Class 42 Warship locomotive

A reader of a 1960 Ian Allan ABC would have found these locomotives listed as the BR Swindon Type 4, the machines now grouped under TOPS Class 42. They were a diesel-hydraulic express type built for the Western Region, part of that region’s decision to follow German hydraulic practice rather than the diesel-electric traction adopted across the rest of British Railways. Named after Royal Navy vessels, the fleet became known as the Warships.

Design and build

The Warships were a lightweight express design on a B-B wheel arrangement, using Maybach engines driving through hydraulic transmission rather than the electric transmission standard elsewhere on British Railways. The fleet came in two closely related classes: the Class 42, built at Swindon works and numbering around 38 locomotives, and the near-identical Class 43 supplied by the North British Locomotive Company. Together the two classes made up around 71 machines. Construction ran from 1958 to 1961.

In service

The class worked Western Region express services, notably the routes to the West of England. They formed part of the region’s diesel-hydraulic programme, an approach that set the Western apart from the diesel-electric fleets running on the other regions. In that role they replaced steam power on some of the region’s principal expresses.

Numbering

The Warships were numbered in a series beginning at D800, and each carried the name of a Royal Navy warship, which is how the fleet came to be known. Because the Class 42 Swindon machines and the Class 43 North British machines shared the same broad design, they were treated together in service and in the numbering sequence.

Withdrawal and preservation

As British Railways standardised on diesel-electric traction, the diesel-hydraulic fleets were withdrawn early, and the Warships had gone by the early 1970s. Two examples survive in preservation, D821 and D832.