British Rail Class 112

British Rail Classes 112 and 113
Last train from Nottingham Arkwright Street, 1969
In service	1960–1969
Manufacturer	Cravens
Constructed	1960
Number built	Class 112: 25 sets (50 cars) Class 113: 25 sets (50 cars)
Number scrapped	All
Formation	Power-twin: DMBS-DMCL
Capacity	DMBS: 52 second DMCL: 12 first, 51 second
Operator(s)	British Rail
Specifications
Car length	57 ft 6 in (17.53 m)
Width	9 ft 3 in (2.82 m)
Maximum speed	70 mph (110 km/h)
Weight	DMBS: 30 long tons 0 cwt (67,200 lb or 30.5 t), DMCL: 30 long tons 0 cwt (67,200 lb or 30.5 t)
Prime mover(s)	One Rolls-Royce C8NFLH
Power output	238 hp (177 kW) per car
Transmission	Class 112: Mechanical 4-speed epicyclic gearbox Class 113: Hydraulic
UIC classification	(1A)(A1)+(1A)(A1)
Braking system(s)	Vacuum
Coupling system	Screw-link
Multiple working	■ Blue Square
Track gauge	4 ft 8 1⁄2 in (1,435 mm)

The Class 112 and Class 113 DMUs used the standard Cravens body used on Class 105s but had a single Rolls-Royce C8NFLH engine rated at 238 hp (177 kW) per car, all of which formed into 'power twins'- two car sets with both vehicles powered.

There were two batches built, the first 50 vehicles (25 sets) had standard mechanical transmission via a gearbox and were allocated the Class 112. The second batch of 50 cars (25 sets) had hydraulic transmission, and became Class 113s.

The cars were built for services in the LMR Central Division and in the Liverpool - St Helens area, where the gradients in the Lancashire & Yorkshire area required more power. Both types also spent some time working from Cricklewood.

The gross weight of a set with all seats occupied was approximately 70 tons, giving 6.8 hp (5.1 kW) per ton. Empty, it was 8.1 hp/ton, which compared favourably with 5.7 hp/ton that the Cravens power/trailer had.

Orders

Lot No.	Diagram	Car Type	Qty	Fleet numbers	Notes
30533	602	Driving Motor Brake Third (DMBS)	25	51681–51705	Class 112
30534	603	Driving Motor Composite with lavatory (DMCL)	25	51706–51730	Class 112
30535	604	Driving Motor Brake Third (DMBS)	25	51731–51755	Class 113
30536	605	Driving Motor Composite with lavatory (DMCL)	25	51756–51780	Class 113

Other technical details

• Coupling Code: Blue Square
• Transmission: Standard Mechanical (Class 112), Hydraulic (Class 113)

Preservation

All 112s and 113s were withdrawn by the end of 1969, and none survive.

References

• The Railcar Association
• Motive Power Recognition: 3 DMUs. Colin J. Marsden
• British Railway Pictorial: First Generation DMUs. Kevin Robertson
• British Rail Fleet Survey 8: Diesel Multiple Units- The First Generation. Brian Haresnape
• A Pictorial Record of British Railways Diesel Multiple Units. Brian Golding