BR Standard Class 4 2-6-4T
|BR standard class 4 tank|
|80152 at Nine Elms MPD, 1965.|
|Builder||Brighton Works (130)
Derby Works (15)
Doncaster Works (10)
|Build date||July 1951 – November 1956|
|Gauge||4 ft 8 1⁄2 in (1,435 mm)|
|3 ft 0 in (0.914 m)|
|Driver diameter||5 ft 8 in (1.727 m)|
|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)|
|Weight on drivers||53.05 long tons (53.90 t)|
|Locomotive weight||86.65 long tons (88.04 t)|
|Fuel capacity||3.50 long tons (3.56 t)|
|Water capacity||2,000 imp gal (9,100 l; 2,400 US gal)|
|Boiler pressure||225 psi (1.55 MPa)|
|Firegrate area||26.7 sq ft (2.48 m2)|
Tubes and flues
|143 sq ft (13.3 m2)|
|1,223 sq ft (113.6 m2)|
|Superheater area||240 sq ft (22 m2)|
|Cylinder size||18 in × 28 in (457 mm × 711 mm)|
|Tractive effort||25,100 lbf (111.7 kN)|
|Number||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|Withdrawn||July 1962 – July 1967|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.
Design and construction
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.
130 of the class of 155 were built at Brighton, 15 (80000–80009, 80054–80058) at Derby Works and 10 (80106–80115) at Doncaster Works between 1951 and 1956. The first to emerge was 80010 from Brighton in 1951. Fifteen that were due to be constructed in 1957 were cancelled due to impending dieselisation, and the last five would have been too had they not been at an advanced stage of construction when the order came to cancel them.
No significant modifications were made to the design. The tank vent was found to restrict the driver's vision and was moved further forward from 80059. Initially built with fluted coupling rods, these caused problems on other classes and from 80079 plain section coupling rods were substituted.
The BR standard class 4 4-6-0 was essentially a tender engine derivative of the Standard Class 4 tank.
The Standard 4 tanks were originally allocated to all regions of British Railways, except the Western. They became particularly associated with the London, Tilbury and Southend Line (LT&S) working commuter services out of London until that route was electrified in 1962. They were also widely used in East Sussex and Kent working from Brighton, Tunbridge Wells and Three Bridges on those lines of the former London Brighton and South Coast Railway that were not electrified. Another group worked from Polmadie depot in the Scottish region on the Glasgow commuter services. Note that from July 1962, a batch displaced by electrification of the LT&S was transferred to the Western Region's Swansea (East Dock) and Shrewsbury districts, as well as other regions.
In the 1960s there was a mass withdrawal of steam locomotive classes. Older types were withdrawn in preference to the Standard 4s, which class remained intact until 1964. The final nine were withdrawn from the Southern Region on 9 July 1967. One Scottish Region example, 80002, remained in Glasgow past the end of steam haulage until 1969 as a static carriage heating boiler.
No. 80103 was withdrawn in 1962 after being reported for rough riding. It was towed between two other locomotives to Stratford Works, where it was discovered that the mainframe was broken in half. Considered beyond economic repair, 80103 was withdrawn and scrapped. It was the first of the 'Standard' locomotives to be withdrawn and the only one scrapped at Stratford.
No fewer than fifteen Standard Four tanks have survived the cutter's torch. This is the highest number for any preserved BR standard class, and is second only to the now 18 strong LMS Black Fives as the most preserved main line type, unless the Bulleid Light Pacifics are counted as one class (there are twenty Light Pacifics in preservation). All but three (80097, 80100 and 80150) have operated in preservation.
|Details of preserved engines|
|80002||Keighley and Worth Valley Railway||Operational|
|80064||Bluebell Railway||Awaiting major overhaul|
|80072||Llangollen Railway||On loan to North Yorkhire Moors Railway for summer 2011 season|
|80078||Swanage Railway||Boiler certificate expired 2010. Awaiting overhaul|
|80079||Severn Valley Railway||Cosmetically restored in The Engine House.|
|80080||Midland Railway - Butterley||Operational at the East Lancashire Railway|
|80097||East Lancashire Railway||Currently under restoration|
|80098||Midland Railway - Butterley||Awaiting Overhaul|
|80100||Bluebell Railway||Awaiting restoration|
|80105||Bo'ness and Kinneil Railway||Boiler certificate expired 2010. Undergoing major 4 year overhaul|
|80135||North Yorkshire Moors Railway||The only Class 4MT preserved in British Railways green livery. No 4MTs ran in British Rail green in main line service. Recently withdrawn from service, awaiting a full overhaul|
|80136||Crewe Heritage Centre||Boiler ticket expired in 2008, and currently nearing the end of a major 10 year overhaul at Crewe Heritage centre|
|80150||Mid Hants Railway||Still as recovered from scrapyard. Awaiting restoration|
|80151||Bluebell Railway||Static display. Boiler ticket expired in May 2012|
- Bradley, Rodger P. (1984). The Standard Steam Locomotives of British Railways. David & Charles Publishers plc.
- Chancellor, Paul J. (December 1997). Taylor, R. K., ed. A Detailed History of British Railways Standard Steam Locomotives: vol 3 Tank Engine Classes. Railway Correspondence and Travel Society (RCTS). ISBN 0-901115-77-0.
|Wikimedia Commons has media related to: BR Standard Class 4 2-6-4T|
- Preserved engines