November Newsletter

HGVs are required to have at least 4 roller brake tests per annum including the “statutory test”. More may be stipulated in, however there is more to it than just getting a report with the words “pass” at the bottom.

Roller brake testing in the UK is carried out on a wheel by wheel basis with the final result being calculated from the total brake force of all the wheels. There is the further caveat that if more than half the brakes lock, then the test is deemed to be passed. This test isn’t necessarily a true indication of a vehicle’s braking performance when driven on the road.
 
In order to test brakes meaningfully, some preparations should be made and the resulting report should be thoroughly examined. Start off with the vehicle details, are they correct. The DtP number gives the plated weight, the specified minimum brake performance, types of brake systems used on the vehicle etc.

Testing unladen vehicles is effectively meaningless. The braking effort generated by a wheel is dependent on the load on the axle, an unladen wheel will lock up at very low values, unladen tractor units can record braking values typically generated by cars. On the road, they would normally be laden and much of the trailer weight will transfer to the tractor under braking.