Overview
London Underground uses a numbering system comprising the wagon number prefixed with a letter which designates the wagon's type. These are summarised below.
| Prefix | Type | Description |
|---|---|---|
| B | Brake van | Manned wagon used for guard's accommodation and for braking purposes. No longer used. |
| BW | Ballast wagon | Open wagon, for transport of ballast |
| C | Crane | Powerful crane for track laying/lifting and/or recovering de-railed rolling stock |
| DEC | Diesel-electric crane | |
| DHC | Diesel-hydraulic crane | |
| CM | Cement mixer wagon | Specialist flat wagon, with a cement mixer. These wagons have been modified and now form part of Tubelines's DISAB ballast sucking machines. |
| CW | Cable drum wagon | A short wagon for transporting cable drums through deep level tunnels. For signal wiring |
| FW | Flat wagon | Flat wagon, for transport of rails or sleepers Now only used in train formation with tampers 771,772 and 773. |
| FB | Flat brake | Flat wagon, with brake van compartment. No longer used. |
| GP | General purpose wagon | General purpose wagon |
| HD | High deck wagon | to carry a stack of track panels no more than 4 panels high. |
| HW | Hopper wagon | Hopper, for transport of fresh ballast |
| J | Jib carrier | Specialist flat wagon, for carrying the arm (jib) of a crane |
| JC | ||
| JLE | Jubilee Line Extension | The same as General Purpose wagons (GP), used in the construction of the Jubilee Line Extension. Only difference is that the JLE's wagons have larger handbrake wheels. |
| MW | Match wagon | Wagons paired with the cement mixer wagons. Now used as GP wagons semi-permanently coupled together. |
| RW | Rail wagon | Specialist flat wagon, for transport of rails |
| SB | "Turbot" ballast wagon | Specialist ballast wagon, that will deliver ballast to the trackbed. Can also be used to transfer plant, used ballast or scrap. |
| TMM | Tamping machine | Ballast tamper for packing ballast to make lines more durable. Numbered 771, 772, 773 and 774.
771, 772 and 773 can only be transported through deep-level tunnels in train formation. 774 is for sub-surface lines only. |
| WPW | Well wagon | Specialist flat wagon, with lowered central section to enable larger loads to be carried. All have prefix JLE. Commonly known as a 'Low Loader'. |
Read more about this topic: London Underground Engineering Stock