Doing away with signalling?

[BigDog]

I have heard rumours that we are planning on doing away with signalling and using block markers and GPS, is there any truth to this and if so, what's the timescale?

 

[Llanigraham]

How long is a piece of string?

And it doesn't "do away with signalling", it just moves the signalling from physical items rail side to in the cab.

 

[12LDA28C]

I have heard rumours that we are planning on doing away with signalling and using block markers and GPS, is there any truth to this and if so, what's the timescale?

Are you talking about ETCS? This is currently being trialled on the ECML but is many years away from being introduced nationwide, if ever.

 

[Moonshot]

Oddly enough myself and a colleague were discussing this .....we reckon 50 years.

 

[The Planner]

Are you talking about ETCS? This is currently being trialled on the ECML but is many years away from being introduced nationwide, if ever.

Its been installed on the Cambrian for over a decade. ECML and WCML will be getting instalations over the next decade.

== Doublepost prevention - post automatically merged: 24 Oct 2024 ==

I have heard rumours that we are planning on doing away with signalling and using block markers and GPS, is there any truth to this and if so, what's the timescale?

Its not doing away with it, its just another type of it.

 

[Horizon22]

Its been installed on the Cambrian for over a decade. ECML and WCML will be getting instalations over the next decade.

== Doublepost prevention - post automatically merged: 24 Oct 2024 ==


Its not doing away with it, its just another type of it.

Also an overlay already on parts of the GWML.

 

[12LDA28C]

Its been installed on the Cambrian for over a decade. ECML and WCML will be getting instalations over the next decade.

== Doublepost prevention - post automatically merged: 24 Oct 2024 ==


Its not doing away with it, its just another type of it.

Of course, ERTMS on the Cambrian was introduced some time ago but I was referring more to the introduction of the system on mixed traffic high speed lines.

I'm still not convinced it will spread as quickly as some people anticipate due to the huge cost, including that of retro-fitting it to existing stock although I accept that new stock should have the in-cab equipment already installed at manufacture.

 

[northscots]

Given large parts of the country are still using victorian era semaphore signal systems, I doubt it'll be widespread in any of our lifetimes.

 

[Harpo]

The railway is funded for a 25 year signalling renewal cycle and the signalling industry has the same capability, about 1/25th per year.

With so little going to ETCS currently, two renewal cycles and 50 years is a decent guess.

 

[The Planner]

Given large parts of the country are still using victorian era semaphore signal systems, I doubt it'll be widespread in any of our lifetimes.

Large?

 

[rf_ioliver]

ERTMS. Lots of good information here: https://www.ertms.net/facts-figures/ertms-factsheets/

It is more moving signalling to a data centre and running digital twins. Worked on some of the cybersecurity and telecoms related to this.

 

[northscots]

Large?

Do you want to split hairs over the choice of words? Would you rather significant? It's certainly pretty common on secondary intercity and rural lines

 

[yorkie]

I have heard rumours that we are planning on doing away with signalling and using block markers and GPS, is there any truth to this and if so, what's the timescale?

Where did you hear this? As stated above, it appears a misunderstanding has occurred.

 

[BigDog]

Where did you hear this? As stated above, it appears a misunderstanding has occurred.

On a safety critical course, one of the trainers mentioned so.

 

[yorkie]

I think they meant doing away with traditional signalling equipment; and it's already happened on some routes. Certainly not doing away with signalling per se.

 

[plugwash]

I have heard rumours that we are planning on doing away with signalling and using block markers and GPS, is there any truth to this and if so, what's the timescale?

There is a plan to move from Lineside signals to the European train control system. This is an ongoing project, a handful of lines are already using this system and there are plans for more but it will likely take many decades for the whole network to switch over,

I belive the plan is, at least initially to use "level 2" ETCS, where movement authorities are transmitted to the train over GSM-R, but the network is still split into blocks, with fixed infrastructure used to detemine the progress of trains through said blocks.

There also exists level 3 ETCS, which aims to do away with traditional blocks entirely, but I think that is still in the experimental stages.

 

[james_the_xv]

Much like how Absolute Block still exists in many parts of the network, colour light TCB will be around on secondary/tertiary lines for another 100+ years.

We'll probably see large parts of ECML, WCML, GWML with ETCS within 50 years (perhaps ETCS L3 eventually). It will only happen in places where the capacity/economic benefit outweighs the considerable cost.

 

[BigDog]

There is a plan to move from Lineside signals to the European train control system. This is an ongoing project, a handful of lines are already using this system and there are plans for more but it will likely take many decades for the whole network to switch over,

I belive the plan is, at least initially to use "level 2" ETCS, where movement authorities are transmitted to the train over GSM-R, but the network is still split into blocks, with fixed infrastructure used to detemine the progress of trains through said blocks.

There also exists level 3 ETCS, which aims to do away with traditional blocks entirely, but I think that is still in the experimental stages.

So, what are the benefits and what impacts will it have on engineering and maintenance works?

 

[plugwash]

I'm no expert but I think there are serveral benefits

1. There is no need to maintain lineside signals (though balises and train-detection do still need to be maintained).
2. There is no need to worry about signal sighting issues and driver confusion between signals on adjacent lines. So blocks can be placed wherever makes most sense for capacity rather than having to worry about those issues.
3. It's easier to use large numbers of small blocks to increase capacity.
4. There is positive full-supervision train protection (unlike AWS/TPWS which provide only limited spot protection).
5. It should reduce the need to route knowlege on the part of drivers (though how this will play out politically I have no idea)

 

[Bald Rick]

Also an overlay already on parts of the GWML.

And the Thameslink core

The railway is funded for a 25 year signalling renewal cycle and the signalling industry has the same capability, about 1/25th per year.

With so little going to ETCS currently, two renewal cycles and 50 years is a decent guess.

It is not funded for a 25 year replacement cycle, far from it! There is a lot of computerised signalling out there well over 25 years old, and thats before we twlk about the 70s / 80s era PSBs.

Do you want to split hairs over the choice of words? Would you rather significant? It's certainly pretty common on secondary intercity and rural lines

Sempahore signalling is not pretty common on the network as a whole. There is some, yes, but it is not on large parts of the network, far from it.

 

[The Planner]

Do you want to split hairs over the choice of words? Would you rather significant? It's certainly pretty common on secondary intercity and rural lines

The word doesn't matter, i disagree with the fact a significant amount is semaphore.

== Doublepost prevention - post automatically merged: 24 Oct 2024 ==

It is not funded for a 25 year replacement cycle, far from it! There is a lot of computerised signalling out there well over 25 years old, and thats before we twlk about the 70s / 80s era PSBs.

Indeed, design life is normally 40 years and the amount of 50 year old installations around where you don't dare alter them now is growing.

 

[MarkyT]

I'm no expert but I think there are serveral benefits

1. There is no need to maintain lineside signals (though balises and train-detection do still need to be maintained).

Points actuation and detection equipment are also part of signalling, and still required.

2. There is no need to worry about signal sighting issues and driver confusion between signals on adjacent lines. So blocks can be placed wherever makes most sense for capacity rather than having to worry about those issues.
3. It's easier to use large numbers of small blocks to increase capacity.

The spacing of block markers is decoupled from braking distance, and the train creates its own safe speed envelope dynamically based on physical characteristics of the train, infrastructure and the extent of movement authority.

Extra short blocks can be packed around stations easily to provide closing-up capability, even multiple blocks along a platform, as on Thameslink, to allow a second train to start to enter before a forward train has completely left the platform.

4. There is positive full-supervision train protection (unlike AWS/TPWS which provide only limited spot protection).

And every part of the equipped network is protected unlike with TPWS, provided only at selected higher-risk signals including all those protecting possible junction conflicts

5. It should reduce the need to route knowlege on the part of drivers (though how this will play out politically I have no idea)

ETCS also manages junction signalling more effectively, with diverging speed differences applied accurately from the turnout rather than a restrictive traditional approach release control at the signal, especially when the turnout is far from the signal.

 

[Harpo]

It is not funded for a 25 year replacement cycle, far from it! There is a lot of computerised signalling out there well over 25 years old, and thats before we twlk about the 70s / 80s era PSBs.

ORR’s Signalling Market Study of November ‘21 shows planned signalling renewals at 2000 SEU/yr, rising to 4000 SEU/yr on an asset base of 65000 SEU across NR.

Refurbishment counts as a partial SEU renewal hence why old stuff survives well beyond 25 years with those life extensions funded from the same renewals capital spend.

 

[12LDA28C]

I'm no expert but I think there are serveral benefits

1. There is no need to maintain lineside signals (though balises and train-detection do still need to be maintained).
2. There is no need to worry about signal sighting issues and driver confusion between signals on adjacent lines. So blocks can be placed wherever makes most sense for capacity rather than having to worry about those issues.
3. It's easier to use large numbers of small blocks to increase capacity.
4. There is positive full-supervision train protection (unlike AWS/TPWS which provide only limited spot protection).
5. It should reduce the need to route knowlege on the part of drivers (though how this will play out politically I have no idea)

Point 4 - Similar to full ATP supervision with continuous loops, then.
Point 5 - I don't predict any point in the future where drivers' route knowledge would be allowed to be any less extensive and detailed than it is currently.

 

[northscots]

The word doesn't matter, i disagree with the fact a significant amount is semaphore.

== Doublepost prevention - post automatically merged: 24 Oct 2024 ==


Indeed, design life is normally 40 years and the amount of 50 year old installations around where you don't dare alter them now is growing.

Lines where semaphore signals are still used

When I visited Deal a few weeks ago, I was surprised that semaphore signalling, something which should have long gone into history, was still used there in front of a modern high-speed bullet train. Where in the national mainline network are semaphore signals still used?

www.railforums.co.uk

 

[Bald Rick]

ORR’s Signalling Market Study of November ‘21 shows planned signalling renewals at 2000 SEU/yr, rising to 4000 SEU/yr on an asset base of 65000 SEU across NR.

Thats the Market study. Now see the actual funding.

 

[MarkyT]

Point 4 - Similar to full ATP supervision with continuous loops, then.

ETCS+ GSMR radio is the modern standardised ATP interface. Administrations can also use ETCS standard equipment to recreate the functionality of legacy protection systems in modern form, emulated in the same onboard computers and control screens. Sweden is engaged in replacing its legacy ATP trackside hardware with ETCS kit, but the cab interface will remain based on the legacy ATP crew have been familiar with since its initial rollout from the 1970s and 80s.

Point 5 - I don't predict any point in the future where drivers' route knowledge would be allowed to be any less extensive and detailed than it is currently.

The nature of the knowledge will change. It will no longer be necessary to recall the details of traditional route indications and speeds applicable for every junction encountered for example.

 

[cool110]

Another benefit is allowing line speeds to be raised above 125mph

 

[Bald Rick]

Another benefit is allowing line speeds to be raised above 125mph

Strictly speaking, enabling the removal of any signalling factors in linepseed limits.

I very much doubt you will see any stretches of line in this country lifted above 125mph as a direct result of ETCS.

 

[12LDA28C]

The nature of the knowledge will change. It will no longer be necessary to recall the details of traditional route indications and speeds applicable for every junction encountered for example.

I don't see that happening. Drivers will not be expected to use ETCS as some kind of SatNav and will still need to know the associated speeds and route indications for the journey they are making, otherwise how will they know if they've been wrong routed?