Power type Steam Builder BR Swindon Works Total produced 80 | Designer R. A. Riddles Build date May 1951 – May 1957 Configuration 4-6-0 | |
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The British Railways Standard Class 4 4-6-0 is a class of steam locomotives, 80 of which were built during the 1950s. Six have been preserved.
Contents
Background
The class was introduced in 1951. They were designed for mixed traffic use on secondary routes where the otherwise ubiquitous BR standard class 5 and their predecessors, the Black Fives, would be too heavy. They were essentially a tender version of the standard 4 2-6-4T, with similar characteristics to the GWR Manor Class, though unlike the Manors they were built to the universal loading gauge. They used the same running gear as the tank engine (with the leading bogie from the Standard Class 5), and substantially the same firebox, smokebox and boiler, although the boiler barrel was increased in length by 9 inches (229 mm).
Design work was done at Brighton by R. A. Riddles, with help from Swindon, Derby and Doncaster. Construction was at the BR Swindon Works.
The engine weighed 67.90 long tons (68.99 t; 76.05 short tons), was 60 ft 0 in (18.29 m) long, with 5 ft 8 in (1.727 m) diameter driving wheels. It had two cylinders of 18 inches (457 mm) diameter and 28 inches (711 mm) stroke operated at maximum boiler pressure of 225 lbf/in2 (1.55 MPa), to produce 25,515 lbf (113.5 kN) tractive effort. Its British Railways power classification was 4MT.
It normally used the standard BR2 or BR2A tender, which weighed 42.15 long tons (42.83 t; 47.21 short tons) and carried 3,500 imp gal (16,000 l; 4,200 US gal) of water and 6.00 long tons (6.10 t; 6.72 short tons) of coal. In this configuration its route availability was 4, almost universal over the British Railways network.
In service
The class was initially allocated to the London Midland Region (45) and the Western Region (20). The last 15 were allocated to the Southern Region. The Southern batch were built with BR1B tenders, which weighed 49.15 long tons (49.94 t; 55.05 short tons), and carried 4,725 imp gal (21,480 l; 5,674 US gal) of water and 7.00 long tons (7.11 t; 7.84 short tons) of coal. This reduced their route availability to 7, the same as the Standard Class 5.
Preservation
All but 75079 have worked in preservation at some point. None of the class are presently mainline approved but three of them (75014, 75029 and 75069) have worked on the main line. Two members of the class (75014 and 75078) are presently operational with 75014 returning to service in December 2016. 75029 was passed to work on the main line between Battersby and Whitby but is presently awaiting boiler work.
Modelling
Bachmann and Hornby have both recently released models of these engines in 00 gauge.