Not making a connection to HS1 has to be a huge mistake. An underground 4 platform Euston/Kings Cross/St Pancras station, with trains terminating out at Ebbsfleet where there is a lot more room, land costs are lower and disruption would be less, calling at Stratford on the way
Whilst I quite agree that an HS2 to HS1 link is a missed opportunity, it is only so in the context of the UK in Schengen, as others have said. Given that was such a remote possibility when the project was being developed, and even less of a possibility now, there was and is simply no realistic possibility of building it without it becoming “l’éléphant blanc” and an even more totemic angle for the HS2 antis to hang their hats on.
Meanwhile we have done the HS2 to HS1 link may times on these pages, including the (in)famous thread where one correspondent reckoned you could do it for a hundred million quis while no-one was looking, and have trains reverse in each St Pancras international platform 8 times an hour. The mental scars are still healing.
One more point, a 4 platform underground through station in the vicinity of Euston / St P / KX is simlly not possible.
Firstly it’s not enough platforms. It would need to be six, probably 8 - work out the dwells for a long distance service where several hundred people will be alighting, and another several hundred people boarding, on trains up to 400m, with single leaf end doors and luggage, then add on platform reoccupation times, thenadd ona s,all buffer so that you don’t use all the capacity, thenmultiply by 16 trains each way.
Secondly, it’s not physically possible without widespread demolition above grouns and / or extensive disruption to existing undergorund facilities, including the underground, Thameslink, the Fleet sewer, numerous deep cable tunnels, uitilities, foundations, and the deep basements of the British Library and the Francis Crick Institute.
Given the length of the route even if built in full I can see no reason why it was specced for 250mph/400kph, even the Chinese, with 1000 mile + high speed lines are sticking to around 220mph, and the French, with much longer distances bewteen major centres of population have stuck to 200mph
HS2 has an alignment for 400kph for about 2/3rds it’s length, and the formation is built to take that. However it will run at 350/360 on those sections, the same as in China. AIUI Chinese High speed lines are designed to the same alignment spec.
The route, I think the 'roughly following the M1/M6' would have made more sense, rather than trying to drive it through the Chilterns, it would also have allowed MML long distance services to benefit in the future.
Again this has explained before, but the short version is that a team of experts across all disciplines (engineering, construction, consents, environment, land specialists, noise specialist (there’s only one), demand forecasters, transport planners, political, estimators, planners, and more) assessed scores of potential route variants and scored them on a multi-criteria framework to nsrrow down options for more detailed study, and narrowed them down further before selecting a preferred route. There was peer review, internal and external challenge panels the whole way. This took many, many thousands of ‘person days’. It is reasonable to assume that what they selected made the most sense. Or at least more sense than the opinion of one person who has looked at a map and had a quick think. (There are many, many people who do this, some of them even used to attend cabinet)
Back to speed, if the issue is WCML capacity then a 155mph capable 140mph service speed would be plently for the journey lengths involved
Back to the point above. If you are going to the expense of building a long distance new line, and the incremental cost for speed is almost lost in the roundings, then the higher speed and resulting (much) hugher benefit almost comes for free.
As been highlighted, as far as I can see HS2 terminating at Euston is a complete waste of money, OOC gives far superior connectivity for around London.
See above, and whilst OOC helps, it patently is not better than Euston for connectivity.
Of course the value of such a link is severely diminished by the British refusal to join Schengen, however in the name of interesting discussion I do wonder about the value of this refusal, and how things might be different if the UK had embraced Schengen.
It’s reasonable to assume that if the UK was reliably in Schengen in 2010, the HS2 to HS1 link would have happened. Indeed the existing WCML / ECML to HS1 links would be seeing pretty regular use now. I’m more than happy to say I wish this was the case.