British Rail Class 12

4 ft 8+1⁄2 in (1,435 mm) standard gaugeWheel diameter4 ft 6 in (1.372 m)Wheelbase11 ft 6 in (3.51 m)Length29 ft 5+1⁄2 in (8.98 m)Width9 ft 0 in (2.74 m)Height12 ft 8+1⁄2 in (3.87 m)Loco weight48 long tons (48.8 t; 53.8 short tons)Fuel capacity660 imp gal (3,000 L; 790 US gal)Prime moverEnglish Electric 6KTGeneratorEnglish Electric 801/7D (DC)Traction motorsEnglish Electric 506A, 2 offTransmissionDiesel electric, double reduction gearingMU workingNot fittedTrain heatingNoneTrain brakesNone; 15230–15232 Air from 1970

Performance figures
Maximum speed	27.5 mph (44.3 km/h)
Power output	Engine: 350 hp (261 kW)
Tractive effort	Maximum: 24,600 lbf (109.4 kN)

Career
Operators	British Railways
Class	D3/13, later 3/9, later Class 12
Numbers	15211–15236
Axle load class	RA 5
Withdrawn	1968-1971
Preserved	15224 at the Spa Valley Railway
Disposition	One preserved, remainder scrapped

References: ^[1]

The British Rail Class 12 is a diesel locomotive built primarily for shunting duties around London.

History

This was the second batch of Southern Railway shunters based on the English Electric 6KT 350 hp (260 kW) diesel engine. The first experimental batch (BR numbers 15201–15203) were designed by Richard Maunsell of the SR in 1937 and were later classified D3/12. These locomotives were Oliver Bulleid's development of Maunsell's original design, but were significantly lighter. They featured Bulleid's distinctive BFB wheels, and incorporated a number of details from the diesel-electric shunters produced by the London, Midland and Scottish Railway 1936–39.^[2] They were built at the BR Ashford Works over the period 1949–1952 and numbered 15211–15236. They later became Class 12, but no locomotives survived long enough to acquire Class 12 TOPS numbers.

Technical details

The diesel engine is an English Electric 6-cylinder, 4-stroke, 6KT and the traction motors are two EE506 axle-hung, nose-suspended, force-ventilated traction motors with 17.5:1 double reduction gear drive. The main generator is an EE type EE801/7D, flange-mounted single bearing rated at 490 kW.

Operational details

The locomotives were designed for use in the two South London marshalling yards at Norwood Junction and Hither Green, and remained there for much of their working lives.

Four (15230–15233) were fitted with air train braking originally for the 1966 Bournemouth line electrification scheme and the need for air brake depot shunters and station pilots; based at Bournemouth 1967 but re-allocated 1968 to Ashford and then often used at Dover shunting continental ferry vans before Classes 08 and 09 were generally converted to this system. They were also utilised as works shunters at Ashford, Brighton and Eastleigh.

Withdrawal and preservation

The entire class was withdrawn between 1968 and 1971 and most were scrapped soon afterwards. However, three were sold for industrial use with two of those locomotives being scrapped later on.^[3] One, 15222, had been used as a generator by a quarry in South Wales having been acquired from the Newport scrapyard of John Cashmore Ltd. A second, 15231, was sold by BR to Tilling Construction at Grassington. The third, 15224, was sold by BR to the National Coal Board for use in the Kent Coalfield. It was used at Betteshanger and Snowdown collieries, and was preserved in 1982. It is now the only surviving locomotive of the class, and is awaiting overhaul at the Spa Valley Railway, Royal Tunbridge Wells. A detailed overhaul and restoration scoping plan is in development; the locomotive requires a complete re-wire as the original wiring is suffering age related deterioration. As of January 2021, the project is on hold awaiting suitable funding.

Table of withdrawals^[3]

Year	Quantity in service at start of year	Quantity withdrawn	Locomotive numbers
1968	26	4	15213/15/34/36.
1969	22	5	15216/23/26/28/33.
1970	17	3	15217–18/27.
1971	14	14	15211–12/14/19–22/24–25/29–32/35.

Footnotes

References

• Bradley, D.L. (1975). Locomotives of the Southern Railway, Part 1. Oxford: Railway Correspondence and Travel Society. ISBN 0-901115-30-4.
• Marsden, Colin (1981). The diesel shunter: a pictorial record. Oxford: Oxford Publishing Company. ISBN 0-86093-108-0.
• Strickland, David C. (September 1983). Locomotive Directory: Every Single One There Has Ever Been. Camberley: Diesel and Electric Group. ISBN 978-0-906375-10-5. OCLC 16601890. OL 27959920M. Wikidata Q105978499.

Further reading

• McManus, Michael. Ultimate Allocations, British Railways Locomotives 1948 - 1968. Wirral: Michael McManus.