Class 13 (BR/English Electric 0-6-0+0-6-0 Diesel-Electric)

Tinsley goods yard was an example of what was known as a "hump yard". Wagons were pushed over the hump or high point in the yard and then gravity (and a complicated control system) could do the rest. The yard needed a more powerful locomotive than the standard Class 08 shunter [1] and so with typical British Rail ingenuity a "new" locomotive was created out of two Class 08s! The two shunters were connected in a master and slave arrangement, with the cab of one locomotive controlling both. The shunter was known as the Class 13, three such conversions were made in the mid-1960s.
13 001 at Tinsley yard (KD Collection)

Information
Number built:
Built: 1965 (Conversions from Class 08)
Builder: BR Darlington
Motor: 2 English Electric 6KT diesels
Power: 700 hp (522 kW)
Wheel arrangement: 0-6-0+0-6-0

At first the two locomotives were connected with the cabs together in the middle but later on the cab from the master locomotive was placed outmost to aid visibility. The cab from the slave unit was removed. Extra weights were added in the bufferbeams to aid tractive effort (the weight of a Class 13 was 120 tons [2], 20 tons more than two Class 08s would be). The locomotives were withdrawn in the early 1980s as the practice of hump shunting ended. None of the Class 13s were preserved.

[1] Colin J Marsden, Diesel & Electric Locomotive Recognition Guide (Ian Allan, 2011) p. 95
[2] Brian Haresnape, Diesel Shunters (Ian Allan, 1984) p. 75