GWR 4073 Class.html



GWR 4073 Castle class

5034 Corfe Castle fresh from Swindon Works, 1954.
Power type	Steam
Designer	Charles Collett
Builder	GWR / BR Swindon Works
Build date	1923–1950
Total production	171
Configuration	4-6-0
UIC classification	2'Ch4
Gauge	4 ft 8½ in (1,435 mm)
Driver size	6 ft 8½ in (2.045 m)
Locomotive weight	79.85 long tons (81.13 t)
Tender weight	46.70 long tons (47.45 t)
Boiler pressure	225 psi (1.55 MPa)
Cylinders	Four
Cylinder size	16 mm × 26 mm (0.63 in × 1.0 in)
Valve gear	Inside cylinders: Walschaerts Outside cylinders: derived from inside cylinders via rocking bars.
Valve type	Piston valves
Tractive effort	31,625 lbf (140.68 kN)
Career	Great Western Railway British Railways
Power class	GWR: D BR: 7P
Number	4073–4099; 5000–5099; 7000–7037.
Axle load class	GWR: Red

Earl Bathurst

Earl Bathurst on a railtour

GWR Caerphilly Castle

The GWR 4073 Class or Castle class locomotives were a group of 4-6-0 steam locomotives of the Great Western Railway.¹ They were originally designed by the railway's Chief Mechanical Engineer, Charles Collett, for working the company's express passenger trains.

History

A development of the earlier Star Class, one hundred and seventy-one (171) were built, over a 25 year span from August 1923 to August 1950. They were numbered 4073–4099; 5000–5099; 7000–7037.

Although most were built new, sixteen locos were rebuilt from older locomotives—fifteen Star Class locomotives; and the Great Western Railway's sole 4-6-2 locomotive, number 111 The Great Bear.

The Castle class was noted for superb performance on the Cheltenham Flyer during the 1930s: on 6 June 1932, pulled by 5006 Tregenna Castle, the train covered 77 miles (124 km) from Swindon to Paddington at an average speed of 81.68 miles per hour (131.45 km/h). This world record for steam traction was widely regarded as an astonishing feat.

In 1926, number 5000 Launceston Castle was loaned to the London, Midland and Scottish Railway where it ran trials between London to Carlisle. It was rumoured that LMS tried to persuade GWR to build a batch of Castles for use on the West Coast Main Line.

Withdrawal started in the 1950s; the last to be withdrawn was Clun Castle at the end of 1965.

Specifications

Cylinders: 4; 16 in (406 mm) diameter, 26 in (660 mm) stroke
Valve gear: inside cylinders – Walschaert's; outside cylinders – derived from inside cylinders via rocking bars.
Valves: piston valves
Boiler pressure: 225 lbf/in² (1.55 MPa)
Driving wheel diameter: 6 ft 8.5 in (2.04 m)
Tractive Effort: 31,625 lbf (140.675 kN)
Engine weight: 79 tons 17 cwt (81.1 Mg)
Tender weight: 46 tons 14 cwt (47.44 Mg)

List of locomotives

See List of GWR 4073 Class locomotives

Preservation

Eight Castles survive in preservation:

References

• Brian Haresnape (1978). Collett & Hawksworth Locomotives—A Pictorial History. Ian Allan Ltd. ISBN 0-7110-0869-8. 

External links

• Daniel, John. "4073 'Castle' class introduction". Great Western steam locomotives.