11.2 Blocking, Dunnage, Containers, Pipes and Lashings

Match the equipment to the load

Restraint hardware is useful only when its design, condition and arrangement suit the cargo. Begin with the load’s mass, shape, packaging, centre of gravity and potential sliding, rolling or tipping. Identify where forces will go into the vehicle. A familiar arrangement used on a different load is not proof that today’s cargo is secure.

The handbook names blocking, stakes, gates, crowned and divided loads, dunnage, containers, lashings, ropes, belly wrapping, pipes, anchorage and tarpaulins. These are related methods and components, not interchangeable shortcuts. Use the Load Restraint Guide and any engineered loading instructions to determine their actual contribution.

Blocking, stakes and gates

Blocking limits movement against a suitable structure. Close gaps where the design requires contact and make sure the structure and its vehicle attachment can carry the force. A headboard that protects the cab from small items may not have capacity for the entire forward demand of heavy steel. Obtain the rating rather than infer strength from its thickness.

Stakes and stanchions can support or contain loads such as timber or pipes. They must be suitable, secure and used within their design. Gates can contribute when rated and properly retained, but an unrated gate should not be credited with an assumed capacity. It is equally wrong to state that all gates have zero capacity: the actual rated construction decides.

Crowned and divided loads

A crowned load is arranged so the upper profile helps a lashing contact and compress the load rather than bridge over lower parts. The purpose is useful clamping throughout the arrangement. It does not mean placing heavy items high merely to make a crown. Stability and axle distribution remain important.

A divided load contains separate stacks or bundles. A strap spanning a gap can clamp only the outer edges or highest pieces, leaving others insufficiently held. Restrain divisions individually or use a suitable designed arrangement so every part receives the required restraint. After removing one division, recheck the remaining restraint rather than leave a slack bridge across the empty space.

Dunnage and contact

Dunnage supports cargo, distributes pressure, provides separation or improves the restraint geometry. It must be strong enough and placed so the load cannot tip, roll or punch through. Suitable material depends on the design; it is not restricted to one universal timber species. Weak or compressible packing can settle and reduce lashing tension.

Place supports consistently beneath items so bending or uneven loading does not damage them. Secure loose dunnage too: an unloaded timber block can become road debris. Suitable friction material may be used where its properties are known, but it does not replace the vertical and horizontal checks of the full system.

Containers and large pipes

A shipping container should be secured with the proper compatible locks and fittings, engaged and checked through the correct procedure. Inspect corner fittings, locks and chassis mountings. Securing the container to the vehicle does not secure the cargo inside it; internal restraint and distribution are separate. A sealed container can still contain an unsafe load.

Large pipes and cylindrical loads can roll or spread. Use appropriate cradles, chocks, blocking and lashings, and assess both rolling and sliding. A single strap over a pipe without suitable support may not keep it stable. Multiple layers need a designed arrangement that restrains individual items and prevents the stack spreading. Keep people clear when releasing restraints because stored movement can occur.

Lashings, ropes and belly wrapping

Use marked, suitable chains or webbing and compatible tensioners and fittings. Check wear, corrosion, cuts, heat damage and distorted hooks. A chain grade by itself does not establish the complete system’s allowable load; transport and lifting ratings must not be casually substituted. Follow the equipment instructions and protect edges that can damage the lashing.

Ropes can suit some light or specifically designed applications, but knots, condition and unknown strength can reduce reliable capacity. Do not use an ordinary rope as a universal substitute for rated heavy-load lashings. Belly wrapping routes restraint around the load to provide direct restraint in a designed direction. Its effectiveness depends on geometry, anchorage and the complete arrangement; it still needs the other directional demands addressed.

Sheets and tarpaulins

A tarpaulin can contain loose light material or protect cargo from weather. It generally does not replace the main restraint of pallets, machinery or other heavy items. Fasten the covering so it cannot detach, flap dangerously or obscure lamps and plates. The load beneath must still be suitably placed and restrained.

Plan unloading before releasing any restraint. Know whether cargo can fall, roll or spring outward when a gate or lashing is removed. Stand clear of the likely movement and use suitable equipment and help. Recheck the new arrangement before every departure after partial unloading.

Key decisions

Verify ratings and contact, restrain each independent part and account for rolling or tipping. Covering, packaging and a strong-looking fitting do not prove a complete system.

Official sources

Official handbook, loading methods and equipment; NHVR Load Restraint Guide; key restraint elements. Sources checked 10 October 2026.