Similar improvements with revenue were seen across the board after the introduction of later DMUs. Both cars in this initial batch were powered with Leyland engines and had torque converter transmission. Mechanically these units were based on pre-war LMS designs and proved troublesome in service [2].
| Information | |
|---|---|
| Number built: | 217 (1, 2 and 4-car sets) |
| Built: | 1954-55 |
| Builder: | BR Derby |
| Motor: | Leyland or BUT (AEC) 6-cyl horizontal diesels |
| Power: | (Leyland) 250hp (186kW) (BUT) 300 hp (224 kW) |
| Formation: | (Preserved set) Driving Motor Brake Standard (DMBS) +Driving Trailer Composite Lavatory (DTCL) |
The second batch were built in a variety of configurations (the single railcars have been dealt with separately). They were fitted with BUT (AEC) diesels and had a different transmission and gearbox (fluid flywheel and preselector gearbox). This arrangement proved more reliable and popular with BR and indeed became the standard for the hundreds of BR DMUs which followed in the 1950s and 1960s.
Being non-standard the Derby Lightweight DMUs were withdrawn fairly early and all had gone from revenue service by 1969. However a 2-car set and a railcar survived into departmental use. The 2-car set became an ultrasonic test train and traversed the entire network returning data on track conditions [3]. Following withdrawal in the mid-1980s it has been preserved and in the process of being restored.
 |
| M79018 at Wirksworth |
 |
| Restoration continues |
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| M79018 at Wirksworth (a Class 122 to the left) |
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| Another view of M79018 |
[1] Brian Haresnape, Diesel Multiple Units: The First Generation (Ian Allan, 1985) p. 22
[2] Colin J Marsden, DMU and EMU Recognition Guide (Ian Allan, 2013) p. 26
[3] Colin J Marsden, Departmental Stock (Ian Allan, 1984) p. 28