Potential solutions for rough seas at Dawlish e.g. enclose the line in a concrete tunnel

[R G NOW.]

Moderator note: Split from https://www.railforums.co.uk/threads/waves-smash-train-windows-at-dawlish.198525/

This now happens, why did the Victorians build the line in such a stupid place?. Having looked at google maps it appears they would have needed tunnels. Did they have this problem in their days with wind.

The permanent solution to this is to enclose the line in a concrete tunnel with stone walling on the road side to make it more attractive.

 

[MarkyT]

Moderator note: Split from https://www.railforums.co.uk/threads/waves-smash-train-windows-at-dawlish.198525/

This now happens, why did the Victorians build the line in such a stupid place?. Having looked at google maps it appears they would have needed tunnels. Did they have this problem in their days with wind.

The permanent solution to this is to enclose the line in a concrete tunnel with stone walling on the road side to make it more attractive.

The coastal line was fairly cheap to build compared to an inland route I expect. I understand there were also early proposals to get to Plymouth over Dartmoor using steep rope-worked inclines! The GWR had a plan in the 1930s to build an inland route mostly in tunnels between Exminster and Newton Abbot. They obtained powers and even bought some land, but WW2 intervened and BR then sold off the land, much of which was subsequently built over. NR no doubt looked at many options for the Dawlish-Teignmouth section before settling on the new offshore alignment that is proving so controversial among locals. The sea wall is being rebuilt and strengthened just to the west of Dawlish and is considered already resilient enough to the east and along the two estuaries.

 

[John Webb]

Don't forget that stretch of line was planned by Brunel to use his atmospheric railway system, and he wanted to keep the line level as much as he could. Unfortunately the materials of the day were not up to doing the job he hoped they would.

To enclose the line in a tunnel as suggested would be an even greater upset to the locals than NR's present proposals......

 

[60019]

Don't forget that stretch of line was planned by Brunel to use his atmospheric railway system, and he wanted to keep the line level as much as he could. Unfortunately the materials of the day were not up to doing the job he hoped they would.

To enclose the line in a tunnel as suggested would be an even greater upset to the locals than NR's present proposals......

Something like a Swiss avalanche shelter would probably be preferable for the locals further along where NR want to move the line away from the cliff across the beach. Where the line runs along the foot of the cliffs, walling it in might be acceptable if the wall were decorated, especially with stone facing, but that would obviously be even less popular than raising the sea wall in front of the towns unless they used something transparent.

 

[Peter Mugridge]

As far as I understand it, there will be a substantial avalanche shelter type construction adjacent to Parson's Tunnel, but it will be open on the seaward side specifically to allow rail passengers to continue to see the views.

 

[Meerkat]

As far as I understand it, there will be a substantial avalanche shelter type construction adjacent to Parson's Tunnel, but it will be open on the seaward side specifically to allow rail passengers to continue to see the views.

I would have thought being open was cheaper and less onerous on tunnel safety standards??

 

[MarkyT]

Don't forget that stretch of line was planned by Brunel to use his atmospheric railway system, and he wanted to keep the line level as much as he could. Unfortunately the materials of the day were not up to doing the job he hoped they would.

He also built the Devon banks beyond Newton Abbot which were among the steepest UK mainline gradients of all time, and they were initially intended for the atmospheric system, although the Totnes pumping station was never completed before the idea was abandoned.

To enclose the line in a tunnel as suggested would be an even greater upset to the locals than NR's present proposals......

Probably true. They are also worried about losing the wall as a heritage asset which, inevitably, will be hidden for a distance by the new extended railway 'shelf'. Their own alternative scheme envisages a reinforced prefabricated shelter structure over the railway supporting a regraded cliff slope above, but that might also require some changes to the existing wall to provide sufficient foundation strength for the structure columns as well.

A second round of public consultation is being held currently with revised proposals being exhibited at various venues around the area over the next few weeks. I'll try and get to one of these and will report any new info back here. Spotlight, the BBC local TV news programme, reported from the first show yesterday, which featured a large scale model illustrating the new offshore alignment built out over a shorter length than previously proposed, presumably value engineered in response to new risk assessments on the various parts of the cliff face, while addressing some of the concerns expressed by locals in the last consultation, particularly concerning the beach effects.

Documents Here
https://consultations.networkrail.c...-s-tunnel-to-teignmouth-resilience-project-2/

Parsons Tunnel to Teignmouth Resilience Project

To improve resilience of the railway we propose to move it away from the most potentially hazardous areas of the cliffs to allow us to undertake corrective measures in order to stabilise the cliffs. This will not only protect the railway for generations to come but also result in the creation of new amenities such as new and improved walking routes. Feedback from the public consultation in summer 2019 has helped inform the further development of our proposals and we want to hear the views of passengers, communities and businesses on these updated proposals.