For enthusiasts and researchers of the Great Eastern Railway

M15/M15R Class 2-4-2T 1884-1886, 1903-1909

LNER Class F-4 & F-5

71-80, 91-111, 140-149, 170-189, 211-235, 236-244, 572-591, 650-679, 780-799

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In 1884 Worsdell introduced the first of his M15 class 2-4-2T Radial tank engines for the heavier passenger traffic. As with his G14 2-4-0s (q.v.), these had Joy valve gear, and radial axles at each end. This photograph shows the prototype engine, No. 650 as built. No cover plate was provided over the cylinder ends, in the Crewe style, showing the position of the steam chests above the cylinders. The engine is in the earlier style of the standard GER blue livery introduced under Worsdell, with small GER initials. The original thirty engines completed under Worsdell proved to be heavy on coal and water, gaining the nickname ‘Gobblers’, an epithet that stuck for all time for all GER 2-4-2Ts, long after their appetites had been cured!

m15

When James Holden succeeded Worsdell as Locomotive Superintendent in 1885, he determined to curb the appetites of the M15s. Suspicious of the Joy valve gear, Holden built another ten engines, but with cylinders and Stephenson motion of the same pattern as the Y14 0-6-0s (q.v.). These were much more economical, and when the original thirty engines required new boilers in the mid-1890s, he had them all rebuilt with Stephenson’s motion. However, the cylinders and motion were of the same pattern as on his contemporary N31 class 0-6-0 goods engines (q.v.) with the valves beneath the cylinders, thus saving the expense of replacing the crank axles. This is No. 664 as rebuilt in 1895. A hinged cover plate was fitted to the cylinders and – as can be seen – this was noticeably higher than the framing beneath the smokebox. The smokebox front also had wing plates originally, masking this feature as viewed from the front, again as seen here, but later disappeared when flanged front plates became the norm.

798 1003H. Gordon-Tidey/GERSHC 798/1003

During the 1880s and 1890s, Holden rebuilt the existing 0-4-4 tank engines built under Johnson, Adams and Bromley with new boilers, enclosed cabs and other modernised details. However, by the early 1900s these were coming due for replacement, so Holden resurrected his own version of the M15 class with the Y14 cylinders and motion, and a further 120 were constructed at Stratford down to 1909. This is No, 236, built in July 1906, fitted with condensing gear like many of its class-mates.

798 0641Locomotive & General/GERSHC 798/0641

James Holden retired in 1908 and was replaced by his son Stephen. In 1911 Stephen Holden built another twenty 2-4-2Ts, essentially identical to the M15 class, but with larger tanks and higher-pressure 180 lb. boilers with a sloping grate, known as class G69 (q.v.). At the same time a programme of fitting the higher-pressure boiler to the later M15 class was begun. Known as class M15R, these engines were at first visually distinguished from the unrebuilt engines by their built-up rimmed chimneys, as well as the forward position of the 4-column safety valves of the higher pressure boilers. The photograph shows No. 96 as rebuilt in 1911. The introduction from 1914 of A.J. Hill’s L77 class 0-6-2Ts (q.v.) and the advent of the First World War meant that only 32 M15s were rebuilt before the process ceased in 1921. In the meantime, production of the 160 lb. boiler for the M15s had also ceased, and although many were then fitted with the higher-pressure boilers – including one or two of the original Worsdell engines – the safety valves were set to the lower pressure on the engines not deemed to have been ‘rebuilt’. This would seem to indicate that some other modifications were made to the M15R rebuilds that precluded the unrebuilt locomotives from working at the higher pressure, but despite extensive research, the reason has so far not been discovered. In time, all of the surviving M15s had these boilers.

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Stephen Holden’s G69 class engines also had cabs with high, arched roofs and side windows. In 1912 M15s 789 and 790 were rebuilt as M15Rs, and additionally given similar cabs as an experiment. This is No. 789 as rebuilt. Under the LNER, the M15 class became class F-4, and the higher-pressure M15Rs class F-5. The G69 class with larger tanks became class F-6. However, the new cabs on 789 and 790 seem to have confused the LNER authorities, for they were classified F-6 as well. In the early BR period they were correctly re-classified as F-5s. The number of available 2‑4‑2Ts had dwindled by this period, and because of the larger side tanks of the F-6s, they had a more-restricted ‘route availability’ than the F-4s and F-5s.

7018 110LPC/GERSHC 7018/110

This illustration shows the former M15 class 2-4-2T No. 222 (now LNER 7222), which was transferred to Scotland for working the St. Combs branch, for which it had to be fitted with American cow-catchers front and rear, for part of this line was un-fenced. The engine has gained an LNER-pattern cast, rimmed chimney before transfer, as was fitted to all of the ex-GER 2-4-2Ts, but it had not been fitted with the higher steel roof added to the surviving members of the class from the late 1920s. It later gained external sliding glazed shutters on the cab sides to keep out the worst of the Scottish weather!

700 1199E.E. Smith/GERSHC 700/1199

This photograph shows No. 7185 around 1939. Although a low-pressure F-4 (ex-M15), it has by this time gained a down-rated 180 lb. boiler, LNER chimney and raised steel cab roof and – from this side at least – is indistinguishable from the F-5 class. From the opposite side, the Westinghouse brake pump was usually a distinguishing feature, for the F-5s had the larger 8/8½-in. pump mounted alongside the smokebox, whereas the F-4 retained the smaller 6/6½-in. pump in front of the tank, however, this was not 100% reliable. Further confusion arose due to the LNER’s comprehensive locomotive renumbering scheme of 1946 as – by co-incidence – 29 engines were given new numbers that were previously carried by other members of the class.

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Although many British locomotives – including some from the former GER – were loaned to the War Department during the Second World War – the sixteen F-4 and F-5 2-4-2Ts that were conscripted were armour-plated and used with coastal defence trains from 1940. These trains were stationed all around the east and south-east coast of Britain, from Aberdeen to Canterbury. This is F-4 No. 7172 as War Department ‘A’ following conversion at Stratford Works. It will be noted that this is an example of an F-4 with one of the larger 8/8½-in. Westinghouse pumps, hidden in the casing alongside the smokebox. Only one genuine F-5 was armoured, becoming War Department ‘M’. As the threat of German invasion receded, most of the engines were returned to the LNER in 1943 and the armour removed. However, four others were retained until 1945.

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This photograph illustrates the sorry condition that most British locomotives exhibited during the Second World War. F-4 No. 7584 is seen here at Palace Gates in 1943. This was one of 36 F-4s and F-5s set aside in 1939 to work on the London Transport Metropolitan and District Lines, should bombing result in damage to the main power stations. For these duties they had to have their chimneys shortened to suit the LT loading gauge. This was done by cutting off the rimmed top, the result being almost identical to the original GER stovepipe chimneys. As with this example here, the engines gradually drifted back into normal service as the war progressed.

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This photograph shows No. 67218, formerly hybrid F-5 No. 789 in BR condition. This was one of five F-5s that were altered to vacuum brake only and fitted with vacuum-operated push-pull gear for working the service between Epping and Ongar.

 

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