BR standard class 4 tank

BR standard class 4 tank

80152 at Nine Elms MPD, 1965.

Type and origin Power type Steam Designer R.A. Riddles Builder Brighton Works (130) Derby Works (15) Doncaster Works (10) Build date July 1951 – November 1956 Total produced 155

Specifications Configuration: ​  • Whyte 2-6-4 T  • UIC 1′C2′ h2t Gauge 4 ft 8 1⁄2 in (1,435 mm) Leading dia. 3 ft 0 in (0.914 m) Driver dia. 5 ft 8 in (1.727 m) Trailing dia. 3 ft 0 in (0.914 m) Length 44 ft 10 in (13.67 m) Width 8 ft 9 1⁄4 in (2.67 m) Height 13 ft 0 in (3.96 m) Axle load 17.95 long tons (18.24 t; 20.10 short tons) Adhesive weight 53.05 long tons (53.90 t; 59.42 short tons) Loco weight 86.65 long tons (88.04 t; 97.05 short tons) Fuel type Coal Fuel capacity 3.50 long tons (3.56 t; 3.92 short tons) Water cap 2,000 imp gal (9,100 l; 2,400 US gal) Firebox:  • Firegrate area 26.7 sq ft (2.48 m2) Boiler ABR5 Boiler pressure 225 psi (1.55 MPa) Heating surface:  • Tubes and flues 143 sq ft (13.3 m2)  • Firebox 1,223 sq ft (113.6 m2) Superheater: ​  • Heating area 240 sq ft (22 m2) Cylinders Two, outside Cylinder size 18 in × 28 in (457 mm × 711 mm)

Performance figures Tractive effort 25,100 lbf (111.7 kN) Factor of adh. 4.65

Career Operators British Railways Power class 4MT Numbers 80000–80154 Axle load class Route availability 5 Withdrawn July 1962 – July 1967 Disposition 15 preserved (list), remainder scrapped

The British Railways Standard Class 4 tank is a class of steam locomotive, one of the BR standard classes built during the 1950s. They were used primarily on commuter and outer suburban services.

On the nationalisation of British Railways (BR) in 1948 the London Midland Region had a number of ex-London, Midland and Scottish Railway 2-6-4T and the Western Region a number of GWR Large Prairie 2-6-2T types. These tank engines were particularly suited to commuter and secondary services. However, particularly in Scotland and the Southern Region, the situation was not so good with large numbers of pre-grouping types struggling on.

On the decision to build the BR standard series of locomotives, a series of class four tank engines was ordered, based on the ex-LMS Fairburn 2-6-4T with some modifications. The lineage of the class could therefore be tracked through the LMS/BR Class 4 2-6-4T locomotives back to the Fowler design of 1927.

Design work was done at Brighton, the overall programme being overseen by R.A. Riddles. The principal modifications to the Fairburn design involved the reduction of their envelope to enable them to fit into the L1 loading gauge. To do this the tanks and cab were made more curved than the Fairburn design, the Fairburn having a straight-sided tank. The biggest mechanical change was a reduction in cylinder size, also to reduce cross-section, and a corresponding increase in boiler pressure to compensate. Other visible changes include the reintroduction of plating ahead of the cylinders.