HS2: what signalling system is planned? also is the Handsacre connection no longer going ahead?

Discussion in 'Infrastructure & Stations' started by kevin_roche, 12 Feb 2020.

  1. kevin_roche

    kevin_roche Member

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    Moderator note: Split from https://www.railforums.co.uk/thread...ive-high-speed-rail-line-the-go-ahead.200154/

    One of the possible areas for cost reduction is the signalling required to manage the planned number of trains per hour.

    I wonder what signalling system is planned and how it would be reduced to save money?

    I believe the current ORR rules say HS2 must use ETCS/ERTMS. What changes could make it cheaper?
     
    Last edited by a moderator: 14 Feb 2020
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  3. hwl

    hwl Established Member

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    Not much, higher frequencies depend on lots of factors, the only major signalling cost is the effective block size needs to go down - the frequency cost saving thinking bit is mostly around junction infrastructure and number of platforms which is where the expected cost saving are meant to come from.

    They have big worries about the Euston grade separated throat design so reducing frequency would make this less complicated and cheaper.

    The planned tph is higher than other HS networks so a number of areas need to be pushed to squeeze out some more performance hence the thinking not to do this and de-risk/de-cost.
     
  4. edwin_m

    edwin_m Veteran Member

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    Oakervee recommends deleting the Handsacre connection, which was originally going to carry all the services to the north between Phase 1 and Phase 2. If Phase 1 and 2a open together as recommended, it is left with the Stafford-Stoke-Macclesfield service. Taking this off HS2 also contributes to the recommended reduction in frequency.

    I can see this being a major political headache, with Staffordshire now 100% Tory and the sort of area they have promised to help. Putting in an alternative junction or Parkway station would push Phase 2a back several years due to the need for new Parliamentary approval, and in the case of the junction wouldn't allow any service reduction. I'd expect for this reason that Handsacre will stay and a train to somewhere else will get chopped instead.
     
  5. 158756

    158756 Member

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    This is really bad planning for a government and a scheme which claims to want to heal the regional divide (and has just won all the relevant parliamentary seats). North Staffordshire is already one of the most 'left behind' areas of the country, and HS2 only promises to make the situation worse.
     
  6. Bald Rick

    Bald Rick Established Member

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    As @hwl says, it’s going to be ETCS, as required for all new high speed lines in Europe (nothing to do with ORR). The architecture of the system on high speed lines is designed around speed rather than capacity, principally because at 360kph there is well over 10 miles between trains on standard headway. The reduction in planned capacity will make no difference at all, it would be the same at 2tph.

    What could make it cheaper is to install ETCS level 3, as that removes the need for continuous track based train detection, which removes a fair bit of cabling and trackside equipment. Unfortunately that doesn’t exist in service anywhere in the world. More likely is Level 2 hybrid, which is a halfway house.

    Even then, you might save a £100k per mile of route. Peanuts really. I’d be surprised if the whole signalling system wa# more than 1% of the cost.
     
  7. Belperpete

    Belperpete Member

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    And because it doesn't currently exist, specifying level 3 would significantly increase the risk to the project, and risk = increased project cost. Look at what happened to the WCML upgrade, that was originally supposed to be ETCS level 3!
     
  8. Bald Rick

    Bald Rick Established Member

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    Actually, it was’t. It was originally supposed to be ‘TCS’, which also didn’t exist. Albeit the functional specification for TCS was very similar to what became ETCS L3, and indeed they may be closely related ;)
     
  9. MarkyT

    MarkyT Established Member

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    The level 2/3 hybrid system is highly likely to be available within the timeframe and could do away with most fixed train detection on plain line. Like metros, the all-new HS2 rolling stock can be specified to know its length and be able to confirm train integrity at all times, so should be able to reliably report when it's rear is clear of virtual fixed blocks without train detection boundaries. The block markers provided also provide useful degraded mode targets for verbal authorities given during times of failures and engineering work. I'm not convinced moving block level 3 will ever be a thing on main lines, except used selectively as a modern safe way of achieving routine 'passenger permissive' working in platforms with both trains moving, because short virtual blocks provide all the capacity needed at speed, and won't be as communications and computing bandwidth-intensive and failure-prone as the constantly changing moving authorities of true moving block. Taking away most fixed train detection should also improve reliability, as track circuits and axle counter malfunctions are a significant root cause of signalling failures.
     
  10. Belperpete

    Belperpete Member

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    You may be right. However, having worked on the WCML TCS project, I am certain that everybody involved clearly saw it as ETCS Level 3, albiet tailored to NR requirements. I gained a near book-case full of ETCS specs while working on the WCML TCS project (some of which I read!).
     
  11. Belperpete

    Belperpete Member

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    I don't doubt that a hybrid level 2/3 system should be available within the required timescale, and should have significant benefits, but then the system used on Crossrail should have been available well within their timescale.....

    There is always a risk on applying untried technology, and I wonder how much risk HS2 are prepared to take. Particularly as they are required to make their contractors shoulder that risk, and include the cost of shouldering it into their estimates. If I were trying to limit the costs of HS2, with that costing regime, I would start by removing as much risk as possible.

    Mixed-traffic lines with variable-length trains and a plethora of operators will have major problems with train integrity and train length reporting, and will be the last to ever (if ever) have level 3. Lines that only run with fixed-formation captive stock, inherently capable of reporting train length and integrity as you describe, should be relatively easy to implement Level 3. HS2 would have been a good proving-ground for level 3, if it had been anywhere-near sufficiently developed.
     
  12. CdBrux

    CdBrux Member

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    I think from the hansard script I quickly read Boris indicated Handsacre would stay
     
  13. MarkyT

    MarkyT Established Member

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    I'm not convinced Handsacre is at all optimised for its long term role. It introduces a lot of flat junction conflicts with other services around Rugely and Colwich. Better to join the Trent Valley north of Colwich and ideally after the double-track constraint of Shugborough tunnel. I was under the impression recommendations include dropping the Handsacre link which could be achieved by simply not building those particular elements of the authorised works in Phase 1. The Ph.2A Act would then pick up almost immediately and extend the blind mainline spur provided under the Phase 1 Act. Service to Stoke is a political necessity I think but could be provided by other means. There's been a Meaford link proposed in the past, but that bypasses Stafford, so isn't optimal. My suggestion is a new HS2 junction near Hixon, with a link heading west to cross the Trent Valley fasts & take over the TV slow pair on approach to Stafford, the correct side to take advantage of the Norton Bridge flyover towards Stoke. No conflict would remain at all with TV fasts which could then concentrate on lashings of nice fast freight paths intertwined with a few regional expresses. Works for the alternative link could be amended into the Ph.2A act or placed in a small supplemental act or T&W order to be fast-tracked to gain powers before start of phase 2 construction. It would then be the first element of Phase 2A to be completed, allowing start of CC services to other WCML destinations before full completion of 2A all the way to Crewe. Might allow the Hixon route from Colwich Jn to close eventually. Another option could be to connect HS2 directly to the Hixon line in the vicinity they cross, but clearly that would be less flexible as it only gives good access to Stoke/ Macclesfield, not Stafford and all points north.
     
  14. Ianno87

    Ianno87 Established Member

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    Given it's long-term role is only for one train per hour (effectively replacing multiple Pendolinos per hour at present), I doubt it's a big deal.
     
  15. edwin_m

    edwin_m Veteran Member

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    It would be easy enough just to not build the Handsacre connection and leave the rest of the line alone, but building something else instead triggers at least one new round of design and consultation and another Hybrid Bill (or at the very least a TWAO). So it would be several years behind the main route. Handsacre also allows Stoke to be served by either route.
     
  16. Roy Badami

    Roy Badami Member

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    Isn't that an EU requirement? So obviously, it was spec'd as ETCS, but I think they would have freedom to pick what they want now - i.e. if there was something else they preferred, I doubt they'd be any legal impediment.

    That said, I doubt the UK railway will change tack away from using ETCS for next gen signalling projects

    EDIT: To be more precise, yes, technically it will remain a legal requirement for now, but one that could easily be changed after the end of the year should there be a need or desire
     
    Last edited: 14 Feb 2020
  17. Roy Badami

    Roy Badami Member

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    And just to follow up - it's not just high speed lines - as I understood it, it's all new railways. Crossrail required a derogation to install Trainguard MT rather than ETCS level 3, with - theoretically - a commitment to resignal to ETCS level 3 when it becomes commercially available. I imagine the requirement to resignal will be completely dropped post Brexit (because it never really made any sense anyway).

    But I'm going off topic here.
     
  18. Bald Rick

    Bald Rick Established Member

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    The U.K. rail industry has made it clear that it will continue to abide by interoperability regs.

    There isn’t a high speed line in Europe that’s been built on the last decade that hasn’t been fitted with ETCS from the start.
     
  19. Roy Badami

    Roy Badami Member

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    True. But there is absolutely no need for interoperability between Crossrail and trains in mainland Europe except "rules is rules".

    And, lacking a connection (or any plan for a connection) with HS1, there is no real reason for interoperability in HS2, either.

    ETCS will remain, not because it's a legal requirement, nor because of the need for interoperability with European trains, but because it makes commercial and engineering sense to continue to use the dominant European technology.

    And also, perhaps, because European standards may well over time become de facto worldwide standards (or nearly so), much like the EU project to standardise mobile phone systems across the continent - GSM - gained massive worldwide adoption outside of the EU, despite only being legally mandated here in Europe.
     
    Last edited: 14 Feb 2020
  20. R G NOW.

    R G NOW. Member

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    Now that we are out of the EU I had thought the UK would no longer be able to use the above systems and we would have to use the systems we have now, TCB with just longer spacing of signals and two signals placed side by side to allow drivers to see them at higher speeds. I do not think this will be cheaper though.
     
  21. PG

    PG Member

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    Even if this was the case, which I seriously doubt, I'm sure that the ETCS could be licenced for use here.
     
  22. agbrs_Jack

    agbrs_Jack Member

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    Surely if Handsacre was binned that'd leave Stoke and Macclesfield without a fast London service, therefore there would be a need to serve both with a classic service.
    This would mean very little capacity is released for Colwich - Stoke - Stockport and it'd also eat up released capacity Colwich - Euston (plus takes up a classic platform at Euston).

    Would also be much harder to increase Congleton's service with that capacity missing.
     
  23. Maurice3000

    Maurice3000 Member

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    Leaving the EU won't change the ability to implement ETCS. There are easily a dozen countries that would never be allowed to join the EU, from Australia to Thailand, that use ETCS.

    Those countries don't use ETCS because they have to, they use it because it works, they don't need to reinvent the wheel and it will almost always be cheaper (and with fewer headaches) than some bespoke solution that delivers similar benefits.
     
    Last edited: 15 Feb 2020
  24. Bald Rick

    Bald Rick Established Member

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    Surely a ;) required there?
     
  25. Ianno87

    Ianno87 Established Member

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    ETCS is the standard system used in a number of non-EU countries. Australia and China for two example currently adopting it. It is a standard developed by the EU, but adopted by other countries to use as a basic standard.
     
  26. Austriantrain

    Austriantrain Member

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    No doubt that at the end of the transition period there will be no legal obligation whatsoever for the UK to use ETCS. However, ETCS2 is now widely used for High-Speed lines around Europe, and I think elsewhere too, and once bedded-in is very reliable, so it would not make a lot of sense for the UK to invent a new, different standard. The transition to ETCS3 could always be made at a later date; of course the infrastructure needs to be built now for a possible later capacity increase. No signalling system can remove capacity constraints created by badly designed junctions, stops on high-speed lines that only certain trains stop at etc; the best they can do is mitigate them slightly. If a train, say, has to slow down from 330 kph to 160 because the junction it uses to leave the HSL does not allow for more, this will reduce overall capacity by a not insignificant amount no matter how sophisticated the signalling is.
     
    Last edited: 15 Feb 2020
  27. carriageline

    carriageline Established Member

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    Whilst you do make a very good point, but ETCS can improve things, even slightly in that situation.

    If you adopt ETCS, you have to adopt ATO if you want the full benefits from it.

    ETCS will remove approach control restrictions, which avoids drivers creeping up to restrictive aspects. ETCS will allow a train to slow down a lot later. Couple that with ATO, the train can slow down much more efficiently with braking at a much later point. ATO/ETCS can eliminate some, if not a lot of defensive driving techniques.

    Whilst that should be no excuse for poorly designed junctions, your still half a step forward as it will be slightly more efficient than conventional lineside signalling.
     
  28. Meerkat

    Meerkat Established Member

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    How does ETCS/ATO eliminate defensive driving in regard to railhead concerns?
     
  29. The Planner

    The Planner Established Member

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    They would get an hourly service. It would still be two per hour taken out of Colwich. Euston isn't going to be devoid of platforms until 2B actually opens.
     
  30. hwl

    hwl Established Member

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    If you have ETCS compatible trains (which HS2 will be) the cost of an ETCS install is surprisingly low.

    I suspect we will shortly reach the tipping point in many parts of the UK with ETCS ready stock enabling ETCS installs on renewal.
    The tipping point will be the freight fleet being fitted...

    ETCS basically leaves the interlocking being the only proprietary bit of kit.
     
  31. Bald Rick

    Bald Rick Established Member

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    There’s a long answer, which I won’t give, and a short answer, which is that the ATO can be programmed to drive more conservatively when and where railhead conditions are poor. This is done for sure on the surface sections of the Central line, and I assume the others with ATO on LU.
     

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