4-4-2 Steam Locomotives in Great Britain

Class 1 Class (Locobase 3214)

Data from English Mechanic and the World of Science, No 1084 (1 January 1886), p. 370 and accessed from [],M1 on 31 January 2009. (Thanks to Peter Christener for his 23 April 2025 email giving the full Class ID for these engines.) Works numbers were 2880-2891 in1880, 2969-2971 & 3018-3020 in 1881, 3217-3228 in 1884.

William Adams designed this tank engine, which became the model for several batches of LT&SE engines over the next 30 years. Their trailing axles were equipped with radial axle boxes that allowed lateral play and shrank the rigid wheelbase considerably.

Class 31 Class (Locobase 5703)

Data from American Engineer and Railroad Journal - March 1893. (Thanks to Peter Christener for his October 2025 email correcting the name.) Works numbers were 425-430 in 1893.

Thomas Whitelegg's continuation of the Adams tank engine design that first entered service in 1880 (Locobase 3214). Other than a slight reduction in the number of tubes, they followed the original specifications.

Class 37 Class (Locobase 10080)

Data from "The History and the Locomotives of the LT&SR.," The Locomotive & Railway Carriage & Wagon Review, Volume III [3] (January 1898), p. 4. (Thanks to Peter Christener for his October 2025 email correcting the name and suggesting deleting the LMS power class.). Sharp, Stewart supplied the first six (works numbers 4245-4250 in 1897), and Dubs added the other sextet (works numbers 3666-3671 in 1898).

In 1900, Sharp, Stewart added 12 more, all with names,as class 51, that varied only in detail and mounting a larger boiler.

These were slight enlargements designed by the L T & SR's Thomas Whitelegg of the earlier Adams-designed tanks that were standard equipment on the L T & SR (See Locobase 3214 for the original 1880 engines). Reports at the time said that class "...doing good work and give every satisfaction."

These were later (1906) rebuilt with a larger boiler that measured 55 7/8" internal diameter, was pressed to 170 psi, grew to 1,099 sq ft total heating surface, and held a grate measuring 19.7 sq ft in area. Cylinders increased 1" in diameter, thus generating 17,388 lb in calculated tractive effort. The water tanks capacity also grew to 1,614 Imp gall (1,938 US gal).

Class 79 Class (Locobase 2312)

Data from E L Ahrons, The British Steam Locomotive from 1825 to 1925 (London: Ian Allan, 1926); and "The London Tilbury and Southend Railway", (29 May 1909), p. 2671. See also "3P 41928 - 41978 (LTSR 37 & 79 Classes) 4-4-2T LTSR Whitelegg Tilbury Tank" on the Preserved British Steam Locomotives website at [], last accessed 8 October 2022. (Thanks to Peter Christener for his October 2025 email correcting the name and suggesting deleting the LMS power class.) Robert Stephenson & Company works numbers were 3366-3369 in 1909, Derby Works delivered ten in 1923, Nasmyth, Wilson five in 1925 (works numbers were 1448-1452 in 1925), then 20 from Derby in 1927 (10) and 1929 (10).

Later version of Adams' outside-cylinder tank engine by T Whitelegg; this was an enlargement of the first Whiteleggs of 1893 (see Locobase 5703). Classic suburban tank locomotives, these could reach 65 mph (105 kph).

The PBSL website's account of the 79s and successors looked at the continued production the LTS design and concluded: " The construction of non-superheated passenger tank engines as late as 1930 was an anachronism, (although the LMS also built ten 0-4-4Ts two years later). These were also the last British tank locomotives to be built with coupled wheels as large as 6ft 6in in diameter."

The latter distinction remained unchallenged, said PBSL, because a well-publicized derailment in 1927 by a Southern Railway River class 2-6-4T at Sevenoaks killed 13 people and injured another 132.

Still, the LMS 3P 4-4-2Ts headed up the former LTS suburban services for years before being replaced and relocated to other ex-MR routes. Retirements began in 1951 and ended in 1959.