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Is it REALLY a "P" Type?

(Wooden Railway Phones)


I'm sure that many of us have looked at that funny looking wooden box type ex-railway telephone and wondered whether it was genuine or just a "Jerry Bilt" product designed to attract the unwary.

You know the kind. The correct size and shape for a Western Electric 1317 ("P" Type) but....

Doesn't have bells and doesn't even have the holes for bells or has had the bell holes covered by a strip of timber.
Doesn't have a generator.
May not be made of the genuine American quarter sawn oak.
Originally had a separate transmitter but now the holes are covered with a Bakelite plate and it has a Bakelite handset.
Probably has a "Press to speak, release to listen" button somewhere on the front or side. Some had press to speak handcombs in latter years.

The mystery may now be solved. It is probably an ex-NSW-Railways Train Control telephone and it is genuine and a real telephone. As the name suggests, these telephones were used to control trains and were vital to the safe working of the railways for many years. The sort of instructions which passed along the line included orders to hold a train to let another pass, to release a train ahead of another, etc, etc. The system was only taken out of service about 10 years ago.

The telephones formed part of a very long party line. A section of train line may be as long as 140 miles and the entire section was under the eye of a single train controller. A control telephone was sited at every signal box and station along the entire 140 miles. There may have been as many as 30 or 40 stations on one line. The catch was that only the controller could initiate calls. The individual station could call by picking up the handset and waiting for a break in conversation, and saying the station's name. The train controller listened on a speaker.



But wait - there's more. Associated with every control telephone is another control box, slightly smaller than the "P" class, but essential to make the system operate. This other box contains a bell, some capacitors, a couple of chokes and a funny looking gizmo called a selector.

If it was a party line, why not use code ringing just like the PMG did? Probably four reasons - (1) The length of line and number of stations made it doubtful that bells at the end of the line would ring satisfactorily (2) The number of stations would make codes very long and easy to get wrong (3) Signal boxes and stations are busy places and if you didn't hear the first time the code had to be repeated until someone answered, and (4) If you weren't wanted, your phone did not ring.

The system worked like this. When the train controller wished to speak to a particular signal box along the route, he would turn a small handle on his panel corresponding with the station he wanted. This spring loaded handle was attached to a mechanism, which would send out a series of 17 pulses to line. These pulses were direct current, selectively negative or positive and were at approximately 140 volts.



The selector in each control box along the route was set up to recognise only its own code. At the first of the 17 pulses, all selectors would step off normal but as the pulses continued, most would find the code did not match their settings and would reset and step back to normal. Only one would make the full 17 steps and this would result in the bell in the control box being rung and a successful call could take place.

But wait, I hear you say. What rung the bells in the control box? That's easy. Whilst the bell looks like an ordinary 500 + 500 ohm magneto bell, it is, in fact, a 8.75 + 8.75 ohm double coil trembling bell which operates from the 3 volts supplied by the dry cells in the bell box. There is a very ingenious changeover springset attached to the bell striker, which switches between the two coils - just like a trembler DC bell. And the bell will keep on ringing until answered or until the caller gives up (assuming the batteries do not go flat).


Train controllers were very busy people and an additional feature was provided where codes were setup to call a number of stations simultaneously so important messages needed to only be given once.

There was also Line isolating switch at most Stations which took the form of a smallish box about 8 inches high, 4 inches wide and 1.5 inches deep which contained two small knife switches. The first one labeled line would open circuit the line on the far side of the station/signalbox concerned; the other one labeled selector would open circuit the selector at that station. These switches also had the unusual feature that if the lid of the box was closed it would reclose the knife switches inside. Therefore in fault conditions the cover of the box would be left open to serve as a visual reminder to the operator.



Written by Bill Ryan and Bob Mills









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