The design was introduced in 1881 by F.W. Webb and had the same cheaply produced cast iron wheels and H-section spokes as the tender engines. A trailing radial truck supporting the bunker was added also with two similarly cast iron wheels. Three hundred were built between 1881 and 1897.
Four (LNWR nos. 178, 484, 1257, 69) were withdrawn in January–February 1920 and a further four (LNWR nos. 142, 994, 782, 1012) in July and November 1922, so at the 1923 grouping, 292 passed to the London Midland and Scottish Railway (LMS). They were renumbered from the LNWR's random allocation based on vacant numbers, to a solid block sequence 7550–7841, and given the power classification 1F. Many locomotives still in service in 1934 were renumbered by the addition of 20,000 to their number.
Sixty-four locomotives passed into British Railways ownership in January 1948 and they were numbered 58880–58937, but not all examples survived long enough to carry their BR numbers.
The surviving Coal Tank wearing LMS unlined 1920s livery as No. 7799 when visiting the Severn Valley Railway in September 2012
One Coal Tank number BR 58926, ex-LMS 7799, originally LNWR 1054, has survived in preservation on the Keighley and Worth Valley Railway, normally carrying its LNWR livery and number. On 10 February 2012, the locomotive was photographed, newly restored to BR livery and numbered 58926. In summer 2012, it was repainted in its 1920s LMS scheme as No. 7799.
Baxter, Bertram (1979). Baxter, David, ed. British Locomotive Catalogue 1825-1923, volume 2B: London and North Western Railway and its constituent companies. Ashbourne: Moorland Publishing. ISBN0-903485-84-2.