GWR locomotive numbering and classification

The GWR was the longest-lived of the pre-nationalisation railway companies in Britain, surviving the 'Grouping' of the railways in 1923 almost unchanged. As a result, the history of its numbering and classification of locomotives is relatively complicated. This page explains the principal systems that were used.

* For information about individual classes and locomotives, see: Locomotives of the Great Western Railway

Numbering

Broad Gauge Era

From the start, the GWR gave names only to its broad gauge locomotive stock. However, many classes carried 'themed' names, e.g. stars or signs of the zodiac, which aided identification of locomotives to some extent. "See List of broad gauge (7 feet) railway locomotive names"

The exception to this rule was that any broad gauge locomotives the GWR absorbed from other railways (in particular, the South Devon Railway and Bristol and Exeter Railway) were given numbers in the 2000-2199 series. This applied even where locomotives had carried names under their previous owner (indeed, these names were usually removed by the GWR) and even when the locomotives had originally belonged to the GWR and had been sold out of stock!

Towards the end of the broad gauge era, a number of locomotives were built to a design that enabled them to be easily converted from one gauge to the other (hence the term 'convertibles' used for these locomotives). These engines also carried numbers in the standard gauge series, whether or not they were running in broad gauge form.

tandard Gauge 1854-1884

Initially standard gauge locomotive numbering was a simple sequential system, starting from 1. Numbering in this series eventually reached 2799. While large classes of engine normally took the next new numbers available, smaller classes would often been numbered so as to reuse numbers left vacant by the withdrawal of older locomotives, especially where they were designed as direct replacements.

tandard Gauge 1884-1912

This approach was later modified so that there were various different series in use. At this time new classes usually commenced from the number xx01, with any prototype locomotives taking low numbers below 110. As mentioned above, broad gauge engines absorbed from other railways took numbers in the 2001-2199 series; express passenger locomotives were numbered in a consecutive series commencing at 3001; and a series commencing at 3501 was used for 2-4-0T locomotives.

The locomotives inherited by the GWR from other concerns were renumbered as follows:
* Ex-Cleobury Mortimer and Ditton Priors Light Railway 0-6-0T engines became 28-29.
* Locomotives from the Llanelli & Mynydd Mawr Railway, Powesland and Mason and Swansea Harbour Trust were absorbed after the original numbering series had been drawn up, and these were fitted into available gaps without reference to the original number ranges. In some case they took the numbers of other absorbed engines that had already been withdrawn.
* In the 1940s, the Corris Railway and Weston, Clevedon and Portishead Railway were absorbed. The four engines inherited from these two concerns took GWR numbers 3-6.

1946 Renumbering

By 1946, the majority of the locomotives inherited at the 1923 Grouping had been withdrawn, as had most of the older GWR engines numbered below 2000. In order to tidy up the gaps in this number range, it was decided to renumber the surviving locomotives from each pre-Grouping company together. The series used were:
* 7-9: ex-Vale of Rheidol Railway
* 30-96: ex-Rhymney Railway
* 193-399: ex-Taff Vale Railway and Barry Railway
* 421-436: ex-Brecon Mountain Railway
* 1140-1147: ex-Swansea Harbour Trust
* 1150-1153: ex-Powesland and Mason

Application by British Railways

When the GWR was nationalised as part of British Railways in 1948, its steam locomotives retained their numbers unchanged and new steam engines built to GWR designs continued to be allocated numbers in the same way as the GWR had done. However, its diesel locomotives were completely renumbered. They took numbers 15100-15107 in the 15xxx series allocated to pre-Nationalisation design diesel shunters.

* see: British Rail locomotive and multiple unit numbering and classification

Classification

A very simple system was adopted, whereby the name (for broad-gauge locomotives) or number of the first locomotive in a class became the classification for all locomotives in that class (e.g. 'Sun Class', '4000 Class'). After the end of the broad gauge, names were applied to principal passenger and mixed-traffic standard-gauge locomotives. These were often based on a single theme, which could also lend its name to describe a class, for example 'Stars', also known as the '4000 Class', whose names included 'North Star', 'Rising Star' etc.

However, the classes of locomotives inherited at the Grouping in 1923 continued to be referred to by the classification allocated to them by their original owner.