Train Reporting Number - Special Numbering

Special Numbering

It is common practice for empty coaching stock (class 5) trains on the way to form a service or returning to depot having completed a service, to run with the same code as that service, with the 5 prefix. For example, 5M37 may be going to form or coming off either 1M37 or 2M37. Similarly, locomotives on the way to pick up a train or running round to change the direction of travel are given the train number but with a 0 prefix.

An unusual situation arose with the opening of the Channel Tunnel: many continental train reporting numbers are all numeric. Eurostar trains therefore have a 9Oxx or 9Ixx reporting number in Britain and a corresponding 90xx or 91xx number on the continent, neatly utilising the similarity between the letters O and I, and the numbers 0 and 1 to unite the two reporting number systems.

Trains with some specific requirements, such as out-of-gauge loads or the Royal Train, run with the letter X, and special trains not in the regular train service (e.g. charter services, railtours, emergency trains or as-required locomotive moves) have Z. Automatic Route Setting code prevents the automatic routing of trains with the letter X in their headcode and signallers must route these trains manually. The former White Rose service from London King's Cross to Leeds ran with a prefix of 1X due to the train's unusually long length.