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-footed locomotive designs with good adhesion. The largest opportunity to any GWR Chief Mechanical Engineer 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.
Philosophy Churchward's design philosophy followed a number of streams of development, for which he thoroughly researched both competitor UK designs, as well as European and
North American locomotives. 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. 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.
1901 outline scheme In 1901 Churchward produced a scheme of six different locomotive types based on a few standard parts. All would have cylinders with diameter and stroke, piston valves of diameter, and all leading or trailing wheels would be diameter. Locomotive classes corresponding to all these proposals were eventually built, with some differences in the dimensions.
Notable locomotives GWR 4-4-0 3700 Class In September 1902 Churchward had a member of the
Atbara Class, no. 3405
Mauritius, reboilered with a
Belpaire firebox and the first use of a tapered boiler on the GWR. 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).
Experimental 4-6-0 locomotives 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, diameter outside cylinders with piston stroke, and boiler pressure of . 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 to . No. 171 was out-shopped in December 1903, incorporating the improvements to No. 98 but with a 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. 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, 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. A further 13 engines in the Saint class were also originally built as 4-4-2s. 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".
Standard locomotive classes The Saints and their derived classes were only part of Churchward's scheme. Based on a limited number of standard parts—including boilers, cylinders, wheels and valve gear—he planned a range of locomotives for duties such as express passenger, mixed traffic, heavy freight and suburban trains, with both tender and tank versions. He began to construct some of his designs immediately; he also extended the range of designs as the demands of the business required, producing the
4300 Moguls and
4700 express freight engines. His mixed-traffic design did not appear until Collett built the Granges in 1936.
GWR 4-6-0 4000 Class The
Great Western Railway 4000 or
Star class were 4-cylinder
4-6-0 passenger locomotives introduced from early 1907. The prototype was built in May 1906 as a 4-4-2 Atlantic (but later converted to 4-6-0). The design benefited from experience gained from the 'Saint' class and the De Glehn engines. The locomotives proved to be very successful, handling the heaviest long-distance express trains, reaching top speeds of , and they established the design principles for GWR 4-cylinder classes over the next twenty-five years.
The Great Bear Pacific 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 , 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 axle load, the locomotive was restricted to the
Paddington to Bristol main line, mainly under Paddington 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.
Legacy 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. ==Death==