The operation of the instruments is fairly simple. Should a train be ready to depart the Station Foreman at station A will place a tablet from the main magazine into the Rotary magazine of the Instrument and then tap the necessary code** on the send button. If the following station B is willing to accept the train he will repeat the code and hold down the send button of his instrument and by so doing send current through to the instrument at A. The Foreman at Station A will press the receive button and turn a tablet out of the instrument while the send button at station B is being held down. The tablet is then removed from the instrument, placed in the appropriate pouch and handed to the driver. When the train leaves, the signal "Train entering section" will be sent by tapping 2 which the station at the other end will repeat

The same procedure is followed when a train arrives at the next station. The foreman at B will send the message "Train has arrived" (2.1) The foreman at A will repeat the code and hold down the send button. The foreman at B can then, while pressing in the receive button, turn the tablet back into the instrument.

What happens is that current is sent through from one instrument to the other, which then releases the rotating magazine thus enabling a tablet to be obtained. The instruments are synchronized in such manner that once a tablet has been removed a second tablet cannot be obtained from any one of the two instruments until the tablet, which has been removed, has been replaced. Where you have Instruments for the stations on either side you cannot place a tablet into the wrong instrument as the tablets are slotted and only fit into the right instrument

** BELL SIGNAL CODES.

Bell signal codes as published in GENERAL TRAIN REGULATIONS dated 1st October 1913.

Absolute instruments have a Galvanoscope fitted. This is a round window in the top of the instrument behind which are two indicators (needles) one marked IN and the other OUT. By pressing the receive button it gives you an indication as to whether a tablet has already been removed or replaced. During normal procedures it will show OUT if you ask for a tablet and the opposing station gives you current to remove one or IN if you are about to turn a tablet back into the instrument.

The Van Schoor makes provision for a single train to be dispatched from one station to another which is known as Absolute working. Once a Tablet (token) is taken from one of the instruments at one or other end of the section to which the Instrument applies, no other Tablet can be taken out of the Instruments until such time that a Tablet which has already been removed, has been replaced in one of the Instruments. Thus it is impossible to get more than one Tablet so allowing more than one train to occupy a section between two stations simultaneously.

Permissive working was also possible whereby two or more trains could be dispatched in long sections by maintaining a specified interval of twelve minutes between trains. This was made possible by installing a second instrument known as a permissive instrument. A tablet would be obtained from the Absolute instrument, placed into the permissive instrument and by so doing release a second rotating magazine from which up to nine tablets could be obtained simultaneously. Permissive working has now been abandoned and is no longer in use.

Where you have an Interloop where two opposing trains can cross between two stations, there will also be an Intermediate instrument. Intermediate instruments have two magazines, one containing the crossing tablet and the other for inserting an absolute tablet which in turn releases the crossing tablet. Once the Crossing tablet has been removed the magazine containing the Absolute tablet is locked and the Absolute tablet will not be released until the Crossing tablets at both ends of the section have been replaced in the instruments.

When two trains are ready to depart from both stations:

B will hold the Send button of his instrument down enabling A to obtain an Absolute tablet.

A takes out the Absolute tablet and places it into the magazine on the Intermediate instrument. The magazine is lifted 45 degrees which then locks that magazine and simultaneously unlocks the magazine containing the Crossing tablet A removes the Crossing tablet and then sends current to B by means of a crank on the Intermediate instrument.

B can then remove the Crossing tablet from his instrument

After the arrival of both trains, and both tablets has been replaced into the instruments, the magazine containing the Absolute tablet will be released. A will place the tablet back into the Absolute instrument in the normal manner, thereby canceling Intermediate working.

The names of the station and Interloop between which the tablet is valid are inscribed on the tablet. The tablets are also slotted and will only fit into the magazine of the correct instrument.

When the two trains arrive at the interloop the drivers will exchange tablets, thus taking the tablet back to the station of origin.

The pouch in which the tablet is placed distinguishes the nature of a tablet handed to a driver. The tablets used for absolute and permissive are identical, a round disc upon which the names of the two stations at either end of the section are inscribed. The tablet also has a number from one to twenty four, which is the amount of tablets provided between two stations. An absolute tablet is placed in a round pouch while the pouch for permissive working was triangular. A crossing tablet on the other hand is square and placed in a square pouch.

The Van Schoor system is a very safe and reliable method of train control but as a result of increasing theft of copper wire, telephone lines are being removed on most sections and the Van Schoor instruments replaced with the Telegraph Order system. Radios are installed for communication.

NOTES REGARDING TRAIN WORKING RULES.

Train working rules were first issued in book form in 1913 and the Wooden Train Staff and Telegraph Order system has been in use since those early years. Applicable rules in use today are basically still the same as described in those early years with very few changes. Only the Telegraph order system has seen changes, mainly with the removal of what was known as Out of course train orders which were identified by an X, e.g. CX, GX and so forth. The other change being the Orders C, E, and G were then Station to Siding orders. Sidings are no longer Crossing places and are used for placing for loading or offloading. Interloops are provided for crossing purposes, hence the wording on the above orders now reading Station to Interloop.

Bell code signals were also provided in 1913 for use on what was known as Webb and Thompson’s Electric Train Staff System. Those signals are still in effect to this day. A few of the code signals regarding Banking engines and Permissive working have been removed from the list, as they are no longer in use.