Nationwide GSMR outage 19/05

[QueensCurve]

Most services being limited to 100mph max as per rulebook but expect issues for remainder of the day

Why is that?

 

[GraphitProjekt]

Considering SPTs went down, is it actually a GSMR issue or an issue with the wider telecoms system? GSMR is just the first thing people are likely to find not working properly. Is there something more specific that runs on the telecoms network links SPTs and GSMR together but excludes SCADA traffic for signalling/electrical assets?

 

[Surreytraveller]

What's causing all of these outages, is it just coincidence?

Probably a software update

 

[Raikkonen7]

Why is that?

Speed reduced to 100mph in the first 4 hours of GSMR network failure and 60mph thereafter if it hasn’t been resolved. Clear safety implications if trains are running around at line speed without the usual means of communication working.

 

[68000]

Considering SPTs went down, is it actually a GSMR issue or an issue with the wider telecoms system? GSMR is just the first thing people are likely to find not working properly. Is there something more specific that runs on the telecoms network links SPTs and GSMR together but excludes SCADA traffic for signalling/electrical assets?

The most likely cause of the SPTs not working is much simpler, nobody uses them and they probably have not worked in years

 

[Kilopylae]

Network Rail were saying earlier that disruption was only expected until 6.00 pm. Have things more or less cleared up now?

 

[43096]

Speed reduced to 100mph in the first 4 hours of GSMR network failure and 60mph thereafter if it hasn’t been resolved. Clear safety implications if trains are running around at line speed without the usual means of communication working.

And how, exactly, is that going to be implemented if the means to communicate it to drivers isn't working?

 

[choochoochoo]

Speed reduced to 100mph in the first 4 hours of GSMR network failure and 60mph thereafter if it hasn’t been resolved. Clear safety implications if trains are running around at line speed without the usual means of communication working.

So you can run without the GSM-R. What happens with respect to Railway Emergency Calls ? Now they can't be made/received, is it a case of the signaller stopping all movements solely via signalling ? Another reason to limit speed to 100mph ?

I know on the Northern City Line (even before ETCS) if there was a radio failure, then the train can't run in passenger service, and a competent person needs to travel with the driver.

 

[Raikkonen7]

And how, exactly, is that going to be implemented if the means to communicate it to drivers isn't working?

Because network failure doesn’t always mean that you can’t communicate with the signaller. I’ve had it before where I couldn’t register my headcode on GSMR but I was still able to communicate. Drivers can still receive emergency calls as long as GB is displayed on the GSMR unit.

Regarding today, dispatchers at a station affected by the issue were being told to dispatch trains even if the driver couldn’t contact the signaller on GSMR as long as GB was displayed and to not exceed 100mph.

== Doublepost prevention - post automatically merged: 19 May 2026 ==

So you can run without the GSM-R. What happens with respect to Railway Emergency Calls ? Now they can't be made/received, is it a case of the signaller stopping all movements solely via signalling ? Another reason to limit speed to 100mph ?

I know on the Northern City Line (even before ETCS) if there was a radio failure, then the train can't run in passenger service, and a competent person needs to travel with the driver.

As long as GB is displayed on the GSMR unit, then emergency calls are able to be made/ received.

If GB wasn’t displayed, I’m guessing that it’d be a job stopper?

If it’s just a unit issue, then you could have a competent person travel in the rear and monitor the GSMR for emergency calls providing they have a means of contacting the driver although that’ll be more TOC specific as to when that’s authorised.

 

[Geeves]

As above that's what we did up here in Northern Land, of course the100mph part wasn't too much of a worry but the timer had started that said if the issue wasn't fixed within four hours the speed drops to 60!

 

[Firestarter]

Speed reduced to 100mph in the first 4 hours of GSMR network failure and 60mph thereafter if it hasn’t been resolved.

Is the first 4 hours and 60mph thereafter actually in the rule book as I see no mention of time listed?

 

[Raikkonen7]

Is the first 4 hours and 60mph thereafter actually in the rule book as I see no mention of time listed?

It’s what I was taught during training however it doesn’t seem to specify a time in the rule book like you said. It could be a TOC specific instruction.

 

[43096]

Speed reduced to 100mph in the first 4 hours of GSMR network failure and 60mph thereafter if it hasn’t been resolved. Clear safety implications if trains are running around at line speed without the usual means of communication working.

This is just riddled with inconsistency and a complete lack of logic. Why a maximum of 100mph? If there are clear safety issues (which presumably means no way of making REC calls), then 100mph vs 125mph makes little difference. Why not 50? Or 25? Or man walking in front carrying a red flag?

The four hours at 100mph then 60mph makes no sense either. What is the risk difference after four hours?

All rather smacks of typical railway: make up random restrictions in the name of safety, which have little basis in reality.

 

[Iron_Duke]

Is the first 4 hours and 60mph thereafter actually in the rule book as I see no mention of time listed?

Yes - TW1/26.3 outlines it in a paragraph at the bottom.

 

[Supercoss]

Rule book module TW5. Quotes “
you are told that there is a radio network failure, you may be told

not to allow the speed of your train to exceed 100 mph (160 km/h) or

60 mph (100 km/h) while passing through the area affected by the

failure. You must control the speed of your train to no more than the

speed that you have been told.

09/25


“
Subject to any lower line speed of course…..

Failure continuing for more than four hours

If a failure affecting more than approximately 10 km (6 miles) of route is likely to

persist for more than four hours, then transport operators shall implement an

emergency timetable that will reduce the train service sufficiently to facilitate the safe

introduction of a 95 km/h (60 mph) blanket speed restriction through the affected

area.

Transport operators shall work collaboratively to implement an emergency timetable

no later than four hours after the failure occurred.

Rationale

See clause G 3.1.5.

See clause G 3.1.6.

Page 16 of 28 RSSB


and a quote from the standard , area and time length of outage

 

[ponponjo]

Why is 100mph running considered safe (or at least sufficiently safe) for the first four hours, but then suddenly becomes unsafe (or at least insufficiently safe) after that time? I understand there's a balance to be struck between risk and practicality, but it seems a peculiarly arbitrary rule. Surely 100mph running without GSM-R carries the same risks in the first four hours as it does after that time has elapsed.

 

[35B]

Rule book module TW5. Quotes “
View attachment 204526
“
Subject to any lower line speed of course…..View attachment 204527

and a quote from the standard , area and time length of outage

Thanks for sharing. Slightly confusing that the Rule Book says “you may be instructed…” whereas the standard requires those instructions. Is that an editing error, or am I missing something?

 

[The exile]

Why is 100mph running considered safe (or at least sufficiently safe) for the first four hours, but then suddenly becomes unsafe (or at least insufficiently safe) after that time? I understand there's a balance to be struck between risk and practicality, but it seems a peculiarly arbitrary rule. Surely 100mph running without GSM-R carries the same risks in the first four hours as it does after that time has elapsed.

That was my thought also - although I suppose that with the passage of time the risk of something untoward having happened that can’t be communicated increases (the risk of any event happening doesn’t increase but there has been longer for those event to occur).

 

[Dieseldriver]

Why is 100mph running considered safe (or at least sufficiently safe) for the first four hours, but then suddenly becomes unsafe (or at least insufficiently safe) after that time? I understand there's a balance to be struck between risk and practicality, but it seems a peculiarly arbitrary rule. Surely 100mph running without GSM-R carries the same risks in the first four hours as it does after that time has elapsed.

My understanding is that it basically gives the companies a period of time to start winding down services and introducing a reduced timetable to accommodate the 60mph blanket speed. Much like when a storm is forecast and blanket speeds are enforced except with a storm, generally it is known about in advance with weather forecasting.
A network wide GSMR failure could happen at a moments notice and it would cause widespread problems if it instantly resulted in a 60mph blanket speed restriction.

 

[Raikkonen7]

This is just riddled with inconsistency and a complete lack of logic. Why a maximum of 100mph? If there are clear safety issues (which presumably means no way of making REC calls), then 100mph vs 125mph makes little difference. Why not 50? Or 25? Or man walking in front carrying a red flag?

The four hours at 100mph then 60mph makes no sense either. What is the risk difference after four hours?

All rather smacks of typical railway: make up random restrictions in the name of safety, which have little basis in reality.

What logical solution would you propose then in this instance?

 

[E27007]

I was stopped approaching Newark North Gate. SG didn't work and the GSMR wouldn't connect a call. The SPT wasn't working either.

After a while the SG worked, I got a Wait back. The signal then cleared and I continued north about half an hour late.

Nobody ever told me to only do 100mph.

Section TW5 in the Rulebook, you will be told of GSMR failure and to run at maximum speed of either 60 mph or 100 mph.
In my opinion the Rulebook needs more detail of procedures drivers will need to follow when GSMR network fails, perhaps not published in the Rulebook in a belief the GSMR network is infallible in service.
I was told by platform staff, for the ECML, once train movements recommenced, trains were running a maximum distance of about 75 miles and then temporarily stopped in Stations for the purpose of the signaller and driver to exchange messages.
So there may be plans and procedures written up to follow in a major GSMR outage, does anyone on the forum know if they are accessible to footplate crew?
Postscript, perhaps the Master Rulebook has the details in the Signallers modules?

 

[trundlewagon]

Section TW5 in the Rulebook, you will be told of GSMR failure and to run at maximum speed of either 60 mph or 100 mph.
In my opinion the Rulebook needs more detail of procedures drivers will need to follow when GSMR network fails, perhaps not published in the Rulebook in a belief the GSMR network is infallible in service.
I was told by platform staff, for the ECML, once train movements recommenced, trains were running a maximum distance of about 75 miles and then temporarily stopped in Stations for the purpose of the signaller and driver to exchange messages.
So there may be plans and procedures written up to follow in a major GSMR outage, does anyone on the forum know if they are accessible to footplate crew?
Postscript, perhaps the Master Rulebook has the details in the Signallers modules?

The 75 miles comes from the distance a train is allowed to be moved, to get it back to a maintenance depot, if it has a failure of GSMR equipment whilst in service.

 

[35B]

Section TW5 in the Rulebook, you will be told of GSMR failure and to run at maximum speed of either 60 mph or 100 mph.
In my opinion the Rulebook needs more detail of procedures drivers will need to follow when GSMR network fails, perhaps not published in the Rulebook in a belief the GSMR network is infallible in service.
I was told by platform staff, for the ECML, once train movements recommenced, trains were running a maximum distance of about 75 miles and then temporarily stopped in Stations for the purpose of the signaller and driver to exchange messages.
So there may be plans and procedures written up to follow in a major GSMR outage, does anyone on the forum know if they are accessible to footplate crew?
Postscript, perhaps the Master Rulebook has the details in the Signallers modules?

The excerpt pasted states “you may be…”. That suggests that there is either bad drafting or the rule is not black & white

 

[Dave W]

Whilst I note the implications of the system not working, I still can't fathom why 100mph is okay to start with, but then not okay 4 hours later. I guess I understand the logic of a stepped wind down, but even then the 4 hour timeframe and the speed limits in question feel rather arbitrary.

 

[rmHawk765]

Are the tunnel telephones still in place?

To my best knowledge yes, as it is an LU requirement.

== Doublepost prevention - post automatically merged: 22 May 2026 ==

Like with the last GSM-R outage, there is also a Three Mobile and o2 outage that started at the same time.

I seem to have had significantly degraded signal in North London on this day, I guess that explains it.

 

[E27007]

It’s what I was taught during training however it doesn’t seem to specify a time in the rule book like you said. It could be a TOC specific instruction.

Not a TOC specific instruction, module TW5 for Drivers.
When I have time I will download and study the Master Rulebook, I guess the full operational procedures will be found in the Signallers modules, module TW5 is silent for most of the details

 

[357]

Section TW5 in the Rulebook, you will be told of GSMR failure and to run at maximum speed of either 60 mph or 100 mph.

I will repeat, I was not told of a failure. I was aware of an issue while stopped, but I would say it's reasonable to believe my GSMR was working again when I started getting "Wait" back to SG messages, was still registered with GSMR GB, and the signal in front of me cleared.

I was told by platform staff, for the ECML, once train movements recommenced, trains were running a maximum distance of about 75 miles and then temporarily stopped in Stations for the purpose of the signaller and driver to exchange messages.

I was given no messages from platform staff at any point. The staff on the platform at Newark or Grantham didn't seem to be expecting me to stop, and nobody came to see me at Doncaster or any other calling points afterwards.

So there may be plans and procedures written up to follow in a major GSMR outage, does anyone on the forum know if they are accessible to footplate crew?

My rule book (driver) seems to rely on me being told of a GSMR failure.

 

[rd749249]

Our TOC supplies telephone numbers for signallers in case of emergency. TVSC are happy to be contacted that way if necessary. So long as you have GSMR-GB you will still receive RECs. What happened the other day for my TOC was that most if not all trains were held at signals. Protocol dictates use of GSMR, portable GSMR, SPTs then mobile. A call to control informed me of the problem. A call to the signaller then set expectations. It was over in 30 minutes.

 

[E27007]

I worked a night turn to Blackfriars on Monday night, held at a red for a long time around midnight, the signaller called to confirm the running and said he was having issues with indications on his panel, I think it was headcode information, then the signal changed to proceed. It is possible the GSMR system was struggling to keep up with movements

 

[Belperpete]

I worked a night turn to Blackfriars on Monday night, held at a red for a long time around midnight, the signaller called to confirm the running and said he was having issues with indications on his panel, I think it was headcode information, then the signal changed to proceed. It is possible the GSMR system was struggling to keep up with movements

I am not aware of any indications on a panel, including the train describer displays, that are dependent on the GSMR. I understand that the GSMR gets data from the train describer, but not the other way around.