Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
These locomotives were an improved version of the Class S56 tanks, and the final development of James Holden's Class T18 tank locomotives, sharing the same 16.5-by-22-inch (419 mm × 559 mm) cylinders, 4-foot-0-inch (1.219 m) driving wheels, and 13-foot-10-inch (4.22 m) wheelbase. There were three orders, each of ten locomotives, all built at Stratford Works between 1912 and 1923. The first batch were built as suburban passenger tanks and were fitted with Westinghouse air brakes. The second and third batches were built as shunting tanks and were fitted with steam locomotive brakes and vacuum train brakes.
Table of orders and numbers
Year
Order
Quantity
GER Nos.
LNER Nos.
1946 Nos.
Notes
1912
C72
10
41–50
7041–7050
—, 8638–8646
Passenger service
1913–14
G75
10
21–30
7021–7030
8647–8656
Shunting service
1923
L89
10
31–40
7031–7040
8657–8666
Shunting service
The last batch did not emerge from Stratford until after the grouping.
One locomotive was lent to the War Department in October 1939, and sold 12 months later, It was used on the Longmoor Military Railway before being moved to the Bicester Central Ordnance Depot, and then the Military Port No. 1, Faslane. The remaining locomotives were renumbered 8638–8666 in order of construction. At nationalisation in 1948 they passed to British Railways, who added 60000 to their numbers. Post war withdrawals started in 1958, and all were gone by 1961.
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. pp. 103–104. ISBN978-1-905505-26-5.
Tourret, R. (1995). Allied Military Locomotives of the Second World War. Abingdon, Oxon: Tourret Publishing. ISBN0-905878-06-X.