In the case of very heavy loads, it may be convenient to secure the cargo by lashing using chains approved according to the EN 12195-3 standard, instead of web lashings approved according to EN 12195-2 standard. This is to limit the number of lashings required, since chains provide a much higher securing force than web lashings.
The specifications and performance of the chains that can be used for securing the cargo in road transport are described in the EN 12195-3 standard, lashing chains. Like the web lashings used for lashing, chains cannot be used for lifting, but only for the securing of the cargo.
The chains must be equipped with a plate that shows the LC value, i.e. the capacity of the chain expressed in daN, as shown in the example in the figure.
Usually the chains are of the short-link type. At the ends there are specific hooks or rings to be fixed on the vehicle, or connecting the load in case of direct lashing.
Chains are provided with a tensioning device. This can be a fixed part of the chain or a separate device that is fixed along the chain to be tensioned. There are different versions of tensioning systems, such as a ratchet type and a turn buckle type. In order to comply with the EN 12195-3 standard, it is necessary that there are devices capable of preventing loosening during transport. This would in fact compromise the effectiveness of the fastening. The post tensioning clearance must also be limited to 150 mm, in order to avoid the possibility of load movements with consequent loss of tension due to settling or vibrations.
Use of chains
The video shows the correct use of chains for fixing a machine.
The minimum number and arrangement of the chains can be determined using the formulas contained in the EN 12195-1 standard, while it is necessary to check that the vehicle lashing points to which the chains are attached offer sufficient strength, as required by the EN 12640 standard.
Before use, a check that the chains are in good condition and are not excessively worn shall be made. With wear, chains tend to stretch. A rule of thumb prescribes to consider excessively worn a chain with a length exceeding more than 3% of the theoretical value.
Particular care should be taken when the chain are in contact with the load or with an element of the vehicle, such as a wall. The chains in fact develop a high friction with the contact element. This, in addition to damage to the load, could cause a loss of tension along the branches of the chain. Therefore, apart from observing particular precautions, it is recommended to use chains only for direct lashing. In this way a point of the load and a point of the vehicle are connected by the chain without the interposition of other elements, as shown in the figure.