The extra capacity is primarily a result of improvements in design and the shrinking of the electronic sand mechanical fits.
The power cars on the Horizon are going to be substantially shorter than on a traditional TGV thanks to the advances in technology.
A TGV Duplex is a 90s design, 30 years is a long time in technology.
Even the Ouigo layout surrenders the lower deck below what would have traditionally have been the buffet car for "technical areas".
Those are apparently no longer required with the more modern design.
And the reduction in length of the power cars is a major deal
Hence why I used the 740 people train you used as an exemplar, not the one with fewer seats than a hypothetical 8-car Class 80x! I was pointing out that you were picking up a decent modern train and making the best case you could.
I'm rather confused about why we care what the end car carries?
The end car has to be present either way.
So you can know how I came up with my figure of 600. Sure it doesn't matter whether there's a bouncy castle, or a kitchen, or bike racks, or whatever. What matters is that even wasting space on a single-deck train, double-decking doesn't offer that much more seating.
I'd imagine that the Horizon number would include some space given over to on-board facilities beyond toilets, even if Ouigo (a specifically low-cost product) replaces those spaces with seat. I think it fairer comparison to take out some space for such facilities.
The better way to do this is to go to the
seating plan provided by the LNER.
Why LNER's layout, and not the GWR one I described? It doesn't matter, but it just strikes me like you are trying to nitpick a fight for the sake of it rather than actually address the meat of my argument.
So in an all second class configuration we end up at about 640 seats.
So about what I said to start with.
Sure, will go with an even lower seat increase from adding a double deck! What is wrong with single deck trains if they can hold 85% of your exemplar high-capacity double-deck high speed train?
Given how you've decided to go into nitpicking rather than clearly answer when the percentage was 80%, I don't hold much hope for any better argument when the percentage is 85% making it harder?
'Facilities and Services' are entirely worthless.
The journeys are far too short, beyond toilets all that matters is seats seats seats seats.
OK, fine. I don't know why you are rejecting the stuff I'm putting on the single-deck train to reduce the amount of seats and make your argument for double-decker trains stronger, but whatever. If you want to shoot your own foot, go for it!
And do we even need toilets, given how Class 345s (Reading-Shenfield is 20 minutes longer than London-Leeds), S stock (Chesham will be as far away from Euston as Manchester Interchange), etc don't have them?
Luggage racks are a thing too you know, and electrical equipment cabinets and the likes tend to fill those spaces.
Sure, and why can't they do that on the staircase from mezzanine down? If it's, say 4 steps down from a mezzanine and that space is dead, that space under the bottom 4 steps on a staircase to the top deck would be just as dead on a bottom-loading bi-level train!
And you want people to climb from their 915mm height platforms in these places into a 1200mm height train?
No. Never said 1200mm was the way to go, just that the low platforms (which suddenly become double-deck trains rather than low platforms, moving the goal posts in a failed attempt to have a convincing argument) that you want aren't the capacity improvement you said they were.
Why do people on the bottom deck have to go up to the top deck?
A bit fraction of the seating is on the bottom deck, if the disabled toilet is on the bottom deck then there is no need for them to go upstairs.
Then why do they have to leave the vestibule on mezzanine double-deckers if the seats and toilets are there (maybe at the ends of the train, akin to Class 80x layouts. After all, you're going to need more technical/electrical stuff there - which can go under and over the mezzanine)? You were rightly annoyed about the possibility of them being stuck in some allotted area when it was a bi-mode with high-platform level access...
The Horizon press releases talk about the train's autonomous accessibility for disabled passengers including fancy lifting platforms in each carriage (
this video shows one being used to go
down from the door to the bottom floor. Yes your exemplar double-decker makes everyone boarding/alighting use steps/lifts, just as you don't want!). Surely, 10+ years later (2032) we'd have similarly good stuff on this double-deck train you want to have on HS2 - if not better. Accessibility should be to as much as possible, not some allocated area.
Because 3+2 and double deck are not mutually exclusive are they?
Sure they aren't, but who would want to spend 49 minutes in such cramped conditions, let alone 81 minutes? Do we really need to sacrifice comfort that much to eke out every last drop of capacity when we're doubling it on captive corridors as a base level?
There's clearly a reason why even suburban bi-levels in Europe don't do 3+2 seating (the examples I found were all Asian).
I know outer-suburban 3+2 have narrower seats than a captive stock 3+2 would have, but people get off, the trains empty and so you don't have to sit in the middle seat the whole journey. You are going to be in that middle seat for some time on HS2 - far more than London Commuters would tolerate.
Outer-suburban services are slowly getting rid of their 3+2 seating. In part as you can fit more on standing (don't get ideas!
) and the trains need the capacity boost, but mostly as people would rather stand for 20 minutes than sit in a middle seat for that long!
But lets say we assume both double-decking (which you have as 15%) and 3+2ing yield 20% increases. Doing both gives 44% increase over doing neither. Given we're already roughly doubling capacity on captive lines by roughly doubling train length, do we really need to make it a near tripling from the get go?