Why would they have happened before a 400m train? The few examples we have today, eg Gloucester, might be Victorian.
No, the buffers are still hundreds of metres apart, the approaches much further. The bulldozable route through Birmingham closely matches the Birmingham-Leicester route.
Which junction? Handsacre? There is no proposal to do anything with Colwich as it stands.
Birmingham Interchange is a six platform through station on greenfield, with full and dedicated access. Euston is a 11, no 6, no 10, is it still 10? platform terminus with limited access, angry neighbours, live rail beside and below, and many other improvements, such as tube and oversite development, lumped in.
I think Handsacre will be grade separated, though there might have been talk at one time of descoping that when it was going to see barely any trains. I'd be surprised if it wasn't grade separated with the truncated HS2 that's being built now, since it'll be a lot busier and the lines are paired by direction through there.
IIRC the long platform at Gloucester was created (in the 1970s?) to facilitate HSTs and their reversal there?
There's the obvious extra cost of property, which is a sunk cost now effectively, and the cost enabling over-sight development. I'd advocate for a simple concrete box with 8 platforms (enabling easier over station development) and closing/demolishing 4 more platforms at Euston so there's only 12 platforms. A 12 platform classic Euston is not an issue, it would be a similar platform utilisation to EMR at St Pancras. 6 platform Euston will destroy long term capacity. 8 platforms is an absolute minimum and having some space between HS2 and classic stations is likely to save some money, while a single phase is also cheaper. I've heard over station development at Euston is limited due to protected views, which could be amended to ensure maximum value from the Euston site, given the views of the current government on planning.
Handsacre was always going to be grade seperated. The connections will be on the slow lines.
Slow lines? That's a surprise...
Fast line connection was too expensive.
No. The original plan had HS2 landing between the fast lines.
Seems to me like a great way to ensure you don't get the maximum benefit from the expenditure.
It doesn't make a huge amount of difference.
No. The slow line option was drawn up long before Rishi canned 2A.
I apologise for that.
I look at Carlisle and the layout doesn't look very amenable to serious extensions.
On the face of it it doesn't look terrifyingly expensive to widen the viaduct and extend platform 1 to the north, probably adding another platform alongside it. If you were taking it further north and adding another stop, then rather than splitting at Lockerbie you might as well go to Carstairs and save a path up Beattock.
The original plan was to divide and join the two double set HS2 trains London Euston to and from Glasgow and Edinburgh each hour at Carlisle.
Searching for hs2 carlisle plans returns a bunch of PDFs. In particular https://assets.hs2.org.uk/wp-content/uploads/2021/06/N13_CS1420a_In-Your-Area-Carlisle_Feb-22.pdf contains a map showing that they are/were proposing to fill in platform 2, extend 1 and 3, and build a platform 0 to make up for platform 2.
I think that Carstairs was the original intention before someone pointed out that it was silly stopping the train in what is basically the middle of nowhere when you could split at Carlisle, a station you'd call at anyway.
Isn't it a function of needing to spread what are now immense construction costs over a longer period to actually be able to afford them, rather than a measure of how long it would take to build if it were more affordable?