GWR 2900 Class

Great Western Railway 2900 Saint class
2981 Ivanhoe at Tilehurst in 1948
Type and origin Power type Steam Designer George Jackson Churchward Builder GWR Swindon Works Build date 1902-1913 Total produced 77
Specifications Configuration: ​  • Whyte 4-6-0 (thirteen examples were built as 4-4-2 but rebuilt to 4-6-0 1912/13).  • UIC 2'Ch2 Gauge 4 ft 8+1⁄2 in (1,435 mm) standard gauge Leading dia. 3 ft 2 in (0.965 m) Driver dia. 6 ft 8+1⁄2 in (2.045 m) Trailing dia. 4 ft 1+1⁄2 in (1.257 m) (4-4-2 only) Wheelbase loco: 27 ft 1 in (8.26 m) – 27 ft 7 in (8.41 m) loco & tender: 53 ft 4+3⁄4 in (16.28 m) – 53 ft 10+3⁄4 in (16.43 m) Length 63 ft 0+1⁄4 in (19.21 m) Width 8 ft 11 in (2.718 m) Height 13 ft 3+1⁄2 in (4.051 m) Axle load 18 long tons (18 t; 20 short tons) Loco weight 68.30 long tons (69.40 t; 76.50 short tons) Tender weight 43.15 long tons (43.84 t; 48.33 short tons) Fuel capacity 5 long tons (5.1 t; 5.6 short tons) Water cap. 3,500 imp gal (16,000 L; 4,200 US gal) – 4,000 imp gal (18,000 L; 4,800 US gal) Firebox: ​  • Grate area 27.22 sq ft (2.529 m2) Boiler GWR Standard No. 1 (with variations) Boiler pressure 225 psi (1.55 MPa) (production series) Heating surface: ​  • Firebox 154.94 sq ft (14.394 m2)  • Tubes and flues 1,485.96 sq ft (138.050 m2) Superheater: ​  • Type "Swindon No. 3"  • Heating area 307.52 sq ft (28.570 m2) Cylinders Two, outside Cylinder size 18 in × 30 in (457 mm × 762 mm) or 18+1⁄2 in × 30 in (470 mm × 762 mm) Valve gear Stephenson Valve type 10 inches (254 mm) piston valves (2935 rebuilt with poppet valves)
Performance figures Tractive effort 20,530 lbf (91.32 kN) – 24,395 lbf (108.51 kN)
Career Operators Great Western Railway British Railways Class 2900 or Saint Power class GWR: C BR: 4P Number in class 76 Numbers 2900–2955, 2971-2990, 2998 Axle load class GWR: Red Retired 1924–1953 Disposition One rebuilt as Hall class (2925/4900 Saint Martin), remainder scrapped; One 4900 example has been backdated to 29XX specification

The Great Western Railway 2900 Class or Saint Class, which was built by the Great Western Railway's Swindon Works, incorporated several series of 2-cylinder passenger steam locomotives designed by George Jackson Churchward and built between 1902 and 1913 with differences in the dimensions. The majority of these were built as 4-6-0 locomotives; but thirteen examples were built as 4-4-2 (but converted to 4-6-0 during 1912/13). They proved to be a highly successful class which established the design principles for GWR 2-cylinder classes over the next fifty years, and influenced similar classes on other British railways.