There were two batches built, the first 50 vehicles (25 sets) had standard mechanical transmission via a gearbox and were allocated the Class 112.

Due to incidents that occurred when Class 113 units (which had hydraulic transmission and automatic gear change) were coupled to a unit with mechanical transmission and gear change - usually, a Class 112 - the Class 113 units were changed to the Red Triangle coupling code (the Red Triangle code had previously been used for the early Derby Lightweight DMUs used in the Leeds area, but those were all now withdrawn).

The Class 112 and 113 units looked similar and one assumes this led to the driving errors.

General withdrawal of class 113 began in February 1969, and was completed in July the same year.

[1] Some were cut up at BR workshops such as Derby and Doncaster, but most were sold to scrap merchants.