|Design: English Electric|
|Engine: English Electric Eight Cylinder 8SVT (1000hp)|
|Main Generator: English Electric|
|Traction Motors: English Electric|
|Wheel Arrangement: Bo-Bo|
|Total Built: 228 (1957-68 at Vulcan Foundry & RSH)|
Built by English Electric and introduced to BR from 1957, the 20's were the only successful type one design. Originally built for light trip freight work, but as this traffic disappeared in the mid sixties they were primarily used in pairs on coal trains in the midlands, although could be seen on most parts of the BR network with members of the class also based on the scottish and eastern regions. A few of these engines are still working in mainline service for DRS and HNRC.