One of the most recognisable British-built diesel locomotives is the Class 58 - a successful design which never quite achieved its potential, as EVAN GREEN-HUGHES explains.
In the late 1970s there was dissatisfaction within British Rail’s freight fleet, which was largely as a result of the poor performance and prolonged acceptance period of the new Class 56s.
These locomotives were of integral construction with no separate frames and their power unit and all other equipment was within a full-length body derived from the earlier Class 47s. This meant access to equipment was difficult and the locomotives were costly to produce.
Above: BR Railfreight liveried Class 58 58013 passes through Stamford on the Leicester to Peterborough line with a Ratcliffe to Fletton fly ash train on May 30 1985. John Chalcraft/Railphotoprints.uk
As a result, in 1977, Derby Works’ design office was asked to investigate an alternative design with conventional frames onto which would be bolted modules containing power and electrical equipment, as well as driving cabs. This type of locomotive, it was thought, would be cheaper to construct, easier to maintain, and would also have export potential.
Derby came up with a design with a strong load-bearing fram…
