HS3 Paddington to Newport

[HSTEd]

I'll address your first point here:

Let me give an example to show you that quicker intermediate stops on longer runs using spurs are possible. So westbound HSR trains stopping at Reading would leave the mainline at Winnersh Interchange on the M4, and follow a HSL standard spur on the A329(M)/A3290 to the mainline at Suttons Seeds/west end of Thames Valley Park, then into Reading station.

Approx. 4.84 miles of the 6.07 miles from the main HS3 line at Winnersh Interchange will be on HSL, leaving a mile and a quarter into the station. Is this going to have a massive impact on deceleration?

Modern high speed trains are capable of accelerating and decellerating extremely rapidly by the standards of the past. An N700S trainset has acceleration limited by wheelspin up to about 65mph! (And that has virtually all, or all axles motored).
It's also worth noting that pointwork will place limits on the diverging route's speed due to its design and construction. The precise value is not easily available to me at this time but it is much lower than the typical linepseed of a high speed line.

I admit the first section of the route west out of Reading would be lower speed, with the 60 limit at Southcote Junction, then 100 up to the westbound spur at the M4 overpass near Calcot and Theale. It would be approx. 5 miles from Reading station back up to the HS3 mainline at the approaches for M4 J12.

Reading to Theale station currently takes 6 mins on a Class 387, with the superior acceleration and slightly shorter distance to the HS3 mainline, this could be cut to 5 mins. Is around 15 mins for the stop at Reading and return to the HS3 mainline really a massive issue?

Yes, because almost all non-all-stop journeys on this high speed line will be well under an hour - because we will run out of country at that point.
There is only ~210-250km to Cardiff.
For comparison, the first rural "beet station" on the LGV Sud-Est (Le Creusot TGV) would end up somewhere west of Cardiff.

15 minutes is rather a lot in that environment.

As to your second point, I think it is prudent to point out that current passenger volumes to more far flung destinations are suppressed by price and time taken to reach key destinations.

For example, Bristol currently has an average of 55 coaches a day to London (according to Trainline), and even half of that total coach capacity would be an extra 1500 passengers a day. The Annual Average Daily Traffic (AADT) for sections of the M4 east of Bristol is around 30k a day, a large portion of that will be heading east towards the Thames Valley and London.

Viability of a HSR line has to rest on significant abstraction from other sources, and this would be no exception.

1500 coach passengers is not nothing, but its about 1.5 train loads per day.
And even 30k cars per day is going to be about 3 trains per hour, assuming they all switch. And obviously, they won't all switch.

It's a significant chunk, sure, but compared to the capacity of a modern high speed line, it's not that much.
The line is not going to be anything close to full on that basis, we have to get more traffic.

A HSR line through both Reading and Oxford towards the West Country and South Wales is impossible without taking an long detour. If you want additional capacity towards Oxford, the obvious and cheaper thing to do (as well as HS3 along the M4 corridor) would be reinstatement of 4 track, speed upgrades and electrification of the entire Chiltern Main Line, and the branch from Bicester to Oxford.

Firstly, the Chiltern Main line is a terrible substitute for a high speed connection at Oxford, it is inherently slow and connected to a tiny, crowded and poorly positioned london terminus.
Marylebone has appalling onward connections and I am skeptical it can truly take more trains. In any case, if a classic rail connecton is built for a high speed line at Reading - noone will want to run via Chiltern.

Secondly, the "long detour" I propose (Reading-Oxford-Swindon, as opposed to Reading-Swindon) nets out at about 20 25km, which a 300kph train would eat up in four five minutes.

EDIT: to correct the distance for the Oxford detour.

 

[Meerkat]

The pillars for the viaduct would be in the median as much as possible

If they are switching in and out of the median the structures will be huge, unsightly, expensive, and massively disruptive.

my tunnel through the Heathrow station starts at Heston services and ends at M4 Junction 5 in Langley

I thought this was a HS line? Your line seems to be very twisty.

I'm not convinced that a viaduct would be particularly visible from Osterley Park house, given that the treeline on the M4 boundary is quite high, but the option is there with.

It would be very visible from the park. And again….it’s very twisty for an HS line.

HSL standard spur on the A329(M)/A3290

The viaduct here and past Windsor/Slough would have to be really high to clear everything, particularly where the M4 is on an embankment. I think you are hugely wrong that the residents in the areas abutting the route will be shut up with the statement “you already have a motorway there”!
And you really need to look at Streetview for the M4 - in some areas the median is literally just a concrete wall. There is nowhere near enough space for the pillars for a railway (plus the significant protection to stop a lorry demolishing them….)

 

[cle]

I really think this is just a tunnelled express line to Reading with a stop at Heathrow Central or T5. It can then rejoin the GWML somewhere (Iver/Langley per WRATH, or maybe beyond Slough for capacity reasons) - and then the network continues as is.

Facts:
>Six tracks to Airport Junction or even Slough are needed far more than journey times
>Journey times to Cardiff and Bristol already came down through wiring (Bristol might see a shade more, via Bath?) - these are good for the distance
>Demand is to Reading, Oxford, Slough. And Hayes/Ealing/Maidenhead etc - plus Heathrow. This is the corridor.
>The only true long distance route is that to Penzance - which due to being on the B&H by iself, isn't viable for wires or higher speed. Stopping patterns and additional semi fast services are what improve this route.
> Due to OOC, journey times will go up a tiny bit. But connectivity will dissuade this. And if you're changing to EL, like many, it's quicker (e.g. going Bath to Liverpool St) - certainly the long distance segment will come up shorter as the last leg into Paddington will carry the padding!
> Demand isn't huge for Newport, Cardiff, Bristol Parkway - beyond what is already there. It's a good service right now. Bristol didn't warrant the 4tph - who gobbled those super-fasts? Well, Slough, Maidenhead and Twyford. Plus Didcot/Oxford on the path swap. All busier with the exception of BTM.
> These places all need better regional services. Cross-Severn links, EWR/Oxford links, more Bristol area services, more towards the South Coast, etc. London is well catered for

An actual high speed line isn't needed as the demand splits into branches too quickly, and getting to Exeter through Bristol quicker, is not really possible. Whicvh might have been a more compelling line to the South West, but this is really a E-W / M4 line in its core.

 

[Bald Rick]

Sometimes this forum is comedy gold!

1.) The pillars for the viaduct would be in the median as much as possible - I accept this won't be possible everywhere.

The M4 from Heathrow to the other side of Reading has a median barely wide enough for a lamp post, let alone viaduct pillars weighty enough to support a high speed line plus all the collision protection required to withstand a 44t truck hitting it at 60mph without causing any deflection of the structure.

 

[HSTEd]

An actual high speed line isn't needed as the demand splits into branches too quickly, and getting to Exeter through Bristol quicker, is not really possible. Whicvh might have been a more compelling line to the South West, but this is really a E-W / M4 line in its core.

Well if the train can make it from Reading to Bristol in less than ~45 minutes it would be competitive with the B&H route.
That would convert the rump B&H into something more along the lines of the West of England line I imagine.
A high speed line should be capable of that.

The biggest restriction on such an operation would be the lack of a high performance electrodiesel (at least one capable of more than 250kph anyway). Concentrating most London-South West England traffic via Bristol might boost your case for electrification, especially if it came with significant journey time savings.

Otherwise, I think a London-Heathrow-Reading-Oxford-Swindon-Bath-Bristol Shinkansen could serve the majority of the traffic. Even with stops it would still beat the regular Bristol service (if anyone is interested I will do the actual estimate).

 

[AlastairFraser]

I think myself and other posters have strongly differing views about the purpose and route of a HS3 route designed to relieve the GWML.

What is the point of spending billions and billions on a tunnel from London to Reading via Heathrow, when rail already takes a high percentage of the market share in this area, and it would just shift the bottleneck to the Reading-Didcot section of the GWML (which will be very expensive to expand on the current alignment)?
To achieve a profitable HSL along the M4 corridor or anywhere in close proximity, we need to target modal shift of as many passengers as possible from the West Country/South West/South Wales, and a line ending in Reading just won't do that.

 

[cle]

HSTEd: Otherwise, I think a London-Heathrow-Reading-Oxford-Swindon-Bath-Bristol Shinkansen could serve the majority of the traffic. Even with stops it would still beat the regular Bristol service (if anyone is interested I will do the actual estimate).

Even on the classic route to Exeter, un-improved? As I can't think improvements would be viable with the 1tph XC and the slow (Cardiff-Cornwall) and some locals.

Re the Shinkansen - I don't think the populations, the rail traffic and the distances are comparable.
Is that something that a OOC-Reading-Bath stopping pattern couldn't beat? Vs going via Oxford.

 

[Mr. SW]

Sometimes this forum is comedy gold!

It's insane.

I was brought up in West London and know places like Ealing, Southall, Osterley, Hounslow and Heston very well. And the GWML.

Putting the line on stilts along the M4?
What? What? What? What?

Look at this

OSTERLEY PARK, Non Civil Parish - 1000287 | Historic England

List entry 1000287. Grade II* Park and Garden: Osterley Park. May include summary, reasons for designation and history.

historicengland.org.uk

Historic England entry on Osterley Park.

Now read this about a house nearby.

Windmill Lane by The Aviary © Robin Webster

The Aviary, behind the brick wall, is one of the occasional residences of the Sultan of Brunei. This very powerful man seems to have prevailed on Google not to show any of this road by his property on Street View. Why he should be so sensitive is obscure, as all that can be seen is a high brick...

www.geograph.org.uk

You're not going to build anything near there!

An appreciation of the Geography, Topography and Geology of the area might not go amiss, too.

It is hard enough getting HS2 through the Chilterns...

 

[HSTEd]

Even on the classic route to Exeter, un-improved? As I can't think improvements would be viable with the 1tph XC and the slow (Cardiff-Cornwall) and some locals.

Assuming we can get a sufficiently high-performance electrodiesel, yes.
Reading to Exeter is about ~1hr43
Bristol to Exete ris about ~0hr57.

If a train can make it from Reading to Bristol in ~45 minutes then the via BRistol route would usurp the B&H.
Assuming of course, that a sufficiently high performance train can be built that can operate to Devonwall.

[As noted below that would probably be unachievable for a full-stopping Shinkansen, but if you drop even one or two stops you would manage it easily - and even with full stops the disadvantage would not be large.]

Re the Shinkansen - I don't think the populations, the rail traffic and the distances are comparable.
Is that something that a OOC-Reading-Bath stopping pattern couldn't beat? Vs going via Oxford.

I can't easily model Paddington to Old Oak Common because its such a short jump that there isn't really anything remotely comparable on the Shinkansen system that I know of.
In any case, since the classic train will have to stop there anyway we can just model it as Paddington and reduce the journey time by about ~2 minutes or so.

Old Oak Common - Heathrow would be ~7 minutes
1 minute dwell time
Heathrow-Reading would be ~12 minutes
1 minute dwell time
Reading-Oxford would be ~13 minutes
1 minute dwell time
Oxford-Swindon would be ~14 minutes
1 minute dwell time
Swindon-Bath would be ~15 minutes
1 mintue dwell time
Bath-Bristol would be ~7 minutes again

Total of ~73 minutes.

~75 minutes equivalent for today's Paddington journeys.
I'm not sure what today's fastest train Bristol TEmple Meads to Paddington is - but there don't seem to be many (if any) that get close to ~1hr15.

When you are capable of ~300kph and can accelerate like an N700S trainset, many things are possible.

EDIT:
If we assume a suitable high performance train can reach Exeter by whatever means, via Bristol and stopping at all these stations we'd be looking at ~2hr10. That appears to be comparable to the best Exeter trains today, with all the connectivity advantages of going via Bristol - and if we were able to drop some stops it would easily triumph.

 

[cle]

I don't think Swindon needs to be on such a route - it's very well served and would continue to be.

Paddington-OOC is similar to the short hops to Ueno or Shinagawa, useful to have that second call - here, especially if OOC has other dispersal options like LO added - Crossrail being shared of course. There is HS2 too.

I just can't see the money for this - or that any similar investment wouldn't trump something which served East Midlands-Sheffield-Leeds.

 

[AlastairFraser]

I don't think Swindon needs to be on such a route - it's very well served and would continue to be.

True, but the HS3 line needs to at least bypass it to reach South Wales or the West Country in a decent enough time to justify the investment.

 

[HSTEd]

I don't think Swindon needs to be on such a route - it's very well served and would continue to be.

I think we have to go where the traffic is, I don't think an urban centre of the scale of Swindon can simply be left on the table.

Paddington-OOC is similar to the short hops to Ueno or Shinagawa, useful to have that second call - here, especially if OOC has other dispersal options like LO added - Crossrail being shared of course. There is HS2 too.

It is way shorter than any of those, so I can't really model it.
The only section of Shinkansen with such a short station spacing is the Gala Yuzawa Line and that is literally a station built on the maintenance depot access line.

So it was never really built for passenger operations, so is not a great example.

EDIT:
I don't think a Shinkansen set would manage much better performance than an IEP between Paddington and Old Oak Common, so I decided to just estimate journey times to/from Old Oak Common and avoid the issue.

 

[The Ham]

I've previously suggested that HS Wales and West doesn't bother with a direct connection to Central London.

Rather, following the building of HS East Coast (with an outer London hub and a central London station) it would run to Old Oak Common before continuing to Stratford via the HS East Coast outer London hub.

This would provide interconnectivity between all four HS lines (HS1, HS2, HS East Coast and HS Wales and West). Whilst it slows down the connection to a Central London station it would give access to 3 (Paddington, Euston and wherever the HS East Coast goes to) as well as three Outer London hubs (with their ability to connect to other areas), as such there's a fair chance that a significant number of journeys would be faster than currently and very few actually more than a couple of minutes slower.

Further out, I'd have it serving Salisbury and radiating out from there (including to Southampton, to the B&H and to Wales, the latter would probably require some new track to get journey times down a bit too better the existing).

Basingstoke to much of London (other than Waterloo) would likely be faster via this route, so would free up capacity into Waterloo as well as well as meaning XC south of Basingstoke was almost pointless (due to the faster South Coast to Midlands and Northern journey times being faster with a change at Old Oak Common and the ability to run a more frequent service)

Depending on the route, you could create a spur to Reading (to continue to Oxford and Swindon so they still had fast services) and then convert the existing GWML between Reading and Paddington to an all stops railway.

2tph to Exeter (and beyond), splitting at Salisbury with each half servicing the WofE Line and the B&H
6tph to Bristol/Cardiff/Bath (maybe with some half services heading to Cheltenham)
4tph to Wessex, splitting at Salisbury with each half servicing Basingstoke and the South Coast

That would still allow capacity for 4tph to go to Reading with them splitting to serve Oxford and Swindon.

As well as one or two spare paths for other services if needed.

 

[Mgameing123]

I've previously suggested that HS Wales and West doesn't bother with a direct connection to Central London.

Rather, following the building of HS East Coast (with an outer London hub and a central London station) it would run to Old Oak Common before continuing to Stratford via the HS East Coast outer London hub.

This would provide interconnectivity between all four HS lines (HS1, HS2, HS East Coast and HS Wales and West). Whilst it slows down the connection to a Central London station it would give access to 3 (Paddington, Euston and wherever the HS East Coast goes to) as well as three Outer London hubs (with their ability to connect to other areas), as such there's a fair chance that a significant number of journeys would be faster than currently and very few actually more than a couple of minutes slower.

Further out, I'd have it serving Salisbury and radiating out from there (including to Southampton, to the B&H and to Wales, the latter would probably require some new track to get journey times down a bit too better the existing).

Basingstoke to much of London (other than Waterloo) would likely be faster via this route, so would free up capacity into Waterloo as well as well as meaning XC south of Basingstoke was almost pointless (due to the faster South Coast to Midlands and Northern journey times being faster with a change at Old Oak Common and the ability to run a more frequent service)

Depending on the route, you could create a spur to Reading (to continue to Oxford and Swindon so they still had fast services) and then convert the existing GWML between Reading and Paddington to an all stops railway.

2tph to Exeter (and beyond), splitting at Salisbury with each half servicing the WofE Line and the B&H
6tph to Bristol/Cardiff/Bath (maybe with some half services heading to Cheltenham)
4tph to Wessex, splitting at Salisbury with each half servicing Basingstoke and the South Coast

That would still allow capacity for 4tph to go to Reading with them splitting to serve Oxford and Swindon.

As well as one or two spare paths for other services if needed.

Im sorry but Reading still needs its direct trains to Wales & The West. It's a major hub for the current GWML.

== Doublepost prevention - post automatically merged: 17 Aug 2024 ==

Assuming we can get a sufficiently high-performance electrodiesel, yes.
Reading to Exeter is about ~1hr43
Bristol to Exete ris about ~0hr57.

If a train can make it from Reading to Bristol in ~45 minutes then the via BRistol route would usurp the B&H.
Assuming of course, that a sufficiently high performance train can be built that can operate to Devonwall.

[As noted below that would probably be unachievable for a full-stopping Shinkansen, but if you drop even one or two stops you would manage it easily - and even with full stops the disadvantage would not be large.]



I can't easily model Paddington to Old Oak Common because its such a short jump that there isn't really anything remotely comparable on the Shinkansen system that I know of.
In any case, since the classic train will have to stop there anyway we can just model it as Paddington and reduce the journey time by about ~2 minutes or so.

Old Oak Common - Heathrow would be ~7 minutes
1 minute dwell time
Heathrow-Reading would be ~12 minutes
1 minute dwell time
Reading-Oxford would be ~13 minutes
1 minute dwell time
Oxford-Swindon would be ~14 minutes
1 minute dwell time
Swindon-Bath would be ~15 minutes
1 mintue dwell time
Bath-Bristol would be ~7 minutes again

Total of ~73 minutes.

~75 minutes equivalent for today's Paddington journeys.
I'm not sure what today's fastest train Bristol TEmple Meads to Paddington is - but there don't seem to be many (if any) that get close to ~1hr15.

When you are capable of ~300kph and can accelerate like an N700S trainset, many things are possible.

EDIT:
If we assume a suitable high performance train can reach Exeter by whatever means, via Bristol and stopping at all these stations we'd be looking at ~2hr10. That appears to be comparable to the best Exeter trains today, with all the connectivity advantages of going via Bristol - and if we were able to drop some stops it would easily triumph.

Why does Oxford, Swindon & Bath need to be served? These stations can just be linked up using the tracks west of Reading or via some HS3 spurs that divert to the existing mainline. We shouldn't force people heading to Cardiff & Bristol to have to go via Swindon and Oxford. Its too long of a detour.

== Doublepost prevention - post automatically merged: 17 Aug 2024 ==

Blue is my idea (obviously the real thing won't be as straight as that) and red is your idea.

Assuming we can get a sufficiently high-performance electrodiesel, yes.
Reading to Exeter is about ~1hr43
Bristol to Exete ris about ~0hr57.

If a train can make it from Reading to Bristol in ~45 minutes then the via BRistol route would usurp the B&H.
Assuming of course, that a sufficiently high performance train can be built that can operate to Devonwall.

[As noted below that would probably be unachievable for a full-stopping Shinkansen, but if you drop even one or two stops you would manage it easily - and even with full stops the disadvantage would not be large.]



I can't easily model Paddington to Old Oak Common because its such a short jump that there isn't really anything remotely comparable on the Shinkansen system that I know of.
In any case, since the classic train will have to stop there anyway we can just model it as Paddington and reduce the journey time by about ~2 minutes or so.

Old Oak Common - Heathrow would be ~7 minutes
1 minute dwell time
Heathrow-Reading would be ~12 minutes
1 minute dwell time
Reading-Oxford would be ~13 minutes
1 minute dwell time
Oxford-Swindon would be ~14 minutes
1 minute dwell time
Swindon-Bath would be ~15 minutes
1 mintue dwell time
Bath-Bristol would be ~7 minutes again

Total of ~73 minutes.

~75 minutes equivalent for today's Paddington journeys.
I'm not sure what today's fastest train Bristol TEmple Meads to Paddington is - but there don't seem to be many (if any) that get close to ~1hr15.

When you are capable of ~300kph and can accelerate like an N700S trainset, many things are possible.

EDIT:
If we assume a suitable high performance train can reach Exeter by whatever means, via Bristol and stopping at all these stations we'd be looking at ~2hr10. That appears to be comparable to the best Exeter trains today, with all the connectivity advantages of going via Bristol - and if we were able to drop some stops it would easily triumph.

 

[HSTEd]

Why does Oxford, Swindon & Bath need to be served? These stations can just be linked up using the tracks west of Reading or via some HS3 spurs that divert to the existing mainline. We shouldn't force people heading to Cardiff & Bristol to have to go via Swindon and Oxford. Its too long of a detour.

== Doublepost prevention - post automatically merged: 17 Aug 2024 ==

View attachment 163798 Blue is my idea (obviously the real thing won't be as straight as that) and red is your idea.

Comparing a completely straight line from Reading to Bristol to a line through Oxford, Swindon and Bath, we get ~140km versus ~110km. So a net of around ~30km.
At a pedestrian 300kph that extra distance would be eaten up in six minutes if the trains ran non-stop, which we could do if the line isn't too crowded. Personally I think stops would be called for given that Oxford or Swindon are more heavily trafficked destinations than Bristol, Newport or Cardiff.

We also have to consider the lengths of these branches and how expensive they will be to build.
The one you have laid out from this straight line to the GWML at Didcot is ~17.5km alone.
The one from Swindon is ~20km again.

The one near Chippenham could be quite short, but the branch proposal will require significantly more track length to be built. This will raise costs.

Additionally, given how short the distances are here, any train that leaves the high speed line is going to be of little use beyond it. If a train goes to Bath it is probably not going to be popular with people in Bristol etc.
Which means we could end up running trains full of air (or artificially short trains) in order to get an attractive service frequency.

All in all, given that the dominant traffic centres are the likes of Reading, Oxford and Heathrow, I am not convinced the "branches" solution is particularly attractive, again considering just how fast we run out of country.

 

[Meerkat]

I’m curious how a east-west HS line is going to get across Oxford…….

 

[Mgameing123]

Comparing a completely straight line from Reading to Bristol to a line through Oxford, Swindon and Bath, we get ~140km versus ~110km. So a net of around ~30km.
At a pedestrian 300kph that extra distance would be eaten up in six minutes if the trains ran non-stop, which we could do if the line isn't too crowded. Personally I think stops would be called for given that Oxford or Swindon are more heavily trafficked destinations than Bristol, Newport or Cardiff.

We also have to consider the lengths of these branches and how expensive they will be to build.
The one you have laid out from this straight line to the GWML at Didcot is ~17.5km alone.
The one from Swindon is ~20km again.

The one near Chippenham could be quite short, but the branch proposal will quite significantly more track length to be built. This will raise costs.

Additionally, given how short the distances are here, any train that leaves the high speed line is going to be of little use beyond it. If a train goes to Bath it is probably not going to be popular with people in Bristol etc.
Which means we could end up running trains full of air (or artificially short trains) in order to get an attractive service frequency.

All in all, given that the dominate traffic centres are the likes of Reading, Oxford and Heathrow, I am not convinced the "branches" solution is particularly attractive, again considering just how fast we run out of country.

Well the main point of the proposal is to make the biggest cities of the Western country better connected together and with London of course. Demand wouldn’t be a problem if the UK actually cared about local transport outside of London.

 

[Meerkat]

Well the main point of the proposal is to make the biggest cities of the Western country better connected together and with London of course. Demand wouldn’t be a problem if the UK actually cared about local transport outside of London.

When questioned about viability blame London.
Its one of the rules of crayoning isn’t it!

 

[Topological]

I’m curious how a east-west HS line is going to get across Oxford…….

I was assuming an Oxford South station, somewhere between Radley and Kennington to allow the HS line to pass north of Abingdon. No idea on the precise land conditions, but it looks possible to provide sensible road access, an interchange with the existing line and to form a route East-West.

The big difference between the way I would build compared to @HSTEd route is that I would not serve Reading with the high speed line, instead building Heathrow as a terminus and then connecting with HS2 in the Colne Valley area (as planned for Heathrow). The HSGW line would then roughly follow the M40 to Oxford.

In my proposal Reading would continue to be served by non stop 80x from London. Trains to Gloucester/Hereford and along the B&H would still be 80x so should give Reading a solid service. I would also have Bristol Temple Meads via Bath as a 80x service too. Only Reading to South Wales would be disconnected. IF Oxford terminators became a thing on the HS line then one of the South Wales to London could leave HS near Swindon and continue through Reading.

I also would not build into Bristol itself. An expanded Parkway station just to the East would serve Bristol and the fast trains would continue straight on past Stoke Gifford rather than following the existing route to Severn Tunnel. A full metro connection would then serve Bristol Temple Meads.

 

[Meerkat]

I was assuming an Oxford South station, somewhere between Radley and Kennington to allow the HS line to pass north of Abingdon. No idea on the precise land conditions, but it looks possible to provide sensible road access, an interchange with the existing line and to form a route East-West.

The big difference between the way I would build compared to @HSTEd route is that I would not serve Reading with the high speed line, instead building Heathrow as a terminus and then connecting with HS2 in the Colne Valley area (as planned for Heathrow). The HSGW line would then roughly follow the M40 to Oxford.

In my proposal Reading would continue to be served by non stop 80x from London. Trains to Gloucester/Hereford and along the B&H would still be 80x so should give Reading a solid service. I would also have Bristol Temple Meads via Bath as a 80x service too. Only Reading to South Wales would be disconnected. IF Oxford terminators became a thing on the HS line then one of the South Wales to London could leave HS near Swindon and continue through Reading.

I also would not build into Bristol itself. An expanded Parkway station just to the East would serve Bristol and the fast trains would continue straight on past Stoke Gifford rather than following the existing route to Severn Tunnel. A full metro connection would then serve Bristol Temple Meads.

So only parkway stations, encouraging car use in a horribly congested area. If a HS line doesn’t go into central Oxford I’d it actually going to be any quicker than the current line?
You aren’t going to get a HS line through the Chilterns - one of the lessons of HS2.

 

[Topological]

So only parkway stations, encouraging car use in a horribly congested area. If a HS line doesn’t go into central Oxford I’d it actually going to be any quicker than the current line?
You aren’t going to get a HS line through the Chilterns - one of the lessons of HS2.

I would be stopping all but CrossCountry at the new station, though probably CrossCountry would end up calling as well. Extending services like EWR through as well. That should provide sufficient frequency to cover for Oxford HS station not being central.

Bristol likewise, a significantly enhanced connection would be offered.

But yes, these are parkway stations. Bristol near the M4/M32 and Oxford near the A34. Most people would benefit from driving to the station. Better that than drive all the way to London. Bristol Parkway already gets a lot of use in that function, as do Swindon and Didcot. I think it is good if the HS design reflects that. The land around these stations can also be used for high density development, solving the housing issues too.

YES there will be NIMBYs, but if we only explored options that pleased NIMBYs then very little would get done.

 

[HSTEd]

I’m curious how a east-west HS line is going to get across Oxford…….

Well if the line approaches from Reading it will be approaching the city along a very similar bearing to the existing railway.
North is more challenging, however it we design around the premise that all trains would stop at Oxford it would be possible to have a turn to the west immediately north of the station so that the line can bear on Swindon.

== Doublepost prevention - post automatically merged: 17 Aug 2024 ==

You aren’t going to get a HS line through the Chilterns - one of the lessons of HS2.

Unlike HS2, this line will provide tangible benefits to people near it by virtue of stopping at stations they might actually use.
I would anticipate somewhat less trouble as a result, although it would only add a couple of kilometres to just dogleg around the south end of the Chiltern National landscape in any case.

== Doublepost prevention - post automatically merged: 17 Aug 2024 ==

Well the main point of the proposal is to make the biggest cities of the Western country better connected together and with London of course. Demand wouldn’t be a problem if the UK actually cared about local transport outside of London.

Yes, and what better way to connect them together than to have a train that takes you to any of them at a high frequency?

6 trains per hour or more that stop at Cardiff, Newport, Bristol, Bath, Swindon, Oxford, Reading, Heathrow and London is quite attractive on that score! (Plus extas heading to the secondary destinations that leave the line partway along).
2 trains per hour to each is less so, even if the journeys are somewhat faster.

By amalgamating flows onto a single service we can dial the frequency sky high.

 

[The Ham]

Im sorry but Reading still needs its direct trains to Wales & The West. It's a major hub for the current GWML.

They can still have some direct services to Reading using the existing lines, however Reading would become less of a hub.

Starting from the GWML (west) working clockwise, you've got:

- Oxford, still would need a change at Reading, however could have a direct service which then goes to Cambridge via East West Rail
- London, would still be able to get there without using Reading
- Stops between Reading and London (including Heathrow), would need to change from the retained services (potentially along the B&H from Salisbury as well as a reduced service frequency along the GWML west) as they would become an all stops service between Reading and Paddington
- Line through Bracknell, as above
- Line to Guildford, as above or via Basingstoke and Woking
- Line to Basingstoke, change at Salisbury and Basingstoke if not using the retained services

The retained services would likely be quieter as the London bound travellers wouldn't be on them.

 

[Shrop]

HS3 to Paddington to Newport? Don't forget that it used to be possible to do this very journey every two hours in not much over 80 minutes almost 50 years ago when HSTs were first used. Faster than it's possible today even after the enormous costs of electrification. So beware of any thoughts of a fast route to Newport, it might just get hijacked by a perceived need to service all sorts of places en route, as a frequent service to intermediate places can trump the need for a fast end to end journey!

 

[Mgameing123]

HS3 to Paddington to Newport? Don't forget that it used to be possible to do this very journey every two hours in not much over 80 minutes almost 50 years ago when HSTs were first used. Faster than it's possible today even after the enormous costs of electrification. So beware of any thoughts of a fast route to Newport, it might just get hijacked by a perceived need to service all sorts of places en route, as a frequent service to intermediate places can trump the need for a fast end to end journey!

Well the reason why its proposed to be high speed is because it needs to call at multiple trip generators between Paddington & Newport. (Old Oak Common, Heathrow, Reading, Bristol).

 

[Shrop]

toWell the reason why its proposed to be high speed is because it needs to call at multiple trip generators between Paddington & Newport. (Old Oak Common, Heathrow, Reading, Bristol).

So not much benefit to passengers who want to get quickly from London to South Wales then? Okay, I understand about major calling points (although calling at both OOC AND Heathrow doesn't do much for high speed to anywhere), but would your scheme have any fast trains (ie non stop to Newport or perhaps calling only at Bristol) to South Wales?

 

[HSTEd]

So not much benefit to passengers who want to get quickly from London to South Wales then? Okay, I understand about major calling points (although calling at both OOC AND Heathrow doesn't do much for high speed to anywhere), but would your scheme have any fast trains (ie non stop to Newport or perhaps calling only at Bristol) to South Wales?

I am skeptical there is much point in non-stop trains, the journey distances are so short that the journey time advnatage from frequency may overcome speed related journey time advantages.

Going from half hourly to four-hourly reduces the average waiting time by 7.5 minutes and the worst case waiting time by 15 minutes.

If South Wales is faster than today and at higher frequency, I am not sure there would be much market left for the hastle of non stop trains that will almost inevitably not be full.
If a Shinkansen type route did reach Newport you'd be looking at ~85 minutes, several times per hour.

 

[Shrop]

I am skeptical there is much point in non-stop trains, the journey distances are so short that the journey time advnatage from frequency may overcome speed related journey time advantages.

Going from half hourly to four-hourly reduces the average waiting time by 7.5 minutes and the worst case waiting time by 15 minutes.

If South Wales is faster than today and at higher frequency, I am not sure there would be much market left for the hastle of non stop trains that will almost inevitably not be full.
If a Shinkansen type route did reach Newport you'd be looking at ~85 minutes, several times per hour.

It's an interesting point about having non-stop trains, but I believe it isn't properly tested. Okay, London to Newport presently has only 3 or 4 stops, but other routes (especially XC) have many more. It would be digressing to go into all of this here, but perhaps worthy of a new thread, which I may start some time.

As for Shinkansen, people refer to this a fair bit on this forum but I can't really find a good definition of it. I know it's a Japanese concept, but what is it other than a high speed railway?

 

[HSTEd]

As for Shinkansen, people refer to this a fair bit on this forum but I can't really find a good definition of it. I know it's a Japanese concept, but what is it other than a high speed railway?

Well Shinkansen are high speed trains in Japan (and also in Taiwan), they appear to have some operational characteristics that differ them from systems like those in France.

1. Large numbers of intermediate stations, with average station spacings being around 30-40km
2. Completely dedicated alignment, totally separated from conventional services.
3. Comparatively simple track layouts, for example the Tokaido Shinkansen terminates at Tokyo station with six platforms, the Tohoku Shinkansen with four

Whilst some "conventional" narrow gauge routes have been converted to small cross section standard gauge lines (the "Mini" Shinkansen lines), they are still pretty much entirely separated from conventional lines.
Indeed, in one case they've gone so far as to build standard gauge versions of conventional EMUs for local services on a converted line.
Not much dual gauge track at all (indeed the only long distance I know of is the linethrough the Seikan tunnel)

In the UK context, I would suggest it would be the stop spacings and dedicated infrastructure that would be the defining characteristics.
Whilst Shinkansen have mixed stopping patterns in Japan, given the short distance here, I'm not sure mixed stopping patterns are that useful.

For example, if the fastest service out of Tokyo on the Tokaido Shinkansen was on this route to Newport, it's first stop would be somewhere near Llanelli.

 

[Mgameing123]

So not much benefit to passengers who want to get quickly from London to South Wales then? Okay, I understand about major calling points (although calling at both OOC AND Heathrow doesn't do much for high speed to anywhere), but would your scheme have any fast trains (ie non stop to Newport or perhaps calling only at Bristol) to South Wales?

The main goal of HS3 is moving fast trains away from the GWML. It’s not about nonstop trains.