This is a large (11.6 cm long) model of a NSWGR Staff for use by trains on track sections. In use the Staff was given to the driver of a train and gave that train permission to use the next section of track until it was required to be handed in at the end of the section at the next signal box or station.
Staffs came in four types, at the end of each Staff was a round section within which was a hole shaped like a circle, square, triangle or a heart. Each different Staff was for a different section of track. The Staffs would repeat for the fifth section and beyond.
In support of the Staff was the Ticket. A Ticket was used when more than one train needed to use the next section of track. The first train was given a filled in Ticket to carry and hand in at the end of the section. More Tickets could be used as required for subsequent trains heading onto the same section. The Staff was used for the last train. Trains proceeding in the opposite direction could not do so until the Staff was at the other end of the section.
The Staff was also a key to the Staff Box in which the Tickets were held. The Staff was used to unlock the Staff Box to gain access to the Tickets.
The model Staff has tabs along its length that could be used in a small Staff Box made from say MDF. The tabs can be used with appropriately placed micro switches in the Staff Box to electrically 'unlock' the Staff Box.
In addition or alternatively, the model Staff has a hole in the outer end which could have a 3mm stereo plug screwed in.The stereo plug could be wired from contact to contact to give different electricaly switching similarly to the tabs as described above. Some Staffs actually had a key on the this end and some didn't.
The NSWR document covering the use of the Staff and Tickets can be found here: NSWR Using Train Staffs
A PDF with 4 NSWGR Single Line Tickets can be found here: NSWGR Single Line Tickets