GWR 4900 Class

Specifications
Specifications
Configuration:;
• Whyte	4-6-0
• UIC	2′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.	6 ft 0 in (1.829 m)
Minimum curve	8 chains (528 ft; 161 m) normal,; 7 chains (462 ft; 141 m) slow
Length	63 ft 0+1⁄4 in (19.21 m) over buffers
Width	8 ft 11+1⁄4 in (2.724 m)
Height	13 ft 3+1⁄4 in (4.045 m)
Axle load	18 long tons 19 cwt (42,400 lb or 19.3 t); (21.2 short tons)
Adhesive weight	57 long tons 0 cwt (127,700 lb or 57.9 t); (63.8 short tons)
Loco weight	75 long tons 0 cwt (168,000 lb or 76.2 t); (84.0 short tons)
Tender weight	46 long tons 14 cwt (104,600 lb or 47.4 t); (52.3 short tons)
Fuel type	Coal
Fuel capacity	Churchward tender: 7 long tons (7.1 t; 7.8 short tons); Collett/Hawksworth tender: 6 long tons (6.1 t; 6.7 short tons)
Water cap.	Churchward tender: 3,500 imp gal (16,000 L; 4,200 US gal) ; Collett/Hawksworth tender: 4,000 imp gal (18,000 L; 4,800 US gal)
Firebox:
• Grate area	27.07 sq ft (2.515 m2)
Boiler	GWR Standard No. 1
Boiler pressure	225 lbf/in2 (1,550 kPa; 15.8 kgf/cm2)
Heating surface:
• Firebox	154.78 sq ft (14.380 m2)
• Tubes and flues	1,686.60 sq ft (156.690 m2)
Superheater:;
• Heating area	262.62 sq ft (24.398 m2)
Cylinders	Two, outside
Cylinder size	18.5 in × 30 in (470 mm × 762 mm)

Type and origin
Type and origin
Power type	Steam
Designer	Charles Collett
Builder	GWR Swindon Works
Order number	Lots 254, 268, 275, 281, 290, 297, 304, 311, 327, 333, 338, 340
Build date	1928–1943
Total produced	258
Rebuilder	GWR Swindon Works
Rebuild date	1924
Number rebuilt	1 (4900 Saint Martin)

GWR 4900 Class
GWR 4900 Class
	5900 Hinderton Hall at Didcot in 2010
Power type
Type and origin
Power type	Steam
Designer	Charles Collett
Builder	GWR Swindon Works
Order number	Lots 254, 268, 275, 281, 290, 297, 304, 311, 327, 333, 338, 340
Build date	1928–1943
Total produced	258
Rebuilder	GWR Swindon Works
Rebuild date	1924
Number rebuilt	1 (4900 Saint Martin)
Configuration:;
Specifications
Configuration:;
• Whyte	4-6-0
• UIC	2′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.	6 ft 0 in (1.829 m)
Minimum curve	8 chains (528 ft; 161 m) normal,; 7 chains (462 ft; 141 m) slow
Length	63 ft 0+1⁄4 in (19.21 m) over buffers
Width	8 ft 11+1⁄4 in (2.724 m)
Height	13 ft 3+1⁄4 in (4.045 m)
Axle load	18 long tons 19 cwt (42,400 lb or 19.3 t); (21.2 short tons)
Adhesive weight	57 long tons 0 cwt (127,700 lb or 57.9 t); (63.8 short tons)
Loco weight	75 long tons 0 cwt (168,000 lb or 76.2 t); (84.0 short tons)
Tender weight	46 long tons 14 cwt (104,600 lb or 47.4 t); (52.3 short tons)
Fuel type	Coal
Fuel capacity	Churchward tender: 7 long tons (7.1 t; 7.8 short tons); Collett/Hawksworth tender: 6 long tons (6.1 t; 6.7 short tons)
Water cap.	Churchward tender: 3,500 imp gal (16,000 L; 4,200 US gal) ; Collett/Hawksworth tender: 4,000 imp gal (18,000 L; 4,800 US gal)
Firebox:
• Grate area	27.07 sq ft (2.515 m2)
Boiler	GWR Standard No. 1
Boiler pressure	225 lbf/in2 (1,550 kPa; 15.8 kgf/cm2)
Heating surface:
• Firebox	154.78 sq ft (14.380 m2)
• Tubes and flues	1,686.60 sq ft (156.690 m2)
Superheater:;
• Heating area	262.62 sq ft (24.398 m2)
Cylinders	Two, outside
Cylinder size	18.5 in × 30 in (470 mm × 762 mm)
Tractive effort
Performance figures
Tractive effort	27,275 lbf (121.33 kN)
Operators
Career
Operators	GWR » BR
Power class	GWR: D,; BR: 5MT
Numbers	4900–4999, 5900–5999, 6900–6958
Official name	Hall
Axle load class	GWR: Red
Withdrawn	1941 (4911 Bowden Hall, was destroyed beyond repair during a bombing raid and then cut up), 1959–1965 (remainder)
Preserved	4920, 4930, 4936, 4942, 4953, 4965, 4979, 5900, 5952, 5967, 5972
Disposition	Ten preserved or extant (two operational as of March 2021), ; one rebuilt as Saint class,; remainder scrapped

The Great Western Railway 4900 Class or Hall Class is a class of 4-6-0 mixed-traffic steam locomotives designed by Charles Collett for the Great Western Railway. A total of 259 were built at Swindon Works, numbered 4900–4999, 5900–5999 and 6900–6958. The LMS Stanier Class 5 4-6-0 and LNER Thompson Class B1 both drew heavily on design features of the Hall Class. After nationalisation in 1948, British Railways gave them the power classification 5MT.