Ah yes' coming around again ... https://www.taylorfrancis.com/chapt...28046-9/fall-rise-solent-city-nicholas-phelps
Can't the existing railway be 4-tracked?
A bit hopeful is an understatement.
Someone local maybe able to offer some thoughts, but a look at the map before I replied indicates not much...
They can barely get freight through the tunnel. Though, once you accept ripping up the road, as this plan seems to require, the existing tunnel can easily be remade while it’s open.
On its own that doesn't really help the Southampton - Portsmouth axis. My idea would be to reroute the limited stop services via the Botley line with a new curve near Eastleigh:
The structure has always been a problem. The ground conditions are very poor I understand. Part of it collapsed during construction and hence what was originally designed as one tunnel actually became two, with a short section of retained cutting between them. There was an additional bypass alignment built around the tunnel to the south soon after the original line, but this finally closed in the 1970s and is use as a leisure path today, with some building development on the trackbed. I wouldn't count on ever being able to double through the tunnels, but a (say) 1 km section of single line remaining on an otherwise fully doubled line would probably be manageable. Power supply capacity may still be an issue for an expanded electric service, as it was a late electrification carried out at minimum cost on a similar basis to the Weymouth extension.
As much as I think this is a great idea, I’m not sure if it will be practical or economical to tunnel directly underneath an active airport and through a depot. It would probably be just as effective to reverse trains at Eastleigh like the few GWR/Southern services do now.
For local services, Eastleigh is probably a signficant traffic source and so would not be worth bypassing. However, rerouting of the Botley Line over your proposed line with a curve to face North would permit a much simplified (and therefore faster) remodelling of Eastleigh station. Also there's an old alignment straight to the Botley Line, so the wiggle to rejoin the alignment could be avoided.
Something similar is the new dual carriageway road skirting the eastern end of the runway at Gibraltar International Airport in a tunnel, a project that was begun in 2008 and might finally be completed this year! This should allow the closure of Winston Churchill Avenue as a through route for motor vehicles, a road that crosses right across the middle of the runway on the level!
I was thinking mainly of an alternative route for fast services between Fareham and Southampton which could avoid having to slot between stoppers on the Netley line and be able to gain the potentially lucrative stop at Southampton Airport Parkway, and crucially also increasing stopping train capacity on the Netley line. Stoppers via Botley are mainly/solely Waterloo semi-fasts via Basingstokes today I think, which should definitely still all call at Eastleigh, although your suggestion of a relocated junction further south for this axis would definitely improve matters, potentially allowing Portsmouth to Waterloo trains to access the up side of the station and thus a wider choice of platforms. With my chord, this would create a complete new triangular junction at the north end of the runway.
But reversals are inherently bad, inefficient, and add about three hours to every journey. We must spend billions preventing them!
Maybe the tunnel is being proposed to enable easy movement of troops for an invasion
Yes, by all accounts. It's worth noting that Transport for the South East, the proposers of this, seem to be mainly part of East Sussex County Council and their offices are in Lewes.
£4 billion is probably an underestimate of the cost as well. Is it clear how the route would interact with existing stations?
I think hate is strong. Maybe totally uninterested, or ambivalent ? It’s one of these end to end journeys emphasised by rail fans but possibly not actually used or needed so much in the real world.
The hate was strong enough that when Portsmouth's Spinnaker tower was illuminated in red because of a commercial sponsorship, the footballing rivalry was strong enough (Southampton play in Red & White, Portsmouth in blue) to mobilise enough Portsmouth Residents that the colours were changed.
I’ve lived a few miles due north of Fareham for over 40 years now, no train service as I’d have needed the Meon Valley line to be open. Portsmouth, Southampton and Winchester are all similar distances, so it’s sort of neutral territory! But although neighbours work all over the area, with possibly a slight majority in Portsmouth, in my experience nobody really commutes locally by train. I think if you actually lived on Portsea Island, or in Southampton itself, there’d not be many reasons to go to the “other place” - although Southampton’s probably got the better range of shopping.
This was my understanding of the Solent area travel as well - people living in between each place may well go to both, but actual Centre-to-centre travel between the 2 cities is quite small. This whole proposal seems to be a bit of professional-veneer crayoning to generate headlines and put pressure on the govt to give some money to the SE when they're looking at which projects to proceed with.
