British Rail Class 150 - Prototypes

Prototypes

In 1984, BREL built two prototype 3-car Class 150/0 units, numbered 150001 and 150002. 150001 was fitted with Cummins engines and Voith hydraulic transmission, and 150002 was fitted with Perkins (Rolls-Royce) engines and Self-Changing Gears mechanical transmission.

The design specifications of the prototypes were similar to the later production units, but they were to remain the only Class 150s built as 3-car units. Additional three-car units were created later by re-marshalling a 150/2 car in the middle of a 150/1 set, but only the prototypes had purpose-built centre cars without driving cabs. Both cab doors are air-operated unlike the Class 150/1 production model, but as seen in the 150/2.

150002 proved to be the worse of the two for reliability and was consequently chosen for use as the testbed for the Class 158, being re-geared to a maximum speed of 90 mph (140 km/h) and fitted with Cummins engines and Voith transmission and a Class 158 interior. One car was fitted with the Class 151 Twin Disc 'hot-shift' transmission which it used successfully once the control software was sorted out. To distinguish this unit it was reclassified as the Class 154. It has since been returned to the standard configuration and reverted to its original number. Both prototypes were still in service with London Midland until 2011. 150001 entered service with First Great Western in January 2012, with 150002 to follow after refurbishment and relivery.

At the same time that BREL built the 150/0s, Metro-Cammell built two prototype Class 151 units at its Washwood Heath plant. The two types of unit were exhaustively tested, with a view to placing further orders for the more successful. In the event, the two Class 150 units proved to be more reliable, and as a result an order for 50 two-car units was placed with BREL.