LSWR 415 class

LSWR/SR 415 class
415 class No. 30583 at Tipton St Johns in 1953, while on a railtour.
Type and origin Power type Steam Designer William Adams Builder Robert Stephenson & Co. (28); Dübs & Co. (20); Neilson & Co. (11); Beyer Peacock (12) Serial number RS 2501–2518, 2601–2610 Dübs 2000–2009, 2105–2114; Neilson 3200–3210; BP 2167–2178 Build date 1882–1885 Total produced 71
Specifications Configuration: ​  • Whyte 4-4-2T Gauge 4 ft 8+1⁄2 in (1,435 mm) Leading dia. 3 ft 1 in (0.940 m) Driver dia. 5 ft 7 in (1.702 m) Length 36 ft 5+1⁄2 in (11.11 m) Loco weight 55 tons 2 cwt (124,200 lb or 56.3 t) Fuel type Coal Fuel capacity 1 long ton (1.02 t; 1.12 short tons) Water cap. 1,200 imp gal (5,500 L; 1,400 US gal) Boiler pressure 160 psi (1.10 MPa) Cylinders Two, outside Cylinder size 17.5 in × 24 in (444 mm × 610 mm)
Performance figures Tractive effort 14,919 lbf (66.36 kN)
Career Operators London and South Western Railway, Southern Railway, British Railways Class 415, later 0415 Power class LSWR / SR: K, BR: 1P Nicknames Radial Tank Locale Great Britain Withdrawn 1916–1928, 1961 Preserved No. 488 Disposition One preserved, remainder scrapped

The LSWR 415 class is a 4-4-2T steam tank locomotive, with the trailing wheels forming the basis of its "Radial Tank" moniker. It was designed by William Adams and introduced in 1882 for service on the London and South Western Railway (LSWR).

Originally rostered for suburban traffic, the class was soon displaced to the countryside by Dugald Drummond's M7 class. Most of the class was scrapped around the end of the First World War, and further decreases meant that all of them were due to be withdrawn by 1929. However, the class was noted for its long service on the Lyme Regis branch line, and three members of this long obsolete class were utilised on this duty until 1962, when suitable replacements became available. One has survived and can be found on the Bluebell Railway.