British Rail Class 56

British Rail Class 56

Electroputere-built 56 006 at Doncaster in 2003 painted in rail blue livery

Type and origin Power type Diesel-electric Builder Electroputere (56 001–56 030) BREL (56 031–56 135) Build date 1976–1984 Total produced 135

Specifications Configuration Co-Co UIC class Co'Co' Gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge Length 63 ft 6 in (19.35 m) Width 9 ft 2 in (2.79 m) Height 12 ft 9 in (3.89 m) Loco weight 123 long tons (125 t) Fuel capacity 1,150 imp gal (5,200 l; 1,380 US gal) Prime mover Ruston-Paxman 16RK3CT MU working ◆ Red Diamond Train heating None Train brakes Air

Performance figures Maximum speed 80 mph (129 km/h) Power output Engine: 3,250 bhp (2,424 kW) at rail: 2,400 bhp (1,790 kW) Tractive effort Maximum: 61,800 lbf (275 kN) Continuous: 53,950 lbf (240 kN) at 16.8 mph (27 km/h) Loco brakeforce 59 long tons-force (588 kN)

Career Operators British Rail Colas Rail English Welsh & Scottish Floyd Zrt. UK Rail Leasing Numbers 56 001–56 135 Axle load class Route availability 7

The British Rail Class 56 is a type of diesel locomotive designed for heavy freight work. It is a Type 5 locomotive, with a Ruston-Paxman power unit developing 3,250 bhp (2,423 kW), and has a Co-Co wheel arrangement. The fleet was introduced between 1976 and 1984.

The first thirty locomotives (Nos. 56 001 - 56 030) were built by Electroputere in Romania, but these suffered from poor construction standards and many were withdrawn from service early for extensive rebuilding before re-entering revenue service. The remaining 105 locomotives were built by BREL at Doncaster Works (nos. 56 031 to 56 115) and Crewe Works (Nos. 56 116 to 56 135). Enthusiasts nicknamed them "Gridirons" (or "Grids" for short), due to the grid-like horn cover on the locomotive's cab ends fitted to nos. 56 056 onwards.

When specifying the Class 56, British Rail chose its bodyshell design to be based on the Brush-built Class 47 design, minus some features like the obsolete headcode panel.

When introduced, the Class 56s were arguably the first of the "second generation" of UK diesel locomotives.

The engine is a direct descendant of English Electric CSVT types, its closest relative being the 16CSVT used in the Class 50. Technical advances included significantly uprated turbochargers, gear driven camshafts in place of the timing chain used on Class 50s, and uprated cylinder heads, fuel pumps and injectors. The engine was nominally rated at 3,520 hp (2,620 kW), but was set at 3,250 hp (2,420 kW) for rail use.

A key difference between the Class 56s and the earlier designs of the 1950s and 1960s is the use of self-exciting alternators rather than direct current (DC) generators for the generation of traction current and auxiliary supply. This produces a far more robust power unit, and greatly reduces the risk of flash-overs and other earth faults. Traction supply was rectified since the type employs DC traction motors. Many auxiliary machines (such as compressors and traction motor blowers) used the unrectified 3-phase AC output of the auxiliary alternator, and therefore run at a speed proportional to engine r.p.m.