To facilitate commissioning of the power car, in the absence of complete trailer rakes, a special power car test train has been assembled; this consists of a prototype (Class 252) HST power car, a generator car with a 140KVA diesel-alternator set (TSC 8), the APT-P power car and a test car (TC 5). An air compressor located in TSC 8 supplies the power car test train brakes when the HST engine is shut down.
A similar train, to commission trailer rakes, will consist of the other prototype HST power car, a test car (TSC 9) and an APT articulated trailer rake.
TSC8, TC5 and TSC 9 are all fitted at one end with the appropriate APT gangway, jumpers and a 'Tightlock' coupler. Both of the HST power cars have been fitted with additional controls that enable the train to be powered by either the HST diesel or the APT electric power car. The brake control is through the normal handle but an interface box in TSC 8 converts the brake pressure signal into the electrical signal required by the APT braking system. This interface unit is also to be used in the driving cab of the APT and will enable a towing locomotive to tow an APT rake with brake control throughout the train.
Take a look at www.traintesting.com for more information and photographs of the test train vehicles.