GER Class L77

The Great Eastern Railway Class L77, classified N7 by the London and North Eastern Railway, was a class of 0-6-2T steam tank locomotives designed by Alfred John Hill and introduced in 1915 for London suburban passenger services. The engines had superheaters and piston valves and, unusually for inside-cylinder locomotives, Walschaerts valve gear, and as London suburban engines they were fitted with Westinghouse air brakes. Some carried condensing apparatus for working on the Metropolitan line and the East London Line, which was removed between 1935 and 1938. Nigel Gresley continued the design after the 1923 grouping, and the LNER built a further 112 between 1925 and 1928, so that 134 were built in all across sub-classes with Belpaire or round-top fireboxes. British Railways renumbered the survivors 69600 to 69733, and one LNER example, No. 7999, is displayed at the East Anglian Railway Museum.