A number of different numbering and classification schemes were used for the locomotives owned by the London, Midland and Scottish Railway (LMS) and its constituent companies; this page explains the principal systems that were used.
The following abbreviations for the constituent companies are used on this page:
Principal constituents
Caledonian Railway (CR), Furness Railway (FR), Glasgow and South Western Railway (GSWR), Highland Railway (HR), Lancashire and Yorkshire Railway (LYR), London and North Western Railway (LNWR), Maryport and Carlisle Railway (MCR), Midland Railway (MR), North London Railway (NLR) and North Staffordshire Railway (NSR) Minor companies Cleator and Workington Junction Railway (C&WJR), Glasgow and Paisley Joint Railway (G&PJR), Knott End Railway (KER), Stratford-upon-Avon and Midland Junction Railway (S&MJR), and Wirral Railway (WR) Later additions Somerset and Dorset Joint Railway (S&DJR) - absorbed October 1936
For information about individual classes and locomotives, see Locomotives of the London, Midland and Scottish Railway.
Numbering
Constituent companies
London and North Western Railway
The LNWR inherited its numbering system from one of its constituents, the Grand Junction Railway. In short, locomotives were numbered in a series commencing at 1. No gaps were allowed in the series, so a new locomotive would either be numbered at the end of the series or would reuse the number of an older locomotive.
Older locomotives would then be either withdrawn or renumbered into the 'duplicate list' series used for those no longer in capital stock but which not yet completely life expired. These engines were numbered in various series over time: initially they took an 'A' suffix to the original number, then from 1862 they were renumbered above 1100, from 1870 above 1800, and from 1886 in the 3xxx series.
The GJR and LNWR also named their passenger tender locomotives (indeed, all locomotives were named until 1858), and often the same name and number combinations would be applied to new locomotives as they replaced older ones. The removal of names attached to freight engines after 1863 allowed them to be re-applied to the increasing stock of passenger engines, including those running on the former London and Birmingham Railway area of the LNWR, where locomotives had not been named.
Midland Railway
The MR undertook a wholesale renumbering of its locomotive stock in 1907 based on usage, wheel arrangement, power classification (see classification section below), and age, with locomotives of the same class numbered together. The least powerful and oldest classes took the lowest numbers and locomotives were renumbered in order of age.
When the London, Tilbury and Southend Railway (LTSR) was absorbed by the MR in 1912, its locomotives were renumbered into this scheme. It had only two tender engines, both 0-6-0 types, and these became 2898 and 2899. The rest were tank locomotives of varying wheel arrangements, which required the adoption of new number ranges at the end of the tank engine series. In all, the number ranges used by the MR were as follows:
Note: While the majority of ex-MR locomotives were left unrenumbered by the LMS at Grouping in 1923, the ex-LTSR locomotives were subject to several renumberings to clear space for new stock, which changed the number ranges set out above.
Post-grouping numbering
Shortly after the LMS was formed in 1923, it developed a new numbering scheme for all the locomotives that it had inherited. The scheme dealt with two key problems faced by the new company: There were many locomotives with the same number, as each of the constituent companies had used a series starting at number 1 Many of the constituent companies had numbered their locomotives in a somewhat random way, and the renumbering allowed for all locomotives in the same class to be given consecutive numbers and similar classes to be numbered in blocks
These advantages more than overcame the disadvantage of the effort involved in renumbering almost every locomotive and giving them a number that usually bore no relation to its pre-Grouping identity, except for the Midland Railway locomotives that had been renumbered along similar lines in 1907 and mostly retained their numbers.
The system comprised four groups of numbers into which locomotives from a set of railways were numbered:
Within each group, locomotives were numbered in blocks which ran (low to high numbers) as set out below. Within each block, the least powerful locomotives took the lowest numbers.