"Digitising” the signalling system

[mdvle]

 

 

In the five years between 2019 and 2024, the aim is to install digital technology on the commuter lines into Britain’s busiest station, London Waterloo, routes across the Pennines and the southern part of the East Coast main line.

 

https://www.independent.co.uk/travel/news-and-advice/uk-trains-digital-signalling-railways-delays-times-speed-journeys-a8344616.html

[St. Simon]

This already has been done to death in several different topics recently.

 

Simon

[TheSignalEngineer]

This already has been done to death in several different topics recently.

 

Simon

And in many other places since computers got small enough to fit on a single 19 inch rack. If i'd held my breath when I first heard it discussed I wouldn't have been around for the last 40 years.

[david.hill64]

This already has been done to death in several different topics recently.

 

Simon

But this article seems to imply ETCS level 3.............

[St. Simon]

But this article seems to imply ETCS level 3.............

 

Reliable ETCS Level 3 has yet to be invented really, it's more of a concept, I as far as I'm aware there is no plan to install ETCS Level 3 on the National Network at the moment (only ETCS Level 2 without Signals). The only place I can immediately think of is the Crossrail Core, but even that'll be 10 to 20 years I think.

 

The article is about the announcement made a few weeks ago by Mark Carne and Chris Grayling, which has been referenced in other threads. I think the implication that ETCS Level 3 will be installed in the article is actually just the simplistic overview of in-cab signalling by the various articles that were written around the announcement.

 

Simon

Edited May 22, 2018 by St. Simon

[david.hill64]

Reliable ETCS Level 3 has yet to be invented really, it's more of a concept, I as far as I'm aware there is no plan to install ETCS Level 3 on the National Network at the moment (only ETCS Level 2 without Signals). The only place I can immediately think of is the Crossrail Core, but even that'll be 10 to 20 years I think.

 

The article is about the announcement made a few weeks ago by Mark Carne and Chris Grayling, which has been referenced in other threads. I think the implication that ETCS Level 3 will be installed in the article is actually just the simplistic overview of in-cab signalling by the various articles that were written around the announcement.

 

Simon

Not quite correct. Bombardier has an ETCS level 3 system up and running in Kazakhstan, the only non-compliance with the draft principles of ETCS 3 being the use of TETRA radio as the transmission medium.

 

The Independent article specifically mentions moving block (not implied as I wrote originally).

 

There is a whole lot of misinformation being promulgated by DfT at present, including increase capacity by 30%.

[jjb1970]

But its digital, it must be good! Now we need it to become an autonomous digital railway and Robert will be ones uncle

[Fat Controller]

ETCS Level 3, nevr!

They're looking at DCC, but are having trouble fitting the chips

[4630]

ETCS Level 3, nevr!

They're looking at DCC, but are having trouble fitting the chips

I thought their aspiration was to run the whole network with just one pair of wires.

[Oldddudders]

I thought we had digital signalling a century ago. Most semaphores were either on or off.

[Peter Crawford]

People are unwilling to pay. 'Operation through a small-hours operation reset' is a novelty! Just ditch TPWS, then put KVB on and TVM on the faster lines.

[Fat Controller]

People are unwilling to pay. 'Operation through a small-hours operation reset' is a novelty! Just ditch TPWS, then put KVB on and TVM on the faster lines.

TPWS is very good at what it does, cheaply (relatively).

TVM is fine if all trains using a line run at very similar speeds; if they're not, then line capacity reduces significantly. To that end, the signallers I work alongside will advise drivers of faster trains of the speed of the train in front, so that they can regulate their speed accordingly. If not, then a Eurostar following a 100kph freight will run at 160 kph until it approaches the freight, then the driver will get '80 Flashing' followed by '80 in cab', as 80 kph is the next speed band for the version of TVM430 fitted to E*.

[Peter Crawford]

Moving Block then.

[Christopher125]

Reliable ETCS Level 3 has yet to be invented really, it's more of a concept, I as far as I'm aware there is no plan to install ETCS Level 3 on the National Network at the moment (only ETCS Level 2 without Signals). The only place I can immediately think of is the Crossrail Core, but even that'll be 10 to 20 years I think.

ERTMS Level 3 - A possible way forward

 

The best chance of Level 3 happening looks like the hybrid approach being developed by Network Rail described in the Rail Engineer article above:

 

"Known as Hybrid Level 3, it has been in development since 2013 as a joint effort by Network Rail and ProRail with Alstom and Bombardier both supplying equipment that demonstrated the feasibility. The stage has been reached whereby a potential application to the ‘real’ railway can be considered.

 

The crux of the proposed system is to retain any existing track-circuit or axle-counter sections and to then create ‘virtual blocks’ as sub sections within these. The operation would be:

 

- A train equipped for ETCS Level 3 operation would receive an MA allowing it forward into the block section which, if no other train is preceding it, might be to the end of the section or even beyond.

- A following train that is also equipped for Level 3 operation would receive an MA to enter the same section with an MA to the limit of a safe stopping distance of the first train, taking into account the distance and speed of both trains. If speeds were low, then the second train could close up on the first under moving-block principles.

- Any subsequent train also equipped for Level 3 operation would follow in the same way.

- If a train only equipped for Level 2 operation were to approach the section, it would not receive an MA until all preceding trains had cleared the track circuit or axle counter section. Once this has occurred, the train would receive an MA to the end of the track- circuit or axle-counter section. Any following train would not receive an MA until the Level 2 train had cleared the complete section."

Edited May 24, 2018 by Christopher125

[DY444]

Let's hope this Hybrid Level 3 doesn't become totally bespoke to the UK because you then have costs inherent in developing, testing and acceptance of a unique system for every new type of traction going forward.  Costs need to be reduced and a home grown system (if that's what it is) isn't the way to do that.  

 

There seems to me to be this paradox in some NR/DfT circles with on the one hand the Informed Sources law about the attractiveness of a railway product being proportional to the square of the distance from the factory to the UK, and, on the other hand proven, basic foreign products having to be re-engineered (and often over engineered) at great cost to meet what on the face of it are unnecessary NR standards (F&F kit on the GWML electrification for instance).  I hope this venture into Level 3 isn't another example.

Edited May 28, 2018 by DY444

[Christopher125]

It's being developed with ProRail, Network Rail's Dutch equivalent so it shouldn't be a bespoke UK-only system.

Edited May 28, 2018 by Christopher125

[Mike Storey]

As per Post #14 - I am not so sure this domestic development of a system that would potentially allow phased entry, is a bad thing. What other system is being developed that doesn't require total changeover and a dedicated fleet, or each phase? If this works, it will allow far more economic evolution to ERTMS 3, and could have enormous export potential.

[jjb1970]

Not quite correct. Bombardier has an ETCS level 3 system up and running in Kazakhstan, the only non-compliance with the draft principles of ETCS 3 being the use of TETRA radio as the transmission medium.

 

The Independent article specifically mentions moving block (not implied as I wrote originally).

 

There is a whole lot of misinformation being promulgated by DfT at present, including increase capacity by 30%.

 

Silence! If we wanted to be told that something which we all know to be impossible has already been done in a country that none of us has ever heard of and have less interest in then we'd remove our tin foil hats  

[Peter Crawford]

ERTMS 3 could work, but adopting high-tech solutions like automatic operations on lines <75mph and moving blocks/TVM on faster lines is, in my opinion, the way forwards.

[The Stationmaster]

ERTMS 3 could work, but adopting high-tech solutions like automatic operations on lines <75mph and moving blocks/TVM on faster lines is, in my opinion, the way forwards.

 

But don't forget that TVM is very much 1960s technology and uses coded track circuits to communicate with trains - which aren't much use on infrastructure which has been altered to using axle counters for train detection purposes and where physical insulated joints have in consequence been bonded.   It seems slightly daft to me to start using something (TVM) where the display technology is extremely basic relying on filament lamps and mirrors and which while generally very reliable is getting on for half a century old in concept and equipment design.

[St. Simon]

ERTMS 3 could work, but adopting high-tech solutions like automatic operations on lines <75mph and moving blocks/TVM on faster lines is, in my opinion, the way forwards.

 

ETCS (not ERTMS) Level 3 is moving block technically and works much like TVM, but uses radio communications not coded track circuits. ATO can be fairly easily be bolted onto ETCS at any level.

 

Simon

[Fat Controller]

But don't forget that TVM is very much 1960s technology and uses coded track circuits to communicate with trains - which aren't much use on infrastructure which has been altered to using axle counters for train detection purposes and where physical insulated joints have in consequence been bonded.   It seems slightly daft to me to start using something (TVM) where the display technology is extremely basic relying on filament lamps and mirrors and which while generally very reliable is getting on for half a century old in concept and equipment design.

Other problems arise because TVM relies on the wheel-rail interface to send information to the train; a rigorous regime of de-rusting has to be carried out on a (preferably) daily basis. This includes all points and crossovers; it's manageable on a 'closed' system like the one I work on, but much more difficult to apply on a long mainline, or a station with multiple routeing possibilities. If the link twixt train and track  is broken more than momentarily, then the train has an emergency brake application applied automatically, whilst the pantograph also drops.

[Peter Crawford]

But don't forget that TVM is very much 1960s technology and uses coded track circuits to communicate with trains - which aren't much use on infrastructure which has been altered to using axle counters for train detection purposes and where physical insulated joints have in consequence been bonded.   It seems slightly daft to me to start using something (TVM) where the display technology is extremely basic relying on filament lamps and mirrors and which while generally very reliable is getting on for half a century old in concept and equipment design.

 

 

Other problems arise because TVM relies on the wheel-rail interface to send information to the train; a rigorous regime of de-rusting has to be carried out on a (preferably) daily basis. This includes all points and crossovers; it's manageable on a 'closed' system like the one I work on, but much more difficult to apply on a long mainline, or a station with multiple routeing possibilities. If the link twixt train and track  is broken more than momentarily, then the train has an emergency brake application applied automatically, whilst the pantograph also drops.

 

TVM is this technology here: https://fr.wikipedia.org/wiki/Transmission_voie-machine

 

If we are on the same page, then I might as well re-define it as the tech used on LGVs, moving block, GSM-R etc.

[Mike Storey]

Other problems arise because TVM relies on the wheel-rail interface to send information to the train; a rigorous regime of de-rusting has to be carried out on a (preferably) daily basis. This includes all points and crossovers; it's manageable on a 'closed' system like the one I work on, but much more difficult to apply on a long mainline, or a station with multiple routeing possibilities. If the link twixt train and track  is broken more than momentarily, then the train has an emergency brake application applied automatically, whilst the pantograph also drops.

 

How times change. It used to be mandatory for new apprentices at the CE depot at Gillingham, to be told to go to the stores to ask for the Rouillegelais paint, so that they could paint the rust on to the tracks......

[david.hill64]

If you look at modern MRT signalling systems they are significantly more advanced than ETCS. Moving block is normal as is the application of mixed moving block and fixed block systems. For example a system can have lineside signalling for freight trains and moving block for the metro trains (which observe for example a purple aspect which means 'follow your cab signalling instructions').

 

Siemens, Thales and Bombardier all have advanced moving block systems, but without any interchangeability. Therein lies the rub and the rationale behind the ETCS. The trouble is that defining standards that are suitable for varied signalling principles and do not disadvantage any country's domestic suppler results in very extended periods to agree the standards,

 

The other issue is that signalling systems are now basically software running on rapidly developing hardware platforms. 10 years after introduction they are obsolete. If you lock yourself into a situation where it takes you 20 years or more to agree a standard then any system developed to that standard is already obsolete,