The history of London Underground's rolling stock is as complicated as the history of the network itself. A wide variety of types have been operated, from the early days of steam locomotives and carriages through to today's electric multiple units.

Classification

There are two distinct types of line on the London Underground, the sub-surface lines (the earlier lines built on the cut-and-cover method and which use trains that are more or less the same size as those on the national railway network) and the deep-level 'Tube' lines. The former includes the District and Metropolitan lines, the latter the Central and Northern lines. The method of classification depends on which type of line the type of train is designed to use:

• Tube Stock is classified by year in which they were ordered, e.g. 1992 Stock.
• Sub-Surface Stock is classified by a letter, which is sometimes followed by the last two digits of the year they were ordered, e.g. Q23 Stock.

It is important to recall that the year in which the stock entered service may be a year or more after the placing of an order.

For completeness, stock used by the London Post Office Railway is also listed here.

Numbering

Each carriage carries its own unique number, and carriages within a unit usually all share the same last two digits. Numbers are not applied to describe a whole unit. Carriage numbers have been allocated in a variety of different series over the years, so the current list of numbers looks rather random.

List of types

Stock shown in red has been withdrawn from traffic.

Locomotives

• Steam locomotives — withdrawn by 1971
• Electric locomotives — withdrawn from service by 1962
• Diesel locomotives — DL81-DL83 — withdrawn from service
• Battery-electric locomotives — still in service