GWR 4000 Class

Great Western Railway 4000 Star class
4054 Princess Charlotte
Type and origin Power type Steam Designer George Jackson Churchward Builder GWR Swindon Works Order number Lots 161, 168, 173, 178, 180, 195, 199, 217 Build date 1906–1923 Total produced 73
Specifications Configuration: ​  • Whyte 4-6-0 (prototype built as 4-4-2 but rebuilt to 4-6-0 1909).  • UIC 2′C h4 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 3 in (8.31 m) Loco weight 75.8 long tons (77.0 t; 84.9 short tons) Tender weight 40 long tons (41 t; 45 short tons) Water cap. 3,500 or 4,000 imp gal (16,000 or 18,000 L; 4,200 or 4,800 US gal) Firebox: ​  • Grate area 27.1 sq ft (2.52 m2) Boiler GWR Standard No. 1 (with variations) Boiler pressure 225 psi (1.55 MPa) Heating surface: ​  • Firebox 154.8 sq ft (14.38 m2)  • Tubes 1,686.6 sq ft (156.69 m2) Superheater "Swindon No. 3" Cylinders 4, (2 outside, 2 inside) Cylinder size 14+1⁄4 in × 26 in (362 mm × 660 mm) - 15 in × 26 in (381 mm × 660 mm) Valve gear Walschaerts inside Valve type Piston valves
Performance figures Tractive effort 25,090 lbf (111.61 kN) - 27,800 lbf (123.66 kN)
Career Operators Great Western Railway British Railways Class 4000 or Star Power class GWR: D BR: 5P Numbers 4000–4072 Axle load class GWR: Red Withdrawn 1926–1957 Disposition 15 rebuilt as Castle class, 1 preserved, remainder scrapped.

The Great Western Railway 4000 or Star were a class of 4-cylinder 4-6-0 passenger steam locomotives designed by George Jackson Churchward for the Great Western Railway (GWR) in 1906 and introduced from early 1907. The prototype was built as a 4-4-2 Atlantic (but converted to 4-6-0 during 1909). They proved to be a successful design which handled the heaviest long-distance express trains, reaching top speeds of 90 mph (145 km/h), and established the design principles for GWR 4-cylinder classes over the next twenty-five years.^[1]