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 Older locomotives would then be either withdrawn or renumbered into the 'duplicate list' series used for those no longer in capital stock but which not yet completely life expired.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