ETCS Level 2 Rollout

[Railsigns]

Question about Thameslink ECTS [sic] - in the case where a 700 is worked into a section behind another, but after a colour light signal, will the traditional signal show clear or danger?

The signal will show single yellow.

 

[ComUtoR]

The signal will show single yellow.

Are the signals then set deliberately to single yellow ? Why wouldn't it show a Red if there is a train in the section or are the traditional signals ignored when on ETCS ?

Why not show a Red with a PoSA ?

I'm confused that a signal would show a single yellow if there is a train in the section and thought that the two system were overlaid but still worked as designed ie. section occupied = Red.

Is there a sim anywhere or video of how this looks to a Driver as they are driving through it ?

Cheers in advance.

 

[Bald Rick]

Correct, the lineside signals are to be ignored in the core when operating in ETCS or ATO.

 

[carriageline]

The signal will clear to a single yellow when it's clear to the next block marker, the train has been given it's MA and the train is in ETCS.

I've got a presentation comutor that shows (in theory) how it's going to work with trains following trains.


Sent from my iPhone using Tapatalk

 

[HSTEd]

I imagine there would be a psychological issue with showing a red that is to be ignored under ETCS control - after all that would dilute the driver's reflex to stop at any and all reds.

 

[gsnedders]

ETCS does. Also used on the Westinghouse system on the Victoria Line.

Rather, some ETCS implementations do. ETCS only defines requirements that implementations must meet for location reporting.

Similarly, the reason why we don't see serious trials of Level 3 yet is there are currently no known ways to meet the requirements for it, AIUI.

 

[Railsigns]

I quite like what happens on the East Rail Line in Hong Kong. Signals display a blue aspect when a train running under cab signalling is approaching.

 

[MarkyT]

Paul Bates, Project Director - High-Capacity Infrastructure at Network Rail gave a talk to the IET about Thameslink and its signalling. Video here:

https://tv.theiet.org/?videoid=5091

Screenshot attached (41:32) shows arrangement whereby signal aspects are modified according to whether ETCS is active on a particular approaching train. I recommend watching the entire video if you have time as it is very informative about the project as a whole and the control systems.

 

[MarkyT]

I quite like what happens on the East Rail Line in Hong Kong. Signals display a blue aspect when a train running under cab signalling is approaching.

I believe that's quite common on many modern metros around the World, either a blue or white aspect.

 

[DerekC]

But Derek from what I've read this Level 3 thing is just mere fantasy at the moment. A sort 'wouldn't it be nice to have'. And this is what I mean by lots and lots of looking good on paper but in the real world doesn't work. They still don't know what the actual capacity gain from Level 2 is even though they keep banding out this 40% figure even though the people who know what they are talking about say it will be closer to 10-15%. You need systems that actually work in the real world and not just on paper and in an engineers head.

Level 3 is a bit more than fantasy. It's exactly the same in principle as the radio based CBTC systems used on metros - and the Regional ERTMS deployed in Sweden was a step towards it. It is perfectly feasible technically. It would give big cost savings and greatly increased flexibility - you wouldn't have to decide once and for all what capacity you are designing for, which is then locked into the block layout for the next 30 years. No, it hasn't been demonstrated yet, but it's time it was.

The capacity gains from ETCS Level 2 will be modest in most real situations. What you can't do is quote a global figure which will apply everywhere, because practical capacity is limited by infrastructure layout, platforming, service mix and so on. However 10% to 15% is a reasonable figure to keep in mind. 40% (which I have seen quoted by people who should know better) is a following headway figure taken in one particularly favourable situation, without considering the other constraints - and it was for Level 3 with ATO. It doesn't mean you can run 40% more trains on the route. Level 3 will give a bit more than Level 2 - but the point of Level 3 is that the extra capacity is virtually free.

 

[Dave1987]

Level 3 is a bit more than fantasy. It's exactly the same in principle as the radio based CBTC systems used on metros - and the Regional ERTMS deployed in Sweden was a step towards it. It is perfectly feasible technically. It would give big cost savings and greatly increased flexibility - you wouldn't have to decide once and for all what capacity you are designing for, which is then locked into the block layout for the next 30 years. No, it hasn't been demonstrated yet, but it's time it was.

The capacity gains from ETCS Level 2 will be modest in most real situations. What you can't do is quote a global figure which will apply everywhere, because practical capacity is limited by infrastructure layout, platforming, service mix and so on. However 10% to 15% is a reasonable figure to keep in mind. 40% (which I have seen quoted by people who should know better) is a following headway figure taken in one particularly favourable situation, without considering the other constraints - and it was for Level 3 with ATO. It doesn't mean you can run 40% more trains on the route. Level 3 will give a bit more than Level 2 - but the point of Level 3 is that the extra capacity is virtually free.

Reading exactly what Level 3 does it all sounds merely like an engineers wet dream TBH and I can see it having very serious issues in the real world. We do not live in a perfect world and some aspects of Level 3 I find mildly terrifying knowing how things happen in the real world.

 

[MarkyT]

Level 3 is a bit more than fantasy. It's exactly the same in principle as the radio based CBTC systems used on metros - and the Regional ERTMS deployed in Sweden was a step towards it. It is perfectly feasible technically. It would give big cost savings and greatly increased flexibility - you wouldn't have to decide once and for all what capacity you are designing for, which is then locked into the block layout for the next 30 years. No, it hasn't been demonstrated yet, but it's time it was.

The capacity gains from ETCS Level 2 will be modest in most real situations. What you can't do is quote a global figure which will apply everywhere, because practical capacity is limited by infrastructure layout, platforming, service mix and so on. However 10% to 15% is a reasonable figure to keep in mind. 40% (which I have seen quoted by people who should know better) is a following headway figure taken in one particularly favourable situation, without considering the other constraints - and it was for Level 3 with ATO. It doesn't mean you can run 40% more trains on the route. Level 3 will give a bit more than Level 2 - but the point of Level 3 is that the extra capacity is virtually free.

Some good points there, particularly about service type and infrastructure constraints. The capacity improvements on Cambrian were all down to additional and extended passing loops, not the signalling at all.

You have to ensure the radio system and central processing system has sufficient capacity and reliability to handle all the continuously refreshed incoming position messages then calculate and broadcast all those realtime movement authorities for the desired capacity. Then there's the small matter of being able to accurately determine where the rear of all possible train formations are, including variable length freights and engineering trains, and you have to do all that to an extraordinary level of safety (SIL4) which you have to prove and have independently reviewed. I'm not convinced a system engineered initially for say 4 trains an hour with moving block would be able to automatically cope with 16 trains an hour 'for free'.

 

[edwin_m]

I think the point is that once you've set up the safety-vital radio communication between the train and the interlocking for level 2, it's relatively easy in theory to use it for transmitting train positions inwards as well as movement authorities outwards. In practice it may be more difficult, particularly as GSM-R is based on the now-obsolete 2G GSM and probably needs upgrading to 4G or 5G to provide enough capacity reliably.

 

[HSTEd]

In practice it may be more difficult, particularly as GSM-R is based on the now-obsolete 2G GSM and probably needs upgrading to 4G or 5G to provide enough capacity reliably.

I very much doubt it, if all you are doing is providing signalling information then the ~4-5kbit/s of a GSM voice circuit in each direction are easily sufficient.

The last balise passed's number is going to be sixty bits at most (giving a billion billion balise numbers) - and a distance could be provided out to 1000km using only 20 bits with an accuracy of one metre.

So you need a couple of hundred bits a second for the signalling system at most. Probably less in reality.
It only gets hairy when epople try and tie everything on the train into the GSM-R system.

 

[rebmcr]

I very much doubt it, if all you are doing is providing signalling information then the ~4-5kbit/s of a GSM voice circuit in each direction are easily sufficient.

The last balise passed's number is going to be sixty bits at most (giving a billion billion balise numbers) - and a distance could be provided out to 1000km using only 20 bits with an accuracy of one metre.

So you need a couple of hundred bits a second for the signalling system at most. Probably less in reality.
It only gets hairy when epople try and tie everything on the train into the GSM-R system.

It's not the size of packets that bandwidth is critical for here, it's the volume of traffic from many simultaneous trains all Tx/Rx-ing at once, probably multiple times per second.

A cell near one of the routes into London from the south could feasibly have 100s of trains registered.

 

[Roast Veg]

Thanks for the answers guys, it's not an especially important issue (with the in cab always being correct regardless) but my curiosity has now been sated.

 

[Trainfan344]

Hope this is the right place, if not I hope someone can point me in the right direction, but with Brexit happening now, will this affect the rollout of ETCS?

 

[Noddy]

Hope this is the right place, if not I hope someone can point me in the right direction, but with Brexit happening now, will this affect the rollout of ETCS?

This has been asked and answered before: Not directly. Just look at all the places not in Europe which are deploying it:
https://en.wikipedia.org/wiki/European_Train_Control_System#Deployment

The only impact of Brexit that might affect the rollout will be the economic impact.

 

[LNW-GW Joint]

Hope this is the right place, if not I hope someone can point me in the right direction, but with Brexit happening now, will this affect the rollout of ETCS?

There's no reason why it should.
ETCS is the only widely-agreed signalling standard for in-cab digital operation.
All the manufacturers of signalling equipment happen to be major European companies.
This includes Hitachi who now own Ansaldo of Italy, whose technology was used on the Cambrian trial.
It has also been selected by some railways outside Europe (eg China, Turkey).
Network Rail has no alternative but to roll it out, and it is expected to reduce costs and increase capacity.
A bespoke UK alternative would be horrendously expensive.
Brexit will mean we do not have to adopt the EU's Railway Packages which are mainly about competition and governance.
On the interoperability front all the manufacturers will be building to EU standards.