different builders were awarded contracts for Type 2 locomotives under
the BTC Modernisation Scheme. Brush was given 20 locomotives to build
a design which led to subsequent orders being placed for over 200
locomotives. When built all had a Mirrlees 12JVS12T power unit which,
was soon found to become prone to crankcase and bedplate fractures and
resulted in the whole of the class being re-engined with English
Electric 12SVT units. Throughout their lives the locomotives proved
popular with crews and could be seen in almost all parts of the UK.
All are now withdrawn from regular service, although a few still run
main line, owned by Fragonset, based in Derby. 29 survived the cutters
torch, and are preserved in locations all over the UK.
Engine: English Electric 12-cyl 12SVT of 1470bhp (1097kW)
Numbers: 31 001-31 019, 31 101-327. (At this time, locos were converted for electric train heating. These were taken from this number series at random, and renumbered 31 401 onwards.)
Previous No. Series: D5500-5699, D5800-5862.