11001

11001 was one of the first British Railways diesel locomotives, built in 1949 at British Railways' Ashford Works. It was designed by O. V. S. 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 an 0-6-0 wheel formation.

Its main duties were on branch lines and shunting. It survived until 1959, when it was withdrawn in August and cut up at Ashford Works in December.

Oddly, the locomotive's controls were laid out as in a steam locomotive, because there were at that time no drivers with experience of driving diesel engines.