《船舶结构与设备》课程教学资源（文献资料）A Masters Guide to Container Securing.pdf_大学文库

The Standard P&I Club The Standard P&I Club’s loss prevention programme focuses on best practice to avert those claims that are avoidable and that often result from crew error or equipment failure. In its continuing commitment to safety at sea and the prevention of accidents, casualties and pollution, the Club issues a variety of publications on safety-related subjects, of which this is one. For more information about these publications, please contact either the Managers’ London Agents or any Charles Taylor office listed in this guide. The Lloyd’s Register Group Lloyd’s Register is directed through its constitution to: ‘secure for the benefit of the community high technical standards of design, manufacture, construction, maintenance, operation and performance for the purpose of enhancing the safety of life and property both at sea and on land and in the air’, and to advance ‘public education within the transportation industries and any other engineering and technological disciplines’. A MASTER’S GUIDE TO CONTAINER SECURING IS THE FIFTH PUBLICATION IN THE MASTER’S GUIDE SERIES. Authors Eric Murdoch BSc, MSc, MRINA, C.Eng Director of Risk Management Charles Taylor & Co Limited 1 St Katharine’s Way London E1W 1UT UK Telephone (44) 20 7522 7440 Email eric.murdoch@ctcplc.com www.standard-club.com David Tozer BSc, MSc, FRINA, C.Eng Business Manager Container Ships Lloyd’s Register 71 Fenchurch Street London EC3M 4BS UK Telephone (44) 20 7709 9166 Email david.tozer@lr.org www.lr.org The authors acknowledge technical contributions from colleagues and associates. The authors express their particular thanks to: Bob Thompson, Principal Specialist, Lloyd’s Register EMEA; Colin Clifford-Smith, Lead Specialist, Lloyd’s Register EMEA; Tony Bowman, Managing Director, TMC (Marine Consultants) Ltd; Roy Smith, Safety Manager (Operations), Hutchison Ports (UK). Thanks also for assistance to: German Lashing Robert Bock GmbH; SEC - Ship’s Equipment Centre Bremen GmbH; Mediterranean Shipping Company S.A; Maersk Line Limited; MacGregor (DEU) GmbH

NTRODUCTIONThe development of containerisation was a giant step forward inLashing systems are only tested during bad weather; if they failcarrying general cargo by sea.At thetime,it was correctlythen containers may be lost. Indeed, the growing numberofpredictedthatunitcostswouldfall andcargodamagebecomeacontainerslostoverboardhas causedconcernthroughoutthething of the past. This has been true until recently.marine industry. Cargo claims have increased and floatingcontainers pose a hazard to navigation.Shipmasters need toIn the early days of containerised transport, ships carried containersunderstand the strengths and weaknesses of container securingstowed on hatch covers, three or fourhigh.A varietyof lashingsystems.It is essential thatmasters be aware ofwhat can be donesystems were in use. However, the most reliable system consistedtoprevent container loss.ofstacking cones,twistlocks,lashing bars,bridgefttings andturnbuckles (bottle screws).These systems were effective inThe purpose of this guide is to discuss container securing systems,lashing containers carried on deck to thethird tier.the causes of lashing failureand tooffer advice as to how lossescan be minimised.Today,shipsarebiggerandapost-Panamaxcontainershipwillcarrycontainersondeckstackeduptosix,sevenoreighttiershigh. However, while the ships are able to carry containers stackedEric Murdochhigher,thelashingsystems arestill onlycapableof lashingtothebottom of thethird tier containers or the bottom of the fourth orfifth tier containers when a lashing bridge is fitted. Ship designhasdevelopedbutcontainerlashingsystemshavenotA classification society will approve a ship for the carriage ofcontainers.Regulations stipulatethattheshipmust carryacargosecuring manual.This willcontain instructions as tohow cargoshould be secured. However, approval of the arrangements in themanual will not necessarily mean that cargo-securing arrangementswill withstand foul weather.A ship sailing in a seaway has six deqrees of freedom -roll, pitchITISESSENTIALTHATheave,yaw,sway and surge.Theship itself bends and twists asMASTERSBEAWAREOFwaves pass.Hatch covers can move relative to the hatch openingand a stack of containers can move as tolerances in lashingWHATCANBEDONETOequipmentaretaken up.It isthelashing system alonethat resistsPREVENTCONTAINERLOSSthesemovements andattemptstokeep containersonboard

2 The development of containerisation was a giant step forward in carrying general cargo by sea. At the time, it was correctly predicted that unit costs would fall and cargo damage become a thing of the past. This has been true until recently. In the early days of containerised transport, ships carried containers stowed on hatch covers, three or four high. A variety of lashing systems were in use. However, the most reliable system consisted of stacking cones, twistlocks, lashing bars, bridge fittings and turnbuckles (bottle screws). These systems were effective in lashing containers carried on deck to the third tier. Today, ships are bigger and a post-Panamax container ship will carry containers on deck stacked up to six, seven or eight tiers high. However, while the ships are able to carry containers stacked higher, the lashing systems are still only capable of lashing to the bottom of the third tier containers or the bottom of the fourth or fifth tier containers when a lashing bridge is fitted. Ship design has developed but container lashing systems have not. A classification society will approve a ship for the carriage of containers. Regulations stipulate that the ship must carry a cargosecuring manual. This will contain instructions as to how cargo should be secured. However, approval of the arrangements in the manual will not necessarily mean that cargo-securing arrangements will withstand foul weather. A ship sailing in a seaway has six degrees of freedom – roll, pitch, heave, yaw, sway and surge. The ship itself bends and twists as waves pass. Hatch covers can move relative to the hatch opening and a stack of containers can move as tolerances in lashing equipment are taken up. It is the lashing system alone that resists these movements and attempts to keep containers on board. Lashing systems are only tested during bad weather; if they fail then containers may be lost. Indeed, the growing number of containers lost overboard has caused concern throughout the marine industry. Cargo claims have increased and floating containers pose a hazard to navigation. Ship masters need to understand the strengths and weaknesses of container securing systems. It is essential that masters be aware of what can be done to prevent container loss. The purpose of this guide is to discuss container securing systems, the causes of lashing failure and to offer advice as to how losses can be minimised. Eric Murdoch INTRODUCTION 2 IT IS ESSENTIAL THAT MASTERS BE AWARE OF WHAT CAN BE DONE TO PREVENT CONTAINER LOSS

BASICADVICEThere are certain actions which should always be taken to preventCheck that all cell guides are clear of obstacles, are straightcontainers from being damaged or lost overboard.Thefollowing isand not buckled.considered best practice:Check that turnbuckles arefully tightened. Loose lashings will.Check stack weights before stowage. It is important not tcbe ineffective.exceedallowable stackweightsotherwisefailure of thecormerCheck lashing equipment for defects and discard worn orposts of the containers stowed at the bottom of thestack isdamagedequipment.Avoid using left-handandright-handpossible. If the stow is too heavy,the lashings may havetwistlocks on the same ship.insufficient strength to hold the containers in place if badweather is encounteredRegularly examine lashing components, including ship fttings.for wear. Replace any worn or damaged fitting, repair any wornNever deviate from the approved lashing plan except to addordamagedshipfitting.Checkall equipmentnot justadditional lashings.Calculateforces using the approved loadingequipment in reqularusecomputer.It is difficult to know when lashing components should be.Consult the lashing manual before applying lashings.replaced.Feworganisations are confident to issuecriteriaIf stack weights are high and bad weather is expected then fitfor replacement' which means that the company or individualadditional lashings.master will need to exercise judgement. If in doubt,replacethe equipment. Give special attention to dovetail or sliding:Trytoavoidisolatedstacksofcontainerswhenstowedonsocket foundations.deck, especially if at the ship's side. Where possible, loadcontainers so they are evenly distributed.Toassist the shore lashing gang.give them preciseinstructionsas to how containers should be secured.Avoid loading heavy containers above light containers and atthe top of a stack.Remember that during ship rolling,forces on container cornerposts can be up to three times greater than the uprightKeep your system of lashing simple using the highest ratedcompressionforce.Weatherrouteinanattempttoavoidthecomponents.worst of themeteorological systems orareas where high seasExaminecontainersforphysicaldefects-checkthecornerpostsin winter are common.carefully.ThecornerpostshavetoresisthighcompressionforcesTry to avoid loading'high cube'containers on deck in thefirstas aresult of static weights from containers stowed on top andor second tier. Lashing rods are more difficult to fit and specialfromdynamicforcesthatoccur whentheshiprolls,heavesandrods with extension pieces are often needed.Identify wherepitches. Containers with damaged corner posts placed in the"high cubecontainers are to bestowed before loading.It maybottomofa stoware likelyto collapse.Rejectdamagedbe necessary to reposition them.containers

3 There are certain actions which should always be taken to prevent containers from being damaged or lost overboard. The following is considered best practice: • Check stack weights before stowage. It is important not to exceed allowable stack weights otherwise failure of the corner posts of the containers stowed at the bottom of the stack is possible. If the stow is too heavy, the lashings may have insufficient strength to hold the containers in place if bad weather is encountered. • Never deviate from the approved lashing plan except to add additional lashings. Calculate forces using the approved loading computer. • Consult the lashing manual before applying lashings. • If stack weights are high and bad weather is expected then fit additional lashings. • Try to avoid isolated stacks of containers when stowed on deck, especially if at the ship’s side. Where possible, load containers so they are evenly distributed. • Avoid loading heavy containers above light containers and at the top of a stack. • Keep your system of lashing simple using the highest rated components. • Examine containers for physical defects – check the corner posts carefully. The corner posts have to resist high compression forces as a result of static weights from containers stowed on top and from dynamic forces that occur when the ship rolls, heaves and pitches. Containers with damaged corner posts placed in the bottom of a stow are likely to collapse. Reject damaged containers. • Check that all cell guides are clear of obstacles, are straight and not buckled. • Check that turnbuckles are fully tightened. Loose lashings will be ineffective. • Check lashing equipment for defects and discard worn or damaged equipment. Avoid using left-hand and right-hand twistlocks on the same ship. • Regularly examine lashing components, including ship fittings, for wear. Replace any worn or damaged fitting, repair any worn or damaged ship fitting. Check all equipment not just equipment in regular use. • It is difficult to know when lashing components should be replaced. Few organisations are confident to issue ‘criteria for replacement’ which means that the company or individual master will need to exercise judgement. If in doubt, replace the equipment. Give special attention to dovetail or sliding socket foundations. • To assist the shore lashing gang, give them precise instructions as to how containers should be secured. • Remember that during ship rolling, forces on container corner posts can be up to three times greater than the upright compression force. Weather route in an attempt to avoid the worst of the meteorological systems or areas where high seas in winter are common. • Try to avoid loading ‘high cube’ containers on deck in the first or second tier. Lashing rods are more difficult to fit and special rods with extension pieces are often needed. Identify where ‘high cube’ containers are to be stowed before loading. It may be necessary to reposition them. BASIC ADVICE

DO'S AND DON'TSALWAYS:NEVER:Rejectacontainerfoundoverweightand likelytogiveriseMix left-hand andright-handtwistiocks;tothepermissible stack weightbeing exceeded;Applyfullyautomatic twistiocks withoutfirstcheckingthe?Rejectabuckled,twistedordamaged containermanufacturer's instructions for use,Arrangestowagesothat containersdonot needtobeUsecorrodedorbuckledlashingrodsunloaded at a port other than the designated dischargeUsetwistlocksthat are not certifiedport;.Use improvised equipment to secure containers;.Regularlychecklashingcomponentsforconditionanddiscard components that appear worn oraredamaged;.Load containers ofa non-standard length exceptwhenthe ship is designed and equipped for the carriage of:Inspect D rings,ring bolts,cell guides and sliding socketnon-standard length containers:foundations for wear ordamaqe before containersareloaded, and arrange for the necessary repairs;Usetwistlocksfor liftingcontainers exceptwherethetwistlocks arespecificallyapproved forthis purpose;Regularly check lashings during the voyage;Open containers afterthey havebeen loaded;:Inspect and tighten lashings before the onset ofbad weather;.Connectreefer containersto damagedor broken electricasockets;Take care when handling container fittings because theyare heavy.Avoid dropping them;.Load containers in a con-bulkerthat requires fittingabuttress,unlessthebuttress isalreadyfitted;:Stowlooselashingcomponents,twistlocksandlashingrods safely in designated baskets or racks;Droporthrowfittings,especiallytwistlocks,fromagreaheight onto a steel deck or other hard surface;:Buy components thatare supported byatest certificate.The strength of equipment withoutatest certificate mayLash to the top ofa containeralways lashtothebottombe unpredictable;ofthenexttierabovewhereverpossible;Have more securing equipment than necessary;Workdangerously with containers.Never standorclimbontothem,orunderorbetweenthem..Avoid extreme values of GM, whether high or low;Avoid geographical areas where conditions for parametricrollingexist;Look for indications of water leakage into the container

4 DO’S AND DON’TS ALWAYS: • Reject a container found overweight and likely to give rise to the permissible stack weight being exceeded; • Reject a buckled, twisted or damaged container; • Arrange stowage so that containers do not need to be unloaded at a port other than the designated discharge port; • Regularly check lashing components for condition and discard components that appear worn or are damaged; • Inspect D rings, ring bolts, cell guides and sliding socket foundations for wear or damage before containers are loaded, and arrange for the necessary repairs; • Regularly check lashings during the voyage; • Inspect and tighten lashings before the onset of bad weather; • Take care when handling container fittings because they are heavy. Avoid dropping them; • Stow loose lashing components, twistlocks and lashing rods safely in designated baskets or racks; • Buy components that are supported by a test certificate. The strength of equipment without a test certificate may be unpredictable; • Have more securing equipment than necessary; • Avoid extreme values of GM, whether high or low; • Avoid geographical areas where conditions for parametric rolling exist; • Look for indications of water leakage into the container. NEVER: • Mix left-hand and right-hand twistlocks; • Apply fully automatic twistlocks without first checking the manufacturer’s instructions for use; • Use corroded or buckled lashing rods; • Use twistlocks that are not certified; • Use improvised equipment to secure containers; • Load containers of a non-standard length except when the ship is designed and equipped for the carriage of non-standard length containers; • Use twistlocks for lifting containers except where the twistlocks are specifically approved for this purpose; • Open containers after they have been loaded; • Connect reefer containers to damaged or broken electrical sockets; • Load containers in a con-bulker that requires fitting a buttress, unless the buttress is already fitted; • Drop or throw fittings, especially twistlocks, from a great height onto a steel deck or other hard surface; • Lash to the top of a container; always lash to the bottom of the next tier above wherever possible; • Work dangerously with containers. Never stand or climb onto them, or under or between them

5LASHINGSYSTEMSCommonFalse BeliefsLashing rods should be tightened as tightas possible-FalseIn theory, excessive tightening of lashing rods will result in the rodsP&I club investigations into container loss indicate that the losstaking additional strain, which can cause rodfailure during loadingoften occursbecauseanapparentweakness has not beenidentified. The following points are worth noting:.It is notnecessarytoadjustthetension inlashings whileat sea-FalseOncecontainershavebeen loadedandsecured,thestowremains in a tight block and does not moveFalseMovement of containers will result in some lashing rods becomingslack.Air temperature differences will cause the tension in theTwistlock and sliding socket clearances will allow containers tolashings to change. Lashings should be checked and tightenedmove before the twistlocks engage.The clearance will permitwithin 24 hours after leaving port and regularly thereafter.This ismovement of the stow. Wear inside the corner fitting can causeespecially true before the onset of bad weather.additional movement.Container strength is equal throughout the containerFalseContainers canbe stowed inanyorderand/or.combination/mixofweights-FalseAlthough strength standards are met,a container is more flexibleat the door end and may be more vulnerable in this area.Themost common mistakemadewhen stowing and lashingAll twistlockscanbeusedtoliftcontainers-Falsecontainersistoloadheavycontainersover lightandto loadso.that themaximum permissible stack weightsare exceeded.Twistlocks can be usedfor lifting containersonly when they haveLashings applied from a lashing bridgebehave in the samebeen approved and certified for that purpose.mannerasthoseappliedatthebaseofastow-False.Twistlocksareall ratedto the samestrength-FalseA lashing bridge is a fixed structure while a hatch cover will moveTwistlocks can be rated for different tensile loads up to 20 or 25whena shiprollsandpitches.Theresultingeffect could bethatatonnes.It is importantnottouseamixof twistlocksthathavelashing from a lashing bridge becomes slack or takes excessive load.different strength ratings.Containers loadedon a pedestal andahatchcoverdonot.All containers have the same strength-Falsesuffer additional loading-FalseContainer strength can vary. There are two ISO standards (pre- andA hatch cover is designed to move as the ship bends and flexes.post-1990).Some owners have their own standards and containersA container stowed on a pedestal,afixed point,willattempt tocan be worn or damaged.resisthatchcovermovement ifalsosecuredtoahatchcover

5 Common False Beliefs P&I club investigations into container loss indicate that the loss often occurs because an apparent weakness has not been identified. The following points are worth noting: • Once containers have been loaded and secured, the stow remains in a tight block and does not move – False Twistlock and sliding socket clearances will allow containers to move before the twistlocks engage. The clearance will permit movement of the stow. Wear inside the corner fitting can cause additional movement. • Containers can be stowed in any order and/or combination/mix of weights – False The most common mistake made when stowing and lashing containers is to load heavy containers over light and to load so that the maximum permissible stack weights are exceeded. • Lashings applied from a lashing bridge behave in the same manner as those applied at the base of a stow – False A lashing bridge is a fixed structure while a hatch cover will move when a ship rolls and pitches. The resulting effect could be that a lashing from a lashing bridge becomes slack or takes excessive load. • Containers loaded on a pedestal and a hatch cover do not suffer additional loading – False A hatch cover is designed to move as the ship bends and flexes. A container stowed on a pedestal, a fixed point, will attempt to resist hatch cover movement if also secured to a hatch cover. • Lashing rods should be tightened as tight as possible – False In theory, excessive tightening of lashing rods will result in the rods taking additional strain, which can cause rod failure during loading. • It is not necessary to adjust the tension in lashings while at sea – False Movement of containers will result in some lashing rods becoming slack. Air temperature differences will cause the tension in the lashings to change. Lashings should be checked and tightened within 24 hours after leaving port and regularly thereafter. This is especially true before the onset of bad weather. • Container strength is equal throughout the container – False Although strength standards are met, a container is more flexible at the door end and may be more vulnerable in this area. • All twistlocks can be used to lift containers – False Twistlocks can be used for lifting containers only when they have been approved and certified for that purpose. • Twistlocks are all rated to the same strength – False Twistlocks can be rated for different tensile loads up to 20 or 25 tonnes. It is important not to use a mix of twistlocks that have different strength ratings. • All containers have the same strength – False Container strength can vary. There are two ISO standards (pre- and post-1990). Some owners have their own standards and containers can be worn or damaged. LASHING SYSTEMS