London Underground rolling stock numbering and classification

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A number of different numbering and classification schemes have been used for the rolling stock owned by the London Underground and its constituent companies. This page explains the principal systems.

Contents

[edit] Electric Multiple Units

The numbering and classification of electric multiple unit stock on the London Underground is usually related to the type of line that the trains are used on. There are two distinct types of line: 'Sub-surface' lines (earlier lines built on the cut-and-cover method, which use trains of similar size to those on the national railway network), and 'Tube' lines (deep-level lines, built to a more restricted size). The 'Sub-surface' lines are the Circle, District, East London, Hammersmith & City and Metropolitan lines; all the other lines are 'Tube' lines.

[edit] Unit Classification

The method of classification depends on the type of line the train operates on:

[edit] Tube Stock

Tube Stock is classified by the year in which it was anticipated at the time of ordering that it would be delivered (this sometimes proves optimistic), e.g. 1992 Stock. This system was commenced by London Underground with the 1935 Stock. The large number of broadly similar Tube trains built for the LER during 1923-1935 were called 'Standard Stock', although there were many detail differences. They replaced the LER's original 'Gate Stock', introduced for the opening of the Bakerloo, Piccadilly and Hampstead (Northern) lines, and the CLR's 1903 Stock, constructed to replace the locomotive and carriage sets used at its opening in 1900.

[edit] Sub-surface Stock

Sub-surface Stock is classified by a letter, usually issued sequentially, and which is sometimes followed by the last two digits of the year of delivery, e.g. Q23 Stock. This system was commenced by the MDR for its stock. When the London Underground was formed the ex-Metropolitan Railway units were fitted into this series (types MV, MW, T, V, VT and W). By 1960, most letters had been allocated, and the decision was taken to re-issue 'A' to the new Metropolitan stock. The next sub-surface types were built for the Circle and District lines, and the opportunity was taken to allocate 'C' and 'D' respectively, omitting 'B'.

[edit] Types of Unit

On most lines, trains are formed from a pairing or triplet of units. Units are 'single-ended', where there is a driving cab at one end only, or 'double-ended', where there is a driving cab at both ends. In addition, some units have no driving cabs, and thus must always be included in the middle of a formation of units.

[edit] Car Classification

The different types of car used to make up electric multiple units are referred to by a series of codes, described below:

Code Description
DM Driving Motor car (with motors and a driving cab)
DT Driving (or 'Control') Trailer car (with a driving cab, but no motors)
NDM Non-Driving Motor car (motored, but with no driving cab)
UNDM Uncoupling Non-Driving Motor car (as NDM, but with controls at one end to permit uncoupling and shunting, but not full driving facilities)
T Trailer car (no motors or driving cabs)

On most lines the end cars of units are described as 'A' end cars or 'D' end cars ('B' end until the 1930s). In general the 'A' end is the north or west end and the 'D' end is the south or east, but the reverse applies on Bakerloo Line. On lines with a loop at the end that allows trains to turn round (e.g. at Heathrow on the Piccadilly Line), this system cannot apply rigidly.

[edit] Car Numbering

Each car carries its own unique number (although many numbers below 10000 have been reused by newer cars after the withdrawal of older trains), and unit numbers are not applied. Although car numbers have been allocated in a variety of different series over the years, two basic principles can be identified:

  • A-end cars have even numbers and D-end cars have odd numbers; cars will usually be renumbered if they are turned to the opposite end. (This principle was applied by the MDR and continued by London Underground.)
  • Cars within a unit usually either share the same last two digits, or one end uses the next odd digit after the other end's even digit; frequently when cars are swapped between units they will be renumbered to maintain this approach. (This principle was introduced by the London Underground.)

[edit] 1931 Numbering Series

In 1931, the LER began a major renumbering of all its multiple unit cars. The series was adopted by the London Underground when it took over in 1933 and renumbered stock inherited from other lines into the LER's series. The table below shows the number ranges used for the inherited stock and initially used by the LER/London Underground for new stock (including the LU-design M and N Stock and Q38 Stock DM cars - Q38 Stock trailers were allocated numbers in one of the new numbering series described later):

Number Series Car Type Line Type Numbers for Inherited Stock Numbers for New Stock Numbers for Converted Stock
1-37 DM Sub-surface (ex-MDR) Surviving unrefurbished B Stock (not renumbered in 1931) - -
1000-1094 T - -
1700-1717 DT - -
2000-2999 DM Sub-surface (ex-Met) 2200-2247 (Hammersmith line stock); 2500-2769 (Main line stock); 2900-2940 (Northern City line stock) - -
3000-3999 Tube 3000-3069 and 3282-3688 (ex-LER); 3912-3999 (ex-CLR) 3070-3281; 3689-3721 3723-3784 (DM cars that changed ends)
4000-4999 Sub-surface (ex-MDR) 4000-4390 and 4591-4645 4391-4437 4620-4642 evens (ex-DT cars)
5000-5999 DT Tube 5000-5359 (ex-LER); 5928-5999 (ex-CLR) - -
6000-6199 Sub-surface (ex-MDR) 6000-6022 - 6100-6109 (ex-DM cars)
6200-6999 Sub-surface (ex-Met) 6201-6264 (Hammersmith line stock); 6500-6735 (Main line stock); 6900-6919 (Northern City line stock) - 6558/6559/6561/6562 (ex-trailers); 6736-6755 (ex-hauled stock)
7000-7999 T Tube 7000-7059 and 7190-7570 (ex-LER); 7901-7999 (ex-CLR) 7060-7189 -
8000-8999 Sub-surface (ex-MDR) 8000-8048 (Composites); 8200-8258 (ex-DM cars); 8500-8535; 8700-8780 (ex-DM cars) 8049-8083 (Composites); 8781-8785 8084-8095 (Composites, ex-Third class); 8786-8799 (ex-DM cars); 8801-8812 (ex-Composites); 8813-8848 & 8900-8904 (ex-DM cars)
9000-9999 Sub-surface (ex-Met) 9200-9259 (Hammersmith line stock); 9400-9799 (Main line stock, 9582-9599 ex-DM cars); 9900-9968 (Northern City line stock) - 9479-9482 (ex-DT cars); 9800-9844 (ex-hauled stock)

Notes:

  • Ex-Met hauled stock retained their original numbers as they did not clash with any of the numbers allocated to the multiple unit stock; they were all numbered between 41 and 510 (511-519 were later allocated to cars converted from multiple unit to hauled stock).
  • A 'Composite' car had both First and Third class seating. All Tube stock was Third class only; all ex-MDR stock was Third class except those trailers identified as Composite. In the ex-Met ranges First class stock took the lowest numbers, then Composites, then Thirds. London Underground gradually declassified all stock to Third class, the process being completed in the early years of World War II.
  • Some cars converted to Trailers after 1935 carried a '0' prefix to their numbers, as was applied to new-build trailer cars in this period. In some cases, such cars briefly retained their original DM numbers but with a '0' prefix before being renumbered into the appropriate range for trailers.

[edit] Later Developments

This standard number series proved to be short lived; from 1935 onwards a variety of different series have been used, so the current list of numbers looks rather random. The table below sets out the numbering systems used for each type of London Underground stock:

Number Series Stock Number Ranges Allocation of Numbers
11-26 1986 11-16 DM;
21-26 NDM		 Formed 1x+2x
100-897 1973 100-253 DM;
300-453 UNDM;
500-696 T;
854-897 DM (from double-ended units)		 All cars in a unit had same last two digits, except double-ended units, which were formed in a series from 854+654+855
1xxx,
2xxx,
9xxx		 1956, 1959 & 1962 1xxx DM;
2xxx T;
9xxx NDM		 All cars in a unit had same middle two digits, fourth digit even for A-end cars and odd for D-end cars
3xxx,
4xxx		 1967, 1972 & 1983 3xxx DM;
4xxx T		 All cars in a unit had same last two digits, second digit even for A-end cars and odd for D-end cars
39xx,
49xx		 1960 39xx DM,
49xx T		 Fourth digit was even for A-end cars and odd for D-end cars; the original trailers (converted from Standard Stock) were later replaced by trailers converted from 1938 Stock, whose numbers did not correspond with the DM cars
5xxx,
6xxx		 A and C 5xxx DM;
6xxx T		 A Stock: four-car units, where all cars in a unit had same middle two digits, fourth digit even for A-end cars and odd for D-end cars; C Stock: two-car units, where both cars had same last three digits
7xxx,
8xxx,
17xxx		 D 7xxx DM;
8xxx UNDM;
17xxx T		 All cars in a unit had same last three digits, except double-ended units, which were formed in a series from 7500+17500+7501
10xxx,
11xxx,
12xxx,
30xxx,
31xxx;
70xxx,
90xxx,
91xxx,
92xxx		 1935, 1938 & 1949 10xxx DM (A-end);
11xxx DM (D-end);
12xxx NDM (T when prefixed by '0');
30xxx UNDM (A-end);
31xxx UNDM (D-end);
70xxx T (ex-Standard Stock);
90xxx DM (nine-car unit A-end);
91xxx DM (nine-car unit D-end);
92xxx NDM (nine-car unit; T when prefixed by '0')		 DM cars had same last three digits, trailer numbers were not matched
13xxx,
14xxx		 O, P and Q38 trailers 13xxx A-end (DM or T when prefixed by '0);
14xxx D-end (DM or T when prefixed by '0'		 DM cars had same final three digits, trailer numbers were not matched. (Q38 Stock DM cars were numbered 4xxx in the original 1931 number series)
2xxxx R 21xxx DM (A-end);
22xxx DM (D-end);
23xxx NDM		 The third digit indicated the position of the car in the unit, A-end to D-end, from 1 to 6 in six-car units and 5 & 6 in two-car units, and each car in the unit had same last two digits
4xxxx 1956 40xxx DM (four-car A-end);
41xxx DM (three-car D-end);
42xxx DM (three-car A-end);
43xxx DM (four-car D-end);
44xxx NDM;
45xxx T (even in four-car, odd in three-car)		 All DM and NDM cars in a unit had same last three digits. All cars were renumbered into 1xxx, 2xxx & 9xxx series when 1959 Stock delivered
51xxx,
52xxx,
53xxx		 1995 51xxx DM;
52xxx T;
53xxx UNDM		 All cars in a unit had same last three digits
53xxx,
54xxx		 CO and CP 53xxx DM (A-end);
54xxx DM (D-end)		 Ex-O and P Stock, 40000 added to original number
65xxx,
67xxx,
91xxx,
92xxx,
93xxx		 1992 65xxx DM;
67xxx NDM;
91xxx DM;
92xxx & 93xxx NDM		 All cars in a unit had same last three digits; units in 6xxxx series are Waterloo & City line and retain their British Rail numbers
75xxx Standard Trailers Ex-DT cars, 70000 added to original number
96xxx 1996 960xx & 961xx DM;
962xx & 963xx T;
964xx & 965xx UNDM;
968xx & 969xx T (fitted with de-icing equipment)		 All cars in a unit had same last two digits

Notes:

  • 17000 and 20000 were used for cars converted from T Stock in 1946/1947 as prototypes for A Stock. 17000 was renumbered 17001 following further modifications.
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British railway rolling stock numbering and classification systems