British Rail 11001
11001
Type and origin Power type Diesel-mechanical Builder BR Ashford railway works Order number 3410 Build date February 1, 1949 (1949-02-01) Total produced 1
Specifications Configuration: ​  • Whyte 0-6-0DM  • UIC C Gauge 4 ft 8+1⁄2 in (1,435 mm) standard gauge Wheel diameter 4 ft 6 in (1.372 m) Length 33 ft 3 in (10.13 m) Loco weight 49.45 long tons (50.24 t; 55.38 short tons) Prime mover Paxman RPH Series 1 Transmission Mechanical, SSS Powerflow 3-speed gearbox Train heating None
Performance figures Maximum speed 45 mph (72 km/h) Power output Engine: 500 bhp (373 kW) Tractive effort 33,500 lbf (149.0 kN)
Career Operators British Railways Numbers 11001 Axle load class Route availability Retired 8 August 1959 Disposition Scrapped at Ashford Works on 31 December 1959

11001 was one of the first British Railways diesel locomotives, built in 1949 at British Railways' Ashford railway works. It was designed by Oliver Bulleid when he was Chief Mechanical Engineer of the Southern Railway. It was powered by a Paxman RPH Series 1 engine, capable of delivering 500 brake horsepower (370 kW) at 1,250 rpm. It was driven via a Vulcan-Sinclair fluid coupling to an SSS (synchro-self-shifting) Powerflow gearbox. The gearbox provided three forward and reverse gears in either high or low range, with top speed ranging from 5 mph (8 km/h) in 1st gear, low range up to 36 mph (58 km/h). It had a 0-6-0 wheel formation, driven by rods from a rear jackshaft on the final drive, and with Bulleid's favoured BFB wheels.^[1]

Its main duties were on branch lines and shunting, working dwindling goods services on the Caterham line during the 1950s.^[2] It was allocated to Norwood Shed, but also has been photographed in Swindon. It was withdrawn in August 1959 and scrapped at Ashford Works in December.

Unusually, the locomotive's controls were laid out as in a steam locomotive, possibly due to few drivers having experience with diesels at the time. There are no known photographs of the interior.