FDF,
However, NHT could be used for thin domestic routes, those that have lost their links to LHR over the years such as , etc., and allow new destinations such as etc..
Some of these areas desperately need regeneration and improved connectivity is essential, and let's face it,
But in many of the cases you mention, there are other reasons why the routes don't exist, nothing to do with LHR - APD and fuel prices being the obvious two.
When was LPL last served from LHR? Gone from LCY - train & APD?
LCY-LBA lasted a month or two? Iirc, BE tried LGW-LBA & MME - short lived.
V train - what that needs is Reading to LHR link, which should come with XRail.
For BLK, read Preston - both do nicely out of being on the WCML route, because of Glasgow, many more trains stop here than otherwise would - hence very difficult for competing air services to work.
INV, JER, NQY, IOM, DND,
Yes, would be good to have at LHR - not to mention places in Ireland, maybe EIN, GRQ, LIL etc.
HOWEVER - SEN could take this as ptp. For connections, that's a lot of movements to get any kind of volume + infra costs + airspace etc.
Don't quite see it working I'm afraid - but apart from DND, all the above could feed in to an expanded hub at LGW
none of these destinations will ever see an HST.
Not so - Leeds is one of the major destinations of Phase2, and by then there should also be a join from HS2 onto the classic line around Preston, good for both BLK & CAX. There will also be a join around York for Darlington (MME).