A Position Light Subsidiary SignalAn additional Semaphore Signal controlling Shunting Movements and movements onto Occupied tracks. More that instructs the driver to ‘draw ahead’,
for example, sufficiently to enable a set back move over a trailing
connection to take place. An alternative term for Calling-on or Shunt-Ahead
SignalA visual display device which conveys instructions or provides prior warning of instructions regarding the driver’s authority to proceed. More.