A switch which, when operated, allows a Signal BoxThe building in which the Signaller(s) is/are situated together with the control and indication system for the signalling. See also Signalling Centre. to be un-staffed for a
period, by registering telephone calls to that Signal BoxThe building in which the Signaller(s) is/are situated together with the control and indication system for the signalling. See also Signalling Centre., usually during quiet
periods.