In 1958, Brush Traction Ltd and Beyer Peacock co-operated to produce five prototype diesel-electric shunting locomotives of 0-4-0 wheel arrangement. They were intended to demonstrate a new generation of diesel shunters for industrial and mainline use. Two were loaned to British Railways for trials, and one was subsequently purchased by BR. However, no large scale orders resulted from these demonstrators.

D2999

D2999 was loaned to BR from 1960 and subsequently purchased by them for further use, being withdrawn in October 1967. It was fitted with a National M4AAV6 engine of 200hp, had a maximum speed of 18mph and weighed 30tons.

D9998

D9998 was on loan to BR for approximately a year from mid-1961. It was fitted with a Petter McLaren engine of 200hp, had a maximum speed of 18mph and weighed 30tons.