GWR 633 Class

GWR 633 Class

Type and origin Power type Steam Designer George Armstrong Builder GWR Wolverhampton Works

Specifications Configuration 0-6-0T Gauge 4 ft 8 ^1⁄2 in (1,435 mm) standard gauge Driver dia. 4 ft 6 ^1⁄2 in (1,384 mm) Wheelbase 15 ft 6 in (4.72 m) Loco weight 14 long tons 12 cwt (14.8 t; 16.4 short tons) Cylinder size 16 in × 24 in (406 mm × 610 mm) dia × stroke

Career Operators Great Western Railway Class 633

The GWR 633 Class were 0-6-0 tank locomotives designed by George Armstrong and built at the Wolverhampton railway works of the Great Western Railway in 1871-2. Unusually, they had side (not saddle) tanks, and inside frames, with wheels of 4 ft 6 ¹⁄₂ in (1,384 mm) in diameter and a wheelbase of 15 ft 6 in (4.72 m). The weight was 34 tons 12 cwt. There were twelve locomotives, numbered 633-644.^[1]

Modifications

Nos. 643 and 644 were fitted with condensing apparatus when built, for working on the Metropolitan Railway Widened Lines and this was added to some others in the 1890s. From 1887 they were reboilered with Dean pattern boilers and the wheels were enlarged by one inch (25 mm) by means of thicker tyres. The class was reboilered again with Belpaire fireboxs (but not pannier tanks) between 1916 and 1925.

Service

They were intended for the Southern Division of the GWR. The condenser-fitted engines worked in the London area, others at Neath in South Wales. Withdrawal took place in 1928-34.^[2]

References

1. Smith, Martin, Steam on the Underground, Ian Allan Publishing 1994, p.22, ISBN 0-7110-2282-8
2. le Fleming 1958, pp. E33-E35.

Sources

• le Fleming, H. M. (1958). The Locomotives of the Great Western Railway, part five: Six-coupled Tank Engines. Kenilworth: RCTS.