|Design: British Railways|
|Engine: Sulzer Six Cylinder 6LDA28 (1160hp)|
|Main Generator: British Thompson Houston|
|Traction Motors: British Thompson Houston|
|Wheel Arrangement: Bo-Bo|
|Total Built: 151 (1958-61 at Derby, Crewe & Darlington)|
|Total : 4|
These engines were the first of the type 2 'Sulzers' and were designated class 24 upon renumbering due to their BTH electrical equipment. Introduced from 1958 they were initially based on the midland and eastern regions, with later examples going to Scotland. Withdrawals started in 1975 and the last member of the class was taken out of service at Crewe in 1981.