Class 159/0s – the first 22

REPLACEMENT of the traction used on the West of England route between London Waterloo and Exeter via Salisbury and Yeovil became critical in the early 1990s.

The performances of locomotive-hauled trains serving the route fell to unacceptable levels, with regular failures causing significant disruption to services, especially over the single-track sections of the route west of Salisbury, despite drafting in additional locomotives from other areas including Class 47/4s and Class 47/7s.

A permanent solution was sought by Network SouthEast management, which considered various options, including new locomotives and stock; electrification or replacement of existing equipment with long-distance Inter-city standard diesel multiple units.

In the event, the solution presented itself by Regional Railways, which was taking delivery of its Class 158 fleet at the time. Under construction at Derby since 1989, the Class 158 had entered service and was settling down following issues with cracks in the aluminium bodyshells and issues with the brakes.

An economic downturn prompted Regional Railways to review its need for Class 158s and it decided to curtail its order with BREL Derby, with Network SouthEast taking up the option for the remaining Class 158 vehicles, the number of which correlated with the need for West of England services.

Built as Class 158s

A total of 22 three-car Class 158s were built at BREL Derby to Regional Railways specification, which was deemed to be inadequate for the long distance Waterloo-Exeter route that was seen to have considerable growth potential.

No agreement could be reached with BREL Derby to change the specification of the units. They were dispatched to Babcock Rail at Rosyth for refitting with better seating, the installation of a First Class saloon with comfortable two plus one seating; improved sound-proofing and other modifications after being released from BREL Derby.