GNR Fireman's call box or plunger

[ColHut]

G'day,

 

I am looking for images of the above on the Great Northern Railway. I think introduced originally by the LNWR in 1907. I have one image of one at Firsby East Junction including 'D' plate on the signal post, but the image is rather small and side on (from Vanns' Illustrated history of GNR signalling p.52).

 

Any help appreciated.

 

regards

Edited October 12, 2018 by ColHut

[LNERGE]

I can help with the signalbox end only i'm afraid.

[ColHut]

Thanks for that. You might know then if they operated on a closed or open circuit, and if they set or held the block to train on line when pressed. Was there an indicator also provided in the signalbox.

 

regards

[jim.snowdon]

The purpose of these devices was normally to tell the signalman that you (or rather, your train or locomotive) was standing at a particular signal. In some instances it would have allowed Rule 55 to be carried out without the need to send the fireman to the signal box. In others, such as at a shed exit, it would be to let the signalman know that the locomotive was requesting a route off shed.

 

Jim

[ColHut]

Thanks Jim,

 

Yes this is in respect of stop signals and compliance with Rule 55. I quite like this early alternative to track circuiting.

I note that at least one accident is recorded as being partially caused by a non-functioning Fireman's plunger operating on an open circuit which was not known to be faulty until it was too late.

 

regards

[RailWest]

Thanks Jim,

 

Yes this is in respect of stop signals and compliance with Rule 55. I quite like this early alternative to track circuiting.

I note that at least one accident is recorded as being partially caused by a non-functioning Fireman's plunger operating on an open circuit which was not known to be faulty until it was too late.

 

regards

If the actual plunger was non-functioning, then I fail to see how a 'closed' circuit would avoid such a problem instead of an 'open' circuit. Surely, whether the plunger fails to close an open circuit, or break a closed circuit, would still have the same 'no action' result? The only difference would be if the failure of the plunger actually broke a closed circuit without the need for it to be pushed first. 

[ColHut]

My understanding is that the "clsed circuit" type in the event of a break in the circuit, would cause a false positive result, a failure in the "open circuit" type would not be noted unless tested, and, as happened, resulted in a delay such that an accident ocurred.

 

regards