A Last Sent Berth contains the TD or Train Description of the most recent train passing along that stretch, on its way to the next signal box.
In the event of a communication failure, the last sent berth enables the signaller to relay the train description by telephone to the next signalbox without trying to recall what the last train was. This is particularly important on busy panels.
Some last sent berths automatically clear-out after a defined time interval such as five minutes. The majority, however, hold the train identity indefinitely. The signaller usually does not have access to the berth to overwrite or cancel the contents.
In SimSig, and on IECC and other systems, the last sent berth is labelled with either "LAST SENT" or "LSNT".
Last edited by GeoffM on 15/09/2016 at 03:00