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Image courtesy of Len Rogers

Load Security

Introduction
During the working year 2006/07, 5 deaths and 216 major injuries were caused by objects falling onto people within the Road Freight industry. Of these totals, 946 more people received injuries severe enough to keep them off work for over three days.
Many of these accident figures were as a result of poor load security (restraint) on goods vehicles being loaded/unloaded in the workplace.

There are measures that could have prevented these accidents from occuring, with top of the list being commonsense. There is no point in loading a heavy (or cumbersome) object on top of something that is lighter or smaller - and before anyone emails us to say that this is blatently obvious - unfortunately it happens, and far too often.

Preventing misshaps from occuring and the resultant injuries (or death) from the actions of poor load security is down to having the correct equipment to secure the load, whether it's inside a refrigerated trailer or on the back of a flat bed.

The Department for Transport produce an excellent publication entitled Safety of Loads on Vehicles - A Code of Practice, currently in its third edition. The information on this page has been reproduced from that publication in part and we would recommend that a copy is downloaded and retained in all Transport Offices as an essential part of a Transport Managers toolkit. A link to this publication is available at the foot of the page.

General requirements for securing loads
The total load restraint system will generally consist of a combination of:

Refrigerated trailer showing load lock and retaining poles In most circumstances it would be appropriate to obtain the majority of the total restraint required from (a), and the remaining part from (b). Benefits accrued from (c) should be regarded as a bonus. Vehicles using fabric sides, for example curtain-siders, will normally require additional internal restraints

In view of the wide diversity of general loads it is not possible to suggest loading methods for all the types of load likely to be encountered. However, the basic precautions outlined above will always be applicable. Vehicles equipped with headboards, tailboards or sideboards, or van bodies will provide some restraint. Additional load restraint will be required under any of the following conditions:

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Loading Arrangements on Vehicles
Two essential requirements must be satisfied when loading vehicles. These are that the load must be distributed so that:

For maximum stability, the items comprising of the total load should be evenly spread to achieve minimum height and be arranged to form a uniform whole so that no excessive stress is applied to whatever restraining devices are used. Where a part of the load is to be picked up or removed during the course of a journey the effect on gross vehicle weight, individual axle weights and on the securing and stability of the load then being carried must be considered during the initial loading and subsequent unloading. For example, removing a part of the load from behind the rear axle of a vehicle or trailer will reduce the gross vehicle weight, but it will increase the weight on the front axles and may cause individual axles to exceed their plated weights.

Principles of Load Safety Principles of Load Safety
The basic principle upon which this Code of Practice is based is that 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 (see Fig 1). Vertical movement may occur but this should be overcome if the above conditions are met. This applies to all vehicles no matter what the size, from small vans to the largest goods vehicles. These principles are based on the maximum forces that are likely to be experienced during normal road use. Greater forces may be encountered if the vehicle, for example, is involved in an accident. The principles should therefore be regarded as minimum requirements.

Restraint Equipment
Various types of equipment can be used for restraining general freight loads. These include rope, chains, steel wire rope, webbing, strapping or netting. For the securing of loads inside van bodies and similar load containers, specially designed shoring piles used in conjunction with the appropriate securing fixtures on the vehicle are suitable. Purpose built restraining devices should only be used for the application, and in the manner approved by their manufacturers.

Boxes
Boxes must be loaded so that they are prevented from moving in any direction. They should interlock if possible, and be loaded to a uniform height. There must be at least one lashing for each row of boxes across the vehicle and any box which is above the general height of the load must have at least one cross lashing, more depending on weight and size.

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Metals
Small relatively heavy items, such as small castings, if not palletised or caged, should be securely restrained and carried on sided vehicles. The headboard, sideboards, and tailboard must be higher than the load and must be strong enough to withstand the forces generated by the vehicle’s motion.

Careful attention should be paid to points where lashings pass over corners of the load to ensure that the load is not damaged by chain links etc. or that the lashings are damaged by sharp edges. Corner protectors and sleeves should be used whenever necessary.

The friction between individual items in a load will generally be low, particularly if the metal is oiled, and should therefore be disregarded when assessing the total load restraint required. The friction between load and vehicle platform will also be considerably reduced if either is wet or greasy. The only exception to this rule is when concrete reinforcing weld mesh is carried. In this case there is significant friction between bundles of the mesh loaded on top of each other.

A large mass can be restrained more effectively than a number of small items and therefore whenever possible loads should be aggregated into the largest or heaviest unit feasible. This will be controlled to some extent by the facilities available at the point of unloading.

Metal loads can take various forms but they can be broadly divided into 9 categories::

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Example of a safely loaded trailer of mixed cargo Fig 2 shows an example of a safely loaded vehicle carrying mixed cargo.

Mixed Loads
When a load is composed of different items each part of the load must be secured in a manner suitable to a load of its type. This applies mainly to cross lashings. The longitudinal lashings must be adequate for the total weight of the load, and separators must be used so that no part of the load can move forward independently. The following procedures should be followed when applicable:

There are many types of load other than mentioned above, a list of other load types include:

Regardless of the load type, they will all require variant forms of restraint and loading in/on the vehicle and the equipment required to ensure full load security in all cases will undoubtedly vary from load to load.

Iso Container Iso Containers
The majority of containers in use are constructed to International (ISO 1496) or British (BS 3951) standards. A common feature in the construction of these containers is that specially designed corner castings are incorporated which can be used. In conjunction with twist locks fitted on the vehicle, to provide a simple and positive means of restraint (see fig 3).

This type of container should only be carried on vehicles fitted with twist locks. Twist locks must be maintained in serviceable condition and a minimum of four used for each container carried. Provided that the twist locks are fully engaged and locked in position, the container will be adequately secured and no further restraint will be necessary.

The operator is confronted with a number of problems when attempting to carry ISO containers on vehicles not equipped with twist locks. Unlike normal box type loads that spread their weight over a large area, containers are designed to stand on the twist lock sockets or feet that protrude down at each corner. With heavy containers this produces high point loading that could over-stress a normal platform floor. Other platform vehicles may have raised or wide section side ledges which would prevent the container from resting on the platform floor. The resultant interface between the side ledges and the container feet would offer little frictional resistance making it virtually impossible to secure the container on to the vehicle safely and the practice should be avoided.

Source - Department for Transport

Further Reading
To download this excellent publication, please use the link below.

Safety of Loads on Vehicles (Code of practive - Third Edition) - Department for Transport PDF File

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