Constituent Companies Great Central Railway From 1859, the GCR identified different classes using an alphanumeric system. The first list of classes was a simple list of numbers from 1 onward. Number 18 was the highest allocated. Thence, newly built classes received class numbers with a letter suffix rather than using more numbers. By 1923, the '9' series (the largest) had reached '
9Q'. Of themselves the letters and numbers had no meaning; they appear to have been allocated randomly. Where new classes were built, or existing classes rebuilt, these were often indicated by adding a more meaningful suffix to the existing alphanumeric class were used. Examples included: • ALT:
Altered • B:
Bogie version • CONV:
Converted • I:
Improved version • M:
Motor train equipment fitted • T:
Tank engine version Locomotives inherited from the
Lancashire, Derbyshire and East Coast Railway retained their existing classifications (lettered A to D) and the locomotive inherited from the
Wrexham, Mold and Connah's Quay Railway was left unclassified.
Great Eastern Railway The principal GER works at Stratford used an order number series that ran from A to Z, then A1 to Z1, A2 to Z2 and so on. This system was used for a myriad of items, including locomotives, but it was these numbers that were used to refer to locomotive classes. Self-evidently this meant there was no continuity in the GER locomotive classification system. The highest-numbered locomotive class was '
H88'. Where more than one order number had been used for a given class, the first order number allocated was used to refer to the whole class. Where locomotives were purchased from outside manufacturers, they were referred to by the lowest number applied to a class member.
Great Northern Railway From 1900, the GNR adopted a system of classification based on a locomotive's wheel arrangemenent (using the
Whyte Notation), with each arrangement being represented by a letter. Initially, the letters A to J were allocated in ascending order of driving axles and descending order of leading axles. Letters K to O were allocated later as new types were introduced and A was re-used once all the 4-2-2 locomotives had been withdrawn. The full list of letters used was as follows: •
A:
4-2-2, later
4-6-2 •
B:
2-2-2 •
C:
4-4-2 •
D:
4-4-0 •
E:
2-4-0 •
F:
0-4-2 •
G:
0-4-4 •
H:
2-6-0 •
I: Unused •
J:
0-6-0 •
K:
0-8-0 •
L:
0-8-2 •
M:
0-4-0 Railmotor •
N:
0-6-2 •
O:
2-8-0 After the letter was a number that identified broadly similar types, although there could be some significant variation within a single class number. In the main, numbers were allocated in descending order of driving wheel diameter.
Great North of Scotland Railway In 1879, every class then in service was allocated a letter between 'A' and 'M' (except 'I'), the oldest types first. From then on, new classes either reused letters that had become free due to withdrawal of older engines, or were allocated a letter at the end of the series. Class 'U' was not used and the highest letter allocated was 'Y'.
Hull and Barnsley Railway Classes were allocated a letter consecutively from 'A', with similar classes being allocated a numeric suffix, or an 'S' suffix to indicate
Superheated. The last class letter allocated was 'L'. When the HBR was absorbed by the NER from April 1922, the suffix '(HB)' was added to all ex-HBR classes to differentiate them from NER classes.
North British Railway In 1913, every locomotive then in service was allocated a letter indicating its power. Letters 'A' to 'G' were used for goods engines and shunters and 'H' to 'R' for passenger engines, most powerful types first. Letters 'O' and 'Q' were not used. This system did mean that each letter covered a variety of different classes of locomotive.
North Eastern Railway Prior to 1886, classes were referred to by the number applied to the first built locomotive within that class. New classes built after 1886 were allocated a letter to describe them, commencing at
A. Where new classes were a modification of an earlier class allocated a letter, then they were allocated that letter with a numeric suffix starting at 1. The series reached
Z in 1911. The next new class was allocated '
D', which had become vacant following rebuilding of the
original class to take that letter. There were some exceptions to this system: • Class BTP: A series of
Bogie
Tank
Passenger locomotives built in 1874. • Class 3CC and 4CC: A series of
3- and
4-
Cylinder
Compound locomotives. • Class
4-6-2: The five
4-6-2 locomotives built in 1922.
Minor Companies The three minor companies absorbed by the LNER in 1923 and 1924 were too small to need to classify their locomotive stock. However, both the M&GNJR and Metropolitan Railway had owned a much larger stock of locomotives. Both railways allocated each class a letter consecutively from 'A'. The highest letter issued by the M&GNJR was 'D', and by the Metropolitan was 'K'.
LNER System Steam Locomotives When the LNER was created in 1923, a new classification scheme was drawn up that could accommodate all the inherited steam locomotives and future new classes, and provide useful information about the features of a given class. The answer, approved in September 1923, was a variation of the GNR system, using a letter to indicate each type's wheel arrangement (based on the
Whyte Notation). The letters were allocated with passenger engine arrangements first in descending order of coupled wheels ('A' to 'H'), then goods engine arrangements in ascending order of coupled wheels ('J' to 'T'). Letters 'X', 'Y', 'Z' were used for a variety of small engine arrangements. The letter 'P' was included in the original list, even though there were no locomotives of the
2-8-2 wheel arrangement until June 1925, because
Class P1 was at an advanced stage of design – the order was placed in November 1923. Letters 'I' and 'U', 'V', 'W' were left unused at the time, but the latter three were later applied when new wheel arrangements were introduced; 'I' was never used. The full list of letters used was as follows: •
A:
4-6-2 •
B:
4-6-0 •
C:
4-4-2 •
D:
4-4-0 •
E:
2-4-0 •
F:
2-4-2 •
G:
0-4-4 •
H:
4-4-4 •
J:
0-6-0 •
K:
2-6-0 •
L:
2-6-4 •
M:
0-6-4 •
N:
0-6-2 •
O:
2-8-0 •
P:
2-8-2 •
Q:
0-8-0 •
R:
0-8-2 •
S:
0-8-4 •
T:
4-8-0 •
U:
2-8-0+0-8-2 •
V:
2-6-2 •
W:
4-6-4 •
X:
4-2-2 &
2-2-4 •
Y:
0-4-0 •
Z:
0-4-2 Many of these letters (A,C,D,E,G,J,N,O) were the same as in the GNR scheme. 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 of age, oldest first In order to indicate variations within a class, subclass 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. 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 latter's classification. In contrast, the ex-
Metropolitan Railway engines (absorbed 1937) were allocated LNER classifications immediately. The
Great Southern Railways of Ireland would later adopt
a similar classification system.
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. ==References==