Changes

The Southern Region of British Railways ordered 98 locomotives from Birmingham Railway Carriage and Wagon Company (BRCW) of SmethickSmethwick, Birmingham (works numbers DEL 92-156, DEL 169-189 and DEL 157-168). The last 12 locomotives were 7 inches narrower, to enable working through the restricted tunnels of the Hastings line. All were delivered between 1960 and 1962 in standard BR loco green, most being repainted BR blue during the late 1960s and early 1970s. The locomotives were of a new design, based on the BRCW Type 2 (later Class 26), with a larger engine. They are powered by a Sulzer 8 cylinder in-line engine of 1,550 bhp, designated 8LDA. The main generator and the four traction motors were supplied by Crompton Parkinson, hence the class's 'Crompton' nickname. The class worked all kinds of duties on the Southern Region including passenger trains, for whey were the first BR diesel locomotives to have electric train heating. During 1967, 19 of the locomotives were fitted with push-pull equipment to enable them to haul 4-TC units on the unelectrified section from Bournemouth to Weymouth, and to carry warning lights and klaxons for boat trains on the road section of the Quay.<ref>[http://www.class33crompton.co.uk/CromptonHistory.htm Cromptons' history, BR Class 33 website] (Retrieved 12 September 2020)</ref> In the TOPS renumbering these were designated Class 33/1 and the Hastings line 'Slim Jims' Class 33/2. Electrification was extended to Weymouth in 1988 and the 33/1 sub-class displaced to wider duties.