The origins of this design can be traced back to the MR engineer Johnson. After the formation of the LMS, Sir Henry Fowler built on this success and provided the company with an improved locomotive with 422 Jinty's being built from 1924 until 1931. So many were required that the LMS (as did the MR) employed sub contractors, such as Vulcan, Bagnall and Hunslet to help with the production orders. The locomotives were versatile, at home shunting in stations, yards, exchange sidings as well as on trip workings moving goods wagons. They could also be found on the S&D until 1930 when they were absorbed back into the LMS. In 1934 the Jinty's were renumbered to 7260-7681 and in 1948 BR prefixed all the numbers with a '4'. The design was very successful and the locomotives remained in service until the mid 1950's when new diesel shunters, e.g. the 08 diesels were introduced. The numbers of locomotives gradually declined with the last of the clas withdrawn in 1967, 10 have survived into preservation.