The Basics of Cargo Lashing and Securing On Ships [PDF]

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The Basics of Cargo Lashing and Securing on Ships By Bikram Singh | In: Marine Safety | Last Updated on October 7, 2017

Cargo is loaded onto a ship when she is floating steadily in the water, upright, or with a practical trim astern. When the ship sails out to sea, it encounters external forces which result in to six forms of motions acting on the ship. These motions are a threat especially for those ships which require cargo lashing and securing it on the open deck (Container ships). To know more about forces and stability of ships read Parametric rolling in container ships and Intact and Damage Stability of Ships. If the storage of cargo is not secure enough then there is no escape from the behavior of the seas and the wind once they show their rage. This in result takes a toll on the loaded cargo, causing damage to other cargo in the vicinity or to the vessel’s structures and fittings and even throwing the cargo overboard. Improper cargo lashing and failure to adhere to the procedures required for cargo stowage on ships is dangerous to property, life and environment at sea.

Credits: Danny Cornelissen/wikipedia.org

To know more about cargo container lashing and stowage on ships, read Planning Cargo Container Stowage and how to take care of cargo on container ships? To avoid getting into situations like these the responsible personnel on board should be competent enough to plan and uphold safe carriage of the cargo at all times. This is done by proper planning of container lashing and securing. Read more about the importance of container lashing here.

Let’s have a look at a few components that are vital for understanding the importance of proper cargo lashing.

Basic Reasons of Loss or Damage to the Cargo

Credits: Danny Cornelissen/wikipedia.org

1. Severe and adverse weather conditions and lack of appreciation of the various forces implicated– Various conditions of the Beaufort wind scale not taken into account as the vessel encounters the worst at any given moment. Responsible personnel looking after the carriage of the cargo sometimes fail to foresee the ship’s characteristics and bad weather behavior

2. Lack of knowledge of relevant rules and guiding recommendations – Failure to follow the guidelines or the regulations for cargo lashing and securing may spell catastrophe 3. Cost control pressures – The economy downfall leads to cost cutting procedures which in turn means less quality cargo securing work 4. Inadequate time and personnel to complete the securing cargo before departure – Due to excessive paperwork and short port turn-around, basics of cargo lashing and handling on ships are sometimes overseen 5. Basic seamanship techniques not applied adequately for total immobility of the cargo – Dunnage not utilized in an effective manner or for that matter taking lashing materials around sharp edges which causes them to part or even insufficient force, steadiness and/or number of lashings 6. Improper usage of the cargo securing gear – Wire loops and eyes made up wrongly. Lack of knowledge in the use of bull dog grips, bottleneck screws, wire slings/strops, etc. 7. Lack of continuity in strength between the various securing components – Ship’s overall characteristics and age of construction play a major role in effective cargo work 8. Incorrect of unbalanced stowage and inadequate weight distribution – Inadequate stability and control measures taken

Points to remember while securing cargo 1. A good tight stowage of cargo containers on ships may avoid the need to totally secure it, provided the cargo is adequately packaged and there are no heavy components

2. Bulky and heavy units may still be required to be secured even if the space around them is filled with other cargo. Particular attention should be paid to the chances of such units sliding or tripping 3. A number of units can be secured or lashed together into one block 4. Permanent securing points on the cargo should be used, but it must be remembered that these securing points are intended for inland transport and may not necessarily be suitable for securing other items onboard ships 5. Independent lashings must only be secured properly to suitable strong points of the ships fittings and structure, preferably onto the designated lashing points 6. Cargo lashings must be taut and as short as possible for a better hold 7. If possible the multiple lashings to one item of cargo should be kept under equal tension. The integration of different material components having different strengths and elasticity should be completely avoided 8. Cargo lashings must be able of being checked and tightened when on a passage 9. Lashings should be enough so as to prevent the loads from moving when the ship rolls through 30 degrees with 13 second duration 10. Tightening the cargo down to the ship will add to a great deal in securing it completely before it shifts

Commonly used Cargo Securing Arrangements for Dry Cargo 1. Lashing is a general term that is used to on behalf of all the securing arrangements onboard: It includes ropes, wires, webbings, bandings, strapping or

chains, bottle screws and other patent tensioning devices mostly used on container ships 2. Tomming: Construction of a support of square section softwood framework, which chocks off the cargo against ship’s structure or other cargo 3. Filling: Use of air bags, empty pallets, old tyres, etc. to fill the voids and broken stowage between items of cargo and between cargo and ship’s structures 4. Anti skid: Flat-boards are used to increase frictional capabilities of the cargoes 5. Binding: Even out a stow with dunnage to make several units into one block. Also stowing bags or cartons in different directions in each layer forms a self-locking slab which is a tight stow for shifting cargoes 6. Structural Modifications: Very heavy and uncomfortably shaped cargo may be secured by welding the unit directly to the ship’s structure or by fabricating a steel framework or other support or chock which is permanently attached to the ship’s structure

Basics of Safe Slinging 1. When loads are lifted on a sling the general idea is to get the load to be as secured in the air as it was on ground 2. The loads must be satisfactorily secured by the slings (a) Loads are completely contained by the slings (e.g. Bags in nets) (b) Use fixed lifting pendants or lugs if available (c) Ropes or wire slings must be completely wrapped around the loads – no loads should be left resting in loose bights of the line

(d) When using specialized components, they must be properly attached to the cargo, and the manufacturer’s instructions should be followed 3. The slings must be sufficiently attached to the lifting appliances 4. The loads must be slung so that they will not collapse or change form when they are lifted 5. The load must not damage the sling, possibly causing the slings to part. Use stuffing or padding at susceptible points or sharp edges 6. Ensure that the loads are not to be damaged by the sling 7. All lifting parts should have their pivoting points as near to the vertical as possible for a clean lift by the crane

CARGO SECURING - DIFFERENT METHODS Securing of cargo can be made by any or in a combination of the following methods:  

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Blocking Examples of blocking: front wall, wedges, dunnage bags, chocks and beams. Lashings Examples of lashings are web lashings, loadbinders with chain and fixed winches. The equipment can be used in different applications e.g. top-over lashings (friction lashing), direct lashings and loop lashings. Locking Means that the cargo is mechanically locked to the load bearer. One example is twistlock for containers.

Different kinds of lashings Web lashings To use a web lashing, or textile lashing, is one of the most common ways of securing cargo. One method that is often used is a top-over lashing (friction lashing). When using a top-over lashing the cargo is pressed down against the load carrier by the tensioning force built up in the lashing, simplified one could say that the weight is “increased”. This combined “weight” in interaction with the actual friction between the cargo and the load carrier's surface prevents the cargo from sliding. This type of lashing is also used to prevent cargo from tipping and/or to wander. The tensioning force for the current lashing can be found on the marking (label) of the lashing and is called STF. When using the lashing as a direct lashing or a loop-lashing the strength in straight pull is used. When doing so the LC, or Lashing Capacity, is used. Chain lashings A chain lashing is used in the same way as a web lashing with the distinction that it is more commonly used as a direct lashing. With a chain lashing in G80 or G100 much higher values for LC and STF are reached. Fixed winches Fixed winches are often mounted on the outside of the load bearer. The can be of a simple configuration with a slotted axis, tensioning device and locking or a little bit more advanced being encapsulated containing a web storage. They can be bolted or welded in place. Click here to see our range of Lashings.

The making of lashing equipement The choice of lashing is decided by what kind of cargo to be secured and also of what kind of load carrier that will carry the cargo (rail, road, sea etc.) Since May 2001, lashing equipment, with few exceptions *, has been manufactured in accordance with EN-12195 ** in all EU countries. Since May 20, 2018, the European Directive 2014/47 / EC states that the

equipment shall fulfill a number of listed standards or otherwise be certified, including EN 12195 **. The Swedish regulations contain this directive in the TSFS 2017: 25 * e.g.a lashing on board a ship can be marked and constructed in a different way. ** EN 12195-2 for synthetic lashings, EN 12195-3 for chain lashings.

The marking of a lashing equipement Lashing equipment must be provided with a marking that at least contains the following information: Lashing capacity (LC) The lashing value allowed to calculate with, received by a straight pull in the endfittings. This value is used when the lashing is used as a direct lashing or loop-lashing. The value is given in daN for web lashings, and kN for chain lashings. 1 daN ≈ 1 kg 1 kN = 100 daN ≈ 100 kg Standard Hand Force (SHF) The Standard Handeling Force the ratchet is designed for. Normally this is 50 daN (50 kg). Standard Tension Force (STF) Indicates the tensioning force received when the ratchet is handled with the given SHF (normally 50 daN). It is this value that is used calculating the need for top-over lashings (friction lashings). Webbing and chain identification On the label (or marking tag) is also noted what material the webbing is made of or what grade the loadbinder and chain is made of. Breaking Strength (BS) The breaking strength is the force a new lashing shall withstand in straight pull. Which means that if the hooks are to be pulled straight away from each other the lashing shall perform at least the breaking strength stated. In general Forankra does not quote this value on our lashings. If you still want to know the approximate breaking strength for a synthetic lashing, the indication is that the lashing must be able handle at least the double LC value without breaking.

Chapter 02 Principles of safe stowage and securing of cargoes Ingangsdatum: 01-07-1996 Permanente link

02.01 Suitability of cargo for transport Ingangsdatum: 01-07-1996 Cargo carried in containers, road vehicles, shipborne barges, railway wagons and other cargo transport units should be packed and secured within these units so as to prevent, throughout the voyage, damage or hazard to the ship, to the persons on board and to the marine environment. Permanente link

02.02 Cargo distribution Ingangsdatum: 01-07-1996 2.2.1 It is of utmost importance that the master takes great care in planning and supervising the stowage and securing of cargoes in order to prevent cargo sliding, tipping, racking, collapsing, etc. 2.2.2 The cargo should be distributed so as to ensure that the stability of the ship throughout the entire voyage remains within acceptable limits so that the hazards of excessive accelerations are reduced as far as practicable. 2.2.3 Cargo distribution should be such that the structural strength of the ship is not adversely affected. Permanente link

02.03 Cargo securing arrangements Ingangsdatum: 01-07-1996 2.3.1 Particular care should be taken to distribute forces as evenly as practicable between the cargo securing devices. If this is not feasible, the arrangements should be upgraded accordingly. 2.3.2 If, due to the complex structure of a securing arrangement or other circumstances, the person in charge is unable to assess the suitability of the arrangement from experience and knowledge of good seamanship, the arrangement should be verified by using an acceptable calculation method. Permanente link

02.04 Residual strength after wear and tear Ingangsdatum: 01-07-1996 Cargo securing arrangements and equipment should have sufficient residual strength to allow for normal wear and tear during their lifetime. Permanente link

02.05 Friction forces Ingangsdatum: 01-07-1996 Where friction between the cargo and the ship's deck or structure or between cargo transport units is insufficient to avoid the risk of sliding, suitable material such as soft boards or dunnage should be used to increase friction. Permanente link

02.06 Shipboard supervision Ingangsdatum: 01-07-1996 2.6.1 The principal means of preventing the improper stowage and securing of cargoes is through proper supervision of the loading operation and inspections of the stow. 2.6.2 As far as practicable, cargo spaces should be regularly inspected throughout the voyage to ensure that the cargo, vehicles and cargo transport units remain safely secured. Permanente link

02.07 Entering enclosed spaces Ingangsdatum: 01-07-1996 The atmosphere in any enclosed space may be incapable of supporting human life through lack of oxygen or it may contain flammable or toxic gases. The master should ensure that it is safe to enter any enclosed space. Permanente link

02.08 General elements to be considered by the master Ingangsdatum: 01-07-1996 Having evaluated the risk of cargo-shifting, taking into account the criteria set out in 1.5, the master should ensure, prior to loading of any cargo, cargo transport unit or vehicle that: .1 the deck area for their stowage is, as far as practicable, clean, dry and free from oil and grease; .2 the cargo, cargo transport unit or vehicle, appears to be in suitable condition for transport, and can be effectively secured;

.3 all necessary cargo securing equipment is on board and in good working condition; and .4 cargo in or on cargo transport units and vehicles is, to the extent practicable, properly stowed and secured on to the unit or vehicle. Permanente link

02.09 Cargo stowage and securing declaration Ingangsdatum: 01-07-1996 2.9.1 Where there is reason to suspect that a container or vehicle into which dangerous goods have been packed or loaded is not in compliance with the provisions of regulation VII/5.2 or 5.3 of SOLAS 1974, as amended, or with the provisions of section 12 or 17, as appropriate, of the General Introduction to the IMDG Code, or where a container packing certificate/vehicle packing declaration is not available, the unit should not be accepted for shipment. 2.9.2 Where practicable and feasible, road vehicles should be provided with a cargo stowage and securing declaration, stating that the cargo on the road vehicle has been properly stowed and secured for the intended sea voyage, taking into account the IMO/ILO guidelines for packing cargo in freight containers or vehicles. An example of such a declaration is given hereunder. The vehicle packing declaration, recommended by the IMDG Code (see 2.9.1), may beacceptable for this purpose. Example Cargo stowage and securing declaration Vehicle No. ....................................................... Place of loading .................................................. Date of loading ................................................... Commodity(ies) .................................................... I hereby declare that the cargo on the above-mentioned vehicle has been properly stowed and secured for transport by sea, by taking into account the IMO/ILO Guidelines for Packing Cargo in Freight Containers or Vehicles. Name of Signatory .................................................. Status ............................................................. Place ........................ Date ........................... Signature on behalf of the packer .................................. Remarks: ........................................................... .................................................................... .................................................................... ....................................................................

Permanente link Permanente link

Cargo handling procedure for general cargo ship It would be normal practice for the Chief Officer to be provided with the cargo manifest by the ship’s agents at the last port of discharge or the next Loading Port. Inspection of this would subsequently provide details on all cargo parcels, inclusive of the tonnages and the destination of said cargo. This would then allow a loading plan to be constructed, preferably prior to arrival. In any event the Chief Officer would note special items on the manifest, in particular: (i) Hazardous cargoes; (ii) Heavy Lift cargo; (iii) Valuable/special cargoes. The Chief Officer is responsible for the safe handling, loading and discharge of the ship’s cargo, and to achieve this safely and satisfactorily he would carry out the following activities and duties: 1. Having obtained the details of tonnages/capacities of cargo from the manifest, the Chief Officer would develop an appropriate loading plan for the ship, to give a hold distribution of the cargo, to allow multiple hatch discharge. 2. The Chief Officer would carry out a ship stability assessment, taking into account the appropriate tonnages, together with bunker capacity, stores and ballast arrangements.This assessment would be expected to confirm an appropriate ‘GM’ for the vessel, and ensure that the vessel does not infringe loadline regulations while on passage. 3. Prior to commencing loading cargo the Mate would order the cleaning of all cargo spaces, the testing of bilges, checks on hold lighting, ventilation, and general hold conditions, inclusive of spar

ceiling and dunnage arrangements. (NB. One of the Chief Officer’s tasks is to order clean dunnage as for the ship/cargo requirements). 4. The Chief Officer would act in a supervisory role of a junior cargo officer and ensure that the cargo plan was being correctly constructed during any loading period. 5. Where special cargo is to be loaded, the Chief Officer would be expected to take a positive role to ensure adequate loading facilities are provided and correct stowage is available, i.e., heavy lift derricks rigged correctly, tally clerks available if required, etc. 6. Documentation on specific cargoes, such as hazardous parcels, live stock, or valuables would be obtained and administered by the Chief Officer. 7. The Ships Mate would monitor the draught and ensure that the Loadline regulations are not infringed causing the marks to be submerged below the summer loadline. He/she would order the density of dock water to be obtained and take into account the Dock Water Allowance. 8. Any damaged cargo received on board would be noted and the Bill of Lading would need to be endorsed. Similarly, on receipt of special cargo the Chief Officer may be called on to issue a ‘Mates Receipt’ for cargo delivered on board. 9. In conjunction with junior cargo officers the Mate would ensure that all cargo is stowed correctly and secured in the stowed position against all expected ship movement when at sea. 10. His/her duties include the despatch of all the relevant cargo documentation including the cargo plan to the company agents prior to sailing departure. Suitable safety nets or temporary fencing should be rigged where personnel have to walk or climb across built-up cargo, and are

therefore at risk of falling. When deck cargo is stowed against and above ship's rails or bulwarks, a wire rope pendant or a chain, extending from the ring bolts or other anchorage on the decks to the full height of the deck cargo, should be provided and used to save personnel having to go overside to attach derrick guys and preventers directly to the anchorages on the deck. Where beams and hatch covers have to be removed at intermediate ports before surrounding deck cargo is unloaded, an access space at least one metre wide should be left adjacent to any part of the hatch or hatchway that is to be opened. If on deck this is impracticable, fencing or lifelines should be used to enable seamen to remove and replace beams and hatch coverings in safety. In the `tween decks, guidelines should be painted around `tween deck hatchways at a distance of one metre from the coamings. Personnel undertaking duties in cargo spaces should move with caution over uneven surfaces or over loose dunnage and be alert to protrusions such as nails etc. Where vessels have been built with corrugated bulkheads precautions such as suitable rails, grids or nets should be erected to prevent cargo handlers or other personnel from falling into the space between the rear of the corrugation and the stowed cargo. Where work is being undertaken on or near the cargo `face', the `face' should be secured against collapse, especially where bagged cargo may be bleeding from damage. Where it is necessary to mount a `face' a portable ladder should be used, properly secured against slipping or shifting sideways, or held in position by other personnel. When work is undertaken in areas where there is a risk of falling, safety net(s) should be erected. Such nets should not be secured to hatch covers. Personnel should be aware that cargoes may have been fumigated

at other points in the transport chain, and there is a risk of that toxic fumes may build up in enclosed spaces. Preventing Ships hull/structure damage during cargo operation All damages should be reported to the ship's Master. Where hull damage is identified, which may affect the integrity of the hull structure and the seaworthiness of the ship, the ship's owner and classification society must be informed. A general inspection of the cargo spaces, hatch covers and deck is recommended to identify any physical damage of the hull structure. Any structural damage found is to be reported to the classification society and for major damage, cargo operations are not to be undertaken. During initial inspection of a vessel's flat bottom in dry-dock, large parts of the duct keel plating were found dented and deformed over almost its entire length. It was later established that overloading of the vessel's keel structure was caused by the owners submitting an outdated docking plan and the yard, unable to use the plan, repositioning the keel blocks without performing additional calculations. There were extensive repair costs, delays and disputes between the owners and yard as to liability. Proper planning of the docking process and a clear contract between the owners and yard are important to help avoid such disputes arising.

Container ship cargo Securing arrangement -Design,Stack weights & Metacentric height factors

Lashing pattern of outboard containers Securing equipment will vary depending on the type of ship but is likely to include; Twistlocks, Lashing bars, Turnbuckles, Extension hooks, Stacking cones (single and double), Twist Stackers, Lashing D rings & Shoes/Sockets for base twistlocks In addition it should be remembered that the container frame itself is an integral part of the securing system. The stow will remain secure only if the frame is in good condition and if the loads acting on it remain within safe limits. Design Details of the securing system and its constraints are set out in the vessel’s approved Cargo/Container Securing Manual. In the event of any amendments, re-approval will be required Securing systems take into account the various forces triggered by violent motion during adverse weather, including those caused by the six degrees of freedom. Within these limits, each item of equipment is designed to function within its predetermined safe working load. However, the calculations assume that the equipment is properly maintained

and positioned. Should some of the items not be deployed as specified in the Cargo/Container Securing Manual or be allowed to deteriorate, the safe working load of the remaining equipment may be exceeded. Stack weights and stack weight distribution It is often thought that by keeping the total stack weight within prescribed limits, the securing system will not be overloaded. This is not necessarily the case, particularly when containers are loaded on deck. It is important to recognize that the total stack weight limit is merely the weight that can be supported safely by the deck or hatch cover, as applicable. The calculations are based on the ship being upright in calm conditions (i.e. in port) and take account of the static weight of the stack due to gravity. The figures also take into consideration the anticipated dynamic stack loads acting on the deck or hatch covers in adverse weather due to the various ship motions described earlier.

Parallel lashing rods and twist locks However, stack weight limits do not ensure that the dynamic loads acting on the container securing system will remain within the margins of safety during heavy weather. Loading the cargo so that each stack does not exceed its total permissible weight is relatively easy to achieve. It is far more

difficult to optimize the stack in terms of weight distribution, port rotation and estimated forces, ensuring that at all times the safe working load of the securing equipment is not surpassed. Therefore it is vital that the Cargo/Container Securing Manual is consulted for guidance. The manual gives illustrations of typical safe stack weight distributions and total safe stack weights based on the design limits of the ship’s securing system. Metacentric height (GM) The higher the GM, the greater is the righting moment when the ship is rolling. Consequently, the transverse acceleration forces acting on a container deck cargo and the securing system intensify with any rise in GM. Such forces are at their highest at the extremity of each roll. It is always important to consider the effect of GM on the securing system when estimating the forces, bearing in mind that GM may not remain constant throughout the voyage.

Estimating the forces Examples of GM values are featured in the Cargo/Container Securing Manual together with acceptable weight distributions in each case. This information should be compared with the actual figures as calculated by the ship. If there are any significant differences, stack weights and/or securing equipment should be adjusted until both are deemed to be within prescribed safe limits. For reliability and accuracy, many vessels are now equipped with a container securing software package. There are several programs of this type on the market, most of which are designed to interface with cargo management or loading computer software. Securing programs will calculate the applicable forces for any given stowage plan, comparing the data with the safe working criteria as specified by class. The effect of wind strength on the outboard stacks is also taken into account, allowing the corresponding load on the securing system to be adjusted accordingly. Most programs will warn if any securing components or individual container frames are likely to be overloaded, and the result of applying additional lashings can be shown. Inspection, Inventory and Maintenance The type of securing equipment used on board depends on the

ship’s design, capacity and trade. Accurate records regarding the quantity, location, inspection, maintenance, repair and replacement of such equipment should always be kept. In general terms there will be a need to: Ensure that the amount of securing equipment and lashing material retained on board is sufficient to properly secure the maximum number of containers to be carried. There should also be an adequate safe margin of spares and replacements. Inspect all portable securing equipment (e.g. turnbuckles, lashing rods, twistlocks, twist stackers etc) for signs of distortion, buckling, corrosion, cracking and/or excessive wear. As far as practicable, such checks should be carried out as a matter of routine before the equipment is reused.

Lubricate turnbuckles and twistlocks frequently. The spring which holds the twistlock in the closed position should be examined regularly as it may become less effective over time, causing the device to unlock if the ship or stow begins to flex on passage. Examine all fixed fittings (e.g. container sockets, elephant’s feet, dovetail connections) routinely for signs of wastage, cracks, distortion and/or general deterioration, including base plates where applicable. Particular care should be paid to the condition of D rings, mindful that wastage of the main shaft may be concealed by the retaining sleeve. Maintain a file of all certificates of approval relating to the portable securing equipment carried on board. Suspect fittings or equipment should always be removed from service when found, and repaired or replaced as necessary.