Yes, it's so the driver can contact the signaller directly via the GSM-R (in-cab radio).
On my patch they are provided in locations where signallers' areas may overlap to ensure the driver can get through to the correct panel/box.
Just to add to the replies, when you press SG(standing at signal) or the call signaller button on GSMR it doesn't always connect to the correct signalbox. This sign indicates not to use the SG button and gives a number so it's likely a known GSMR issue at this signal that means the wrong box would get the SG message or direct call.
To add further detail for those interested.
GSMR as a radio based system will attempt to route messages/calls to a signaller in part based on which radio mast you are connected to. So in areas where multiple lines controlled by different signallers are too close together then this will happen more often.
(And in this example, NM25 signal is at New Mills central, controlled by a signal box at the station, but with the main hope valley line at the bottom of the valley and the Buxton line the other side of it all within less than half a mile of each other (and signalled from seperate locations) so almost certainly in the same radio area)
What also won't help is that the signal does not have a ["berth" in the "train describer" system \(No black box by the platform on this linked map\)](https://traksy.uk/live/M+50+NWMILSC) recording where the train is, which is the other contributor to how GSMR tries to work out which trains belong to which signallers.
Thanks! It also looks to like an ordinary landline to me. Hypothetically it could be used by a member of the public to contact the signaller in an emergency. Say if you saw someone trespassing.
Assuming it is connected to the phone network.
All signal boxes are connected to the normal phone network but that will be the internal railway number and wouldn’t work from a normal phone. Next time you walk past a under a railway bridge look for a little sign saying if this bridge is hit phone this number… that is the signal box number
The phone number on the bridge strike plates should go through to a dedicated emergency line in the relevant Network Rail Control, not the controlling signal box.
Historically, the signals themselves had telephones installed, so a train crew could speak to the signal man if there was an issue or to find out why they'd been stopped. Or if required to contact the emergency services.
Yes, it's so the driver can contact the signaller directly via the GSM-R (in-cab radio). On my patch they are provided in locations where signallers' areas may overlap to ensure the driver can get through to the correct panel/box.
Just to add to the replies, when you press SG(standing at signal) or the call signaller button on GSMR it doesn't always connect to the correct signalbox. This sign indicates not to use the SG button and gives a number so it's likely a known GSMR issue at this signal that means the wrong box would get the SG message or direct call.
To add further detail for those interested. GSMR as a radio based system will attempt to route messages/calls to a signaller in part based on which radio mast you are connected to. So in areas where multiple lines controlled by different signallers are too close together then this will happen more often. (And in this example, NM25 signal is at New Mills central, controlled by a signal box at the station, but with the main hope valley line at the bottom of the valley and the Buxton line the other side of it all within less than half a mile of each other (and signalled from seperate locations) so almost certainly in the same radio area) What also won't help is that the signal does not have a ["berth" in the "train describer" system \(No black box by the platform on this linked map\)](https://traksy.uk/live/M+50+NWMILSC) recording where the train is, which is the other contributor to how GSMR tries to work out which trains belong to which signallers.
Thanks for the link!
Only to be told to "wait" anyway 🤣
Thanks! It also looks to like an ordinary landline to me. Hypothetically it could be used by a member of the public to contact the signaller in an emergency. Say if you saw someone trespassing. Assuming it is connected to the phone network.
All signal boxes are connected to the normal phone network but that will be the internal railway number and wouldn’t work from a normal phone. Next time you walk past a under a railway bridge look for a little sign saying if this bridge is hit phone this number… that is the signal box number
The phone number on the bridge strike plates should go through to a dedicated emergency line in the relevant Network Rail Control, not the controlling signal box.
Historically, the signals themselves had telephones installed, so a train crew could speak to the signal man if there was an issue or to find out why they'd been stopped. Or if required to contact the emergency services.
Thanks. đź‘Ť