Released Capacity

Discussion in 'Future High Speed Rail' started by KingAugustine, 8 Dec 2016.

  1. edwin_m

    edwin_m Veteran Member

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    The business case for the replacement trains would be built around attracting a new set of passengers by providing more frequent service at the places that don't have HS2 stations. The number, size and type of the new trains for the WCML will be based on the projections of post-HS2 passenger flows. Over a 10-20 year timeframe and with passenger miles by car over 10 times those by train, there is plenty of opportunity to get more people using the train.
     
  2. The Ham

    The Ham Established Member

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    How do you propose we fix the problem of capacity issues in the peaks within 40 miles of London?

    At least with HS2 the is scope to provide some new services within this area, but also within areas around other cities along the WCML. This could either be done by a long distance commuter service or by using one path and splitting it over 2 or 3 shorter services each based around a different city.
    --- old post above --- --- new post below ---
    Interestingly, technology may make long distance rail travel MORE attractive, in that where electric cars have a limited range we could see more people wanting to use trains.

    Owners of such cars would have the choice of driving their car and having to charge it, with the longer journey times that would involve, traveling by train or hiring a different car and paying the fuel cost on that.
     
  3. anme

    anme Established Member

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    This is a really laughable argument. It is saying that we shouldn't improve transport between A and B because there are also problems between X and Y.

    I have a lot of misgivings about HS2 but one thing than convinces me that we need it is the pathetic nature of the arguments given by the anti-HS2 brigade. I wonder if they even read what they write. If that's the best they can come up with then the case must be pretty strong.
     
  4. Voglitz

    Voglitz Member

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    No, it's not saying "we shouldn't improve transport between A and B because there are also problems between X and Y".

    It's saying that prospective transport improvements between A and B, and C through Z, should be assessed on value for money, and not on whether there happens to be a railway between them.

    The Department for Transport "have it both ways", by declining to explain exactly how they "save £8.3 billion", while promising to run a "broadly comparable" classic service post HS2.

    Judging by the HS2 technical director's presentation, the pre-HS2 "express trains" would be "replaced" by more or less the same trains, stopping very slightly more often.
     
  5. MarkyT

    MarkyT Established Member

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    The question should be about released capacity for different stopping patterns. HS2 will not increase the overall number of paths available on the fast lines, but WILL allow more trains to stop at the intermediate stations that deserve a better service of faster trains into London and also to the Midlands and NW. What really saps capacity on a pair of lines is differences in journey time and stopping pattern, so that you can either give preference to the the expresses or to the semis, but you can't have high frequency for both as the fasts keep catching up with the stoppers. This is also why skip stop is so popular on such capacity constrained routes today, to keep overall journey time between the cities the same by having the same number of stops but distributing these calls at different stations for different regular departures from the main cities across the hour. Intermediate stops for 'semis' can also be placed on loops next to the fast lines to allow non stops to bypass them, but this adds significantly to overall journey times for the stoppers and adds performance risk between the service groups and greater track and planning complexity.

    Stoke along with Stafford and possibly Macclesfield could continue to be served easily by a classic compatible service at Phase 2. They are already planned to be served that way at Phase 1.

    Chester could feasibly get a regular CC portion split from a Liverpool service at Crewe, given electrification of the route.

    I keep trying to explain that speed segregation is not just about the top speed capability of the rolling stock used. A much more important factor is differing stopping patterns of the traffic mix using the route. It is notable that south of Rugby, point to point timings of 110MPH capable cl.350s are almost identical to that of (nominally faster) Pendolinos, between Watford Junction and Milton Keynes for instance so if you put all intermediate stops in every train you might push 18-20 trains per hour through the section, just as HS2 plans to do on the new railway with the identical stopping patterns (i.e for HS2 no stops south of Birmingham). If you had no stops at all on the Rugby Euston section you might also achive a similar throughput at maximum tilt enabled speed. What you cannot have is that maximum capacity together with a mix of stopping patterns. The less than ideal technique of skip stopping is used extensively today, but even this saps some capacity, and makes some intermediate journeys difficult. What is certain is that there is no practical margin for service frequency growth on the WCML without moving further towards an all stops or non stop pattern for all trains on this section.

    HS2 will allow more intermediate stops on remaining WCML services due to the line capacity factors explained above and also because there will be capacity aboard the trains, which will no longer be carrying the current volume of longer distance travellers from the major north western cities. So for Rugby, Milton Keynes, Coventry, expect maybe a very slightly extended journey on some trains but also the possibility of many more departures per hour and much more likelyhood of a seat, especially in the peaks.

    Thus I maintain there IS capacity released by HS2. Capacity for these intermediate journeys at the southern end of the WCML as part of broader service pattern changes made possible by the new route.
     
    Last edited: 11 Jan 2017
  6. anme

    anme Established Member

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    Are you arguing that a new railway line between Luton and Milton Keynes has a better business case than HS2? Because I'd like to see those numbers.
     
  7. Voglitz

    Voglitz Member

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    I'm going by the McNaughton 'released capacity' presentation, which does not show generalised large-scale improvements for intermediate stations.

    In the case of West Coast south fast lines, stopping pattern does not play much of a role in capacity sapping. A limiting factor is the flat crossings to the slow lines, one of several design errors of the modernisation.

    They may or may not add 'significantly' to overall journey times and add performance risk, but loops are commonplace on legacy and new build railways. HS2 is supposed to have such loops.

    You wrote, "the new line will be able to take the complete high frequency London service of the fastest trains from the major NW cities and Birmingham".

    I don't think it could. The current Stoke to London service isn't 1 train per hour, for example.

    You can have a nonidentical stopping patterns, without losing throughput. Provided the loop on and off mainline, for stopping trains, is at mainline speed.
     
  8. The Planner

    The Planner Established Member

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    The flat crossings are the limiting factor? How many trains per hour cross on the flat or actually require to? What you are saying does not tally with what McNaughton has said, which at the end of the day he has no influence on anyway.
     
  9. Voglitz

    Voglitz Member

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    A, not the limiting factor. One of several design errors of the modernisation.

    What Mr McNaughton has said, or is reported to have said, does not always tally with the actuality.
     
  10. Trog

    Trog Established Member

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    How else do you expect trains to cross between the fasts and the slows?

    The loop would also have to be long enough to allow braking from line speed to a stand and acceleration back to line speed in conditions of poor adhesion. Two loops (one in each direction) that long through a built up area with high speed swing nose S&C at each end would cost an absolute fortune. Provided you could even get permission for all the demolitions that would be required to get the land.
     
  11. The Planner

    The Planner Established Member

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    And also one of very minor significance.
     
  12. Joseph_Locke

    Joseph_Locke Established Member

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    Within earshot of trains passing the one and half
    9km long with 225kph entries and exits, if I remember the guidance from HS2 correctly. The track interval also has to be about 4m at those kinds of speeds.
     
  13. Grimsby town

    Grimsby town Member

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    There's a lot of discussion going on about capacity being freed on the WCML but it's not only the WCML that will benefit. The ECML will benefit from increased capacity south York to run new services between cities like Leeds and Newcastle and Cambridge.

    It also offers a chance to serve new markets. I currently commute from Bawtry to Leeds. Even though the ECML runs through Bawtry I have travel to Doncaster to catch a train. Once HS2 is open new stations can be opened in areas that are currently not served such as Bawtry and many areas between Leeds and Wakefield.
     
  14. edwin_m

    edwin_m Veteran Member

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    If a stopping train is looped and overtaken at a station stop, it needs a second path a few minutes after its original one to drop into when it re-starts. So unless stopping trains are so frequent that one is entering the loop just before the previous one re-joins the main line in its path, stops on loops still have a cost in capacity.
    --- old post above --- --- new post below ---
    East West Rail looked at providing a link between Luton and Milton Keynes but couldn't make a business case. However it will make rail more viable for many east-west journeys in the counties north of London.

    Similarly a business case seemingly can't be made for increasing service frequency on the Abbey line. Extending it to City would be hugely costly and disruptive, for very little overall benefit because it provides for few through journeys and many that it does provide would also be possible by changing at Bedford and Bletchley.

    So there is a need for east-west links, but money is being found to address this as well as to provide HS2.
     
  15. najaB

    najaB Veteran Member

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    9km long loops at most (all?) intermediate stations? Might as well just build a new pair of tracks.
     
  16. Trog

    Trog Established Member

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    Perhaps we should build them on a new alignment so as to avoid having to demolish a swathe through the line side towns and to get a better alignment allowing higher speed running.
     
  17. HSTEd

    HSTEd Established Member

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    Why wouldn't they be after all?
    If we are doing a loop-Shinkansen type job we might as well do it properly.
    There is also the fact that it is far easier to put this stuff in at the time of construction than after the fact.
    This is why I often proposed a London-Birmingham shinkansen with a half dozen intermediate stations. And several 'all shacks' trains an hour that would take the same time as the current fastest train [and recent advances in timings on the Tokaido Shinkansen lead me to believe that that time has probably shrunk by seven or eight mintues since then]
     
  18. edwin_m

    edwin_m Veteran Member

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    I expect the population density along the actual Shinkansen in Japan is enough to have the previous stopping service dropping into the path of the next one as I suggested in my previous post. However, with a stop and re-start from high speeds costing around 6min, this would mean every second train being a stopper. There may also be some skip-stopping options that use capacity efficiently with fewer stops at the intermediate stations, but then there are no links between the intermediate stations, worse than something the WCML is criticised for today.

    The route of HS2 was chosen, among other reasons, to avoid centres of population as far as possible. Therefore if intermediate stations were built the demand would relatively small and probably mainly people driving from more populated areas which probably have closer stations on the classic network. They would be similar to the "gares des bettraves" on the French lines, created at great expense in the middle of nowhere (several km of loops wouldn't be cheap) and with relatively little patronage.

    Alternatively HS2 could have been re-routed to serve more intermediate population. Bit then it would have been more costly, attracted a lot more opposition and probably slower too. So why do it when the main centres are already connected by the WCML and the Chiltern line?
     
  19. HSTEd

    HSTEd Established Member

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    I think I would be more operationally comfortbale with every third path being a stopper. It only adds a small handful of minutes to the end to end journey (on the stopper) and has the advantage that the whole thing is a lot less likely to come to pieces the second a train takes longer to load or unload at the intermediate stations. And 6 paths a hour is still easily sufficient.
    It is worth remembering that technical headways are significantly shorter than the proposed timetabled headways, so you can get more paths than it might appear if you get clever - but that sort of thing requires significantly more computation than these estimates. I think 6 and 12 is probably achievable without any
    very poor assumptions.
    I don't think it would have attracted significantly more opposition - because whilst it would require more demolition or other works it would also have tangible benefits to those near the line of route.
    Which it does not currently have.
    Wolly promises of more stopping trains or whatnot are not that useful when they are not clearly linked to, and inherent in, the project created.
    Saying we will create more capacity and then sometime later give you more trains is not as persuasive as showing them a drawing of a station that will be built as part of the project and saying they would have a turn up and go service to a long list of destinations ending at London and Birmingham at the ends of the line.

    And at 320kph you eat 5.3km a minute, the route being marginally longer is irrelevant if you can design to keep the speed up.
     
    Last edited: 12 Jan 2017
  20. tsangpogorge

    tsangpogorge Member

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    Why does every one assume that HS2 is it for ever? Just like the classic network the route will eventually be extended, loops or branches to mid sized cities like Stoke and Coventry will be constructed and maybe in the very distant future the termini stations will be demolished and through routes tunnelled under the West Midlands and Greater Manchester.
     
  21. MarkyT

    MarkyT Established Member

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    Why bother when, without trying to interleave with non-stop trains, you can run that sort of service on the existing fast lines (admittedly not quite as fast as the non stops today) which have established stations in important towns strung loosely along the same corridor. How useful exactly would be some huge Chilterns parkway for example, with access roads, associated car parks etc? Besides being far more obtrusive than the plain line route as planned in the area, much in tunnel, if "successful" such a wheat-field parkway might suck up patronage from surrounding stations over a wide area for those who could afford to drive to it. Where would that leave the economics of parallel operators with just the remaining customers on the classic routes? Could they face service cuts? That wouldn't help much serving the goal of improving overall capacity and network utility. Furthermore, intermediate stations could become a source of significant crowding on trains arriving from further north already well loaded, and if the short distance commuters won't be able to just board the first train, then the supposed time advantages of high speed over such a comparatively short distance start to evaporate.

    Where HS2 does have intermediate stations as at Birmingham Interchange, long 'Japanese style' loops are planned with turnouts as fast as possible.

    The lack of further intermediate stations south of Birmingham contributes to a simpler, more reliable infrastructure, a consistent high speed 'conveyor belt' configured optimally to handle the continuous flow of high speed, high frequency, long distance expresses from all over the north.

    Best for overall capacity to use each pair for one dominant service type: Long distance non-stop on HS2, medium distance fast regional express with limited intermediate stops on the WCML fasts (perhaps with some fast freights squeezed in outside peak hours) and various patterns of stoppers and slower freights on the slow lines, as now.
     
  22. Voglitz

    Voglitz Member

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    Major.
     
  23. HSTEd

    HSTEd Established Member

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    Because very few people outside the railway industry/enthusiast community really believe those services will ever materialise.
    These people expect to be left out in the cold just as they percieve they always have been.
    But I am not proposing a Chiltern parkway - since I would not be following the current alignment, I would be proposing a marginally longer alignment further North, likely sacrificing the questionably useful 360kph alignment for the purpose.
    You expect to fill a 400m Class 395 esque train every ten minutes? according to a diagram I found from Hitachi the intermediate vehilces have 68 seats. That means that a 20 car Class 395 would have something approaching 1290 seats once you add in additional toilets.

    Which will be hamstrung because it will be fed trains from an unreliable network in the north.
    If capacity and reliability is what you want, axe the classic compatibles.
     
    Last edited: 12 Jan 2017
  24. Voglitz

    Voglitz Member

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    About half the classic network has been closed down.
     
  25. edwin_m

    edwin_m Veteran Member

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    An extra 3min on four stops is 12min on the journey, which makes a big dent in the difference between HS2 and classic times.

    I agree 6 trains per hour would be sufficient, in fact I consider it would be grossly excessive for stations in the middle of nowhere (the French ones have a handful of trains every day).

    You are talking about a new railway through built-up areas, where due to the need for loops at stops it will be four track, so with modern clearances for high speed probably at least 50% wider than the WCML. Plus huge stations on prime town centre sites or even underground. How much more will that cost in construction and property acquisition, and what proportion of the local residents will never use it but still have to suffer the inconvenience?

    But to serve all those places will need more curves, so the speed may end up being lower.
     
    Last edited: 12 Jan 2017
  26. HSTEd

    HSTEd Established Member

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    If they want speed end to end I assume they would take the 12 trains per hour that don't stop at the intermediate stations ;)
    And those who don't care particularily about speed could take the other six that could be priced even more cheaply than normal high speed fares.
    Clever layout of stations and station approaches can tend to ameliorate the track spacing requirements, for example if you were to play the 'loop tracks' in the centre with an island platform you don't need the large spacings between the two inner tracks as they won't be high speed for most of their length.

    And track used surface is not actually a large determinant in the width of the alignment.
    After all HS2 states that its normal alignment width fence-to-fence should be 22m.
    Which considering it includes about 3m of actual track width and 4.5m of track spacing demonstrates that it is not.
    There is something of a happy medium between town centre sites and stations in a beet field.
    This project is already costing ludicrous amounts of money. I could have six intermediate stations and spend £2bn on each and every one of them [which should buy a two platform station with two through lines] and not increase the cost of the scheme by more than 30%.
    And be careful where you point that suffering inconvenience for something they will never use argument - that sword cuts both ways.
    Yes, but the alignment at 320kph has a much less stringent set of minimum curve radius requirements than 360kph or 400kph.
    It is highly likely you could arrange an acceptable alignment.

    If high speed rail is going to work in the British environment [given its truly enormous capital cost] it is going to have to be high density, highly reliable and cheap ticketted.
    Scattering short trains to every halt in every corner of the land from its classic compatible accesses will not achieve any of those things.
     
    Last edited: 13 Jan 2017
  27. Starmill

    Starmill Established Member

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    How many crossing moves per direction per hour are there at each location where this happens? How much time does each take to clear? How many extra fast line paths could be available if such crossings weren't neccesary?
     
  28. Trog

    Trog Established Member

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    Surely in that case you would need a large spacing between the loops so you had somewhere to put the island platform!
     
  29. HSTEd

    HSTEd Established Member

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    Not necessarily, since the station is only a few hundred metres long you could cut and cover the fast lines underneath the station. Its just you can't tunnel the entire approach without it becoming absurdly expensive.
     
  30. najaB

    najaB Veteran Member

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    I'm having difficulty picturing how this allows the loops without excessive land take - any chance of a sketch?
     

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