BR Standard Class 3 2-6-0

BR Standard Class 3 2-6-0

BR Standard Class 3 2-6-0 77000 at Darlington Works on 22 March 1959. This locomotive was then currently allocated to Hull (Springhead) MPD (shed code 53C).

Type and origin Power type Steam Designer Robert Riddles Builder BR Swindon Works Build date February – September 1954 Total produced 20

Specifications Configuration 2-6-0 UIC class 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 m2) Boiler BR6 Boiler pressure 200 psi (1.38 MPa) Heating surface:  • Tubes and flues 923.54 sq ft (85.800 m2)  • Firebox 118.42 sq ft (11.002 m2) Superheater: ​  • Heating area 184.50 sq ft (17.141 m2) 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Career Operators British Railways Power class 3MT Numbers 77000–77019 Axle load class Route availability 4 Withdrawn 1965–1967 Disposition All scrapped

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.

The design and construction took place at the ex-GWR Swindon Works, along with the 2-6-2T tank engine version of the class, though some details were designed at Brighton, Derby and Doncaster. 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 (76XXX), which also had 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.

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. 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.