British Railway History Item
George Jackson Churchward
George Jackson Churchward (1857-1933)
The son of a Devon farmer, he was a pupil of John Wright, South Devon Railway and in 1873-77 he was under William Dean at Swindon, Great Western Railway. He was the assistant to the Swindon carriage works manager 1882-85, when he worked on an improved vacuum brake system, and improved axle bearings to minimize overhauls and delays. He was made carriage works manager in 1885 and in 1895 locomotive works manager. From 1897 he was also the main assistant to Dean, whom he succeeded as Chief Mechanical Engineer in 1902.
From 1903-11 he introduced nine standard locomotive types, with maximum component compatibility, of which 1,100 were built up to 1921. There were of advanced design, based on the latest American and European practise, embodying free-steaming tapered boilers and long-lap, long travel valve gear, providing economical use of steam.
His locomotive designs included:
Four-cylinder express locomotives using divided drive and other features from three French Compound locomotives imported by the GWR for tests against Churchward's own simple-expansion locos.
After the French loco experiments, it was decided that the 4-6-0 wheel arrangement was more suitable than the 4-4-2 for GWR requirements and ten four-cylinder simple 4-6-0s were built at Swindon, appearing in 1907 as the Star Class.
New 4-4-0 City class with 6ft 8in coupled wheels, built in conjunction with Dean while he was still chief. The best known is City of Truro, now preserved, which on its high speed run with an up Ocean Mail special on 9 May 1904, achieved a maximum of 102.3mph down Wellington bank; later opinion put this at around 100mph
Two 4-6-0s with different wheel diameters. One of them with 6ft 8.5in coupled wheels was built in 1902 while Dean was still in office. He named it William Dean after his old chief. This prototype was developed into his own characteristic type of two-cylinder 4-6-0, keeping the 18in by 30in stroke cylinders.
His Saint Class 4-6-0s, which were smooth runners at speed, which could sometimes perform better in hard pulling than the later Stars with Walschaerts valve gear.
His one and only Pacific type 4-6-2, The Great Bear. Until the advent of the Gresley Pacifics of 1922, it was the only loco with that wheel arrangement in Britain, its axle load restricting it to use on the Paddington-Bristol main line. When it required a new boiler in 1924, Collett decided to rebuild it as a Castle Class locomotive.
4-4-0 County Class in which the two outside cylinders drove the leading coupled axle. There performance was good, but they attained a reputation as rough riders.
2-6-0 and 2-8-0 tender engines, and 4-4-2, 2-6-2 and 2-8-0 tank engines, all with two cylinders
His piston valves were a hallmark of his design. The advantages to steam distribution of large-diameter valves were well understood, but there were problems in making them steamtight. His solution, after many experiments, was relatively complex, but the valves could be mass produced and so justift themselves economically as well as by performance.
With George Hughes, Lancashire & Yorkshire Railway, he pioneered the British use of superheating, which increased power and efficiency. He was recognised as the most outstanding engineer of his time, his design practise being continued by his successors until 1947 and largely adopted by the CMEs of the other railway companies grouped in 1923. He remodelled Swindon works with a new one and a half acre boiler and erecting shop, and in 1904 built the first successful locomotive testing plant in Europe. His 70 foot main line carriages and other passenger stock gave a considerable advance in comfort.
Last Updated : Friday 14th April 2006 05:45