Whatizit? - W.E. 1317-S with Push Button and No Magneto

[SUnset2]

I recently picked this up cheaply thinking I might use it for parts to fix another phone that is missing some of the parts that this one has, though this one is nicer in some ways, so the other might be the donor phone.  But I'm trying to figure out what this phone really is. 

It's obvious that the transmitter and receiver were taken off of it, but it looks like it never had a magneto.  There is a nice plug over the hole where the crank should go, and the magneto is not on the schematic.  There is also a push button on the side.  Under the schematic is stamped into the wood "Special Type 317 S".

And what could be the meaning of the Seattle No. 138 label.  By the time this phone was made Seattle would have had multiple exchanges, and probably all common battery.
Is this some kind of railroad phone?  or some other type of non-magneto local battery with push-to-talk?

[Jack Ryan]

I would be curious to know where and how that phone was used. A 317-S has a magneto unless, of course, it is special.

It may have been used in conjunction with a Type 60 selector as a Way Station telephone connected to the dispatcher's line.

Jack

[tubaman]

Appears to be using the local battery via the push-button to signal the exchange rather than a magneto?

[Jack Ryan]

Appears to be using the local battery via the push-button to signal the exchange rather than a magneto?

The button is a PTT. The CO wouldn't detect that that button was pressed. It also has no effect unless the receiver is lifted.

It might be CBS-LBT say, for a long line service.

Jack

[tubaman]

The button is a PTT. The CO wouldn't detect that that button was pressed. It also has no effect unless the receiver is lifted.

It might be CBS-LBT say, for a long line service.

Jack

You're quite right, as there is no transmitter circuit unless the button is held in.
Could be for long line service as you say.

[poplar1]

It might be CBS-LBT say, for a long line service.

In the diagram, ringer is connected to L1 (black) and L2 (red). So I don't think it would be for Common Battery Signaling without a capacitor in the ringing circuit.

[Jack Ryan]

In the diagram, ringer is connected to L1 (black) and L2 (red). So I don't think it would be for Common Battery Signaling without a capacitor in the ringing circuit.

True, it would need to be a very high Z (R) ringer without a capacitor. Unless the ringer was grounded  but then the phone would have to be way out in the sticks or the imbalance would create noise.

There is no obvious method of signalling with this telephone and if that is the case, it is only good for receiving calls.

It was made after 1907 so it is not some ancient form of telephony but certainly not for the public telephone network.

Jack