Compounding the issue!
Bachmann’s announcement of three new OO-scale models of the three-cylinder LMS Compounds prompts Pete Kelly to trace the full history of these legendary locomotives – a pedigree going back to the Midland Railway in 1902.
Bachmann's announcement of three new OO-scale models of the three-cylinder LMS Compounds prompts Pete Kelly to trace the full history of these legendary locomotives.
ALTHOUGH compound steam locomotives were used by several of Britain's pre-Grouping railway companies during the late 19th and early 20th centuries – notably the London & North Western, Great Eastern and Great Western (which sensibly bought three examples from France rather than build its own), their performance over simple-expansion types tended to be disappointing and in due course, many were rebuilt as ordinary locomotives.
Compound locomotives used high and low-pressure cylinders to maximise the use of the steam produced, firstly in a high-pressure cylinder (or cylinders) and then, rather than go to waste as exhaust before all of its remaining energy had been captured, in a larger-diameter low-pressure cylinder (or cylinders), potentially also bringing a big saving in coal consumption. In the marine environment, many steampowered tugs and larger vessels went a step further by adopting a triple-expansion arrangement.
The only British compounds to make a truly lasting impression were the 45 three-cylinder passenger locomotives built by the Midland Railway between 1902 and 1909, and the further 195 examples built by the London, Midland & Scottish Railway between 1924 and 1932 after the class was adopted as a standard design and given the 4P power classification.
Sole survivor
The inspiration behind this month's feature is the announcement by Bachmann Branchline that its muchrequested and highly detailed OO-scale model of 1925 Horwich-built LMS 4P Compound No. 1119, in glorious Crimson Lake lined livery, will be in the shops any time now at a recommended retail price of £214.15.
The only life-sized survivor of a class that once numbered 240 is Samuel Johnson's original Midland Compound No. 2631 of 1902, which was renumbered 1000 by his Locomotive Superintendent successor Richard Deeley in 1907.
Deeley oversaw the building of a further 40 modified Compounds to add to Johnson's initial batch of five, and eventually modified those as well, so No. 1000 remains as rebuilt in 1914 rather than in its original condition.
After being withdrawn from British Railways service as No. 41000 in 1951, it was set aside for preservation by the Science Museum. In 1959 it was restored in its 1907 Midland Railway livery for working special trains before being placed on temporary display in Clapham Transport Museum.
In 1975, the year in which York's National Railway Museum opened, No. 1000 took part in the Shildon locomotive cavalcade, celebrating 150 years since the opening of the Stockton & Darlington Railway.
Five years later it made another appearance in the Rocket 150 parade at Rainhill, celebrating 150 years since the opening of the Liverpool & Manchester Railway.
Simpler system
It took part in several main line outings, notably over the Settle & Carlisle line, but has now been dormant for some time and is presently on loan as a static exhibit to the Barrow Hill Roundhouse Museum & Engine Shed in Chesterfield, Derbyshire (once known as Staveley (18D). Until 2014, it also spent some time with the Scottish Railway Preservation Society at Bo'ness.
The inspiration behind Johnson's chosen layout of a single inside high-pressure cylinder and two outside low-pressure cylinders, with a second regulator allowing independent control of the high and low-pressure valve gears so that live steam could be admitted directly into
the low-pressure cylinders for easier starting, came from a system devised by the North Eastern Railway's chief draughtsman, William Smith.
Deeley decided to make the drivers' task a little less complicated by replacing Smith's independent valve gear arrangement with a system that simply allowed full compounding as the single regulator was opened further. At first, the 40 Deeley compounds boasted a higher boiler pressure of 220psi, but this was later reduced to the original 200psi, and their exterior appearance was tidied up by raising the running plate clear of the coupling rods and changing the design of the rear splasher to one that was much easier on the eye.
The Midland Compounds' driving wheel diameter of 7ft allowed speeds well in excess of 80mph to be attained on fast, regular passenger services between major cities and on milk trains, and they also put up some impressive performances on demanding routes such as the Settle & Carlisle.
Adopted as standard
The Compounds were well suited to the Midland Railway's policy of frequent, light trains, and in double-headed formation could even be found on Anglo-Scottish expresses – but they were never large or powerful enough to handle the increasingly heavy trains of the LMS during the latter 1930s and into the Second World War.
One of the most oft-repeated stories in railway folklore concerns the dogged rivalry between the Midland Railway and London & North Western Railway constituents after the formation of the LMS as the biggest of the ‘Big Four' at the 1923 Grouping. Not only that, the LMS also became the biggest commercial operation in the British Empire!
The LNWR's experiments with compounding had not always been a success, and many of its former employees must have viewed with some suspicion the announcement that the newly formed company would be adopting the Midland Compound as a standard 4P design. While most of the LMS 4P Compounds were built under Sir Henry Fowler after he succeeded George Hughes as Chief Mechanical Engineer in 1925, it would be unfair to call him a ‘small engine' man.
After all, he had designed the four-cylinder 0-10-0 Lickey banker ‘Big Bertha' of 1919, with its immense tractive effort of 43,315lb, and was well aware that the LMS needed much more powerful locomotives than 4-4-0 Compounds.
He dreamed of building a compound Pacific, but with the continuing improvements in valve efficiency he was persuaded to go for simple-expansion locomotives instead.
Widespread use
He was deeply involved in the Hughes/ Fowler ‘Crab' 2-6-0s, with their two large outside cylinders, and the LMS certainly benefited from his 2-6-4 tank engines, and three-cylinder ‘Royal Scot' and ‘Patriot'4-6-0s.
The major difference between the LMS Compounds and their Midland Railway predecessors was the reduction in driving wheel diameter from 7ft to 6ft 9in, which gave a slightly higher tractive effort of 22,650lb over 21,840lb. Their cylinder diameters of 19 x 26in (high pressure) and 21 x 26in (low pressure) and boiler pressure of 200psi remained
exactly the same as those on the Midland locomotives. Seventy-five LMS Compounds were constructed at Derby Works, 20 at Horwich Works, 25 by the North British Locomotive Co., and 75 by the Vulcan Foundry at Newton-le-Willows.
Being part of the massive new railway company gave the Compounds plenty of opportunity to operate further afield than ever, and they became widely distributed among locomotive sheds large and small.
But the heavier trains and diminished maintenance standards of the Second World War certainly did them no favours.
Early withdrawals
At around the time of nationalisation in 1948, the Compounds' bases included Rugby (2A), Monument Lane (3E), Crewe North (5A), Chester (6A), Llandudno Junction (7A), Longsight (9A), Trafford Park (9E), Kentish Town (14B), Leicester (15C), Kettering (15B), Bedford (15D), Nottingham (16A), Derby (17A), Rowsley (17D), Millhouses (19B), Leeds (20A), Manningham (20E), Saltley (21A), Bournville (21B), Bristol (22A), Gloucester (22B), Lancaster (23C), Accrington (24A), Agecroft (26B), Bolton (26C), Bank Hall (27A), Southport (27C), Wigan (27D), Walton (27E), Blackpool (28A) and Peterborough ex-LM (35C).
Up in Scotland they could be found at Ferryhill (61B), Perth (63A), Stirling (63B), Dalry Road (64C), Carstairs (64D), St. Rollox (65B), Polmadie (66A), Greenock (66D), Corkerhill (67A), Ayr (67C), Dumfries (68B) and Stranraer (68C), but their days were already numbered, with massive inroads into their ranks throughout the 1950s.
Six of the still-remaining 195 Compounds were withdrawn in 1952, followed by 13 in 1953, 23 in 1954, 37 in 1955, 27 in 1956, 34 in 1957, 36 in 1958, 13 in 1959, six in 1960 and two in 1961, leaving just the original locomotive, which carried the British Railways number 41000, for posterity.
The models
Bachmann's long-awaited intricately detailed OO-scale model of 1925 Horwich-built Midland Compound 4-4-0 No. 1119 in LMS lined Crimson Lake livery should be in the shops imminently. The dazzling cab detail includes separate controls, pipework and instruments, and the model also features an adjustable tender drawbar, poseable loco-tender fall plate, welded Fowler tender, sprung buffers, NEM coupling pockets and accessory pack. The model comes equipped with a 21-pin DCC decoder socket for Bachmann's recommended decoder item 36-557, and is ready to accept a speaker in the tender.
At the same time Bachmann is also releasing two Compound models in British Railways lined black; one as 1925 Horwich-built No. 41123 with early emblems (31-932), and the other as 1925 North British-built No. 41143 with the later crest (31-933A). Each has a recommended retail price of £199.95.
A model of No. 1000 was produced for the National Railway Museum/ Locomotion Models as one of the ‘National Collection in Miniature' exclusives in 2011. It portrayed the locomotive as it exists in its preserved condition rather than as originally built by Johnson.