British Rail Class D3/12
| Southern Railway diesels 1–3 British Rail Class D3/12 British Railways | |
|---|---|
| Class | BR: D3/12; later 3/9A |
| Numbers |
|
| Withdrawn | 1964 |
| Disposition | All scrapped |
British Rail class D3/12 was a class of three experimental
Background and Construction
Once the UK economy began to improve in the mid 1930s, the Southern Railway had further need for heavy shunting locomotives in its marshalling yards around London. The Z class steam locomotives had proved successful for this task but Maunsell wanted to compare their performance with diesel-electric alternatives. He therefore sought authorisation for the construction of three experimental locomotives for use in the busy Norwood marshalling yard where there was a continuous need for such locomotives. No private manufacturer was in a position to build the new locomotives and so they were jointly constructed by the Southern Railway's Ashford works, who constructed the framing, cabs and bodywork, and English Electric Ltd of Preston, who fitted the traction motors. The three locomotives were also provided with duplicate controls to enable them to be driven by one man from either side of the cab. They were delivered during September and October 1937.[2]
Operation
After a few teething problems, the class quickly proved the advantages of diesel electric shunters in terms of effectiveness, cost-saving, and driver comfort. Although at £7,275 they cost £1,100 more to build than a Z class steam locomotive, each one saved about £1,700 per year in operating costs. They could be used continually day and night for six days each week at Norwood without any service requirement beyond refuelling.[3] They were however found to be too slow for their secondary task of freight transfers around the congested passenger lines in the London area, although perfectly well suited to this traffic on rural lines.
As a result of these experiments Maunsell's successor, Oliver Bulleid, received authorisation to build a further eight members of the class in July 1939 but this order was quickly cancelled as a result of the outbreak of the Second World War.[4]
Between 1941 and 1945 the locomotives were commandeered by the
Following the formation of
Although they were still in good operating condition, the locomotives were withdrawn in November and December 1964, as by then the Southern Region had many modern replacements. None have been preserved.
Numbering
The original intention was to number the locomotives 958 to 960, following on from the steam locomotives of the
See also
Footnotes
- ^ Details from Marsden 1981, pp. SR: 1–3
- ^ Bradley 1975, pp. 51–53.
- ^ a b Bradley 1975, p. 51.
- ^ a b Bradley 1975, p. 52.
- ^ Bradley 1975, p. 53.
References
- Bradley, D. L. (1975). Locomotives of the Southern Railway. ISBN 0-901115-30-4.
- Marsden, Colin (1981). The diesel shunter: a pictorial record. Oxford: Oxford Publishing Company. ISBN 0860931080.
- Strickland, David C. (September 1983). Locomotive Directory: Every Single One There Has Ever Been. Camberley: Diesel and Electric Group. p. 63. Wikidata Q105978499.
- Ian Allan ABC of British Railways Locomotives, winter 1962/3 edition, page 229