George Jackson Churchward
|Died||19 December 1933 (aged 76)|
George Jackson Churchward CBE (31 January 1857 - 19 December 1933) was an English railway engineer, and was chief mechanical engineer of the Great Western Railway (GWR) in the United Kingdom from 1902 to 1922.
Churchward was born in Stoke Gabriel, Devon, where his ancestors had been squires since 1457. He was educated at the King Edward VI Grammar School, contained within the Mansion House on Fore Street, Totnes, Devon.
Apprenticed in the Newton Abbot works of the South Devon Railway, he completed his apprenticeship under Joseph Armstrong in the GWR's Swindon Works. There he rose from draughtsman through several positions, including Carriage Works Manager, and in 1897 was appointed Chief Assistant to William Dean.
After 5 years as Chief Assistant, during most of which time Dean was ill and delegating much of his design work to Churchward, in 1903 he formally succeeded Dean as Locomotive Superintendent. In 1900 he became the first mayor of Swindon.
In the 19th and early 20th century, railway companies were fiercely competitive. Speed meant revenue and speed was dependent on engineering. Churchward delivered to the GWR from Swindon a series of class-leading and innovative locomotives. Arguably, from the early 1900s to the 1920s the Great Western's 2-cylinder and 4-cylinder 4-6-0 designs were substantially superior to any class of locomotive of the other British railway companies. On one occasion, the GWR's directors confronted Churchward, and demanded to know why the London and North Western Railway were able to build three 4-6-0 locomotives for the price of two of Churchward's "Stars". Churchward allegedly gave a terse response: "Because one of mine could pull two of their bloody things backwards!"
The biggest engineering challenge of the GWR's operations was travelling over the South Devon Banks, a series of steep inclines linking Exeter and Plymouth in Devon, on the GWR's most important route. Although speed was a key competitive driver across the whole GWR route, the South Devon Banks rewarded sure-foooted locomotive designs with good adhesion. The largest opportunity to any GWR CME was the resulting large loading gauge legacy of the GWR's conversion from Brunel's broad gauge track to standard gauge, allowing for wider and higher designs than any of the other later Big Four railway companies.
Following principles based on Belgian inventor Alfred Belpaire, Churchward preferred free steaming boilers. This resulted in his use of a Belpaire-style rectangular firebox, which due to its greater surface area for evaporation was less prone to foaming and carry over of water to the cylinders. Churchward inherited from Dean a series of parallel cylindrical boilers, but by applying mathematical principles to the flow of boiler water, quickly improved the flow of steam by adopting tapered boilers, which give their largest area to the point of highest steam production. Churchward then dispensed with the need for a large dome to collect steam, using instead top-feed of water supply from injectors, which together with top-fitted clack boxes hidden within a brass "bonnet" minimised boiler stress.
Churchward experimented with compounding, a principle development for marine engines which was widely adopted in European locomotive design. Although through his experimentation Churchward found little difference in operation the total power developed in compounding locomotives, the use of European locomotives in his trial led to his adoption of higher pressure boilers, and drive power split between two axles on four cylinder designs.
His third stream of philosophy was based around piston valves. Churchward's valves were 50% larger than anything seen in the UK to that time, travelled 50% further, and were designed to be concealed. The result gave the minimum loss of pressure as steam passes to the cylinders.
Churchward resulting locomotive designs excluded trailing wheels, which maximised adhesion on the South Devon Banks. He was an early adopter in UK locomotive design of superheating, made efficient through the GWR's exclusive use of the high calorific-value steam coal from the South Wales Coalfield. He also adopted large bearing surfaces to reduce wear, something common in North America.
Churchward is credited with introducing to Britain several refinements from American and French steam locomotive practice. Among these were the tapered boiler and the casting of cylinders and saddles together, in halves. His choice of outside cylinders for express locomotives was also not standard in Britain for that time. Many elements of British practice were retained, of course. His locomotives for the most part used British plate frames, and the crew was accommodated in typical British fashion. The selection of a domeless boiler was more common to Britain than to the US.
In September 1902, whilst still assisting Dean, Churchward had a member of the Atbara Class, no. 3405 Mauritius, reboilered with Belpaire firebox and the first use of a tapered boiler on the GWR. Once he became CME, the boiler became the prototype for Churchward's GWR Standard No. 4 boiler. This experiment led to the design of the City' class, with the first outshopped from Swindon in March 1903, No. 3433 City of Bath. It was fitted with the final form of the Standard No.4 boiler, with slightly curved sides and a tapered top to the firebox. The class soon became one of the most famous classes of locomotives in the world, when City of Truro became the first engine in the world to haul a train at 100 miles per hour in 1904 (although unauthenticated).
In 1901, whilst still assistant to Dean, the GWR board approved Churchward's plan to build a series of two cylinder 4-6-0 locomotives.
No. 100 was out-shopped in February 1902, named Dean (later William Dean) in June 1902 to mark the latter's retirement. It incorporated a domeless parallel boiler, raised Belpaire firebox, 19 in (48.3 cm) diameter outside cylinders with 30 in (76.2 cm) piston stroke, and boiler pressure of 200 psi (1.38 MPa). The piston valves were driven by rocking levers actuated by the expansion link of Stephenson valve gear - this particular design was only used on no. 100.
No. 98 was out-shopped in March 1903, to a similar design but with a taper boiler, re-designed valve gear layout and cylinders, and a shorter wheelbase. Valve diameters were increased from inches (170 mm) to 10 inches (250 mm).
No. 171 was out-shopped in December 1903, incorporating the improvements to No. 98 but with a 225 psi (1.55 MPa) boiler and minor amendments to the heating surface and grate area. Built as a 4-6-0, in October 1904 it was converted to a 4-4-2 to enable better comparison with the performance of the French de Glehn compound; it was reconverted to 4-6-0 in July 1907. Named Albion in 1904, it received a superheated boiler in 1910.
On succeeding Dean, the GWR board authorised Churchward to purchase three French de Glehn-du Bousquet four-cylinder compound locomotives, in order to evaluate the benefits of compounding. Similar to the Paris-Orleans Railway's 3001 class and built by Société Alsacienne de Constructions Mécaniques, the first locomotive no.102 La France was delivered in 1903, with Nos. 103 and 104 purchased in 1905. The locomotives had two high pressure cylinders fitted between the frames, and two low pressure cylinders outside.
Each was initially fitted with a standard-pattern GWR chimney, a GWR tender and had their numbers positioned in GWR fashion on the sides of the cab. They were then each placed into service to evaluate performance, and then following engine crew feedback were modified to test other aspects of Churchward's design experimentation and philosophy. In 1926, the three locomotives were based at Oxford shed. In operational practice, these compounding did not provide any significant improvement in either performance or economy compared to No 171 Albion, Churchward's prototype 4-6-0, which was converted to a 4-4-2 specifically for direct comparison with them.
Experimental 4-6-0 No. 171 formed the basis of the GWR 2900 Saint Class. It appeared in four production series built between 1905 and 1913, each of which differed in dimensions. There were also differences between members of each series in terms of the boilers used, wheel arrangement (Churchward was unsure of the choice between 4-4-2 and 4-6-0), and arrangements for superheating.
The locomotives performed well as passenger locomotives over all the long-distance routes of the GWR and on all but the fastest express trains until they gradually became displaced to secondary services by the Castle Class in the late 1920s and 1930s. However, the 6 ft in (2.045 m) driving wheels limited their usefulness on freight trains. Churchward had recognized this limitation by the introduction of his GWR 4700 Class 2-8-0 design with 5 ft 8 in (1.727 m) driving wheels in 1919, intended for express goods trains. However, Churchward's successor Charles Collett felt that a smaller-wheeled version of the 'Saint' class could form the basis of a successful mixed traffic class of locomotives. He therefore rebuilt No. 2925 Saint Martin with 6 ft (1.829 m) driving wheels to become the prototype of his successful Hall Class locomotives. Thus the 2900 class became a template for later GWR 2-cylinder 4-6-0 classes including the Modified Hall, Grange, Manor and County classes, all of which were of the same basic design.
The class incorporated many revolutionary advances which were influential in British locomotive design for the next fifty years. According to The Great Western Society, 'Saint' class locomotives "represented one of the most important steps forward in railway traction of the 20th century", and they "are now acknowledged to have had a profound influence on almost every aspect of subsequent steam locomotive development".
GWR 111 The Great Bear was the first 4-6-2 (Pacific) locomotive used on a railway in Great Britain, the only one of that type ever built by the GWR, which is today seen as Churchward's notable failure in locomotive design. No clear GWR commercial reason existed for the design, so it is concluded by many as a further Churchward experiment, considered to explore what came beyond the Star Class when train loads increased beyond their capability. Basically a developed Star class locomotive, the larger boiler over trailing wheels allowed a firebox surface of 182 sq ft (16.9 m2), a 17.5% increase in size compared to the Star Class. It was also built with a Swindon No. 1 superheater.
Due to its weight and 20 long tons 9 cwt (20.8 t) axle load, the locomotive was restricted to the Paddington to Bristol main line, mainly Paddington under driver Thomas Blackall, originally from Aston Tirrold, Oxfordshire. Despite later experimental developments, in service the performance of The Great Bear proved to be disappointing, and not a significant improvement on existing classes. The excellent performance of the Star Class and advent of the First World War brought a stop to further experimentation without significant improvement.
Although not a technical success, The Great Bear was considered the company's flagship locomotive from its introduction until Churchward's retirement in 1922. With the introduction of 4073 Caerphilly Castle in 1923 with a higher tractive effort, the locomotive ceased to have any publicity value and became an embarrassment. Due for heavy repairs in January 1924, it was withdrawn from service by Churchward's successor Charles Collett. It emerged from Swindon later that year as a 4-6-0 Castle Class, given the name Viscount Churchill.
In 1922 Churchward retired, and C. B. Collett inherited his legacy of excellent, standardised designs. These designs influenced British locomotive practice to the end of steam. Major classes built by the LMS and even British Railways 50 years later are clearly developments of Churchward's basic designs. The LMS Stanier Class 5 4-6-0 and the BR standard class 5 are both derived from his Saint class early examples of which date to 1902.
BR Western Region class 47 locomotive no. D1664 (later 47079) was named George Jackson Churchward upon delivery in February 1965. It was renamed G. J. Churchward in March 1979, and the name was removed in October 1987.
Although Churchward had retired in 1922, he continued to live in a GWR-owned house near to the line at Swindon, and he retained his interest in the company's affairs. He never married. On 19 December 1933, now with poor eyesight and hard of hearing, he was inspecting a defectively-bedded sleeper on the down through line, when he was struck and killed by a Paddington to Fishguard express, pulled by No. 4085 'Berkeley Castle'. The locomotive was of the GWR Castle class, a successful design by Charles Collett derived from Churchward's "Star" class.
He is buried at Christ Church in Old Town, Swindon.