BR Standard Class 3 2-6-0

The BR Standard Class 3 2-6-0 was a class of mixed traffic steam locomotive designed by Robert Riddles for British Railways. It was essentially a hybrid design, the chassis being closely based on and sharing a number of parts with the LMS Ivatt Class 4, and having a boiler derived from a GWR No.2 boiler as fitted to the GWR Large Prairie 2-6-2T and 5600 Class 0-6-2T tank engines.

BR Standard Class 3 2-6-0
77018 at Bogside Racecourse, 1961.
Type and origin Power type Steam Designer Robert Riddles Builder BR Swindon Works Build date February – September 1954 Total produced 20
Specifications Configuration: ​  • Whyte 2-6-0  • UIC 1′C h2 Gauge 4 ft 8 ^1⁄2 in (1,435 mm) standard gauge Leading dia. 3 ft 0 in (0.914 m) Driver dia. 5 ft 3 in (1.600 m) Length 55 ft 11 ^1⁄4 in (17.05 m) Width 8 ft 5 ^5⁄8 in (2.58 m) Height 13 ft 0 in (3.96 m) Axle load 16.25 long tons (16.51 t; 18.20 short tons) Adhesive weight 48.50 long tons (49.28 t; 54.32 short tons) Loco weight 57.50 long tons (58.42 t; 64.40 short tons) Tender weight 42.15 long tons (42.83 t; 47.21 short tons) Tender type BR2A Fuel type Coal Fuel capacity 6.00 long tons (6.10 t; 6.72 short tons) Water cap 3,500 imp gal (16,000 l; 4,200 US gal) Firebox:  • Firegrate area 20.35 sq ft (1.891 m^2) Boiler BR6 Boiler pressure 200 psi (1.38 MPa) Heating surface:  • Tubes and flues 923.54 sq ft (85.800 m^2)  • Firebox 118.42 sq ft (11.002 m^2) Superheater: ​  • Heating area 184.50 sq ft (17.141 m^2) Cylinders Two, outside Cylinder size 17.5 in × 26 in (444 mm × 660 mm)
Performance figures Tractive effort 21,490 lbf (95.6 kN) Factor of adh. 5.05
Career Operators British Railways Power class 3MT Numbers 77000–77019 Axle load class Route availability 4 Withdrawn 1965–1967 Disposition All scrapped

Design details

The design and construction took place at the ex-Great Western Railway Swindon Works, along with the 2-6-2 tank engine version of the class, though some details were designed at Brighton, Derby and Doncaster.[1] Although the boiler shared flanged plates with the GWR No.2 boiler the barrel was shortened by ​5 ¹³⁄₁₆ inches and a dome added. Strangely the class did not share the same design of wheels as the Doncaster-designed BR Standard Class 4 2-6-0, however both shared the 5 ft 3 in (1,600 mm) driving wheels and the same piston stroke, and hence crank-pin throw.

In common with a number of the other BR Standard Classes, the chassis design used a number of LMS-designed components including Brake Hanger Brackets, Flexible Stretcher Brackets and Reversing Shaft Brackets.

The cylinder covers of engines as built were fitted with "screw-in" type pressure relief valves. From September 1955 revised cylinder covers were introduced for renewals incorporating "bolt-on" type pressure relief valves.[2]

Although the chassis had many almost identical parts to the LMS Ivatt Class 4 the motion brackets were derived from the design of those fitted to the LMS Ivatt Class 2 2-6-0 and LMS Ivatt Class 2 2-6-2T.

Unlike a number of the larger BR Standards the exhaust steam manifold within the smokebox saddle was a steel fabrication that was part of the welded saddle.[3] In a number of the large BR standards (BR Standard Class 6 and Class 7 engines) the exhaust steam manifold was a steel casting welded into the saddle during manufacture.[4]

Service

Only 20 were built, numbers 77000–77019, all at Swindon Works. Their operations were mainly restricted to the North Eastern and Scottish Regions, of British Railways, although 77014 ended its days on the Southern Region. Due to their small number, the class were the antithesis of 'standard' engines and it would probably have been better to build more 2-6-0s to the Standard Class 4 and Standard Class 2 designs instead. None has survived to preservation, though some components were saved from scrapyards for use on a project to build a new Standard Class 3 2-6-2T. This class was the last class of steam locomotive on British Railways to remain complete before suffering its first withdrawal. Number 77014 was transferred from Northwich depot on the London Midland Region to Guildford depot on the Southern Region in March 1966; it was withdrawn in July 1967.[5][6]

Withdrawals

Year	Number in service at start of year	Number withdrawn	Locomotive numbers
1965	20	1	77010
1966	19	16	77000–01/03–09/11/13/15–19
1967	3	3	77002/12/14

References

1. Cooke, B.W.C., ed. (June 1954). "British Railways Standard Class "3" 2-6-0 Locomotives". The Railway Magazine. Vol. 100 no. 638. Westminster: Tothill Press. pp. 418–419.
2. Rear cylinder cover to BR drawing SL/SW/35 being superseded by SL/SW/666 and front cylinder cover to drawing SL/SW/85 being superseded by SL/SW/667 for renewals from September 1955.
3. Confirmed on original BR drawing SL/SW/616 sourced from the NRM
4. Confirmed on original BR drawing SL/DE/19620 sourced from the NRM
5. Teal (1985), p. 74.
6. Walford (2003), p. 226.

Bibliography

• ABC of British Railways Locomotives. Part 3 (Winter 1962 ed.). Ian Allan. p. 175.
• Bradley, Rodger P. (1984). The Standard Steam Locomotives of British Railways. David & Charles. ISBN 0715383841.
• Teal, Paul (1985). BR Motive Power Allocations 1959-1968 - 1: BR Standards & Austerities. Shepperton: Ian Allan. ISBN 0-7110-1540-6.CS1 maint: ref=harv (link)
• Walford, John (2003). "Section 5.7.2 Allocation Summary". In Taylor, R.K. (ed.). A Detailed History of British Railways Standard Steam Locomotives. Volume Two: The 4-6-0 and 2-6-0 Classes. Peterborough: RCTS. ISBN 0-901115-93-2.

External links

• Railuk database
• BR Standard Class 3MT 2-6-0 (SEMG article)