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 Due for heavy repairs in January 1924, it was withdrawn from service by Churchward's successor Charles Collett.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