The DVSA Commercial vehicle brake test has two elements within it to achieve a Pass result; exceeding minimum brake force requirements or pass when more than 50% of wheels lock.
Often it is not understood that these pass criteria can be managed by the operator to give a particular vehicle the best chance of achieving a pass. Some vehicle types are more suited to pass on locks, while other vehicles are better at achieving minimum brake forces.
If you have the facilities to carefully manage the load on the axle during the brake test, the vehicle can be presented for test with best chance of achieving a pass.
Fine adjustment of the axle load can be used to direct the brake result towards either of the two pass criteria, this cannot be achieved using the traditional loading method of placing concrete blocks on the vehicle, a computer controlled chassis loading system is required to make fine load adjustments during the brake test.
BM CLS Chassis Loading System
BM Autoteknik A/S has developed the only two systems that meet the loading requirements and DVSA pit Health and Safety requirements.
The BM Chassis Loading System uses Modular hydraulic units of 5 tonne capacity that are placed on the sidewalls of testlane inspection pit. Loading systems can be installed to load 10, 20 or 30 tonnes on to the vehicle chassis; BM recommends a 20 tonne system for the DVSA brake test.
Hydraulic load units move along rails as the vehicle progresses through the brake test, so the operator only has to attach the load simulator once on to the vehicle, to complete the test.
Loading the chassis, and not the axle, is important as the load sensing system of the vehicle needs to be triggered so that the vehicles brakes are activated.
The control system built into the braketester firmware constantly monitors the load on the axle, if the vehicle has air suspension and the airbags start to inflate and starts increasing the axle load, the control system will automatically compensate and maintain the required axle load during the brake test.
The BM CLS system requires that a BM braketester is mounted across an inspection pit.
BM74000 Chassis Loading system
When a Braketester is fitted in the floor, the BM CLS system cannot be used. BM resolved this by designing the BM 74000 unit that presses down on the bed of the vehicle, or 5th wheel of a tractor unit. The BM74000 utilises sophisticated software to control the vehicle load, giving the same fine control and self regulating capability as the BM CLS system. The BM74000 delivers up to 10 tonne loads very quickly.
Most operators will be familiar with the BM74000 as they are used in DVSA test stations.
Enhance your ATF Lane capability
The DVSA recommend that during a Brake test the vehicle axle is loaded to a minimum of 65% capacity, the BM CLS automatically calculates this from information in the DVSA DTP number database; however 65% might not be the optimum load for a Pass for the vehicle type under test.
The BM CLS and BM74000 systems have the capability for the operator to alter the load within seconds. An ATF lane fitted with BM Chassis loading systems, with thoughtful operation should deliver better pass rates than a lane without load simulation.
Maximise your customer base.
An ATF lane fitted with a load simulation system can be very attractive to vehicle operators seeking to have their fleet tested, as they do not have to load the vehicle themselves; this is especially helpful if they have difficult to load vehicles such as Tippers, Tankers or concrete trucks.
Tractor units can be taken to the ATF without a loaded test trailer attached.
Chassis loading helps to ensure the test lane is fully booked.
John Gul owner of Independent Fleet Care in Barking first installed CLS ten years ago, and in 2014 installed a second ATF lane with CLS capability, and updated the braketesters in both lanes for tachograph testing.
Independent Fleet Care ATF station is testing five days a week and one of the highest utilisation rates in the area.
The capability of the BM CLS system attracts owner operator and Fleet customers from a wide area, as they do not have to self load their vehicles.
BM chassis loading has given Independent Fleet Care a huge advantage in an increasingly competitive ATF market.