave or drum diameter. Sucha modification would not only reduce the groove pressure,but would also improve the fatigue life of the rope.

The pressure of the rope against the sheave also causedistortion and flattening of the rope structure. This can becontrolled by using sheaves with the correct groove profilewhich, for general purposes, suggests an optimum grooveradius of nominal rope radius +7.5%. The profile at thebottom of the groove should be circular over an angle ofapproximately 120o, and the angle of flare between thesides of the sheave should be approximately 52o.

Hardness of Rope Wire

Suggested pulley hardness: 250-300 Brinell for Mn steel orequivalent alloy steel.

If the calculated pressure is too high for the particularmaterial chosen for the pulley or drum, considerationshould be given to increase in pulley or drum diameter.Such a modification would not only reduce the groovepressure, but would also improve the fatigue life of the ropeby reducing the bending stresses imposed.

Pressures between Ropes and Sheaves or Drums

2T sin θ2

2TDd

Min. TensileStrength

2160N / mm2

1960N / mm2

1770N / mm2

1570N / mm2

API 9AGrade

EEIPS

EIPS

IPS

PS

Brinel

480 / 500

470 / 480

445 / 470

405 / 425

Rockwell‘C’

52

51

49

45

Ropegrade

ApproximateEquivalent

ApproximateHardness

5 - 8 Ordinary lay5 - 8 Lang’s lay9 - 13 Ordinary lay9 - 13 Lang’s lay14 - 18 Ordinary lay14 - 18 Lang’s layTriangular strand

20253540424755

404560707585100

105120175200210240280

Number of outer wiresin strands

Groove material

Castiron

kgf/cm2

Lowcarboncast steel

kgf/cm2

11 to 13%Mn steel

orequivalentalloysteelskgf/cm2

BRIDON Oil and Gas


34

Bend fatigue testing of ropes usually consists of cycling alength of rope over a sheave while the rope is under aconstant tension and as part of its ongoing developmentprogramme Bridon has tested literally thousands of ropesin this manner over the years on its in-house own designbend testing equipment.

Through this work, Bridon has been able to compare theeffects of rope construction, tensile strength, lay direction,sheave size, groove profile and tensile loading on bendfatigue performance under ideal operating conditions. Atthe same time it has been possible to compare rope life todiscard criteria (e.g. as laid down in ISO 4309) with that tocomplete failure of the rope, i.e. to the point where the ropehas been unable to sustain the load any longer. As part ofthe exercise, it has also been possible to establish theresidual breaking strength of the rope at discard level ofdeterioration.

Effects of D:d Ratio and loading on fatigue life -Typical example Dyform 6

What needs to be recognised, however, is that very fewropes operate under these controlled operating conditions,making it very difficult to use this base information whenattempting to predict rope life under other conditions. Otherinfluencing factors, such as dynamic loading, differentialloads in the cycle, fleet angle, reeving arrangement, type ofcoiling on the drum, change in rope direction, sheavealignment, sheave size and groove profile, can have anequally dramatic effect on rope performance.

However, the benefit of such testing can be particularlyhelpful to the rope manufacturer when developing new orimproving existing products.

If designers or operators of equipment are seeking optimumrope performance or regard bending fatigue life as a keyfactor in the operation of equipment, such information canbe provided by Bridon for guidance purposes.

Service life curve for various D:d ratios

When considering the use of a steel wire rope around aminimum D:d ratio, it is generally accepted that at below4:1 the effect on the strength of the rope needs to beconsidered. Permanent distortions within the rope will occurwhen using ratios of 10:1 and less and that a minimum ratioof 16:1 be used for a rope operating around sheaves.

Approximate loss in breaking strength due to bending

Bend FatigueNumber of bends to rope failure

30 29 28 27 26

5% MBL

10% MBL

20% MBL

25 24 23 22 21 20 19 18 17 16

D:d ratio0

100

60

40

20

0

5 10 15 20 25 30 35 40 45 50 55 60 65

80

Relative Rope Service Life

Efficiency % MBF

1.0000 10 20 30 40

0.900

0.800

0.700

0.600

0.500

0.400

0.300

0.200

0.100

0.000

D:d rat io

EB = 1 -0.5

D/d

Sheave D:d rat io

BRIDON Oil and Gas


37

Of all the factors which have some influence on the windingof a rope on a smooth drum, the fleet angle, arguably, hasthe greatest effect.

Fleet angle is usually defined as the included anglebetween two lines, one which extends from a fixed sheaveto the flange of a drum and the other which extends fromthe same fixed sheave to the drum in a line perpendicularto the axis of the drum. (See illustration).

Illustration of Fleet Angle

If the drum incorporates helical grooving, the helix angle ofthe groove needs to be added or subtracted from the fleetangle as described above to determine the actual fleetangle experienced by the rope.

At the drum

When spooling rope onto a drum it is generallyrecommended that the fleet angle is limited to between 0.5O

and 2.5O. If the fleet angle is too small, i.e. less than 0.5O,the rope will tend to pile up at the drum flange and fail toreturn across the drum. In this situation, the problem maybe alleviated by introducing a ‘kicker’ device or byincreasing the fleet angle through the introduction of asheave or spooling mechanism.

If the rope is allowed to pile up it will eventually roll awayfrom the flange creating a shock load in both the rope andthe structure of the mechanism, an undesirable and unsafeoperating condition.

Excessively high fleet angles will return the rope across thedrum prematurely, creating gaps between wraps of ropeclose to the flanges as well as increasing the pressure onthe rope at the cross-over positions.

Even where helical grooving is provided, large fleet angleswill inevitably result in localised areas of mechanicaldamage as the wires ‘pluck’ against each other. This isoften referred to as ‘interference’ but the amount can bereduced by selecting a Lang’s lay rope if the reeving allows.The “interference” effect can also be reduced by employinga Dyform rope which offers a much smoother exteriorsurface than conventional rope constructions.

Floating sheaves or specially designed fleet anglecompensating devices may also be employed to reducethe fleet angle effect.

At the sheave

Where a fleet angle exists as the rope enters a sheave, itinitially makes contact with the sheave flange. As the ropecontinues to pass through the sheave it moves down theflange until it sits in the bottom of the groove. In doing so,even when under tension, the rope will actually roll as wellas slide. As a result of the rolling action the rope is twisted,i.e. turn is induced into or out of the rope, either shorteningor lengthening the lay length of the outer layer of strands.As the fleet angle increases so does the amount of twist.

To reduce the amount of twist to an acceptable level the fleetangle should be limited to 2.5O for grooved drums and 1.5O forplain drums and when using rotation-resistant low rotation andparallel-closed ropes the fleet angle should be limited to 1.5O.

However, for some applications it is recognised that forpractical reasons it is not always possible to comply withthese general recommendations, in which case the rope lifecould be affected.

Rope TorqueThe problem of torsional instability in hoist ropes would notexist if the ropes could be perfectly torque balanced underload. The torque generated in a wire rope under load isusually directly related to the applied load by a constant‘torque factor’. For a given rope construction the torquefactor can be expressed as a proportion of the ropediameter and this has been done below..

Variation with rope construction is relatively small andhence the scope for dramatically changing the stability of ahoisting system is limited. Nevertheless the choice of thecorrect rope can have a deciding influence, especially insystems which are operating close to the critical limit. Itshould be noted that the rope torque referred to here ispurely that due to tensile loading. No account is taken ofthe possible residual torque due, for example, to ropemanufacture or installation procedures.

Torsional Stability

The torque factors quoted on page 39 are approximatemaximum values for the particular constructions. To calculate the torque value for a particular rope sizemultiply by the nominal rope diameter. Example: for 52mm dia. Hydra 7500 Dyform Lang’s Lay at20% of minimum breaking force:-

Torque value = torque factor x rope dia.= 1.8% x 52mm= 0.936mm

To calculate the torque generated in a particular rope whensubjected to a tensile load, multiply the load by the torquevalue and conbine the units. Example:- For 20mm dia. Hydra 7500 Dyform Lang’s Lay at 496kN:

Torque generated = torque value x load.= 0.936 x 496= 464Nm

Fleet Angle

Fleet angle

Drum

Sheave

Fleet angle

Drum

Sheave

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40

Some of the More Common Types of Wire Fractures Can Include:

Factors Affecting RopePerformanceMulti-coiling of the rope on the drum can result in severedistortion in the underlying layers.

Bad coiling (due to excessive fleet angles or slackwinding) can result in mechanical damage, shown as severe crushing, and may cause shock loading during operation.

Small diameter sheaves can result in permanent set ofthe rope, and will certainly lead to early wire breaks due to fatigue.

Oversize grooves offer insufficient support to the ropeleading to increased localised pressure, flattening of therope and premature wire fractures. Grooves are deemed tobe oversize when the groove diameter exceeds the nominal rope diameter by more than 15% steel, 20%polyurethane liners.

Undersize grooves in sheaves will crush and deform therope, often leading to two clear patterns of wear andassociated wire breaks.

Excessive angle of fleet can result in severe wear of therope due to scrubbing against adjacent laps on the drum.Rope deterioration at the Termination may be exhibited inthe form of broken wires. An excessive angle of fleet canalso induce rotation causing torsional imbalance.

The continued safe operation of lifting equipment, liftingaccessories (e.g. slings) and other systems employing wirerope depends to a large extent on the operation of wellprogrammed periodic rope examinations and theassessment by the competent person of the fitness of therope for further service.

Examination and discard of ropes by the competent personshould be in accordance with the instructions given in theoriginal equipment manufacturer’s handbook. In addition,account should be taken of any local or application specificRegulations.

The competent person should also be familiar, asappropriate, with the latest versions of related International,European or National standards such as ISO 4309 “Cranes- Wire ropes - code of practice for examination.

Particular attention must be paid to those sections ofrope which experience has shown to be liable todeterioration. Excessive wear, broken wires,distortions and corrosion are the more commonvisible signs of deterioration.

Note: This publication has been prepared as an aid for rope

examination and should not be regarded as a substitute for the

competent person.

Wear is a normal feature of rope service and the use of thecorrect rope construction ensures that it remains asecondary aspect of deterioration. Lubrication may help toreduce wear.

Broken wires are a normal feature of rope service towardsthe end of the rope’s life, resulting from bending fatigueand wear. The local break up of wires may indicate somemechanical fault in the equipment. Correct lubrication inservice will increase fatigue performance.

Distortions are usually as a result of mechanical damage,and if severe, can considerably affect rope strength.

Visible rusting indicates a lack of suitable lubrication,resulting in corrosion. Pitting of external wire surfacesbecomes evident in some circumstances. Broken wiresultimately result.

Internal corrosion occurs in some environments whenlubrication is inadequate or of an unsuitable type.Reduction in rope diameter will frequently guide theobserver to this condition. Confirmation can only be madeby opening the rope with clamps or the correct use of spikeand needle to facilitate internal inspection.

Note: Non-destructive testing (NDT) using electromagnetic means

may also be used to detect broken wires and/or loss in metallic area.

This method complements the visual examination but does not

replace it.

Pictures courtesy of S.M.R.E. Crown Copyright 1966

Guide to Examination

A Severedby wear

B Tension C Fatigue D Corrosionfatigue

E Plasticwear

F Martensite G Shearedend

BRIDON Oil and Gas


41

Troubleshooting Guide

Mechanical damagedue to rope movementover sharp edgeprojection whilst underload.

1 Typical wire fracturesas a result of bendfatigue.

9

Localised wear due toabrasion on supportingstructure.

2 Wire fractures at thestrand, or coreinterface, as distinctfrom ‘crown’ fractures.

10

Narrow path of wearresulting in fatiguefractures, caused byworking in a grosslyoversize groove, orover small supportrollers.

3 Break up of IWRCresulting from highstress application.

11

Two parallel paths ofbroken wires indicativeof bending through anundersize groove in thesheave.

4 Looped wires as aresult of torsionalimbalance and/or shockloading.

12

Severe wear,associated with hightread pressure.

5 Typical example oflocalised wear anddeformation.

13

Severe wear in Lang’sLay, caused byabrasion.

6 Multi strand rope ‘birdcaged’ due to torsionalimbalance.

14

Severe corrosion.7 Protrusion of ropecentre resulting frombuild up of turn.

15

Internal corrosionwhilst external surfaceshows little evidence ofdeterioration.

8 Substantial wear andsevere internalcorrosion.

16

Typical examples of Wire Rope deterioration



42


Mechanical damage caused by the rope contacting thestructure of the installation on which it is operating or anexternal structure - usually of a localised nature.

•Generally results from operational conditions.

•Check sheave guards and support/guide sheaves toensure that the rope has not “jumped out” of theintended reeving system.

•Review operating conditions.

Opening of strands in rotation resistant, low rotation andparallel closed ropes - in extreme circumstances the ropemay develop a “birdcage distortion” or protrusion of innerstrands.

Note - rotation resistant and low rotation ropes are designed

with a specific strand gap which may be apparent on

delivery in an off tension condition. These gaps will close

under load and will have no effect on the operational

performance of the rope.

•Check sheave and drum groove radii using sheavegauge to ensure that they are no smaller than nominalrope radius +5% - Bridon recommends that the sheaveand drum groove radii are checked prior to any ropeinstallation.

•Repair or replace drum/sheaves if necessary.

•Check fleet angles in the reeving system - a fleet anglein excess of 1.5 degrees may cause distortion(see page 37).

•Check installation method - turn induced duringinstallation can cause excessive rope rotation resultingin distortion (See pages 46 - 53).

•Check if the rope has been cut “on site “ prior toinstallation or cut to remove a damaged portion fromthe end of the rope. If so, was the correct cuttingprocedure used? Incorrect cutting of rotation resistant,low rotation and parallel closed ropes can causedistortion in operation (See page 50).

•Rope may have experienced a shock load.

Broken wires or crushed or flattened rope on lower layersat crossover points in multi - layer coiling situations.

Wire breaks usually resulting from crushing or abrasion.

•Check tension on underlying layers. Bridonrecommends an installation tension of between 2% and10% of the minimum breaking force of the wire rope.Care should be taken to ensure that tension is retainedin service. Insufficient tension will result in these lowerlayers being more prone to crushing damage.

•Review wire rope construction. Dyform wire ropes aremore resistant to crushing on underlying layers thanconventional rope constructions.

•Do not use more rope than necessary.

•Check drum diameter. Insufficient bending ratioincreases tread pressure.

The following is a simplified guide to common wire rope problems. More detailed advice can be obtained from any Bridondistributor. In the event of no other standard being applicable, Bridon recommends that ropes are inspected/examined inaccordance with ISO 4309.

Problem Cause/Action

Wires looping from strands. • Insufficient service dressing.

•Consider alternative rope construction.

• If wires are looping out of the rope underneath acrossover point, there may be insufficient tension on thelower wraps on the drum.

•Check for areas of rope crushing or distortion.

BRIDON Oil and Gas


43


“Pigtail” or severe spiralling in rope. •Check that the sheave and drum diameter is largeenough - Bridon recommends a minimum ratio of thedrum/sheave to nominal rope diameter of 18:1.

• Indicates that the rope has run over a small radius orsharp edge.

•Check to see if the rope has “jumped off” a sheave andhas run over a shaft.

Two single axial lines of broken wires running along thelength of the rope approximately 120 degrees apartindicating that the rope is being “nipped” in a tightsheave.

•Check sheave and drum groove radii using sheavegauge to ensure that they are no smaller than nominalrope radius + 5% - Bridon would recommend that thesheave/drum groove radii are checked prior to any rope installation.


One line of broken wires running along the length of therope indicating insufficient support for the rope, generallycaused by oversize sheave or drum grooving.

•Check to see if the groove diameter is no greater than15% greater than the nominal rope diameter.


•Check for contact damage.

Short rope life resulting from evenly/randomly distributedbend fatigue wire breaks caused by bending through thereeving system.

Fatique induced wire breaks are characterised by flatends on the broken wires.

•Bending fatigue is accelerated as the load increasesand as the bending radius decreases (see page 34).Consider whether either factor can be improved.

•Check wire rope construction - Dyform ropes arecapable of doubling the bending fatigue life of aconventional steel wire rope.


Continued on next page

Short rope life resulting from localised bend fatigue wirebreaks.

Fatique induced wire breaks are characterised by flatends on the broken wires.

•Bending fatigue is accelerated as the load increasesand as the bending radius decreases (see page 34).Consider whether either factor can be improved.

•Check wire rope construction - Dyform ropes arecapable of doubling the bending fatigue life of aconventional steel wire rope.

•Localised fatigue breaks indicate continuous repetitivebends over a short length. Consider whether it iseconomic to periodically shorten the rope in order tomove the rope through the system and progressivelyexpose fresh rope to the severe bending zone. In orderto facilitate this procedure it may be necessary to beginoperating with a slightly longer length of rope.



44


Wave or corkscrew deformations normally associatedwith multistrand ropes.

•Check sheave and drum groove radii using sheavegauge to ensure that they are no smaller than nominalrope radius +5% - Bridon recommends that thesheave/drum groove radii are checked prior to any rope installation.


•Check fleet angles in the reeving system - a fleet anglein excess of 1.5 degrees may cause distortion (see page 37).

•Check that rope end has been secured in accordancewith manufacturers instructions (see page 50).

•Check operating conditions for induced turn.

Rotation of the load in a single fall system. •Review rope selection.

•Consider use of rotation resistant or low rotation rope.

Rotation of the load in amulti - fall systemresulting in “cabling” ofthe rope falls.

Possibly due to inducedturn during installation oroperation.

•Review rope selection.

•Consider use of rotation resistant or low rotation rope.

•Review installation procedure (See pages 46 - 53)or operating procedures.

Broken rope - ropes are likely to break when subjected tosubstantial overload or misuse particularly when a ropehas already been subjected to mechanical damage.

Corrosion of the rope both internally and/or externally canalso result in a significant loss in metallic area. The ropestrength is reduced to a level where it is unable to sustainthe normal working load.

•Review operating conditions.


Anchored

Free toRotate

ForceCreates

Turn

Remedy(Release3 turns)

1.5 turnsL.H. cable

RIGHT HAND LAY ROPE

BRIDON Oil and Gas


45



External corrosion. •Consider selection of galvanised rope.

•Review level and type of service dressing.

Internal corrosion. •Consider selection of galvanised rope.

•Review frequency amount and type of service dressing.

•Consider selection of plastic impregnated (PI) wire rope.

Short rope life induced by excessive wear and abrasion. •Check fleet angle to drum.

•Check general alignment of sheaves in the reevingsystem.

•Check that all sheaves are free to rotate.

•Review rope selection. The smooth surface of Dyformwire ropes gives better contact with drum and sheavesand offers improved resistance to “interference”betweeen adjacent laps of rope.

Sunken wraps of rope on the drum normally associatedwith insufficient support from lower layers of rope orgrooving.

•Check correct rope diameter.

•If grooved drum check groove pitch.

•Check tension on underlying layers - Bridon recommendan installation tension of between 2% and 10% of theminimum breaking force of the wire rope - Care shouldbe taken to ensure that tension is retained in service.Insufficient tension will result in these lower layers beingmore prone to crushing damage.

•Make sure that the correct rope length is being used.Too much rope (which may not be necessary) mayaggravate the problem.

Rope accumulating or “stacking” at drum flange - due toinsufficient fleet angle.

•Review drum design with original equipmentmanufacturer - consider adding rope kicker, fleetingsheave etc.

Core protrusion or broken core in single layer six or eightstrand rope.

•Caused by repetitive shock loading - review operating conditions.



46

Ensure that the rope does not make any direct contact with the floor and that there is a flow of airunder the reel.

WARNING

Failure to do so may result in the rope becomingcontaminated with foreign matter and start the onsetof corrosion before the rope is even put to work.

Support the reel on a simple A-frame or cradle,located on ground which is capable of supporting thetotal mass of rope and reel. (See Fig. 2) Ensure thatthe rope is stored where it is not likely to be affectedby chemical fumes, steam or other corrosive agents.

WARNING

Failure to do so may seriously affect its conditionrendering it unfit for safe use.

1.3 Examine ropes in storage periodically and, whennecessary, apply a suitable dressing which iscompatible with the manufacturing lubricant. Contactthe rope supplier, Bridon or original equipmentmanufacturer’s (OEM) manual for guidance on typesof dressings available, methods of application andequipment for the various types of ropes and applications.

Re-wrap the rope unless it is obvious that this will bedetrimental to rope preservation. (Refer to the relevantProduct Data sheets on rope dressings for moredetailed information.)

WARNING

Failure to apply the correct dressing may renderthe original manufacturing lubricant ineffective andrope performance may be significantly affected.

Ensure that the rope is stored and protected in such amanner that it will not be exposed to any accidentaldamage either during the storage period or whenplacing the rope in, or taking it out of storage.

The following Instructions and Warnings combine toprovide guidance on Product Safety and are intended foruse by those already having a working knowledge of wireropes, as well as the new user. They should be read,followed and passed on to others.

Failure to read, understand and follow these instructionscould result in harmful and damaging consequences.

A ‘Warning’ statement indicates a potential hazardoussituation which could result in a significant reduction in ropeperformance and/or put at risk, either directly or indirectly,the safety or health of those persons within the dangerzone of the rope and its associated equipment.

Note: As a result of the creation of the single European market and

the ‘New Approach’ Directives which set out ‘essential requirements’

(e.g. for safety) designers, manufacturers, suppliers, specifiers and

users need to keep themselves abreast of any changes to the

appropriate Regulations and national standards.

1. Storage

1.1 Unwrap the rope and examine the rope immediatelyafter delivery to check its identification and conditionand verify that it is in accordance with the details onthe Certificates and/or other relevant documents.

Note: The rope should not be used for lifting purposes without the

user having a valid Certificate in his possession.

Check the rope diameter and examine any ropeterminations to ensure that they are compatible withthe equipment or machinery to which they are to befitted. (See Fig. 1)

1.2 Select a clean, well ventilated, dry, undercoverlocation. Cover with waterproof material if the deliverysite conditions preclude inside storage.

Rotate the reel periodically during long periods ofstorage, particularly in warm environments, to preventmigration of the lubricant from the rope.

WARNING

Never store wire rope in areas subject to elevatedtemperatures as this may seriously affect its futureperformance. In extreme cases its original as-manufactured strength may be severely reducedrendering it unfit for safe use.

Product Safety: Instructions & Warnings on the use of steel wire rope

Fig 1

Fig 2

BRIDON Oil and Gas


47BRIDON Oil and GasBRIDON Oil and Gas

WARNING

Failure to carry out or pay attention to any of theabove could result in a loss of strength and/or areduction in performance. In extreme cases therope may be unfit for safe use.

2. Certification and Marking

Make sure that the relevant Certificate has beenobtained before taking the rope into use for a liftingoperation. (Refer to statutory requirements)

Check to verify that the marking on the rope or itspackage matches the relevant Certificate.

Note: The rating of a component part of a machine or lifting

accessory is the responsibility of the designer of the machine or

accessory. Any re-rating of a lifting accessory must be approved by a

competent person.

Retain the Certificate in a safe place for identificationof the rope when carrying out subsequent periodicstatutory examinations in service. (Refer to statutoryrequirements)

3. Handling and Installation

3.1 Handling and installation of the rope should becarried out in accordance with a detailed plan andshould be supervised by a competent person.

WARNING

Incorrectly supervised handling and installationprocedures may result in serious injury to persons in the vicinity of the operation as well asthose persons directly involved in the handling andinstallation.

3.2 Wear suitable protective clothing such as overalls,industrial gloves, helmet, eye protectors and safetyfootwear (and respirator, particularly where theemission of fumes due to heat is likely).

WARNING

Failure to wear suitable protective clothing andequipment may result in skin problems from overexposure to certain types of rope lubricants anddressings; burns from sparks, rope ends, moltenlubricants and metals when cutting ropes orpreparing sockets for re-use; respiratory or otherinternal problems from the inhalation of fumeswhen cutting ropes or preparing sockets for re-use; eye injuries from sparks when cutting ropes;lacerations to the body from wire and rope ends;bruising of the body and damage to limbs due torope recoil, backlash and any sudden deviationfrom the line of path of rope.

3.3 Ensure that the correct rope has been supplied bychecking to see that the description on the Certificateis in accordance with that specified in the purchaser’sorder.

3.4 Check by measurement that the nominal diameter ofthe new rope conforms to the nominal size stated onthe Certificate.

For verification purposes, measure the diameter byusing a suitable rope vernier fitted with jaws broadenough to cover not less than two adjacent strands.Take two sets of measurements spaced at least 1metre apart, ensuring that they are taken at thelargest cross-sectional dimension of the rope. Ateach point take measurements at right angles to each other.

The average of these four measurements should bewithin the tolerances specified in the appropriateStandard or Specification.

For a more general assessment of rope diameter usea rope calliper. (See Fig 1)

3.5 Examine the rope visually to ensure that no damageor obvious signs of deterioration have taken placeduring storage or transportation to the installation site.

3.6 Check the working area around the equipment for anypotential hazards which may affect the safeinstallation of the rope.

3.7 Check the condition of the rope-related equipment inaccordance with the OEM’s instructions. Include the following -

Drum

Check the general condition of the drum.

If the drum is grooved, check the radius and pitchand ensure that the grooves will satisfactorilyaccommodate the size of the new rope (see Fig 3)

Check the condition and position of the kicker platesor wear plates, if fitted, to ensure that the new ropewill spool correctly on the drum.


Fig 3

PITCH

RADIU

S


48


Sheaves

Ensure that the grooving is of the correct shape andsize for the new rope

Check that all sheaves are free to rotate and in good condition.

Rope guards

Check that any rope guards are correctly fitted andare in good condition.

Check the condition of any wear plates or rollerswhich are protecting structural members.

WARNING

Failure to carry out any of the above could result inunsatisfactory and unsafe rope performance.

Note: Grooves must have clearance for the rope and provide

adequate circumferential support to allow for free movement of the

strands and facilitate bending. When grooves become worn and the

rope is pinched at the sides, strand and wire movement is restricted

and the ability of the rope to bend is reduced. (See Fig. 4)

When a new rope is fitted a variation in sizecompared with the old worn rope will be apparent.The new rope may not fit correctly into the previouslyworn groove profile and unnecessary wear and ropedistortion is likely to occur. This may be remedied bymachining out the grooves before the new rope isinstalled. Before carrying out such action the sheavesor drum should be examined to ensure that there willbe sufficient strength remaining in the underlyingmaterial to safely support the rope.

The competent person should be familiar with therequirements of the appropriateapplication/machinery standard.

Note: General guidance to users is given in ISO 4309 Code of

practice for the selection, care and maintenance of steel wire rope.

Transfer the wire rope carefully from the storage areato the installation site.

Coils

Place the coil on the ground and roll it out straightensuring that it does not become contaminated withdust/grit, moisture or any other harmful material.(See Fig. 5)

If the coil is too large to physically handle it may beplaced on a ‘swift’ turntable and the outside end ofthe rope pulled out allowing the coil to rotate. (See Fig. 5)

WARNING

Never pull a rope away from a stationary coil asthis will induce turn into the rope and kinks willform. These will adversely affect ropeperformance. (See Fig. 6)

Fig 4

WRONG

Sheave groovetoo narrow

Sheave groove too wide

Sheave groove correctlysupporting the rope for33% of its circumference

WRONG

RIGHT

Fig 5

Fig 6

WRONG

Note the kinks

forming

BRIDON Oil and Gas



Ensure that the reel stand is mounted so as not tocreate a reverse bend during reeving (i.e. for a winchdrum with an overlap rope, take the rope off the top ofthe reel). (See Fig. 7)

3.9 Ensure that any equipment or machinery to be ropedis correctly and safely positioned and isolated fromnormal usage before installation commences. Referto the OEM’s instruction manual and the relevant‘Code of Practice’.

3.10 When releasing the outboard end of the rope from areel or coil, ensure that this is done in a controlledmanner. On release of the bindings and servingsused for packaging, the rope will want to straightenitself from its previously bent position. Unlesscontrolled, this could be a violent action. Stand clear.

WARNING

Failure to control could result in injury.

Ensure that the as-manufacturedcondition of the rope is maintainedduring installation.

If installing the new rope with the aidof an old one, one method is to fit awire rope sock (or stocking) to eachof the rope ends. Always ensure thatthe open end of the sock (orstocking) is securely attached to therope by a serving or alternatively by aclip (See Fig. 9). Connect the two endsvia a length of fibre rope of adequatestrength in order to avoid turn beingtransmitted from the old rope into thenew rope. Alternatively a length offibre or steel rope of adequatestrength may be reeved into thesystem for use as a pilot/messengerline. Do not use a swivel during theinstallation of the rope.

Reels

Pass a shaft through the reel and place the reel in asuitable stand which allows it to rotate and be brakedto avoid overrun during installation. Where multi-layercoiling is involved it may be necessary for the reel tobe placed in equipment which has the capability ofproviding a back tension in the rope as it is beingtransferred from reel to drum. This is to ensure thatthe underlying (and subsequent) laps are woundtightly on the drum. (See Fig. 7)

Position the reel and stand such that the fleet angleduring installation is limited to 1.5 degrees.(See Fig. 8)

If a loop forms in the rope ensure that it does nottighten to form a kink.

WARNING

A kink can severely affect the strength of a sixstrand rope and can result in distortion of arotation- resistant or low rotation rope leading toits immediate discard.

Fig 7

Fig 8

ANGLE OFFLEET

CENTRE LINEOF REEL

CENTRE LINEOF SHEAVE

Fig 9



52

the termination is fitted in accordance with the OEM’sinstruction manual or manufacturer’s instructions.

When re-using a socket and depending on its typeand dimensions, the existing cone should be pressedout. Otherwise, heat may be necessary.

WARNING

When melting out sockets which have previouslybeen filled with hot metal, the emission of toxicfumes is likely. Note that white metal contains ahigh proportion of lead.

Correctly locate and secure any connection pins andfittings when assembling end terminations to fixtures.Refer to manufacturer’s instructions.

WARNING

Failure to pay attention to any of the above couldresult in unsafe operation and potential injury.

3.16 Limit switches, if fitted, must be checked and re-adjusted, if necessary, after the rope has been installed.

3.17 Record the following details on the Certificate afterinstallation has been completed: type of equipment,location, plant reference number, duty and date ofinstallation and any re-rating information/signature ofcompetent person. Then safely file the Certificate.

3.18 ‘Run in’ the new rope by operating the equipmentslowly, preferably with a low load, for several cycles.This permits the new rope to adjust itself gradually toworking conditions.

Note: Unless otherwise required by a certifying authority, the rope

should be in this condition before any proof test of the equipment or

machinery is carried out.

Check that the new rope is spooling correctly on thedrum and that no slack or cross laps develop.

If necessary, apply as much tension as possible to ensure tight and even coiling, especially on the first layer.

Where multi-layer coiling is unavoidable, succeeding layers should coil evenly on thepreceding layers of rope.

WARNING

Any looseness or uneven winding will result inexcessive wear, crushing and distortion of the rope.

With plain barrel drums it is difficult to achievesatisfactory multi-layer coiling beyond three layers.

The direction of coiling of the rope on the drum isimportant, particularly when using plain barrel drums,and should be related to the direction of lay of therope in order to induce close coiling.

(See Fig. 12 for proper method of locating ropeanchorage point on a plain drum.)

When multi layer coiling has to be used it should berealised that after the first layer is wound on a drum,the rope has to cross the underlying rope in order toadvance across the drum in the second layer. Thepoints at which the turns in the upper layer crossthose of the lower layer are known as the cross-overpoints and the rope in these areas is susceptible toincreased abrasion and crushing. Care should betaken when installing a rope on a drum and whenoperating a machine to ensure that the rope is coiledand layered correctly.

3.15 Check the state of re-usable rope end terminationsfor size, strength, defects and cleanliness before use.Non-destructive testing may be required dependingon the material and circumstances of use. Ensure that

Proper method of locating rope anchorage pointon a plain drum

RIGHT HAND

LAY ROPE-UNDERWIND

RIGHT HAND

LAY ROPE-OVERWIND

LEFT HAND

LAY ROPE-UNDERWIND

LEFT HAND

LAY ROPE-OVERWIND

LEFT

HAND

LEFT

HAND

START ROPE

AT LEFT

FLANGE

RIGHT

HAND

Note: Thumb indicates side of rope anchorage

Fig 12


BRIDON Oil and Gas



Note: Shortening the rope re-positions the areas of maximum

deterioration in the system. Where conditions permit, begin operating

with a rope which has a slightly longer length than necessary in order

to allow for periodic shortening.

When a non-preformed rope, multi-layer rope orparallel closed rope ie (DSC) is used with a wedgesocket and is required to be shortened, it is essentialthat the end of the rope is secured by welding orbrazing before the rope is pulled through the mainbody of the socket to its new position. Slacken thewedge in the socket. Pass the rope through thesocket by an amount equivalent to the crop length orsample required. Note that the original bent portion ofthe rope must not be retained within the wedgesocket. Replace the wedge and pull up the socket.Prepare and cut in accordance with section 3.12.Ensure that the rope tail cannot withdraw through thesocket, see section 3.13.

WARNING

Failure to observe this instruction will result in asignificant deterioration in the performance of therope and could render the rope completely unfit forfurther service.

In cases where severe rope wear takes place at oneend of a wire rope, the life of the rope may beextended by changing round the drum end with theload end, i.e. turning the rope ‘end for end’ beforedeterioration becomes excessive.

4.2 Remove broken wires as they occur by bendingbackwards and forwards using a pair of pliers untilthey break deep in the valley between two outerstrands (see Fig. 15). Wear protective clothing suchas overalls, industrial gloves, helmet, eye protectorsand safety footwear during this operation.

WARNING

Do not shear off the ends of broken wires withpliers as this will leave an exposed jagged edgewhich is likely to damage other wires in the ropeand lead to premature removal of the rope fromservice. Failure to wear adequate protectiveclothing could result in injury.

WARNING

Irregular coiling usually results in severe surfacewear and rope malformation, which in turn is likelyto cause premature rope failure.

3.19 Ensure that the as-manufactured condition of therope is maintained throughout the whole of thehandling and installation operation.

3.20 If samples are required to be taken from the rope forsubsequent testing and/or evaluation, it is essentialthat the condition of the rope is not disturbed. Referto the instructions given in 3.12 and, depending onthe rope type and construction, any other specialmanufacturer’s instructions.

4. In Service

4.1 Inspect the rope and related equipment at thebeginning of every work period and particularlyfollowing any incident which could have damaged therope or installation.

The entire length of rope should be inspected andparticular attention paid to those sections thatexperience has proven to be the main areas ofdeterioration. Excessive wear, broken wires, distortionand corrosion are the usual signs of deterioration. Fora more detailed examination special tools arenecessary (see Fig. 13) which will also facilitateinternal inspection (see Fig. 14.)

In the case of ropes working over drums or sheaves itis particularly necessary to examine those areasentering or leaving the grooves when maximum loads(i.e. shock loads) are experienced, or those areaswhich remain for long periods in exposed placessuch as over a Jib Head sheave.

On some running ropes, but particularly relevant tostanding ropes (e.g. pendant ropes) the areasadjacent to terminations should be given specialattention. (see Fig. 14).

Fig 13

Fig 14

Fig 15


drilling operations - shaw's ent · riser tensioner lines present a tough application for wire...

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