Load lashing or Load restraint
Load lashing or load restraint is a vital component for the safe transport of goods whether this is carried out by road, rail or sea. External forces applied to the load caused by the effects of breaking, accelerating or cornering have a dramatic effect on how the load is to be restrained.
In a similar way to how we select lifting equipment, the shape and type of load as well as the effects of the working angles of the lashings, can increase the forces considered and consequently these factors affect the choice of both the type of lashing that should be selected and the method of how they should be used.
Lashing equipment supplied by Gracon is of high quality.We are able to offer lashing chains and components in various grades. All Gracon chain system you choose meet or exceed the British and European standards. Our standard Grade 80 BS EN 12195-1-4 offers the rated kilo newton (kN) lashing capacity for all chain.
BS EN 12195 Parts 1 to 4 were introduced to provide a means of conforming to the essential safety requirements for lashing and load restraint in the Common European market and thus enabling the free movement of goods.
Gracon Load restraining equipment
The selection of the best means of securing a load to a vehicle will depend on the type and composition of the load to be carried. Operators should equip themselves with the correct securing equipment for the types of load carried and where general cargoes are carried various types are available from Gracon. Clamps, special bolts, steel wire ropes, chains, webbing systems are all suitable devices for use in load restraint but it is essential to ensure that they are strong enough for the weight of loads carried.
All equipment used for securing loads should be regularly inspected for wear or damage.
Inspection arrangements can be organised with Gracon to certify all load restraint equipment, Special attention should be paid to webbing and rope to ensure that there is no visible deterioration due to constant use, such as fraying of the strands. They should also be inspected to ensure that they have not been cut or damaged in any other way through misuse. If there is any doubt as to whether repairs are required, please contact Gracon for free expert advice.
Steel Wire Rope
Steel wire rope made up into special straps or slings is suitable for securing a load when used in conjunction with other devices such as shackles and thimbles. The strength of steel wire rope will depend on the grade of the steel used, the number of strands, the number of wires in each strand, the diameter of the rope and the method of construction. Wire ropes must have a safe working load compatible with the requirements of the load being carried.
Recommendations for the minimum breaking load of various sizes and types of wire rope are contained in BS 302, BS 1290 gives safe working loads for wire rope slings, and BS 6210 is a Code of Practice for wire rope slings. Wire ropes having a diameter of less than 8mm are not suitable for load restraint purposes. Wire ropes should be free from rust and must not be used if they show evidence of weakening such as broken wires or strands. Other coupling equipment used with wire rope must be of corresponding quality and strength.
Chains are suitable for lashing loads when used in a similar manner to steel wire ropes. Three properties determine the strength of a chain: the length of its links, the thickness of its links and the quality of the metal used. The longer the link the more susceptible the chain is to damage – long links can easily be deformed if they are tensioned over a corner. The chain used should be compatible with the requirements of the load carried. Where necessary strong packing or bevelled sections should be used on corners or sharp edges which prevent damage to the ropes and chains and also increase the radius around which they bend, thus increasing their effective strength.
Recommendations for the safe working of various sizes of steel chain are contained in BS 1663, BS 4942, BS 6304 and BS 6968 (ISO 3056). The use of iron or split link chain is not recommended. Any joining links in chains should always be inspected before use. Chains should only be used in conjunction with suitable tensioners and turnbuckles with a safe working load that is compatible with that of the chain.
Webbing assemblies are suitable for securing many types of load. They usually consist of a webbing strap with some form of end fittings and incorporate a tensioning device. It is recommended that assemblies manufactured to BS 5759 are used. These are marked with a Rated Assembly Strength (RAS) which should never be exceeded.
Webbing made from polyester, polyamide or polypropylene may be used. Polyester loses a little strength when wet, is highly resistant to moderate strength acid but can be damaged by alkali. Polyamide may lose up to 15% in strength when wet, is highly 0resistant to alkalis but can be damaged by moderate strength acids.
Polypropylene is useful where chemical resistance is a requirement. Before use, care should be taken to ensure that the metal components of the harness are not corroded or damaged, that the webbing is not cut or frayed and that all stitching is sound. If damage is found, advice should be sought from the manufacturers to check if repairs are possible
Principles of Load Safety
When a vehicle changes direction cornering on roundabouts, overtaking etc., friction is not enough to stop unsecured cargo from moving. It is wrong to assume that the weight of the load will keep it in position. In fact heavier loads are more likely to move when the vehicle is in motion due to their kinetic energy being greater. Under heavy braking the weight acting in a forward direction can be equal to that acting down on the vehicle.
Therefore, a load that is not restrained will not be secure. The forces acting on the load during braking increase with the rate of deceleration and the weight of the load. So, when the vehicle brakes the load will want to continue to move in its original direction. The heavier the load and the harder you brake, the more the load will try to move.
Friction alone cannot be relied upon to keep the load in place. When the vehicle is moving, vertical movement caused by bumps will reduce any restraining force due to friction. This can reduce to zero if the load even momentarily leaves the bed of the truck. It requires much more force to stop a load that has started moving than it does to prevent movement in the first place.
It is essential therefore that the load is restrained in such a way that movement of the load on the vehicle is prevented.
The combined strength of the load restraint system must be sufficient to withstand a force not less than the total weight of the load forward, so as to prevent the load moving under severe braking, and half of the weight of the load backwards and sideways . Vertical movement may occur but this should be overcome if the above conditions are met.
Direct Lashings on Plant Equipment
Once loaded, the load should be secured with a suitable number of direct lashings. It is very important to make sure that all parts of the load are secured. All moveable assemblies such as jibs, brackets, booms and cabs etc. must be left in the position recommended for transportation by the manufacturer and must be secured to prevent movement relative to the main body of the machine.
The machine should be restrained against forward, backward and sideways movement by chain or webbing lashings attached to anchorage points on the vehicle.
Gracon offer a wide and varied selection of lashing and load restraint equipment. Such equipment frequently required by customer include short link chain.
|Sling hooks||Bolt on 360* anchor points|
|Grab hooks||Swivel anchor eyes|
|Component Connectors||Ratchet loadbinder|
|Weld on anchor points||Chain & straps|
All lashings should incorporate some form of tensioning device. In deciding the number of anchorage points to be used when arranging a restraint system. The following factors should be considered:
- The need to position the machine to achieve the correct load distribution to meet the legal axle load requirements and to ensure that the vehicle’s handling is not impaired.
- The extent to which other load restraint features is incorporated in the design of the vehicle.
- Whether the machine has wheels, tracks or rollers.
- The weight of the machine to be carried.
- A minimum of four lashings should be used.
- A minimum of four separate anchorage points should be used.