Why is high speed rail in the UK so expensive to construct?

[LNW-GW Joint]

An aside, but I'm surprised it's as little as 410 miles from Paris to Marseille, basically the same distance as London to Glasgow. I would have guessed over 500.

Paris-Marseille via the LGV route is 750km or 466 miles.
So similar to Euston-Glasgow-Perth.

 

[nw1]

It’s 409 miles in a straight line from Gare de Lyon to Marseille St Charles. The train journey is much nearer 500miles.



To add to @Ianno87 ... not all the trains use the line as far as Lyon. There’s services to Geneva, Basel/Zurich, Besançon, Annecy and a few other places that dive off the LGV before Lyon. And plenty more that pass around eg to Grenoble, Chambery, Milan, and of course to Marseille, Nice, Montpellier and the deep South West.

Very few stations get a better than hourly service to Paris. Take Dijon for example - the capital of Burgundy, home to one of the finest wine producing regions of the world, popular with tourists, plenty of business travel, about the same size as Norwich...and a TGV every other hour for most of the day.

Thanks. Was wondering how viable intermediate stations on HS2 out in the sticks would be (e.g. the EWR interchange) as the LGV does have a couple of intermediate stops (Le Creusot and Mâcon-Loché). But presumably the timings are such that those stops fit into 'gaps' in the irregular timetable.

 

[Ianno87]

It’s 409 miles in a straight line from Gare de Lyon to Marseille St Charles. The train journey is much nearer 500miles.



To add to @Ianno87 ... not all the trains use the line as far as Lyon. There’s services to Geneva, Basel/Zurich, Besançon, Annecy and a few other places that dive off the LGV before Lyon. And plenty more that pass around eg to Grenoble, Chambery, Milan, and of course to Marseille, Nice, Montpellier and the deep South West.

Yep - the 10-12tph I quoted applies to the section between the Interconnection junction, and the Dijon chord (Bifurcation de Pasily).

Thanks. Was wondering how viable intermediate stations on HS2 out in the sticks would be (e.g. the EWR interchange) as the LGV does have a couple of intermediate stops (Le Creusot and Mâcon-Loché). But presumably the timings are such that those stops fit into 'gaps' in the irregular timetable.

When I plodded through the timetable, it seems to be those irregularly served Parkway stations that hamstring the whole timetable.

I.e. you have a neat standard hour service, except the hours those stops are made, when the time at Gare de Lyon is off-pattern as a result by departing earlier or arriving later (and thus, in effect, consuming two paths)

 

[Michaeco]

One of the reasons may be the lack of an independent, standing board of neutral persons, sometimes called a dispute avoidance and adjudication board or collaboration facilitation board, to head off and in the end "sentence" technical and people issues, which generally mean time and money. The Standing Conciliator under Public Works Contracts in Ireland is an excellent starting point, as is the inclusion of such boards in the latest version of of the JCT (JCT's Dispute Adjudication Board Documentation 2021). There is plenty of evidence of these boards being widely used by grown up funders, such as the World Bank and the other multilateral development banks, and contributing to keeping major projects moving, money flowing and reducing legal costs.

 

[JamesT]

One of the reasons may be the lack of an independent, standing board of neutral persons, sometimes called a dispute avoidance and adjudication board or collaboration facilitation board, to head off and in the end "sentence" technical and people issues, which generally mean time and money. The Standing Conciliator under Public Works Contracts in Ireland is an excellent starting point, as is the inclusion of such boards in the latest version of of the JCT (JCT's Dispute Adjudication Board Documentation 2021). There is plenty of evidence of these boards being widely used by grown up funders, such as the World Bank and the other multilateral development banks, and contributing to keeping major projects moving, money flowing and reducing legal costs.

I would have thought at least some of those issues should have been sorted by the passage of the legislation through Parliament, with the committee stages examining objections to the scheme and in some cases ordering changes to mitigate them.
Unfortunately in our polarised society this doesn't seem to be sufficient, as people are willing to litigate at the drop of a hat.

 

[BayPaul]

Sorry, but that is an absurd stretch. I'd love to see those tourists faces when they realise they have to cram onto XC and subsequently realise it''ll be faster to go via London... they'll be on the M5 like usual.

I'm fully pro HS2, but also fully aware it's really going to do nothing directly for this area as is everyone else down here - ok the next phases will improve a short section of journey quite a distance away from the area, but I'd be interested to know what percent of travel in & out of Devon & Cornwall goes up there. No need to try and justify it, of course no project of this nature can work for everyone. I also don't think we're in a queue for HS4 - given the eye-watering costs of HS2 I hate to think what dodging all the AONBs on the way to Plymouth from just about anywhere would cost if it was done at 400kmh standards. Or to be honest, any standards better than the current route. Good luck tunneling through all that Dartmoor granite, too

--

That is a pity about the view, which presumably would be something of a standard for any new line. One of the attractions of rail travel is watching the world go by without acres of adjacent concrete...

An HS line all the way to Plymouth is unlikely, but an HS line that benefits Plymouth is entirely possible, in a fairly long time scale admittedly. A London - Bristol area high speed line could reasonably speed up train times and capacity to Devon and Cornwall, as well as to Bristol and South Wales. Ditto a new High Speed line from Bristol to Birmingham.

 

[Irascible]

An HS line all the way to Plymouth is unlikely, but an HS line that benefits Plymouth is entirely possible, in a fairly long time scale admittedly. A London - Bristol area high speed line could reasonably speed up train times and capacity to Devon and Cornwall, as well as to Bristol and South Wales. Ditto a new High Speed line from Bristol to Birmingham.

The slow bits are west of Exeter ( Taunton, really ) - how much time woud HSR really save to Bristol given it's about 90 mins with stops already? and especially journey times to Taunton? going to beat going via Westbury?

Exeter is attempting to grow to 200k pop ( plus all of East Devon ) & Plymouth to 300k, the current infrastructure is going to get... well used, let's say. Certainly isn't 400kmh HSR population, but in future need of something modern which comes with a similar range of issues.

I've raised the idea of sending a line from Exeter-Taunton to OOC via Southampton before, it would provide a new route without going further out of the way than Bristol. Taunton-Bristol could probably be sped up relatively cheaply if there was any point, but given the perennial state of NE-SW services I'm not holding my breath for Brissle-Brum...

 

[24Grange]

One of the problems with Devon & Cornwall is the area always returns "safe " seats to westminster - so there is absolutely no incentive at all for politicians to "level up" the south west. Unlike the "red wall" in the north, which is very susceptible to brown trousered MP's worried about their seats. Cornwall is one of the most deprived areas of the EU, but the "grim up north" ex industrial areas get the majority of help because - well Cornwall is where you go for surfing and beaches , with your second home, so it can't be deprived can it. South west regional assembly would help - but its never going to happen

 

[gysev]

The German, Belgian and Dutch HSLs are virtually all new lines in the country linking to existing main urban stations.
New underground stations at Schiphol (NL) and Frankfurt (DE) airports were a focus for HSL routes and services.
Antwerp, like Lille, involved a deep tunnel under the city and a new underground HSL station.

That is not correct. Schiphol station (and the line to Amsterdam) was opened in 1978, decades before the start of the high-speed network.

In Belgium, HSL lines start well outside the cities:
- L1 to France starts at Lembeek, about 20 km south of Brussels. The existing line was improved (from 3 to 4 tracks).
- L2 (to Liège) begins after Leuven and rejoins the existing line at Ans, 6 km before Liège.
- L3 (to Aachen) begins in chenée (outside Liège) and rejoins the existing line at Hergenrath, well before the German border.
- L4 (to the Netherlands) begins in the northern suburbs of Antwerp
- Between Brussels and Antwerp, the existing line is used (160 km/h)
- The new tunnel in Antwerp is mostly used by local and regional services - there are no HSL platforms.

Lines 2 and 4 are also used by domestic services.

 

[Senex]

That is not correct. Schiphol station (and the line to Amsterdam) was opened in 1978, decades before the start of the high-speed network.

In Belgium, HSL lines start well outside the cities:
- L1 to France starts at Lembeek, about 20 km south of Brussels. The existing line was improved (from 3 to 4 tracks).
- L2 (to Liège) begins after Leuven and rejoins the existing line at Ans, 6 km before Liège.
- L3 (to Aachen) begins in chenée (outside Liège) and rejoins the existing line at Hergenrath, well before the German border.
- L4 (to the Netherlands) begins in the northern suburbs of Antwerp
- Between Brussels and Antwerp, the existing line is used (160 km/h)
- The new tunnel in Antwerp is mostly used by local and regional services - there are no HSL platforms.

Lines 2 and 4 are also used by domestic services.

True, but surely not quite fair to Infrabel given how much work they did on improving the existing lines out to the HSLs. From Brussels Midi to Lembeek the existing line was not just widened by the one track to 4 but was pretty well rebuilt. Line 2 does indeed begin after Leuven, but Midi to Leuven to create Line 36N was a massive civil engineering job, creating a completely new way out of Brussels Nord and then across the existing complex of lines, followed by quadrupling to just before Leuven and then the construction of a new and faster curve for the new route. Likewise with the line to the north. It diverges from the new Line 36N and is then the brand-new Line 25N until just before Mechelen. We've all read about the major works in both Liège and Antwerp, and there are big changes still in progress at Mechelen. Belgian railways set out their plans for high speed for the country some years ago and have steadily followed the plan through. Not perhaps as dramatic as some other places, but a real example of knowing what you want to do and getting it done—an example that doesn't perhaps get the attention and praise it deserves.

 

[nw1]

I've raised the idea of sending a line from Exeter-Taunton to OOC via Southampton before,

What would the idea of a route via Southampton be though? Surely the existing Berks and Hants route is already direct enough, and if there were to be a new HSL it would be better to parallel the Berks and Hants, which manages to find perhaps the best way through the high ground of Wessex between Reading and Exeter.

Trying to route via Southampton would mean somehow dodging the hilly country of West Dorset and Cranborne Chase, as well as the New Forest national park. Possible to find a route through the gap at Blandford I guess, but would be a very indirect and windy route.

== Doublepost prevention - post automatically merged: 14 Jul 2021 ==

Yep - the 10-12tph I quoted applies to the section between the Interconnection junction, and the Dijon chord (Bifurcation de Pasily).




When I plodded through the timetable, it seems to be those irregularly served Parkway stations that hamstring the whole timetable.

I.e. you have a neat standard hour service, except the hours those stops are made, when the time at Gare de Lyon is off-pattern as a result by departing earlier or arriving later (and thus, in effect, consuming two paths)

Interesting they do it by making the Gare de Lyon departure earlier, rather than the arrival at the destination station later. One would think there would be more constraints at the Paris end, so you'd want to keep a clockface pattern at Paris and have irregularities at the less busy 'country' end.

 

[edwin_m]

What would the idea of a route via Southampton be though? Surely the existing Berks and Hants route is already direct enough, and if there were to be a new HSL it would be better to parallel the Berks and Hants, which manages to find perhaps the best way through the high ground of Wessex between Reading and Exeter.

Trying to route via Southampton would mean somehow dodging the hilly country of West Dorset and Cranborne Chase, as well as the New Forest national park. Possible to find a route through the gap at Blandford I guess, but would be a very indirect and windy route.

I think the idea of going via Southampton is to try to link major population centres. Nowhere on or near the Berks and Hants line would justify at high speed stop on its own, so provision would probably be a single stop with drive-up access and hopefully rail connections via the existing line as well. Trying to pick up population further north ends up duplicating the GWML. I do agree trying to serve Southampton runs into some very difficult country.

 

[Irascible]

One of the problems with Devon & Cornwall is the area always returns "safe " seats to westminster - so there is absolutely no incentive at all for politicians to "level up" the south west. Unlike the "red wall" in the north, which is very susceptible to brown trousered MP's worried about their seats. Cornwall is one of the most deprived areas of the EU, but the "grim up north" ex industrial areas get the majority of help because - well Cornwall is where you go for surfing and beaches , with your second home, so it can't be deprived can it. South west regional assembly would help - but its never going to happen

Exeter and Plymouth are generally Labour, but yes between farmers always voting blue, the second home plague, the number of retirees and the gerrymandering it's generally not going to worry anyone. Devon & Cornwall could do with an official regional body perhaps but I'm not sure it'd make any difference at all. Plenty of deprivation in Devon too :/ I'm just a little concerned that west of Exeter is going to get left behind - it's not a great trip round Dartmoor to Plymouth no matter which method you use, really. If only the GWR really had built their new route...

What would the idea of a route via Southampton be though? Surely the existing Berks and Hants route is already direct enough, and if there were to be a new HSL it would be better to parallel the Berks and Hants, which manages to find perhaps the best way through the high ground of Wessex between Reading and Exeter.

Trying to route via Southampton would mean somehow dodging the hilly country of West Dorset and Cranborne Chase, as well as the New Forest national park. Possible to find a route through the gap at Blandford I guess, but would be a very indirect and windy route.

AIUI there is a fair amount of traffic from the SW to the south coast, plus it's a vastly bigger population centre there than the only notable settlements on the B&H - and it really isn't that out of the way. If I'm scribbling I'd look at Taunton-somewhere around Yeovil/Sherborne/-going around south of Cranborne AONB and then I get stuck in the New Forest, but I don't have a geological map to really look at it ( nor do I make any claims to be a civil engineer ). To be fair given HS2 environmental complaints I hate to imagine the New Forest - I guess you could go round the top without adding that much mileage. I think there is maybe room to discuss slightly-less-HSR for situations like this, where the distances don't favour 400kmh builds but the same technology ( high power, modern planning & construction, even larger gauge ) and a good chunk of the same costs would make a big difference to the transport situation.

If you're doing HSR via a pure GW route then surely OOC-Bristol-Taunton-keep going is the sensible one, that way you get Bristol & S.Wales on the way.

 

[nw1]

Exeter and Plymouth are generally Labour, but yes between farmers always voting blue, the second home plague, the number of retirees and the gerrymandering it's generally not going to worry anyone. Devon & Cornwall could do with an official regional body perhaps but I'm not sure it'd make any difference at all. Plenty of deprivation in Devon too :/ I'm just a little concerned that west of Exeter is going to get left behind - it's not a great trip round Dartmoor to Plymouth no matter which method you use, really. If only the GWR really had built their new route...

Though to be fair the rural South West's tendency to vote Tory seems to have only manifested since 2015, and has played quite a significant part in the election results since that date. Before that the Lib Dems had a very significant presence in the region. Unlike the 'red wall' there seems to be little analysis of the rightwards movement of much of the South West in recent years.

AIUI there is a fair amount of traffic from the SW to the south coast, plus it's a vastly bigger population centre there than the only notable settlements on the B&H - and it really isn't that out of the way. If I'm scribbling I'd look at Taunton-somewhere around Yeovil/Sherborne/-going around south of Cranborne AONB and then I get stuck in the New Forest, but I don't have a geological map to really look at it ( nor do I make any claims to be a civil engineer ). To be fair given HS2 environmental complaints I hate to imagine the New Forest - I guess you could go round the top without adding that much mileage. I think there is maybe room to discuss slightly-less-HSR for situations like this, where the distances don't favour 400kmh builds but the same technology ( high power, modern planning & construction, even larger gauge ) and a good chunk of the same costs would make a big difference to the transport situation.

If you're doing HSR via a pure GW route then surely OOC-Bristol-Taunton-keep going is the sensible one, that way you get Bristol & S.Wales on the way.

I would personally say there is far too much 'quality' countryside between Southampton and Exeter to make any high speed rail route viable without the route being rather indirect. Perhaps round the north of the New Forest would be semi-viable (something like Taunton-Ilminster-Yeovil-Sherborne-Blandford-Cranborne-Fordingbridge-Romsey) but you're still talking about quite a bit of locally-valuable quiet countryside... and at the end of the day would it really be worth it?

However, fair point about the B+H lack of population, was just thinking it of the quickest way to get to the far SW. But a via-Bristol route would make sense.

 

[Meerkat]

Though to be fair the rural South West's tendency to vote Tory seems to have only manifested since 2015, and has played quite a significant part in the election results since that date. Before that the Lib Dems had a very significant presence in the region. Unlike the 'red wall' there seems to be little analysis of the rightwards movement of much of the South West in recent years.



I would personally say there is far too much 'quality' countryside between Southampton and Exeter to make any high speed rail route viable without the route being rather indirect. Perhaps round the north of the New Forest would be semi-viable (something like Taunton-Ilminster-Yeovil-Sherborne-Blandford-Cranborne-Fordingbridge-Romsey) but you're still talking about quite a bit of locally-valuable quiet countryside... and at the end of the day would it really be worth it?

However, fair point about the B+H lack of population, was just thinking it of the quickest way to get to the far SW. But a via-Bristol route would make sense.

Wouldn’t it be better just to four track more of Didcot to Swindon and use ECTS to get 140mph on the long straight bits, and build a new line from Yate to Parkway for segregation?
For the far west concentrate on upgrades/ new line to make Newton Abbot to Plymouth maybe 125mph.
IMO the distance to Wales isn’t really worth full HS, and the South West isn’t enough of a market, but both deserve ‘old’ HS - ie 125-140mph. But that is really a result of HS being really expensive here rather answering the original question as to why, though it does indirectly do that by thinking about how much stuff is in the way of nice direct full fat HS lines!

 

[Irascible]

Though to be fair the rural South West's tendency to vote Tory seems to have only manifested since 2015, and has played quite a significant part in the election results since that date. Before that the Lib Dems had a very significant presence in the region. Unlike the 'red wall' there seems to be little analysis of the rightwards movement of much of the South West in recent years.

Local government voting tends to be quite interesting & much more varied, and definitely not a guaranteed Tory win - unfortunately that does nothing for parliament! it's not just the SW that's voted blue in recent years though, you can expect a swing back again IMO.

I would personally say there is far too much 'quality' countryside between Southampton and Exeter to make any high speed rail route viable without the route being rather indirect. Perhaps round the north of the New Forest would be semi-viable (something like Taunton-Ilminster-Yeovil-Sherborne-Blandford-Cranborne-Fordingbridge-Romsey) but you're still talking about quite a bit of locally-valuable quiet countryside... and at the end of the day would it really be worth it?

Taunton-Southampton avoids one large block of AONBs at least. "Is it worth it" is not something I can answer & I doubt anyone could without a major survey! but I looked at it with the idea of seeing if a new route could offer something the current ones don't. Full HS2-spec HSR into the SW is not currently worth it full stop, but even a slower new line which can meander a little more is going to have similar sources of costs & challenges ( which is what the original question of the thread was, why is that? ). There's also an interesting question to answer in how do you plan a route through difficult ( in both geological and social terms ) countryside when you can't sensibly tunnel.

 

[HSTEd]

An HS line all the way to Plymouth is unlikely, but an HS line that benefits Plymouth is entirely possible, in a fairly long time scale admittedly. A London - Bristol area high speed line could reasonably speed up train times and capacity to Devon and Cornwall, as well as to Bristol and South Wales. Ditto a new High Speed line from Bristol to Birmingham.

A high speed line all the way to West Cornwall could potentialy generate enormous additional traffic, as people who normally live in the south east and have holiday homes in the south west simply move down there.

All massve increases in tourism revenue from day trips - again reducing the requirement for holiday homes.

== Doublepost prevention - post automatically merged: 15 Jul 2021 ==

I would personally say there is far too much 'quality' countryside between Southampton and Exeter to make any high speed rail route viable without the route being rather indirect. Perhaps round the north of the New Forest would be semi-viable (something like Taunton-Ilminster-Yeovil-Sherborne-Blandford-Cranborne-Fordingbridge-Romsey) but you're still talking about quite a bit of locally-valuable quiet countryside... and at the end of the day would it really be worth it?

Or just tunnel under it?

 

[Bald Rick]

All massve increases in tourism revenue from day trips - again reducing the requirement for holiday homes.

How does that work?

 

[nw1]

How does that work?

I guess it's based on the theory that people will 'zip down' to Cornwall for the day rather than spend time there on holiday. But that rather negates the point of a holiday, which is being able to spend a significant amount of time out of your normal environment.

 

[HSTEd]

How does that work?

People currently spend hours and hours dragging themselves down to cornwall and thus it is not practical to go for short periods.

If you can reach Cornwall in a tiny fraction of this time, this dramatically reduces the shortest viable trip length.

People would go for the day, just like places like Skegness.

 

[zwk500]

People currently spend hours and hours dragging themselves down to cornwall and thus it is not practical to go for short periods.

If you can reach Cornwall in a tiny fraction of this time, this dramatically reduces the shortest viable trip length.

People would go for the day, just like places like Skegness.

What's the realistic HS journey time to the popular parts of Cornwall, given that it's c.400km with a ruler on a map from Central London to Penzance?

 

[HSTEd]

What's the realistic HS journey time to the popular parts of Cornwall, given that it's c.400km with a ruler on a map from Central London to Penzance?

Assume a terminus in the vicinity of Camborne [reasonably central for many of the popular destinations], and routing via Bristol - I make it roughly ~401km or so to OOC.

With non stop operation average speeds of around 300km/h are probably achievable.

Which would be about ~80 minutes.

A train stopping every ~30km or so could probably achieve about 170km/h average, for about 2hr20

 

[Mikey C]

People currently spend hours and hours dragging themselves down to cornwall and thus it is not practical to go for short periods.

If you can reach Cornwall in a tiny fraction of this time, this dramatically reduces the shortest viable trip length.

People would go for the day, just like places like Skegness.

It would still take ages to get to where they want to go though, as the roads to the coastal towns and villages are slow, twisty and hilly

 

[HSTEd]

It would still take ages to get to where they want to go though, as the roads to the coastal towns and villages are slow, twisty and hilly

I'm assuming if we are going to spend tens of billions of pounds on a line to the South West, we can spare some money for some improvements to transport there!

 

[24Grange]

A regional assembly may vote for a 8 lane motorway from Exeter to Penzance instead, which could be more useful.

Re the title of this thread, one of the reasons I think is the need to " gold plate" everything - design in every eventuality and also the thought that it is the designers " career best" project, so that they design it with every single "bell & whistle" they can think of, just in case its needed. Similar thing happened to the design of the 2 aircraft carriers, which pushed the price up.

 

[Bald Rick]

People currently spend hours and hours dragging themselves down to cornwall and thus it is not practical to go for short periods.

If you can reach Cornwall in a tiny fraction of this time, this dramatically reduces the shortest viable trip length.

People would go for the day, just like places like Skegness.

Skegness is one town. Like Brighton, or Bournemouth, or Blackpool.

Cornwall is a county, with dozens of holiday towns. Bude, Padstow, Newquay, Perranporth, St Ives, Porthleven, Falmouth, St Austell, Mevagissey, Looe, and more. Which part of Cornwall would your line serve for these day trippers?

 

[zwk500]

Re the title of this thread, one of the reasons I think is the need to " gold plate" everything - design in every eventuality and also the thought that it is the designers " career best" project, so that they design it with every single "bell & whistle" they can think of, just in case its needed.

This isn't how it works. The designers design to the spec they are given. If something is included that wasn't on the spec, they'll be asked to justfiy why the additional money needs to be spent. If they can't do so, they'll be told to get rid of it.

Similar thing happened to the design of the 2 aircraft carriers, which pushed the price up.

The principal cause in the cost rise for the Aircraft carriers was the Prime Minister of the time changing his mind to include CATOBAR equipment for better integration with the US Navy, then changing his mind back to Ski-Jump STO/VL when he saw the cost of the changes.

 

[Geoff DC]

A high speed line all the way to West Cornwall could potentialy generate enormous additional traffic, as people who normally live in the south east and have holiday homes in the south west simply move down there.

All massve increases in tourism revenue from day trips - again reducing the requirement for holiday homes.

If you did that you would need to invest in supporting infrastructure that already groans under the massive increase in population during Visitor Season.
For example, another hospital is already desperately needed to cope with the numbers, and getting an ambulance when you need one is often impossible due to the numbers queuing at the one and only A&E in Truro.

 

[Jozhua]

A regional assembly may vote for a 8 lane motorway from Exeter to Penzance instead, which could be more useful.

Re the title of this thread, one of the reasons I think is the need to " gold plate" everything - design in every eventuality and also the thought that it is the designers " career best" project, so that they design it with every single "bell & whistle" they can think of, just in case its needed. Similar thing happened to the design of the 2 aircraft carriers, which pushed the price up.

8-lane motorways have similar or less capacity to a high speed rail line approximately the width of an A-road, cause more congestion on local roads and are contrary to our environmental goals both in terms of local and climate impacts.

"Gold Plating" isn't really a great way of putting what is happening - firstly IRL gold plating doesn't cost that much because the sheets of material used are very thin. I agree with zwk500's assessment that it is simply designed to the specification given. Indeed combining both northbound routes in to a single line southbound from Birmingham will save a lot of money, alongside improving connections other than simply North-South, such as on cross-country.

Now you can talk about construction costs, methodology and general transport strategy, but the actual drawn up plans for HS2 are the cheapest way of delivering this level of service improvement. The key issue is the general management of contracts and supply chains involved in the construction process, which would mostly be the government's fault.

 

[Ianno87]

Assume a terminus in the vicinity of Camborne [reasonably central for many of the popular destinations], and routing via Bristol - I make it roughly ~401km or so to OOC.

With non stop operation average speeds of around 300km/h are probably achievable.

Which would be about ~80 minutes.

A train stopping every ~30km or so could probably achieve about 170km/h average, for about 2hr20

Why would Londoners do that when, for a fraction if the fare and time they can visit multitude of nearer seaside resorts?

The market you're aiming for doth not butter no business case.