cab whilst allowing inter-carriage doors to be fitted.

The powercars were originally powered by V12 turbocharged MAN D3650 engines that were replaced by two turbocharged 6 cylinder Cummins engines under the floor driving a Voith hydraulic transmission in the late 1980s. They usually operated in 2-car (power-trailer) or 3-car (trailer-power-trailer) configurations. It was originally intended that they primarily operate express services