The Class 170/1 was based on the Class 168/0, the first new vehicles ordered since privatisation. Apart from different seating layouts, they have an increased cab rake angle and compatible couplings with the Class 15X “sprinter” units. Their MTU 6R183TD13H engine provides 315kW per car, yet is very quiet in operation. Large windows and 1/3-2/3 doors give the interior an open feel and allow good passenger circulation. The units were built in 1999 for Midland Main Line, being transferred to Central in 2005 upon delivery of the Class 222 trains. The first train entered service in 1998, hence the vehicles are not “regulated vehicles” in terms of the RVAR disability regulations, although they are virtually compliant. The bodyshell is constructed of aluminium extrusions huck-bolted together with a bolted on steel cab. The units feature a Voith transmission and a ZF final drive and are equally useful for long distance and commuter services. They are air conditioned and provide a smooth ride on a development of the highly successful “Series 3” air suspension bogie.