Castles and Kings

"Castles and Kings" are classes of steam locomotives built by the Great Western Railway in Swindon. Developed in the 1920s, the two classes "set a standard for British express locomotives by which all others came to be judged." ("The National Railway Collection", p.68.)

"Castle" class locomotives were introduced in 1923, a development of the 1906 "Star" class, with larger boiler and cylinders. They have been described as being "The most successful of all Swindon express passenger designs" (Nock, p.79).

"King" class locomotives were introduced in 1927.

This very substantial enlargement on the traditional Swindon 4 cylinder 4-6-0 engine [i.e. the 'Star' and 'Castle' classes] was made to provide exceptional tractive power for the heaviest West of England and Birmingham express services. The engines were extremely successful.
(Nock, pp.78-79.)

Here's a photo of the #6000 King George V engine (i.e. one of the Kings), "the most famous GWR locomotive of all" (Ransom, p.188). This engine is now in the Great Western Railway Museum in Swindon.

Sources:

1. The National Railway Collection, 1988
2. O.S. Nock, The Railway Enthusiast's Encyclopedia, 1968
3. P.J.G. Ransom, The Archaeology of Railways, 1981

appears in:

"Red Brick Dream" (now on The Big Express)

further reading:

• A page devoted to the history of the King George V engine.
• Information about the GWR Museum, one of the "places to visit" listed at the Swindon Visitor's Guide.