LNER Class U1

The Worsbrough Bank between Wentworth Junction and West Silkstone Junction on the Manchester, Sheffield & Lincolnshire (later GCR and LNER) main line was one of the steepest stretches of main-line railway in Britain, over 3 miles at 1 in 40, and the route's heavy coal traffic from the Wath yard required mid-train banking assistance to negotiate the climb to Penistone. Two ordinary 0-8-0 banker engines could just about manage but at considerable operational cost; Sir Nigel Gresley proposed a single specialised banker capable of doing the work alone.

The Beyer-Garratt articulated principle, a single boiler suspended on a central frame between two pivoting power units, was a Manchester firm specialty exported widely to African and Australian railways for heavy-haul work on tight curves. Gresley specified a six-cylinder Beyer-Garratt with two three-cylinder power units, each using his patent conjugated valve gear, a 2-8-0+0-8-2 wheel arrangement for sixteen coupled wheels, and a wide firebox boiler larger than any previously fitted to a British locomotive.

The engine, LNER No. 2395, was built by Beyer, Peacock & Co. at the Gorton Foundry, Manchester in June 1925, adjacent to the GCR's Gorton Works which had built Robinson's earlier locomotives for the route. Total weight 175 long tons; total length 86 ft 9 in over buffers; total tractive effort 72,940 lbf. The engine was the largest, heaviest, longest and most powerful steam locomotive ever to run in Britain, and remained so until it was scrapped in 1955.

2395 worked the Worsbrough Bank assist exclusively from 1925 until the 1949 1500 V dc electrification of the Manchester–Sheffield Woodhead Route eliminated the banking requirement. The class's very specific operational pattern, slow heavy-haul banking, rather than mainline running, meant that mileages were modest by British Railways standards, but utilisation was nearly continuous on what was essentially a 24-hour working pattern.

From 1949 the Garratt was largely redundant. British Railways tried the engine on the Lickey Incline (the famous 1-in-37 climb on the former Midland Main Line between Bromsgrove and Blackwell) in 1949–1950, but the Garratt's unique nature made maintenance impractical at Bromsgrove's small banking-engine shed and the trial was not extended.

69999 was returned to Mexborough for storage and occasional banking work, but with the Worsbrough Bank now electrified the engine was effectively redundant. It was withdrawn in December 1955 and scrapped at Doncaster Works shortly afterwards. None of its components were preserved; the class, and Britain's only operational Beyer-Garratt, was extinct by early 1956.

Britain's only operational Beyer-Garratt of the LNER pattern, and the largest steam locomotive ever to run in Britain. The articulated layout, two 2-8-0 units sharing a central boiler suspended between them on a separate frame, was a Beyer-Peacock specialty exported widely to African and Australian railways but rare on British metals. The unique outline, with the boiler appearing to "float" between the two articulated power units, made the engine instantly recognisable. It carried number 2395 throughout its LNER career and 69999 in BR ownership. Initially unnamed; never named throughout its 30-year career. The class wore unlined LNER black throughout (appropriate for a freight engine).

2395 / 9999 / 69999, the unique single member of the class, completed by Beyer, Peacock & Co. at the Gorton Foundry, Manchester in June 1925. The largest and heaviest steam locomotive ever to operate in Britain; the highest tractive effort of any British steam locomotive (72,940 lbf). Worked the Worsbrough Bank exclusively for over twenty years before the 1949 Manchester–Sheffield electrification eliminated the need. Withdrawn December 1955; scrapped at Doncaster shortly afterwards. The engine was never officially named, although Mexborough crews informally referred to it as "Big Six", a reference to its six cylinders.

LNER service (1925–1947): the engine was allocated to Mexborough shed throughout its working life, for the Worsbrough Bank assist working between Wentworth Junction and West Silkstone Junction on the climb to Penistone. The bank itself was 1 in 40 for over 3 miles, too steep for unassisted heavy coal traffic, and required mid-train banking by the U1 Garratt acting as an additional engine in the rear of the train. The engine rarely worked elsewhere; its weight, length and specialised role kept it on Worsbrough Bank duty.

British Railways (1948–1955): renumbered 69999 in 1948. Allocation moved to Bromsgrove for trial use as a banker on the Lickey Incline (the famous 1-in-37 climb on the former Midland Railway between Bromsgrove and Blackwell), where heavier banking power was needed. The Bromsgrove trial was not a long-term success, the engine's unique nature made maintenance impractical, and 69999 returned to Worsbrough until the 1949 1500 V dc electrification of the Manchester–Sheffield Woodhead Route eliminated the Worsbrough banking requirement. Final years on storage; withdrawn 1955.

LNER (1925–1947): standard LNER unlined plain black for goods engines, with simple "L.N.E.R." lettering on the central tank. The engine's freight-only role meant it never received any of the apple-green or lined finishes applied to the LNER express engines.

British Railways (1948–1955): BR mixed-traffic black with simple "British Railways" lettering on the central tank, then the early lion-and-wheel emblem. Plain unlined. Late BR crest applied 1956, but the engine was withdrawn in December 1955, just before the late crest could be applied.