I said six because I was referring to the additional trains only. As I see it, a train every three minutes at that speed is not just impossible, it's mad. AIUI, that means they would have to travel inside double the emergency braking distance. Nevertheless, I did know that was what they were thinking of.
Well they actually project 22 paths per hour being possible using ATO (only 18tph due to the intermediate stops requiring gaps), which will almost certainly be used, since you can eliminate the time the computer takes waiting for the driver to do something since it can just take action immediately.
This is helped by TSIs requiring that all infrastructure be compatible with linear eddy current brakes now, allowing emergency brake forces to exceed adhesion limits, and also by longer 400m trains being able to brake more quickly in adverse conditions using only friction brakes.
(The FASTECH 360Z study came to the conclusion that wet track has no major effect after the first ~120m of the train, so the longer the train the greater percentage of its brake force it has available).
None of that sounds very nice for the poor passengers, but that isn't exactly what I was thinking of. I was thinking that (say) a 350 is a bit late clearing the platforms at Rugby, and can't make up the time by Rugeley, or a late-running freight gets in the way, or whatever. A CC is about to come of HS2 and onto the TVL, but gets signal-checked. This causes the same 'ripple effect' that you get when someone has to brake on a motorway, suddenly everything behind has to brake as well, with the amount of braking increasing until you have a complete snarl-up twenty miles back. A six-minute cushion would prevent this.
Well as I doubt 18tph will be implemented at-least until HS2b (the rest of the Y) is implemented it means that the majority of the trains will be captive sets and only a small number will be classic compatible. (I project 2 each to Leeds and Manchester and none at Rugeley after the Y opens).
You could solve the ripple effect problem by either placing a 250kph PSR on the section of track approaching the junction and then providing a ~500m long loop between the HS tracks and the classic ones, permitting a train to move all the way clear of the line before the next one behind it catches up with it.
Or you could forget a PSR on the running lines and just provide 2-3 miles of "sliproad" lines to allow a train to leave the tracks at ~170kph and brake to a stop once it is clear of the high speed lines.
Going the other way, imagine that a Glasgow-London is checked at Lichfield, just before it reaches the junction. You can't sit the thing on the WCML or in a loop for ages until the next spare path, there simply isn't one. No, you have to feed the thing into the system somewhere. Dumping all the passengers in Birmingham is hardly an inducement for them to travel again, especailly if they end up on a peak-time commuter train (as you suggest it will be) to finish their journey to London. Whatever happens, the Glasgow-London must get through, so do you cancel something else to clear a path? How much compensation do you have to pay out?
Well if you really must get that train through, you would presumably contact the guard/catering staff of all the trains with paths through the core and determine which train has the fewest number of people aboard and truncate that one, load everyone from that train onto others available at Birmingham Int.
I actually did a sample timetable for a "mature" network, with a line to Scotland where I left one path free for International and Fast freight services and one free for ECS moves or whatever to move "spare" sets around, so there would be 1 or two paths free to solve problems like this in some cases.
Either way, it is highly unlikely that the currently planned components of the HS2 "Y" would have Glasgow trains as significant expresses, as this train would be no faster than the Pendolino thanks to being unable to access EPS speeds north of Manchester.
Now I imagine there will be no trouble filling the trains during the peaks, but not off-peak. I've been on off-peak expresses that have left London at one-quarter capacity many times, and assuming that's a standard, 500-seat-or-so HST, you're only moving 125 people plus a lot of fresh air. Will the situation be all that different when HS2 is built? I doubt it. So will they really try to run one train every three minutes off-peak. Of course not, most will be sitting in sidings somewhere. To make up the spare capacity, airport shuttles and international trains could run, otherwise what's the point of all this capacity in the first place?
Well, the dominant operating costs of modern trains seem to be capital cost repayments (which are the same no matter how hard the stock is worked) and staffing costs. However staffing costs for a 400m double deck High speed train-set are actually lower per trip than for the Cl390s, (the same size train crew for far less time).
Virgin currently runs three trains per hour to Manchester even in off peak periods, three per hour to Birmingham throughout the day while there are half hourly trains to Leeds on East Coast throughout the day. This adds up to at-least 8 conventional trains per hour and leads to similar staffing costs as the timetable that I am proposing.
As each train-set would be carrying so many more passengers it is not unreasonable to assume that the market would quickly become saturated with lots and lots of ultra cheap off peak tickets. Cheap to the extent that people in London would go to the Cinema in Birmingham or even Manchester, or that people in Manchester would go out in London.
If very off peak services to Birmingham withdrew the catering staff that would result in further reduction in cost and reductions in the relevant ticket prices.
(Captive trains could even go DOO as a high speed accident either occurs at low speed in a station where there are staff about, or it looks like Eschede and the guard is probably dead already).
So will there be any improvement? Are we really trying to get people out of the air and onto rail? I thought the whole point of HS2 was to extend the European high-speed network northwards into Britain so that people would not have to fly. Regular, direct services to Paris and Brussels are a crucial part of that. If we don't get those, what would decide people travelling to Europe to take the train?
I thought the purpose of High Speed rail in the UK was to erase the north south divide by making the North the South. (Extend the London commuter belt as far north as possible with the lowest possible ticket prices).
But anyway, that one path per hour I reserve in my projections for Freight and/or International trains would provide approximately 1tp2h on each of the branches of the Y to Paris. (Anywhere beyond Paris really runs into the increasing travel times). If you were able to position a hot spare set at Euston and potentially OOC it might be possible to use the path I reserve for "spare" set movements during peak periods to permit extra trains to be run at times of high demand.
I would of-course suggest that all double deck captive sets be identical, permitting any set to substitute for any other as required.
