Run number

A run number is a four character, unique identifier assigned to every service, and by extension, to the train that is running that service.

In this article, 'n' is used to denote a number and 'a' is used to denote a captial letter.

Surburban Passenger Trains
Format: nnna or nnaa or anaa

This format is used by suburban passenger trains, as well as some trains that operate both intercity and suburban services. The numbers are the 'shift' number, and generally remain the same for each service a given train runs in a day. Dashes (-) are used to pad the number to the correct length if it is not long enough. The numbers are usually allocated in blocks, depending on which type of train is rostered on that 'shift'. For example, shifts 1-20 are rostered as B sets. An exception to this rule is Olympic Park shifts, which begin with a letter, which identifies the other terminus (B=Blacktown, L=Lidcombe, S=Sydney Central)

The letter(s) are used to distinguish between each run in the 'shift'. Most runs only use one letter, but short lines (e.g. Olympic Park) may use two to allow for the higher number of runs in day. For example, a train will start the day running run 1--A, then turn around and form run 1--B.

Intercity/Regional Passenger & Inspection Trains
Format: annn or aann

The first letter show which line/region the train is operating on or which line it is leaving Sydney using: The second character indicates what type of train is being used: The last number is even for up trains (toward Sydney) and odd for down trains (away from Sydney), while the other numbers identify where the train is going. For example, SP35 is an Xplorer train leaving Sydney via the Main South Line, travelling to Canberra.

Heritage Trains
Format: nann

The first number identifies the operator of the train: The letter identifies the type of train: The remaining two numbers are used to distinguish individual trains. As with the other formats, the last number is even for up trains (toward Sydney) and odd for down trains (away from Sydney).

Intrastate Non-Passenger Trains
Format: nnnn

The first number identifies the origin region of the train (see the map to the right). The second number identifies the destination region of the train. The third number provides more information about the operator and the narrows down the route of the train. The last number is even for up trains (toward Sydney) and odd for down trains (away from Sydney).

Interstate Trains
Format: naan

Note: NSW TrainLink trains do not use these numbers for interstate XPT services to Melbourne and Brisbane. They use the same regional passenger numbers for these services.

The first character is a number that show the day of the week the train departed at, with 1 = Sunday and 7 = Saturday. The second and third characters show the origin and destination of the train (each location is assigned to a letter). The last number is to differentiate two similar runs. The only rule is that if the last number is 8 then it must a passenger service.