GWR 4900 Class

Background

By the end of 1923 the GWR was well served with express passenger locomotives of the Saint and Star classes and had recently introduced the Castle Class. However the mixed traffic 2-6-0 locomotives of the 4300 Class were beginning to struggle with the increasing loads. George Jackson Churchward had recognised this with the introduction of the 4700 class 2-8-0 with 5 ft 8 in (1.727 m) driving wheels, intended for express goods and relief passenger trains. However, Collett preferred the idea of a Saint Class with smaller wheels to undertake these duties as this would provide a leading bogie. He therefore rebuilt number 2925 Saint Martin with 6 ft (1.829 m) driving wheels.

Prototype

The prototype of the new class was rebuilt in 1924 and the cylinders were realigned in relation to the driving axle and a more modern 'Castle'-type cab was fitted. Saint Martin emerged from Swindon in 1924 and embarked on three years of trials. During this period Collett introduced other modifications such a changing the pitch of the taper boiler and adding outside steam pipes.

Production

After extensive trials during 1925-1927, Collett was satisfied with the performance of his prototype, subject to minor amendments and placed an order for eighty more with Swindon works (Lot 254) in 1928. The prototype was renumbered 4900 in December 1928 and the new locomotives were numbered 4901-80 and appeared at regular intervals until February 1930.They were named after English and Welsh country houses with 'Hall' in their titles and so became known as the 'Hall Class'.

They differed little from the prototype; the bogie wheel diameter had been reduced by two inches from 3 ft 2 in (0.965 m) to 3 ft 0 in (0.914 m) and the valve setting amended to give an increased travel of 7.5 in (191 mm). The overall weight of the locomotive had increased by 2 long tons 10 cwt (5,600 lb or 2.5 t) to 75 long tons 0 cwt (168,000 lb or 76.2 t) but a tractive effort of 27,275 lbf (121.33 kN) compared favourably with the 24,935 lbf (110.92 kN) of the 'Saint'. The original locomotives were built with Churchward 3,500 imp gal (16,000 l; 4,200 US gal) tenders but after 4958 Collett's larger 4,000 imp gal (18,000 l; 4,800 US gal) types became standard although a few later locomotives were fitted with smaller tenders if these were available as they entered service.

The first fourteen examples were despatched to the arduous proving grounds of the Cornish main line. They were so successful here and elsewhere on the GWR system that by the time the first production batch had been completed a further twenty were on order (Lot 268, 4981-99 and 5900). Further orders followed throughout the 1930s and early 1940s. By 1935, 150 were in service and the 259th and last Hall, No. 6958 Oxburgh Hall, was delivered in 1943. Thereafter further deliveries were of the '6959 Modified Hall' class.

Performance

As indicated by their continuing production, the Hall class proved to be very successful in a variety of different roles, although barred from several cross-country and branch lines because of their red weight classification. According to Peter Herring, 'they were the first true mixed traffic locomotives, and as such precursors of the Stanier 'Black Five', Thompson B1 and BR Standard 5MT 4-6-0.' (This may have been true as far as 4-6-0 types were concerned but there were several successful 2-6-0 ‘mixed traffic’ types on the GWR and other British railways before them, - not least the GWR 4300 Class they were designed to replace. )

Modified Hall Class

Although the GWR had been at the forefront of British locomotive development between 1900 and 1930, the 1930s saw a degree of complacency at Swindon reflected in the fact that the design had largely originated in the 1900s and had not fundamentally changed since the mid 1920s. Collett was replaced by F.W. Hawksworth in 1941 who created a modified version of the design, known as the Modified Hall Class. These remained in production under British Railways until 1950, by which time there were a further seventy-one locomotives.

Accidents and incidents

Withdrawal

All but one of the original Collett Halls entered British Railways service in 1948, the exception being No. 4911 Bowden Hall. Official withdrawals began in 1959 with the prototype Saint Martin. Its accumulated mileage, both in its original form and rebuilt form, was a remarkable 2,092,500 miles. Further withdrawals of the production series took place during the 1960s and the class was extinct by 1965.

Preservation

By 1965 the last Hall had been withdrawn from the Western Region without a single one entering the National Collection. Eleven examples of the Hall class have survived to preservation, seven of which have run in preservation. Of the engines which haven't yet operated in preservation, 4942 Maindy Hall is being "regressed" back to a GWR Saint Class, 4979 Wootton Hall is undergoing restoration at The Ribble Steam Railway with work currently focusing on the engines tender, 5952 Cogan Hall is awaiting restoration at The Llangollen Railway with a small number of parts being used in the construction of 6880 Betton Grange & 5967 Bickmarsh Hall is undergoing restoration at The Northampton & Lamport Railway.

Of the remaining seven halls which have run in preservation, six have been operated on the main line: 4930 Hagley Hall, 4936 Kinlet Hall, 4953 Pitchford Hall, 4965 Rood Ashton Hall, 5900 Hinderton Hall and 5972 Olton Hall. 5972 Olton Hall has gained fame as the locomotive used in the Harry Potter film series.

4965 Rood Ashton Hall is the only member of the class operational and presently certified for mainline operation, 4936 Kinlet Hall did have a mainline ticket but was withdrawn for overhaul in Oct 2016.