These locomotives were fitted with 20-by-28-inch (508 mm × 711 mm) cylinders and 4-foot-11-inch (1.499 m) wheels, while the Belpaire firebox-fitted boiler was identical to that fitted to the Class S69 4-6-0s. They were the most powerful 0-6-0 tender locomotive in Britain until the arrival of Oliver Bulleid's Q1 class for the Southern Railway in 1942.[1]
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 D81 locomotives. Between 1943 and 1956 the class was rebuilt with round-top fireboxes, and reclassified as J20/1.[1][2]
At nationalisation in 1948, British Railways added 60000 to their LNER numbers. They all continued in service until 1959, when the first was withdrawn; all were gone by the end of 1962.[1]
Aldrich, C. Langley (1969). The Locomotives of the Great Eastern Railway 1862–1962 (7th ed.). Wickford, Essex: C. Langley Aldrich. OCLC30278831.
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. ISBN978-1-905505-26-5.