Great Western Main Line should be upgraded to 140mph

[FGWHST43009]

I was going to suggest maybe replacing the original road bridge with a combination, given it's 57 years old, but now I see it's Grade 1 listed...

I wouldn't remove the old bridge, too iconic. Ideally the second bridge should've been built to easily allow the addition of rail tracks, cable stayed/viaduct bridges are better for trains than suspension bridges

 

[HSTEd]

If you are going to build a new Severn rail crossing would you necessarily build it near the existing one?

If you used the existing docks branch away from the four way junction you could launch the bridge from the docks area and cross directly to Newport.

Then the whole mass of track between Severn Tunnel Junction and Patchway could be abandoned. And the junction potentially simplified if Patchway is a stub it probably won't need connections directly to the Parkway or Docks directions.

 

[FGWHST43009]

If you are going to build a new Severn rail crossing would you necessarily build it near the existing one?

If you used the existing docks branch away from the four way junction you could launch the bridge from the docks area and cross directly to Newport.

Then the whole mass of track between Severn Tunnel Junction and Patchway could be abandoned.

A new crossing would be in addition to the existing crossing. It would help release capacity on the existing railway. The old tunnel would still be in use for the slower trains. Faster traffic would use the new crossing.

 

[HSTEd]

A new crossing would be in addition to the existing crossing. It would help release capacity on the existing railway. The old tunnel would still be in use for the slower trains. Faster traffic would use the new crossing.

If we are building a new crossing, especially if a bridge, the marginal cost of a third track on the bridge would be relatively minor. And the current tunnel is an operational nightmare given the signalling restrictions on it for safety reasons. 7000m signal section amongst other things. So even a two track bridge would be a dramatic improvement on it in capacity terms.

 

[The Planner]

If we are building a new crossing, especially if a bridge, the marginal cost of a third track on the bridge would be relatively minor. And the current tunnel is an operational nightmare given the signalling restrictions on it for safety reasons. 7000m signal section amongst other things. So even a two track bridge would be a dramatic improvement on it in capacity terms.

5½ minute headway through the tunnel for passenger trains, so 8 or 9 tph would be doable depending on how things land on either side. Freight is the killer as that is up to 8 minute headways.

 

[HSTEd]

5½ minute headway through the tunnel for passenger trains, so 8 or 9 tph would be doable depending on how things land on either side. Freight is the killer as that is up to 8 minute headways.

Are container trains considered to be dangerous goods trains given that they could potentially have almost anything in them?

If so, what impact does the pathing restrictions on dangerous good trains (no passing passenger trains) have?

 

[tomuk]

If not already suggested how about electrification down to whatley/merehead so the stone freights could be accelerated

 

[Irascible]

If you are going to build a new Severn rail crossing would you necessarily build it near the existing one?

If you used the existing docks branch away from the four way junction you could launch the bridge from the docks area and cross directly to Newport.

Then the whole mass of track between Severn Tunnel Junction and Patchway could be abandoned. And the junction potentially simplified if Patchway is a stub it probably won't need connections directly to the Parkway or Docks directions.

I think the residents of Severn Beach might have words although it'd just about miss them - and it's a nice idea, but also about twice as long (conservatively!) a bridge as going the other side of the original road bridge. The Patchway-river bank section would presumably have to be new anyway.

 

[FGWHST43009]

Could have just run down from Whiteball & gone straight to Tiverton town, and then down the Exe valley - other than a bit of a corner at Tiverton ( which would have got a station anyway ) it's fairly straight. It might have actually been a plan too but for objections from the local landowners ( don't quote me on this, that is from long distant memory of local history lessons ). IIRC the B&E originally looked at going to Tiverton & then Exeter via Crediton, which would have been quite some work...

I think most modern trains can ascend Whiteball without much hindrance. If anyone knows how fast trains achieve on that section please let me know. I'd say electrification would be best for the Berks and Hants, it's a bit curvy between Newbury and Pewsey as well as a few others but electric trains can accelerate quicker from these sections than diesel trains