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Washout at Dawlish


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I noticed containers are also being used in the Levels to counter the erosion caused by the outflow from the Dutch pumps.  Standard technique, great minds, or has NR hit on something with wider use? 

 

This reminded me of gabions and Hesco bastions, which when I looked the latter up for a web reference - http://en.wikipedia.org/wiki/Hesco_bastion - I found were originally used for emergency flood defences before seeing military use. They would be more easily transportable than containers and sound as if they might be useful in Somerset but looking at the recent pictures of Dawlish and how much damage the containers have suffered, I guess they'd not be of much use there. Has any RMWebber had experience of using them (for 'flooding control')? 

 

Typo! 

Edited by The White Rabbit
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Like the out-of-the-box thinking. :yes: However, although theoretically it should work, in practice it's far too dangerous, too disruptive both on construction as well as daily use and most of all, too costly. So, not gonna happen :no:

 

costly yes, disruptive yes, dangerous cant see why. steel grid on the track, maybe even just between the rails. safe to walk on and people wouldnt see the water.

 

post-27-0-32168700-1392674794.jpg

 

refinement of the idea for added strength, its basically a bridge over a storm drain.

I realise its not going to be done, but I think Brunel would have liked it :)

 

post-27-0-41851200-1392675093.jpg

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costly yes, disruptive yes, dangerous cant see why. steel grid on the track, maybe even just between the rails. safe to walk on and people wouldnt see the water.

 

attachicon.giftrack5.jpg

 

refinement of the idea for added strength, its basically a bridge over a storm drain.

I realise its not going to be done, but I think Brunel would have liked it :)

 

attachicon.giffff (1).JPG

 

The refined idea it not much better than the existing set up because you're relying on the seawall to support the track, so when the wall fails the track bed collapses with it! With your original design the issue you that you run into is that when the wall fails it can collapse back into the plies supporting the track slab potentially damaging them, backfilling around the piles supporting the track slab prevents that.

 

Regards,

 

Jack

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I also like to see "different" thinking but can't help wondering how the poor residents might feel - having come within less than a whisker of having their homes washed away - about having water permanently closer to their doorsteps.  The sea wall in all its solidness over many years has (until now) held back those waves and prevented the erosion we now see only too clearly.

I agree Rick,

 

Unfortunately no matter how much time or money NR spend on the sea wall, they will never beat nature. I'm sorry but It will happen again and again.

 

Coastal erosion is on going, and is It's been happening here for years, destroying coastal homes, and forcing coastal residents in Hawkes Bay who face the force of the Pacific Ocean's easterly gales in winter, to build their own sea wall as protection, because our local council will no longer repair or replace sea walls to stop coastal erosion, instead it operates what it calls "a managed retreat" for residents along the coast.

 

Then if they are the same as here, soon the insurance companies will refuse to re-insure the coastal homes.

 

I feel so sorry for the residents of Dawlish.

 

Bazza

Edited by bazza.
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The engineers are not saying they can beat nature.the repairs are only going to be as strong as its weakest link.any missed fractures flaws openings what have you along that sea wall will be picked at by the sea like a scab.prey tel we dont see storms like this for 10 or 20 years.

I wonder if a new design of wall might help?

Ive seen some sea walls that rise up into a concave shape.excluding any possible lateral loads from passing trains a traditional vertical wall be taking high loads directly against its face from the sea constantly pummelling the stonework during storms.

A concrete formed wall that deflects wave power back out to sea or dissipates it into the air could be one alternative approach.

Edited by ThaneofFife
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A new wall to modern design could take the worst of the sting out of big waves (e.g the concave profile mentioned by ThaneofFife). However, traffic will always be stopped occasionally when waves are crashing over the top of it.

 

I just hope that such a design is on the agenda rather than just a beefed-up renewal of what was there before which will ultimately suffer the same fate. The houses and roads behind the wall would also be much safer if such a wall were a metre or so higher but I doubt that will happen due to cost and tourism considerations.  

 

Another point is that, unless the current repairs are the beginnings of a proper rebuild of the entire wall to a more storm-resistant design, further sections will be torn apart when similar extreme conditions recur.  

 

Any truly effective long-term solution will be certain to change the appearance of the seafront which may not be to the liking of those who visit the area at more benign times of the year.

 

John

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A new wall to modern design could take the worst of the sting out of big waves (e.g the concave profile mentioned by ThaneofFife). However, traffic will always be stopped occasionally when waves are crashing over the top of it.

 

I just hope that such a design is on the agenda rather than just a beefed-up renewal of what was there before which will ultimately suffer the same fate. The houses and roads behind the wall would also be much safer if such a wall were a metre or so higher but I doubt that will happen due to cost and tourism considerations.  

 

Another point is that, unless the current repairs are the beginnings of a proper rebuild of the entire wall to a more storm-resistant design, further sections will be torn apart when similar extreme conditions recur.  

 

Any truly effective long-term solution will be certain to change the appearance of the seafront which may not be to the liking of those who visit the area at more benign times of the year.

 

John

 

I suspect that this was probably the weakest section of the wall, owing to the lower footpath at this point (so the wall itself isn't as thick) and possibly outward thrust on the wall from the weight of the buildings behind it.

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The engineers are not saying they can beat nature.the repairs are only going to be as strong as its weakest link.any missed fractures flaws openings what have you along that sea wall will be picked at by the sea like a scab.prey tel we dont see storms like this for 10 or 20 years.

I wonder if a new design of wall might help?

Ive seen some sea walls that rise up into a concave shape.excluding any possible lateral loads from passing trains a traditional vertical wall be taking high loads directly against its face from the sea constantly pummelling the stonework during storms.

A concrete formed wall that deflects wave power back out to sea or dissipates it into the air could be one alternative approach.

Hi

 

The sea defences in Mablethorpe used to be like this but now they have banked the sand up to nearly the top as its claimed that the sand can reduce the energy of the waves.

 

Cheers

 

Paul

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You can never beat Nature to be sure, but you can sometimes 'bat out a draw' (to use a cricket analogy).

 

Yes, but to use another cricket analogy, batting against Mother Nature is a Timeless Test, but there will be a winner eventually, and I think I know who that will be.

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When are we going to see the service restored between Exeter & Dawlish warren, and Dawlish or Teignmouth and Newton Abbot, perhaps on a single line token basis?

 

Earlier in the thread (a lot of pages ago now) Captain Kernow said that they were working towards getting the line open to Teignmouth. Around the same time someone else suggested running a shuttle to Dawlish Warren, however Dawlish Warren is/was being used as an access point for the works which would make any timetabling for a service to here challenging.

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A concrete formed wall that deflects wave power back out to sea or dissipates it into the air could be one alternative approach.

 

A new wall to modern design could take the worst of the sting out of big waves (e.g the concave profile mentioned by ThaneofFife). However, traffic will always be stopped occasionally when waves are crashing over the top of it.

 

 

Any truly effective long-term solution will be certain to change the appearance of the seafront which may not be to the liking of those who visit the area at more benign times of the year.

 

 

 

This was done in Burnham on Sea after the the 1981 storms caused massive damage to the sea front .

 

Lots of photos here showing old and new , plus a lot that are not so relevant , I cant take out individual

photo's due to copyright .

 

 

https://www.google.com/search?q=new+sea+wall+site:burnham-on-sea.com&source=lnms&tbm=isch&sa=X&ei=PoYDU6b-JuuA7QbWxIDYBw&ved=0CAkQ_AUoAQ&biw=1267&bih=829&dpr=1

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This was done in Burnham on Sea after the the 1981 storms caused massive damage to the sea front .

 

Lots of photos here showing old and new , plus a lot that are not so relevant , I cant take out individual

photo's due to copyright .

 

 

https://www.google.com/search?q=new+sea+wall+site:burnham-on-sea.com&source=lnms&tbm=isch&sa=X&ei=PoYDU6b-JuuA7QbWxIDYBw&ved=0CAkQ_AUoAQ&biw=1267&bih=829&dpr=1

If it is intended to provide something that can stand-up to this year's battering then I would suggest some form of rock armour is going to be needed.

 

The problem with reflective walls is that they can be undermined quite easily. You need to de-energise the waves before they reach the sea wall.

Edited by meil
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When are we going to see the service restored between Exeter & Dawlish warren, and Dawlish or Teignmouth and Newton Abbot, perhaps on a single line token basis?

The latest media reports are that NR were working towards reopening in time for Easter, but that may have gone down the pan after the further damage last Friday.

 

SS

 

edit. To get rid of spurious capitals.

Edited by Siberian Snooper
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The NOAA Atlantic 48 hour forecast chart continues to updated everyday:

 

http://www.opc.ncep.noaa.gov/shtml/qdtm86bw.gif

 

 

 

Best, Pete.

If the lows track in a Northerly or NNE direction as arrowed on the map then there's a good change the highs will track just to the south of us giving us a decent bit of weather which will help all tbe trouble spots here and the good folk working on them.

 

I have everything crossed.

 

SS

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I think that we should take the information from the Network rail website http://www.networkrail.co.uk/timetables-and-travel/storm-damage/dawlish/ rather than relying on media reports or speculation.

 

Or CK or Gary H. 

 

(Thankyou both for posting photos and updates about the damage and repairs. Stay safe). 

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