British Rail Class 28

Metropolitan Vickers Type 2 British Rail Class 28
Two 'Metrovicks' Nos. D5703 & D5710 passing through Millbrook in 1960
Power type	Diesel-electric
Builder	Metropolitan-Vickers’ Bowesfield Works, Stockton-on-Tees.
Build date	1958–1959
Total production	20
Configuration	Co-Bo
UIC classification	Co'Bo'
Gauge	4 ft 8+1⁄2 in (1,435 mm) standard gauge
Wheel diameter	3 ft 3½ in (1.003 m)
Minimum curve	3.5 chains (70 m)
Wheelbase	42 ft 9 in (13.03 m)
Length	56 ft 7½ in (17.26 m)
Width	8 ft 6 in (2.59 m)
Height	12 ft 1½ in (3.70 m)
Locomotive weight	97 long tons (98.6 t)
Fuel capacity	510 imp gal (2,300 l; 610 US gal)
Prime mover	Crossley HST V8
Traction motors	Metropolitan-Vickers 137BZ, 5 off
Transmission	DC generator, DC traction motors
Multiple working	● Red Circle
Top speed	75 mph (121 km/h)
Power output	Engine: 1,200 hp (895 kW)
Tractive effort	Maximum: 50,000 lbf (222 kN)
Train heating	Spanner steam generator (railroad) of 1,500 pounds (680 kg) per hour
Train brakes	Vacuum
Career	British Railways
Number	D5700–D5719
Axle load class	Route availability 8
Retired	December 1967 – September 1969
Disposition	One preserved, remainder scrapped

The British Rail Class 28 (Metropolitan-Vickers Type 2) diesel locomotives, or 'Metrovicks' as they were popularly known, were built as part of the British Railways Modernisation plan. The locomotives had a Co-Bo wheel arrangement (a 6-wheel bogie at one end, a 4-wheel bogie at the other) – unique in British Railways practice though not uncommon in other countries, notably Japan. This affected their route availability, due to the different axle loading at each end of the loco, and made maintenance more complicated. The maximum tractive effort of 50,000 lbf was unusually high for a Type 2 locomotive but, as there were five (not four) driving axles, the risk of wheelslip was minimal.