LNER Thompson B1 Class

Edward Thompson succeeded Sir Nigel Gresley as chief mechanical engineer of the London and North Eastern Railway in April 1941, on Gresley's sudden death from a heart attack. Thompson inherited a locomotive department that was entering its second world war with a complicated fleet, dozens of pre-Grouping classes still in service, and a small number of expensive three-cylinder express designs that had to be carefully looked after. His brief, openly stated, was to standardise wherever possible, simplify maintenance, and design for wartime conditions of poor coal, scratch crews, and minimal shop time.

The B1 was the cornerstone of that programme. Thompson set out to produce a single mixed-traffic 4-6-0 that could replace the LNER's ageing pre-Grouping classes (the GER B12, NER B16, and so on) on secondary and branch work, and that could substitute for the Gresley three-cylinder Pacifics on the lighter express turns when those were in shop. He chose two cylinders rather than three, a round-topped firebox rather than a Belpaire, and the existing Gresley group-standard B17 Diagram 100A boiler. Where parts could be lifted from earlier classes, they were: the bogie was the standard Gresley pattern, the cylinders were dimensionally similar to those of the V2, and the tender was the LNER group-standard 4,200-gallon type.

The result was a locomotive that was visibly less elegant than its three-cylinder Gresley predecessors but was faster to build, easier to maintain, and capable of being competently driven by a junior crew. The first, prototype 8301 Springbok, entered traffic in December 1942 and was named in early 1943 at a ceremony intended to publicise the LNER's contribution to the war effort. Thompson followed up with further prototypes, then placed orders with Darlington and Gorton Works and with the contractors Vulcan Foundry and the North British Locomotive Company.

410 B1s were built between 1942 and 1952, of which around half were built by NBL and Vulcan and the rest by the LNER's own works. The design proved durable and was produced unchanged through to the BR era; the BR Standard 5MT 4-6-0 (Class 5MT 73000) of 1951 was a more modern equivalent on the same broad pattern, and the two classes worked happily side by side on Eastern Region secondary services for the rest of the steam era.

The B1 spent its working life as the maid-of-all-work of the Eastern, North Eastern, and Scottish regions of British Railways. The class handled the King's Cross to Cambridge buffet expresses, the Liverpool Street to Norwich and Cromer trains in the diesel-replacement period, the secondary East Coast expresses to Newcastle and Edinburgh on shorter relief turns, and a great mass of branch passenger, parcels, milk, and fitted freight work across the former LNER system. They were equally at home on a heavy summer Saturday holiday relief from Liverpool Street to Yarmouth or on a stopping train of three coaches in rural Lincolnshire.

Three engines were lost in service. 61057 was destroyed at Goswick in October 1947 (28 dead). 61251 Oliver Bury was severely damaged in 1956 when its boiler exploded at Witham Junction; the locomotive was repaired and returned to service. 61297 was lost in the Penmanshiel tunnel collapse of 1979, which by that time was after withdrawal but the wreck was buried under the collapsed bore.

Withdrawals began in 1961 with the early-built engines that had run hardest during the war. The class was decimated by the Eastern Region's switch to Brush Type 4 and English Electric Type 3 diesels in the early 1960s, and by 1965 only a small core remained. The last B1 in regular service, 61264 (the future preserved engine), was withdrawn from Low Moor depot in October 1967, by which time it was one of the very last steam locomotives working on the British Railways Eastern Region.

1000 Springbok, the prototype, entered traffic in December 1942 from Darlington Works and was named at a ceremony attended by South African dignitaries.

1057 was destroyed in the Goswick rail crash of 26 October 1947, when an East Coast express overran signals on a temporary deviation north of Berwick-upon-Tweed. The engine and the leading vehicles fell down an embankment and 28 people died. The locomotive was scrapped at the site.

61264 entered service in 1947 and worked from Doncaster, Mexborough, and Colwick depots before withdrawal in November 1965. Saved from Barry scrapyard in 1976, it was returned to traffic in 1997 carrying the borrowed name Mayflower and is now based at the North Yorkshire Moors Railway, where it has been a regular performer in heritage railway service.

61306 Mayflower, originally named in service after the Pilgrim Fathers' ship, was completed in April 1948 and worked from Mexborough, Hull Dairycoates, and Wakefield. Withdrawn in September 1967, it was preserved privately and was for many years one of the few B1s certified for main-line running. It is currently with the Locomotive Services group on the national network and continues to work charters.

The first prototype 8301 (later 1000) appeared in 1942 in plain wartime LNER black, lined out only with the LNER company crest. Production engines emerged from Darlington and the contractors' works in plain unlined black for the duration of the war. From 1946 surviving engines and new production were turned out in LNER apple green with black-and-white lining and serif numerals, although wartime conditions kept many engines in austerity black.

British Railways from 1948 painted the class in lined black with the early lion-and-wheel and (from 1956) late ferret-and-dartboard crests. A small number ran briefly in lined dark green in 1949 to 1951 trials before BR decided to standardise the mixed-traffic 5MT classes in lined black. Both preserved engines have at various times carried LNER apple green and BR lined black liveries.