British Rail Class 28

Metropolitan Vickers Type 2,
British Rail Class 28

Two 'Metrovicks' Nos. D5703 & D5710 passing through Millbrook, Bedfordshire in 1960

Type and origin Power type Diesel-electric Builder Metropolitan-Vickers’ Bowesfield Works, . Build date 1958–1959 Total produced 20

Specifications Configuration Co-Bo UIC class Co'Bo' Gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge Wheel diameter 3 ft 3 1⁄2 in (1.003 m) Minimum curve 3.5 chains (70 m) Wheelbase 42 ft 9 in (13.03 m) Length 56 ft 7 1⁄2 in (17.26 m) Width 8 ft 6 in (2.59 m) Height 12 ft 1 1⁄2 in (3.70 m) Loco weight 97 long tons (98.6 t; 109 short tons) Fuel capacity 510 imp gal (2,300 l; 610 US gal) Prime mover Crossley HST V8 Generator DC Traction motors Metropolitan-Vickers 137BZ, DC 5 off Transmission Diesel electric MU working ● Red Circle Train heating Spanner steam generator (railroad) of 1,500 lb/h (680 kg/h) Train brakes Vacuum

Performance figures Maximum speed 75 mph (121 km/h) Power output Engine: 1,200 hp (895 kW) Tractive effort Maximum: 50,000 lbf (222 kN)

Career Operators British Railways Numbers D5700–D5719 Axle load class Route availability 6 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 1955 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 and uncommon in other countries, although Japan also used some C-B diesel hydraulics. This made maintenance more complicated. The maximum tractive effort of 50,000 lbf (220 kN) was unusually high for a Type 2 locomotive but, as there were five (not four) driving axles, the risk of wheelslip was minimal.

With low-speed Crossley 8-cylinder HST Vee8 two stroke engines, they represented an experiment in two stroke versus four stroke engines for diesel-electric traction.

The engines had exhaust pulse pressure charging and developed 1,200 horsepower (895 kW) at 625 rpm. There were no valves, and inlet and exhaust were via ports in the cylinder walls. The same engine was originally fitted in the Irish A Class and the Western Australian Government Railways X class. A similar, but smaller engine, the ESNT6 was used in the D3/3 shunters, an 08 with a Crossley engine rather than English-Electric.