GWR 4000 Class

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GWR 4000 Star class

A view of the front end of 4003 Lode Star.
Power type	Steam
Designer	George Jackson Churchward
Builder	GWR Swindon Works
Build date	1907–1923
Total production	73
Configuration	4-6-0
UIC classification	2'Ch
Gauge	4 ft 8+1⁄2 in (1,435 mm)
Leading wheel size	3 ft 2 in (0.965 m)
Driver size	6 ft 8½ in (2.045 m)
Fuel type	Coal
Boiler	GWR Number 1
Boiler pressure	225 psi (1.55 MPa)
Fire grate area	27.1 sq ft (2.52 m2)
Heating surface: Tubes	1,686.6 sq ft (156.69 m2)
Heating surface: Firebox	154.8 sq ft (14.38 m2)
Superheater area	262.6 sq ft (24.40 m2)
Cylinder size	15 in × 26 in (381 mm × 660 mm)
Tractive effort	27,800 lbf (123.7 kN)
Career	GWR » BR
Class	GWR: 4000 Star
Number	4000–4072
Withdrawn	1925–1957
Disposition	One preserved, remainder scrapped

4003 Lode Star in the National Railway Museum.

A Star class locomotive was a particular type of steam locomotive of the Great Western Railway. The prototype was an experimental locomotive, North Star (originally given number 40), constructed with the 'Atlantic' 4-4-2 wheel arrangement for comparative trials with 4-cylinder compound locomotives of the de Glehn type that had been purchased from France. This established the benefits of the balanced 4 cylinder layout but the designer, George Churchward, decided that he would continue the class with simple steam expansion, and also with the 4-6-0 wheel arrangement he had introduced with the 2900 class. As in the de Glehn design, the outer cylinders drove the centre driving axle, the inside pair of cylinders were set well forward and drove the leading driving axle.

Construction of the production class began in 1907. In the production class (4001 to 4072) there were just two set of Walschaerts valve gear between the frames, the valves to the outside cylinders being driven by rocking levers.

An enlarged version of the design was introduced in 1923, as the Castle Class, of which about 170 were constructed, including some rebuilds from the 'Star' class.

One example of the 'Star" class, 4003 Lode Star, survives in preservation as a static, non-working, exhibit.

[edit] List of locomotives

[edit] External links

• http://www.greatwestern.org.uk/m_in_str.htm