Besides of the own coupling system of a light vehicle with its trailer, it’s necessary to use safety chains. In case the main system fails, as in any safety mechanism, it’s mandatory to have an auxiliary system that avoids the trailer to get loose.
Safety chains are held to the drawbar*, go under it and are hooked on the back part of the tractor vehicle. There are two connection configurations, simple and double:
Simple connection
Double connection
Advices for the two types of connections:
+ Chains should be held in a crossing way. This way, steering is not completely lost if the trailer separates, because when this moves to one of its sides, it will be supported by one of the chains. Plus, this chain configuration allows one to tense and hold, and the other to loose, keeping the steering percentage.
+ The chains must pass below the drawbar. This is how we can prevent this part from touching the ground.
+ The drawbar must have an element, such as a skate, to allow it to slide on the floor, in case there is a separation between the two vehicles.
* Drawbar: Bar located at the front part of the trailer, which has on its end a part of the coupling device (and, eventually, the overspeed brakes system actuator).
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