Class 40 Diesel Electric Locomotive

The Class was divided in allocation between the Eastern, London Midland and Scottish Regions, the distinctive 1Co-Co1 wheel arrangement giving high route availability. Their genesis, in terms of mechanical function (but not external appearance), can be traced to the 10000 - 10001 early diesels of BR (LMS) and 10201-10203 of BR (SR), the latter in particular. All, with the exception of twenty, saw construction at English Electric Vulcan foundry in Newton-le-Willows.

Twenty-five of the Class received names. Numbers D200 - D323 had train identification discs fitted; corner route-indicator boxes superseded this, which displayed a 4-character reporting system. In early 1961, when nose doors became obsolete D346 - D399 had single, centre-mounted route indicator boxes at the time of construction.

The Forties were especially well-liked machines with their crews and enthusiasts alike, remaining in service until obsolescence in 1985. Several examples of the Class have escaped scrapping by private enthusiast groups.