These locomotives were fitted with 171⁄2-by-24-inch (444 mm × 610 mm) cylinders and 5-foot-4-inch (1.626 m) wheels. They were the final development of the GER's radial (2-4-2T) tank locomotive. Being intended for London suburba service, they were built with condensing gear, and Westinghouse air brakes.
All were still in service at the 1923 grouping, the LNER adding 7000 to the numbers of nearly all the ex-Great Eastern locomotives, including the class G69 locomotives. The LNER added vacuum ejectors to all but one locomotive in 1927; the one exception being fitted in 1929. They also removed the condensing apparatus between 1936 and 1938.
At nationalisation in 1948, British Railways added 60000 to their LNER numbers. They all continued in service until 1955, when the first was withdrawn; all were gone by the end of 1958.
Baxter, Bertram (2012). Baxter, David; Mitchell, Peter, eds. British Locomotive Catalogue 1825–1923, Volume 6: Great Eastern Railway, North British Railway, Great North of Scotland Railway, Midland & Great Northern Joint Railway, remaining companies in the LNER group. Southampton: Kestrel Railway Books. p. 97. ISBN978-1-905505-26-5.