From its opening in 1854, the London, Tilbury and Southend Railway (LTSR) hired locomotives from the Eastern Counties Railway (ECR), and this arrangement continued after the ECR amalgamated with other railways in 1862 to create the Great Eastern Railway (GER). In 1880 the LTSR bought its first locomotive, saving on hiring costs from the GER and further engines followed that year.^[1] The LTSR principally operated tank engines, which it named after towns on the route. The railway's first locomotive superintendent was Thomas Whitelegg, who in 1910 was succeeded by his son Robert. The LTSR became part of the Midland Railway (MR) in 1912, but nevertheless continued to be operated independently. The Midland removed locomotive names and renumbered engines. The Midland, and its successor the London, Midland and Scottish Railway (LMS), continued to build some LTSR designs until 1930.

Steam locomotives are divided into the following classes:

The LTSR 37, 51, and 79 classes were similar, with the 51 class being lighter (67.80 long tons or 68.89 tonnes) than the other two (71.50–71.75 long tons or 72.65–72.90 tonnes).

Only one LT&SR locomotive has survived into preservation: