British Rail regional multiple unit numbering

Prior to the introduction of TOPS, electric multiple unit numbers were allocated by the British Rail regions in their own series. Diesel multiple units did not carry unit numbers at first, but the Scottish and Western Regions later adopted their own series for these units, whilst elsewhere individual depots allocated unit numbers, often prefixed by their two-letter TOPS depot code (e.g. TS for Tyseley).

When TOPS numbers were applied to multiple units, the original unit numbers were simply prefixed by the class number to make up the required new six-digit unit numbers. These regional series have been perpetuated since TOPS because it eases the description of individual units and avoids potential confusion if there is only one unit with a particular identifier working in a certain area.

Southern Region units are excluded from this page, as they perpetuated the four-digit unit numbering series commenced by the Southern Railway. For details of the more involved arrangements on the Southern Region, see SR Multiple Unit Numbering and Classification.

Diesel Multiple Units

London Midland Region

There was never a regional number series for DMUs in this region, but individual depots did have their own series, prefixed by their two-letter TOPS depot code. The table below shows the series used by Tyseley depot (which was part of the Western Region until 1963).

Scottish Region

The table below shows the broad arrangement of multiple unit numbers in this region, though a couple of Class 104 units also took numbers in the 3xx series. The surviving Class 107 units were later renumbered twice, first to 7xx following the introduction of the Class 156 units, which had 4xx unit numbers in the Regional Railways Sprinter series, and then to 0xx following the introduction of the Class 158 units, which had 7xx unit numbers in the Regional Railways Sprinter series.

Western Region

Unit numbers were prefixed by a letter (letters prior to 1970) to indicate which area (or depot) the unit was allocated to. The table below lists the prefixes used; note that Tyseley had transferred to the London Midland Region by the time that the 1971 changes took place so was not included, though it did shorten its prefix to TS.

The unit number ranges used were:

Network SouthEast

NSE adopted the former Western Region series, and expanded it to include its other diesel multiple units (those used on the former London Midland Region), which took unit numbers in the 7xx series. This included units from Classes 101, 104, 108 and 117.

Regional Railways

Sprinter (Class 15x) units carried the same last three digits as the last three digits of their carriage numbers in the 52xxx and 57xxx series. The 6xx series was reserved for use by the aborted Class 157 stock, and so instead was adopted for use by refurbished Class 143 (numbers 601-625) and 101 (numbers 651-695) units. Refurbished Class 117 and 122 units kept their Tyseley 3xx and Laira (Western Region) 1xx unit numbers respectively.

Electric Multiple Units

Eastern Region

When first introduced, the Class 306 units were numbered 01-92 and the Class 307 units were numbered 01s-32s. These numbers were amended as they were converted from 1500 V DC to 25 kV AC operation. Parcels & departmental units in the 99x series have included Classes 308/4, 302/9, 316 and 937.

London Midland Region

Scottish Region