Lashing (cargo securing) is tying down and fixing the cargo with webbing straps, chains or wire ropes to prevent it from sliding, tipping over or shifting on a vehicle, in a container or on a ship. On the road it is calculated according to EN 12195-1; the securing is expected to withstand a force equal to 0.8 times the cargo weight forwards and 0.5 times sideways and backwards.
What does cargo securing prevent?
A load on the road is constantly exposed to forces. Under sudden braking the cargo is pushed forwards, in a bend sideways, and when pulling away or over bumps backwards. Friction alone is not enough to keep the cargo in place, because the vehicle's vibrations momentarily reduce the force with which the cargo presses on the floor. Unsecured or insufficiently secured cargo slides, tips over, upsets the vehicle's stability or falls onto the road. With heavy loads that have a high centre of gravity, a single slide can result in a rollover.
How are the forces calculated?
The standard used as the basis for road transport in Europe is EN 12195-1. It requires the securing arrangement to withstand certain accelerations in proportion to the weight of the cargo:
| Direction | Design acceleration on the road | Example: 10-tonne load |
|---|---|---|
| Forwards (braking) | 0.8 g | A force of about 8 tonnes |
| Sideways (cornering) | 0.5 g | A force of about 5 tonnes |
| Backwards (pulling away) | 0.5 g | A force of about 5 tonnes |
Part of this force is taken up by friction; the rest is carried by the securing equipment. The calculation is explained in detail with an example in the entry calculating lashing force. In sea transport the distribution of accelerations is different, with sideways forces in particular becoming larger; the IMO's CSS Code and the CTU Code jointly prepared by the IMO/ILO/UNECE set separate rules for ships and containers.
Which methods are used?
- Frictional lashing (top-over): A strap is passed over the cargo and tensioned, pressing the cargo down onto the floor. The STF (standard tension force) value on the equipment label is decisive. Suitable for light and medium-weight cargo.
- Direct lashing: A chain or strap is attached from the cargo's lashing point to the vehicle's lashing ring diagonally, straight or as a loop. Here the LC (lashing capacity) value on the label enters the calculation. This is the main method for heavy machinery.
- Blocking: The cargo is kept from moving by bracing it against the trailer's headboard, stanchions or nailed-down chocks.
- Combined method: In practice, most project cargo uses blocking, direct lashing and friction together.
What equipment is needed?
- Webbing straps, chains, wire ropes: Must comply with EN 12195-2, -3 and -4 respectively and be labelled. Which one to choose when is discussed in the entry chains or straps.
- Anti-slip mats: Increase the friction coefficient between the cargo and the floor, noticeably reducing the number of lashings needed.
- Edge protectors: Stop the strap from being cut on sharp edges and spread the tension force evenly over the cargo.
- Chocks and wedges: Prevent cylindrical cargo from rolling. In international shipments, solid wood chocks must bear the ISPM 15 stamp.
Who is responsible?
Article 65 of Highway Traffic Law No. 2918 (2918 sayılı Karayolları Trafik Kanunu) prohibits loading cargo without proper lashing and securing in a way that it could fall, slide, tip over or upset the vehicle's stability; the fine for this violation is TRY 3,000, and TRY 20,000 for vehicles carrying containers or dangerous goods. In practice responsibility is shared: the loading party prepares the cargo in line with the contract, and the driver and carrier check that the securing is adequate before setting off. In the EU, Directive 2014/47/EU provides for cargo securing to be examined during roadside technical inspections as well.
Common mistakes
- Trying to secure heavy machinery with frictional lashing alone.
- Relying on a chain's LC value without checking the capacity of the lashing ring.
- Not re-tensioning straps that loosen on the road at the first stop.
For heavy cargo, the lashing plan is part of the out-of-gauge transport process and in project transport it is prepared in writing before loading.