Specification for TD (Train Data / Track Data)

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See also Wise for more information
on the use of this type of data.
This screen shot shows TD data
displayed along the lines at
London Waterloo Station.

This page primarily refer to the movement of trains. Tram systems use similar information systems.

Track Data (Train Data) is provided as a data feed usual from a signalling centre. It provides details about train movements and signalling instructions. The data is normally provided via a leased line modem. IP based data feeds are also available but only to a very restricted number of companies within Network Rail.

The basic TD data is the result of train movement along the track resulting in berth data being sent back to the system. This data consists or short messages indicating train movement from one berth to the next. The information provided can be used to track train movement and calculate delays as the train approaches the station.

Some train data feeds also provide "ready to depart" and signalling data which can also be used to automatically change platform numbers and clear the train record off the public displays automatically.

It should be noted that train data is only as accurate as the train data being sent out. Signalman are known to change head codes to suit their method of working and occassionally in error. For example if train is waiting at a platform for long periods of time waiting for a joining service the signalman may change the head code temporarily to the time of the expected departure as a reminder.

Train Data use is summarized as follows:

  • Indicates when a train joins the local signalling area
  • Indicates when a train moves between berths
  • Indicates the time of the movement (accuracy to within a minute)
  • Provides time signals once a minute
Data may also be available for:
  • Platform selection
  • Signal state
  • Train ready to depart

The Wise Customer Information System processes these data feeds and supplies the information on a track map showing track movements. This is an optional service available to users of the Wise CIS package.