If all intermediate stations are built on long loops as they should be (and there aren't exactly lots of them, as the Chiltern Line provides the stopping service over the route), it doesn't matter. You just feed in trains at 1-2 minute intervals, and they pop out the other end.
Missing slots only matters when you have complex stopping patterns. HS2 won't have.
Ive no problem with carefully scheduled loops on a main line.
But the case of HS2 on the dozens of miles between Sheffield and somewhere on the outskirts of Nottingham means that a 200mph train is going to share the same platforms, the same tracks, the same flat junctions etc as the local 75mph DMUs.
So itll only take a minor delay (e.g. a Manchester bound Hope Valley stopper cant cross the Chesterfield Sheffield line outside Dore station due to a late running northbound service) to impact upon the path of the hourly HS2 service departing Sheffield.
And given that the eighteen services per hour on the two track line south of Birmingham on HS2 are only going to be a few minutes apart, that means that theres going to be quite a risk that a sluggish freight train not clearing a junction promptly outside Chesterfield means that theres very little margin once the Sheffield London train gets to the Delta outside Birmingham before the next 200mph service from Manchester to London is due.
Im happy with the concept of HS2, Im happy with a segregated high speed line. But if we only have the money to build one pair of tracks from London (to connect it to the West Midlands/ Greater Manchester/ Merseyside/ West Yorkshire/ TynenWear/ Greater Glasgow and various other large conurbations everything funnelling down the same two track line) then Im nervous at the prospect of delays to Classic Compatible services on our Victorian infrastructure impacting upon a High Speed line that is going to be busy from the start. Theres not going to be a lot of margin for error, so forcing Sheffield services to share the same tracks as freight and commuter DMUs seems to be asking for trouble.
I would have thought the less classic compatible the better from a capacity viewpoint, having classic compatible for Sheffield is surely going to reduce capacity. I would go back to the Meadowhall route, for people on that side of Sheffield/Rotherham, Meadowhall is easier to get to than the centre of Sheffield. Meadowhall has a good tram connection and you could look at improved connections on the mainline between Meadowhall and Sheffield, while Sheffield Midland would still retain a MML service.
Good points.
Meadowhall would have been the "least worst" option for Sheffield. And I say that living on the opposite side of town from Meadowhall (Midland is closer for me).
My worry is that (without electrifying the MML any time soon), the "Nottinghamshire to Sheffield" bit of HS2 will be an "easy to cancel" branch that they may sacrifice when costs elsewhere increase.
Sheffield City Region has gone from having a stop on a main line to being an expensive* branch that might be jettisoned if other costs increase.
(* - by "expensive", I mean that they can't piggy-back onto MML electrification having been completed in time)
True, but who knows with Grayling's latest cuts
ad:
Having thought about it, this is what I'd do:
LONDON
-Send HS2 into a rebuilt (again) St Pancras station, eg: a two level station with HS2 underneath the existing station
You mean where Thameslink currently is?
In Leeds, I would redesign the route so that there would be a new through station, through which all HS2 trains to Leeds and beyond would run, saving the need for both a connection to the ECML near York AND a terminal branch to Leeds (they would sort of be amalgamated into one)
At high speeds, under your proposal, by the time a London - "Newcastle" service has taken the slower alignment from Woodlesford into central Leeds, decellerated, dwelt, accelerated, taken the route that you've found through north/eastern Leeds (which isn't going to be particularly straight, unless you tunnel everything) and got back onto the proposed line beyond Leeds, it would have been the other side of York (if it had run on the proposed HS2 route avoiding Leeds.
Great news for Leeds, which would ensure that everything stopped there, but it'll slow down longer distance journeys quite a bit - and be much more expensive to build an alignment north/east of Leeds (compared to taking the proposed "green field" route past Swillington).
1. Through stations in Manchester, Leeds, Sheffield Birmingham, and London rather than terminii
Why through stations (other than because that's what the Victorians did)?
A through station becomes significantly more expensive than a terminus - with a terminus you have to find one route through the suburbs and inner-city areas to serve the heart of the city.
With a through station you have to find two such routes and ensure that they are roughly opposite each other (whereas, with a terminus station, it doesn't matter particularly whether you approach Leeds/ Manchester etc from the east or south or west, since services are terminating there).