mrfs42
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Post by mrfs42 on Dec 20, 2011 8:19:50 GMT
Tube prune, I was under the impression that stock in the west had been retrofitted with ERTMS and the testing was going really rather well. Quite simply untrue - it has improved of late in the light of experience, but AFAIAA there is still the need for a technician to travel with a unit at least once a week. This is an improvement on whenever a train is in service. Movement authorities are delayed - there is a incident under investigation by the RAIB about Llanbadarn crossing, I've experienced several times grinding to a halt at what would be the 'advanced starter' - ie quite a way into the section after a crossing because the interrogation of the eurobaliises hasn't registered at the shoebox in Machynlleth. Eurobalises can only be interrogated on the move: did you realise that Pwllheli and Aberystwyth are the first terminii in the world to be signalled under this scheme? The specifications for ERTMS have been rewritten so the source document is vastly different from that as originally envisaged: reversible road working, leading vehicle not ETRMS fitted, degraded mode working derogations... The list goes on. Have you seen ERTMS resignalling? I really don't want to name drop, but written by a good acquaintance of mine - is the impression that 'the testing was going really rather well' perhaps some hyper-positive spin put out to counteract the unusual occasion of a manager being very frank and honest? ERTMS could be a true low-cost signalling system, if it works; I'm sure that it could by now be regarded as intrinsically safe, but only by dint of the fact that it brings everything to a stand when communication is lost. I do not expect it to offer full bidirectional capability for Crossrail (heading back towards the subject) without yet another visit to the specifications. I'm not a huge fan of recommending other fora, but I would suggest that you look at Cambrian ERTMS; there's 17 pages of discussion there - read that and I hope you still have a positive impression of ERTMS. |
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Post by maurits on Dec 20, 2011 11:56:37 GMT
did you realise that Pwllheli and Aberystwyth are the first terminii in the world to be signalled under this scheme? Interesting. Considering the UK is relatively late with installing ERTMS, I wonder what is that first the Cambrian Line could claim.
- It is not the first ERTMS line in passenger service, that was in Italy in 2005.
- It is not the first in mountainous terrain as the Swiss have been using ERTMS for years.
- It is not the first line to be operated exclusively under ERTMS without a fallback legacy system. The Dutch have a couple of routes that are exclusively ERTMS as they didn't bother to install a legacy system on some newer lines.
- It is not the longest stretch to be used with ERTMS. After a successful pilot in 2002 the Spanish have begun rolling out ERTMS on a frantic pace; now having more than 1500KM signalled with ERTMS and another 3500KM in the planning stage.
- It is not the most ambitious roll-out, Denmark is currently preparing to replace the entire legacy signalling system with ERTMS. They expect to be finished by 2021.
And I am sure there are some records to be found in the ERTMS implementations in Australia, New Zealand, China, Norway, Mexico, Belgium, Poland, Korea, Algeria, Turkey or Croatia. Coldest, hottest, most humid, highest, highest top speed, busiest, fastest roll-out, most remote, most expensive or cheapest for instance. None of which probably held by the Cambrian Line. Perhaps the Cambrian Line is the world's first to retrofit it in such old rolling stock. :-) |
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Post by chrisvandenkieboom on Dec 20, 2011 15:37:48 GMT
ERTMS was done in Holland due to patents owned by I think Alcatel on our regular signalling, so we started using ERTMS. Think it's the Betuweroute.
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Post by maurits on Dec 20, 2011 16:27:17 GMT
ERTMS was done in Holland due to patents owned by I think Alcatel on our regular signalling, so we started using ERTMS. Think it's the Betuweroute. Yes, Betuweroute is ERTMS-only, as is the HSL. The 'Hanzelijn' and the stretch Amsterdam - Utrecht use both ERTMS and the old system. However, the case for new signalling systems pops up after each major rail accident. In the UK the case for ERTMS was made after the Paddington Rail Disaster, in Belgium after Buizingen and in the Netherlands there are now plans to speed up replacement of the old system with ERTMS after the Barendrecht crash. |
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mrfs42
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Post by mrfs42 on Dec 20, 2011 16:34:02 GMT
Perhaps the Cambrian Line is the world's first to retrofit it in such old rolling stock. :-) No. I think the Swiss hold that accolade - but still no termini, apart from the two on the Cambrian. |
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Post by maurits on Dec 20, 2011 17:24:15 GMT
[..] but still no termini, apart from the two on the Cambrian. How does Aberystwyth differ from for instance Valladolid Campo Grande where the ERTMS 2 line from Madrid terminates? Also, what makes termini so special when it comes to signalling then? The turnback facility? |
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mrfs42
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Post by mrfs42 on Dec 20, 2011 18:06:37 GMT
[..] but still no termini, apart from the two on the Cambrian. How does Aberystwyth differ from for instance Valladolid Campo Grande where the ERTMS 2 line from Madrid terminates? Also, what makes termini so special when it comes to signalling then? The turnback facility? ISTR that Valladolid Campo Grande uses wayside signals - however it isn't me that's making the claim, it is the IRSE! (and they ought to know!). Trmini are interesting because balise interrogation has to be done on the move. |
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Post by norbitonflyer on Dec 20, 2011 21:43:56 GMT
network Rail claims Pwllheli/Aberystwyth as the first termini to have ERTMS level 2 installed - an important qualifier. See slide 11 "• First passenger terminus signalled on an ERTMS L2 railway – Pwllheli and Aberystwyth • First train maintenance depot signalled on an ERTMS L2 railway - Machynlleth • Transition from semaphore signalling to ERTMS L2 on the move at Sutton Bridge also a world first" I'm not sure of the exact distinction, but Wikipedia suggests the difference between L1 and L2 is whether fixed signals are still present: L1 uses transponders (balises) to relay the signal aspects to the in-cab equipment, relies on radio messages from a control centre to activate the driver's display, based on the train reporting its own position as determined by odometers, GPS or other means - the balises remain as points of reference to correct the distance measurements. Level 3 will be "moving block". Is that more or less it?
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Post by tubeprune on Dec 20, 2011 22:02:25 GMT
I think we should be careful that we understand that there are different types of ERTMS. Level 1 is what could be described as a slightly more sophisticated version of TPWS. It comes in more than 1 version. Level 2 comes in various versions too.
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Post by eurostarengineer on Dec 21, 2011 15:19:10 GMT
mrfs42, that's much better. Very interesting. Thanks  |
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Post by chrisvandenkieboom on Dec 21, 2011 16:02:48 GMT
Why is ERTMS used in Spain while they have a different track gauge? (other than the few standard gauge lines also used by the SNCF, I suppose)
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Post by maurits on Dec 21, 2011 16:35:38 GMT
Why is ERTMS used in Spain while they have a different track gauge? (other than the few standard gauge lines also used by the SNCF, I suppose) Track gauge is not that relevant. It's more a question of convenience and economy. One of the common issues with the older existing signalling systems is that it is not suitable for higher speed operation. In-cab signalling becomes a must as drivers can't see line-side signals anymore. If you are then faced with choosing a new signalling system you might as well pick a relatively off-the-shelf product that can be bought from a multitude of vendors. The alternative is re-inventing the wheel that might also lock you into buying it from one vendor. That is a problem that Belgium is facing at the moment, their plans to overhaul the mishmash of systems are hampered by a supplier that allegedly refuses to provide them with the technology to develop an ' STM' to run conventional and ERTMS alongside each other. Besides, all new lines in Spain are High Speed lines which all use standard gauge, occasionally with gauge changer for extremities where the last stretch is operated on existing lines. The line between Barcelona and Perpignan that is currently being built is standard gauge too making trains from Paris to Madrid an option in the future. Lastly, if a member state applies for EU subsidy towards a new line, one of the conditions is that it uses ERTMS. In other words, why would they not choose ERTMS? |
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Post by chrisvandenkieboom on Dec 21, 2011 16:57:19 GMT
So what you're saying is that Spain might opt, at some point, to fully go standard gauge, because they can - without adapting signalling systems a lot?
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Post by notatraindriver on Dec 21, 2011 19:39:34 GMT
I don't think we need ATP on the main lines. TPWS and TPWS+ are enough. Maybe for crossrail we could have a system similar to SACEM as used on the RER ligne A in Paris? I don't think conventional signalling is the answer for tunnel sections and short head ways. Drivers are taught to drive defensively particularly on approach to cautionary signal aspects.
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Post by eurostarengineer on Dec 23, 2011 12:16:26 GMT
For the way that railways seem to be going, I don't think many companies are looking at AWS, TWPS etc as it severely limits the amount of trains you can have in an area. And let's face it, it seems that companies are trying to follow suit and walk in LUL's boots with regards to having trains much closer together (TBTC, ATC. Etc)
Of course I'm not talking about now, talking about a few years yet. Also I don't think it'll be too long until mainline start jumpin on the ATO/ATC bandwagon which means for the majority of the time drivers won't be driving defensively when looming upon cautionary aspects.
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