LNER locomotive numbering and classification

A number of different numbering and classification schemes were used for the locomotives owned by the London and North Eastern Railway (LNER) 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"

Great Central Railway (GCR), Great Eastern Railway (GER), Great Northern Railway (GNR), Great North of Scotland Railway (GNoSR), Hull and Barnsley Railway (HBR), North British Railway (NBR), and North Eastern Railway (NER)

* "Minor Companies" (absorbed between July 1923 and July 1924)

Colne Valley and Halstead Railway (CV&HR), East and West Yorkshire Union Railway (E&WYUR), and Mid-Suffolk Light Railway (MSLR)

* "Later Additions"

Midland and Great Northern Joint Railway (M&GNJR) - absorbed October 1936

Ex-Metropolitan Railway steam locomotives (via the London Passenger Transport Board) - absorbed November 1937

* For information about individual classes and locomotives, see: Locomotives of the London and North Eastern Railway

=Numbering=

Constituent Companies

The constituent companies of the LNER operated no specific numbering system. Locomotives were numbered in a range starting from 1, with new locomotives being given numbers according to one of three different ways:
* New numbers at the end of the existing series;
* 'Significant numbers' (e.g. the first of the GER's new passenger locomotive class built from 1900 was numbered '1900', leaving many preceding numbers unused); or
* Filling in blanks left by the withdrawal of older locomotives, or their transfer to the 'duplicate list' (see below).

In the latter case, on the GER at least, some attempt was made to keep locomotives of the same class numbered in sequence. The GCR and GNoSR operated a strict policy of not permitting any gaps in the number series, nominally for accounting purposes, but this was not followed on other lines.

In 1922, the first step towards the 'Grouping' was taken, when the HBR was absorbed by the NER. At that time 3000 was added to the numbers of surviving HBR locomotives which left them well clear of the highest NER numbers then allocated (about 2350).

In almost all cases, the constituent companies used only steam locomotives. The NER had 13 electric lomotives, numbered 1-13, but this was in fact in the company's main locomotive list as the lowest-numbered steam locomotive was numbered 14. The NBR owned a petrol shunter, and this was numbered '1' in its own series.

Duplicate Lists

'Duplicate lists' were operated by most of the constituent companies in which older locomotives, whose capital costs had been written off but which were not yet ready for withdrawal, could be renumbered, releasing space in the main number range for new locomotives. A variety of different approaches to creating a duplicate list were employed:

* GCR: 'B' suffix added
* GER: '0' prefix added
* GNR: 'A' suffix added
* GNoSR: 'A' suffix added
* NBR: 1000 added to original number
* NER: Use of duplicate list abandoned before Grouping

Post-Grouping Numbering

When the LNER was created in 1923, it immediately set about finding a solution to the problem that many of its inherited locomotives carried the same numbers. The first solution, applied from September 1923 was to add a letter suffix to numbers that indicated the original owning company. The first column of the table below shows the letters applied in bold followed by an explanation of the letter in lighter type.

This solution was quickly abandoned as it meant that ex-NBR locomotives were carrying numbers that duplicated ex-GCR locomotives in their duplicate list. Indeed, this system would not have coped well with any of the locomotives in the constituent company's duplicate lists. Therefore, a new system was derived and applied from February 1924. This involved adding a multiple of thousands to each locomotive number, except:
* Ex-NER locomotives which retained their original number;
* Ex-HBR and ex-GCR duplicate list locomotives which were completely renumbered.

Other duplicate list locomotives were renumbered in the same manner as those in the capital list; i.e. with the prescribed multiple of thousands added, but retaining their prefix or suffix as appropriate. Departmental (non-revenue earning) locomotives continued to be numbered in their own, locally-applied, series.

The table below sets out the number ranges used for this system:

In each class, individual engines were numbered in order of construction (with a small number of exceptions, most notably the 'A4' class where locomotives carrying the names of the LNER's directors were given 'significant numbers' 1-4).

Self-evidently the renumbering process was very complicated as the LNER was keen not to have two locomotives running in service with the same number. This meant renumbering engines whose new numbers were already vacant first and then following through the chain of renumberings.

There was a further complication in that part-way through the renumbering, there was a change of plan in terms of the numbers allocated in the 1-999 series (for reasons that are mostly unclear), the 1xxx series (to allow more space for new 'B1' class engines), and the 3xxx series (to allow more space for engines purchased from the War Department). This meant some of these engines were renumbered twice (106 in total - 59 of which were 'O1' or 'O4' engines). The changes were as follows:

The letter 'Z' was initially intended for all miscellaneous classes, including departmental (non-revenue earning types), no matter what their wheel arrangement. However, this application was abandoned in 1927 and the letter was used solely for 0-4-2 types from then onwards.

After the letter was a number, which was unique to a particular class of locomotive. In 1923, these numbers were allocated (with a small number of exceptions) in the following order:
* Tender engines first, then tank engines (except letters 'X' and 'Y')
* Ex-GNR classes first, then ex-GCR, GER, NER (including HBR), NBR and GNoSR classes
* In order of driving wheel diameter, largest first

In order to indicate variations within a class, sublass numbers were issued, taking the form of a suffix to the main class number, e.g. 'D17/1'.

New build and converted locomotives to LNER designs were allocated class numbers in appropriate gaps in the series. On occasions, this led to the re-use of class numbers left vacant following withdrawal or rebuilding of its members. This occurred only infrequently up to 1941, but became more common thereafter. Indeed, on occasions, older classes in the course of withdrawal were reclassified so that new types could have lower numbers; e.g. the old 'B1' class became 'B18' to make room for the new standard LNER 4-6-0 type.

During 1942, three new types were allocated the appropriate letter classification ('A', 'B' and 'D') but without any suffix number; these were prototypes for what were planned to be the new standard LNER classes. However, this approach was not maintained, and the production types were allocated standard class numbers.

It should be noted that a number of classes inherited by the LNER were not formally allocated a place in the new system. Most of these were one-off or departmental engines, or types slated for early withdrawal, although some of the latter survived in stock through to 1928. However, there were some curious gaps in the formal list of class numbers allocated in 1923, and it may be that some of these unused numbers were nominally intended for these classes. Other gaps in the list were clearly left to allow space for the construction of new classes, and many of these gaps were filled in due course.

Engines absorbed from the smaller companies during 1923-1924 (the CV&HR, E&WYUR and MSLR) were either withdrawn before a classification could be allocated or were fitted into appropriate gaps in the class list. For the ex-M&GNJR engines (absorbed 1936), their original single letter classification was maintained through to 1942 when they were, at last, allocated class numbers at the end of the appropriate series. The only exceptions were engines that were identical to ex-GNR designs, which adopted the latters' classification. In contrast, the ex-Metropolitan Railway engines (absorbed 1937) were allocated LNER classifications immediately.

Modern Traction

Diesel and electric locomotives were given three-part classifications, commencing with either 'DE' for Diesel (electric transmission), 'DM' for Diesel (mechanical transmission) or 'E' for Electric, then 'B' for Banking, 'E' for Express, 'M' for Mixed Traffic or 'S' for Shunter, and finally a number issued to different types consecutively from 1.

Note: The LNER's petrol shunters were initially unclassified. When they were allocated a class number in the 1940s, it was 'Y11' in the steam locomotive class series. Similarly, the diesel electric shunters were initially allocated 'J45', being reclassified 'DES1' from September 1945.