HS3 Paddington to Newport

[Shrop]

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.

Thanks for this, it's the second point I hadn't realised about, ie the total separation from other services. Would this ever be likely in the UK though? I mean, I remember thinking how good it was when we got HS1 out of St.Pancras, which I thought would benefit from being separated from other services, yet very quickly our British thinking was all about compromise, ie. "here's a new railway, let's put some extra trains on to it", and internal services to Kent started using it.
In truth I don't think that's turned out too badly as Eurostars generally run pretty well to time, but compared to Japan, the puctuality of UK trains is dire, which I firmly believe is a cultural thing. But that's getting off the point.

 

[Sad Sprinter]

Thanks for this, it's the second point I hadn't realised about, ie the total separation from other services. Would this ever be likely in the UK though? I mean, I remember thinking how good it was when we got HS1 out of St.Pancras, which I thought would benefit from being separated from other services, yet very quickly our British thinking was all about compromise, ie. "here's a new railway, let's put some extra trains on to it", and internal services to Kent started using it.
In truth I don't think that's turned out too badly as Eurostars generally run pretty well to time, but compared to Japan, the puctuality of UK trains is dire, which I firmly believe is a cultural thing. But that's getting off the point.

HS1 is very much a British way of building a high-speed railway. If we were doing HS2 that way, we'd probably:

1. Start the line at an existing Victorian termini and send the existing services elsewhere
2. Run the line with a few more parkway stations en route
3. Have Javelin style trains to Oxford and Milton Keynes
4. Freight loops
5. Terminate the line at Manchester Central

You basically have a new "railway", just a really fast one.

 

[HSTEd]

HS1 is very much a British way of building a high-speed railway. If we were doing HS2 that way, we'd probably:

1. Start the line at an existing Victorian termini and send the existing services elsewhere
2. Run the line with a few more parkway stations en route
3. Have Javelin style trains to Oxford and Milton Keynes
4. Freight loops
5. Terminate the line at Manchester Central

You basically have a new "railway", just a really fast one.

Of course the freight loops would be almost never used!
I think HS1 probably only had them because the siren call of loading gauge advantages, which probably don't apply on the GWML corridor, where almost all the traffic will be aggregates anyway.
Unless you wanted to try and get double stack containers through or something.

Not sure the stations would be necessarily "parkways" - Ashford and Stratford aren't really, at least in the conventional sense.
But fundamentally I agree that HS1 is a superior approach to a HS2 model, although I prefer to go further to the Shinkansen myself.

 

[Sad Sprinter]

Of course the freight loops would be almost never used!
I think HS1 probably only had them because the siren call of loading gauge advantages, which probably don't apply on the GWML corridor, where almost all the traffic will be aggregates anyway.
Unless you wanted to try and get double stack containers through or something.

Not sure the stations would be necessarily "parkways" - Ashford and Stratford aren't really, at least in the conventional sense.
But fundamentally I agree that HS1 is a superior approach to a HS2 model, although I prefer to go further to the Shinkansen myself.

OK sure, there'd be more railheads for sure. At Bicester probably, assuming it went via the M40 which is what would probably happen. Despite the M40 being a less optimal alignment, I wonder whether going via a Heathrow Hub station would have outweighed the slower linespeed via the M40 route due to the potential connections to the SWML system via the Heathrow Southern Rail Link.

 

[Envoy]

If in the future, they were to build a high speed line between London & south Wales, presumably that would involve a new Severn Crossing. It seems to me that it would make sense to build a tidal barrage about 3 miles downstream of the M4 bridge and as well as carrying a new rail crossing, it could generate electricity from the flow of the tides.

I note that there are proposals to build solar farms on the Gwent Levels east of Newport. If these are built, they would be on the route of any new high speed railway.

Funny how the Welsh Government ruled out the desperately needed new M4 south of Newport on the grounds that it would destroy the environmentally sensitive levels yet have not ruled out solar farms that would also destroy this area.

The plans for a huge solar farm which would swamp Welsh village

Plans have been submitted for one of Wales’ largest solar farms to swamp the village of Bishton on the Gwent Levels in Newport

www.walesonline.co.uk

"The plans are happening against a backdrop of similar developments proposed on the levels at Magor Marsh, Redwick, and Wentlooge".

 

[The Planner]

If in the future, they were to build a high speed line between London & south Wales, presumably that would involve a new Severn Crossing. It seems to me that it would make sense to build a tidal barrage about 3 miles downstream of the M4 bridge and as well as carrying a new rail crossing, it could generate electricity from the flow of the tides.

I note that there are proposals to build solar farms on the Gwent Levels east of Newport. If these are built, they would be on the route of any new high speed railway.

Funny how the Welsh Government ruled out the desperately needed new M4 south of Newport on the grounds that it would destroy the environmentally sensitive levels yet have not ruled out solar farms that would also destroy this area.

The plans for a huge solar farm which would swamp Welsh village

Plans have been submitted for one of Wales’ largest solar farms to swamp the village of Bishton on the Gwent Levels in Newport

www.walesonline.co.uk

You mentioned this elsewhere today, considering there are no plans for a high speed link, let alone even a view on its route, its all a bit moot.

 

[Meerkat]

It seems to me that it would make sense to build a tidal barrage about 3 miles downstream of the M4 bridge and as well as carrying a new rail crossing

It can’t just trundle across the top as shipping locks would be needed.
How does a railway compare to lorries on the current bridges in terms of how often the wind would be a problem?

 

[Envoy]

It can’t just trundle across the top as shipping locks would be needed.
How does a railway compare to lorries on the current bridges in terms of how often the wind would be a problem?

Locks for large ships are not needed as this is upstream of the Portbury/Avonmouth docks.

Lorries are not impacted by cross winds on the M4 bridge due to wind deflectors on the sides of the bridge. The older M48 bridge does not have the wind defectors and therefore has better views.

 

[The Planner]

Locks for large ships are not needed as this is upstream of the Portbury/Avonmouth docks.

Lorries are not impacted by cross winds on the M4 bridge due to wind deflectors on the sides of the bridge. The older M48 bridge does not have the wind defectors and therefore has better views.

Does anything come out of Sharpness anymore?

 

[Nick Ashwell]

Does anything come out of Sharpness anymore?

Ships still go up that far yes, not many but they do.

 

[Meerkat]

Locks for large ships are not needed as this is upstream of the Portbury/Avonmouth docks.

Lorries are not impacted by cross winds on the M4 bridge due to wind deflectors on the sides of the bridge. The older M48 bridge does not have the wind defectors and therefore has better views.

Depends on your definition of large. There are docks higher upstream and a reduction in headroom will probably be opposed.