Class 27

The Class 27 was a development and follow-on class of Type 2 diesel-electrics from the pilot-scheme Class 26 (which ironically outlasted the 27s). Compared to the earlier locos the Class 27s had a slightly uprated engine, different electrical equipment and an increased top speed [1]. Originally the Class 27s were allocated to Southern England and Scotland but later the locomotives were concentrated in Scotland.

Information
Number built: 69
Built: 1961-62
Builder: Birmingham Railway Carriage & Wagon Company
Engine: Sulzer 6LDA28B diesel
Power: 1, 250 hp (932 kW)
Wheel arrangement: Bo-Bo

The original locomotives were the 27/0, two sub-classes were later modified for express services in Scotland. Some locomotives were modified for push-pull operations as the 27/1 and some with electric train heat as the 27/2. One of each top and tailed Edinburgh-Glasgow expresses in the 1970s[2] however their reliability suffered on these duties, a number of 27/2s catching fire. By the end of the decade they had been replaced by Class 47/7s[3]. The Class 27s were gradually withdrawn throughout the 1980s with the final withdrawals in 1987 however 8 have been preserved.
D5410 at Kidderminster

[1] Brian Haresnape, Production Diesel-Electrics Types 1-3 (Ian Allan, 1983) p. 40
[2] Chris Heaps, BR Diary 1968-1977 (Ian Allan, 1988) p. 45
[3] John Glover, BR Diary 1978-1985 (Ian Allan, 1985) p. 27