Deck Machinery

TakingAdvantage of Synthetic RopeTechnology lncludesHardware Maintenance ByMerry Schnell

J na 2007 interview,Tom Crowley ProperLine Installation drumto preventrope diving orburying Jr.,CEO ofCrowley Maritime, intothe lowerwrap layers.Tension can I life Isaid thatthe mostsignificant Thefirst defense in theservice becreated by runningthe rope around technicaladvance to effectefficiency of a new ropeis at installation,when a newly resurfacedcapstan, bollar4 in thetanker escort business has been all hardwaresurfaces are exposed and or pin. Another commonmethod to syntheticrope. However, to many,the canbe properly prepared against wear producesignificant back tension is to differencesbetween steel-wire rope causedby abrasion.While properly rig a ropestopper onto the line being and high-performancerope may not designedand engineered ropes made of installed.The friction between the two ropescreates the appropriate tension. Howeverback tension is created,the ropeshould be led throughor around somethingthat is directlyin line with the so it canbe loadedevenly. However,the surfaceof the device usedto createthe tensionshould not be abrasiveto therope and the instal- lationspeed or tensionapplied should not generateexcessive heat build up on the rope. Back tensionis intendedto help eliminatethe rope'stendency to bury itselfon the winchdrum, but howthe line windsonto the winch can help as . The line shouldbe woundonto the winch in a closelypacked forma- tion to minimizeareas where the rope may "dive" or bury into the layersof A crewmemberadds back tension during the installationof rope onto a winch. Eachlayer should be installed courtesyof Samson. thewind. in thevalleys ofthe previouslayers or crossedovereach otherto support each HMPE fibertake maximum advantage be well known;nonetheless, they are subsequentlayer. Layers should never the clear-cut. ofthe cut andabrasion resistance, be stackedon top ofeachother. Steel-wireropes are heavy on the wayinwhichthey wearcan be acceler- deckandhard on the crew; they abrade atedby roughsurfaces. How Willthe andwear machinery and equipment; Often, are found on hardware Hardware Perform? and dependingon the application, surfacesthat caused the abrasion. and Duringinstallation of high-perfor- theyhave a limited servicelife. On a theexternal surface ofthe ropereadily mancesynthetic ropes, it isalso a good size-for-sizebasis, ropes made ofhigh- .In orderto avoid showsabraded timeto considerhow well hardwarewill moduluspolyethylene (HMPE) are as thistype ofwear, all surfacesthat come strongas wire; they areone-seventh performin conjunctionwith the new in contactwith theHMPE line must be lines.HMPE ropes are as strong as the theweight; easier on deckmachinery smoothedto within a surfacerough- with propercare, they wireropes theyreplace, which can dan- andcrew; and, nessof 300microinches" as measured canoutlast wire threeto one. gerouslyemphasize the underdesigned, by a surfacecomparator gauge. For Indeed,HMPE lines can make a worn or damagedhardware on a ship's tugboats,this meansbull nose,cap- hugedifference in the lives of own- deckthat may break or pull free. ers, operators,and crewmembers; stan,H-bitt, and winch surfacesmust WhenEd McCain,marine opera- however,every precaution available be madeand kept as smoothand rust tions managerof HawaiianTug and shouldbe taken to ensurethe long and freeas possible. Barge/YoungBrothers (HTBYB) re- safeservice life of high-performance InstallingRope on the Winch placedtheir traditional heavy lines.These include proper installa- lineswith Samson'sQuantum -l2,they tion; chock and line protection;and After surfaceshave been prepped, foundthattheyneeded to overhaultheir handling, inspection,maintenance, theline may be wound onto a winch. The hardwaretoo. and repairof both the hardwareand workingline shouldbe installedwith "Moving awayfrom thetraditional the linesused on it. tensionand in aclose, tight wind on the syntheticlines was aprocess. Because

24 PacificMaritime . July 2009 . www.pacmar.com Deck Machinery

the lines were no longer the weak link HMPE lines, the amount of friction and offer significant advantagesover in the chain of equipment, we had to required to "roll" the chock cannot be roller chocks, which include easier upgradeour hardware- the lines were created.Instead, the line simply slides maintenanceand reducedabrasion on outperforming it," said McCain. over the roller. high-performancelines. For optimum performance of the Also, specialattention synthetic lines, hardware and their is neededwhere the rope attachmentsshould be maintainedand might exit theroller chock replacedwhen necessaryas part ofthe at a sharp angle, creating ongoing maintenanceof the vessel. "pinch points" that can Abrasion to high-performance lines leadto ropedamage. This can to ropes parting, and while iscommonon spring lines, HMPE may part less violently than where, dependingon the wire rope, it can still be life threaten- varying heights between ing. But perhapseven more dangerous the ship andberth, a moor- is a piece of hardware that breaks or ing linecan get'Jammed" detacheswhile under tension from a between the horizontal high-performanceline. andvertical rollers. Roller chocksrequire additional Closed or Roller Chocks? maintenanceto the bear- Thereis somequestion asto whether ings and the positionsat closedchocks or roller chocks work whichthe rollers are set in A closedchock and line with chafe protection. Photo cour- better with HMPE lines. Most users aneffortto keepthe rollers tesyof Samson. assume that roller chocks are best moving smoothly. simply becausethe chock rolls with Basedon trials conductedby Samson Both closed and roller chocks the line, thereby mitigating abrasion. on both types of chocks, it was con- require basic maintenance, which This is true in theory.However, due to cludedthat properly maintained closed includes keeping the contact surfaces the low coefficient of friction in manv chocks provide a longer service life free from rust and damage.Conversion

conplete coverage of your yaluable r1pes

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www.pacmar.com. July2009 . PacificMaritime 25 Deck Machinery

lessexpensive than roller chocksand havelow maintenance costs.This long-term cost savingscan be a big advantage when converting a vesselfrom wire to HMPE lines. Chafe Protection for Hardware and Lines Typically, the constant movement between the rope and hardwarecan actually keep the hardwaresmooth. But evenwhat appearsto be the smoothesthardware will cause somedamage to the rope. While the most obvious abrasion damage to the rope is external, internal abrasion is more difficult to observe since it is causedby the movement of the internal standsrelative to eachother. Internal abrasion occurswhen the external strandspass over a rough surface, slowing them relative to the internal strandsnext to them. Heat is createdin the process- and heat is among the big- gest enemiesof synthetic ropes. Becauseit is difficult to judge damageto the rope caused A severelyabraded bullnoseon a tugboat. Photo courtesy by internal abrasion,and becauselines are often subjected of Samson. to surfacesnot underyour control, suchas bollards roughenedand scored by wire ropes, proper chafe gear is to high-performancesynthetic lines is a costly expenditure, the secondline of defenseto ensuring the longevity of the but whenconsidering hardware replacements, installing new synthetic high-performanceline. Chafe gear is essentialin closed chocks, instead of new roller chocks, can provide preventing both external and internal abrasion. Properly significant savings.Standard steel closed chocks are rela- designedchafe gear acts as a sacrificial layer for external tively inexpensive,and maintenancecosts are low. Another abrasionfrom rough surfaces,andreduces internal abrasion option is stainlesssteel closed chocks, which, althoughmore by keepingrelative movementat the surfaceof the rope eipensive upfront than plain carbon steel, are still much to a minimum. Chafe gear is a lifeline to HMPE ropes. Rope Handing, Maintenance, Inspection, and Repair Onceyour high-performanceropes are in placeand ready Towing Pin to use, the crew should be trained on handling and safety procedures,rope inspection procedures,use ofchafe gear Stern RoIIer Sets to protect rope in the chocks, and rope repair and splicing techniques.Not all ropemanufacturersofferthoroughtraining and follow through in theseareas, so purchasingdecisions should be made basedon a few considerations: . All synthetic and wire ropes gradually lose breaking strength during use due to factors such as cycle load- ing, shock loading, abrasion wear, cutting, and fiber fatigue. Most injury-related accidents occur becauseof parted ropes and wires. In fact, the UK P&I Club estimates that 53o/oof personalinjuries in mooring operationsare causedby parted ropes and wire. Simple stepsthat include training, inspection, and safe retirement guidelines can be taken to lower the risk to Proudto supply BAYDELTA crewmembers. with Towing Pin Stem The vessel'sofficers and crewmembers should be vigilant Roller Setsfor their four in routinely inspectingand maintaining all metal surfaces, making sure they remain rust free and smooth. It is also new 100' 94 Ton Bollard important the crew be trainedon rope inspectionprocedures Pull Tugs! and splicing techniques.The crew shouldbe responsiblefor replacingworn orcutchafegearand making sureit isproperly positioned. Safe retirement of the lines can be established based on the needs of the vessel, and technical support should be provided by the rope manufacturer.EtrM

Merry Schnell is the marketing communications specialist for Samson and has extensive experience in technical writing and editing in the sciencesand .

26 PacificMaritime . July2009 . www.pacmar.com