Washout at Dawlish

[Captain Kernow]

The cost to reinstate is largely irrelevant if the revenues stack up to pay for it. The planned Bere Alston to Tavistock reinstatement is being taken seriously so presumably the numbers work out for that - and that is only providing extra local services between Tavistock and Plymouth.

 

But unfortunately the revenues won't stack up to pay for the Southern route, if it's to be a purely local line for 51 weeks of the year and a diversionary route for only 1 week each year.

 

Tavistock will happen, I think, but again, subsidies are involved. Also, it is significant that no serious move has yet been made to reinstate regular weekday services from Exeter to Okehampton.

[Etched Pixels]

3- If the LSWR route were to be reopened and used as a diversionary route, I would feel much happier with the associated reversals, or even a change of trains, than I am with the idea of a substitute bus - if I want to use a bus I'll pay bus fares!

 

Big assumption is that they would bother. We have perfectly good diversionary routes here that involve a reverse and some hassle so FGW runs buses instead of diverting their trains. If there was an Tavistock diversion I imagine FGW would run busses instead of using it. So to "fix" the problem you've also got to fix the train operators.

 

Alan

[Captain Kernow]

It doesn't seem unreasonable that reinstating the remaining ?16 miles to Oakhampton could make financial sense when you take into account the revenue from extra local services, savings on road improvements and savings on lost revenue from occasional but catastrophic closures to the costal route.

I think the pay-back period would be far too long to satisfy even the most liberal of business cases. I know for a fact, from work sources, that a substantial amount would have to be spent on Meldon and Tavy viaducts, to bring them up to modern standards, and to run over them at a decent speed, to say nothing of the other missing structures on the closed section, purchasing the trackbed and old station areas that have been sold off and in the case of Tavistock itself, re-developed.

 

Only if the entire Dawlish - Teignmouth coast, to a width of (say) 100 yards disappeared into the sea, never to return, do I think that the inland route would attract a positive business case...!

[Vardnoodleblast]

Dawlish Breach: England Cut-Off 

 

Although I suspect the political interest in the Dawlish breach and a diversionary route will last until approximately one nanosecond after the next general election result, the debate on here is very interesting and it would be good to think that there would be a sensible review by NR of all options to redevelop the rail network through Devon and Cornwall.

 

I recall taking a daytime Penzance-Paddington HST some years ago and at some point en route in Cornwall, from my rear-facing seat, seeing the aft power car and most of the train out of the left hand side window squealing its way around a tight curve on bull-head rail. How that could be left unaddressed in an age where transit time determines commerciality? Look across the Channel to see the propagation of TGV service to their NW Atlantic Coast for example.   

 

I would agree that any putative investment in the ex-LSW route could not simply be on the basis as a diversionary option, so, let's look to a bigger vision for rail in and to the SW! Do a proper job of reinstating and improving the LSW route to Plymouth via Okehampton and extend the franchise to that large unused terminal facility at Waterloo. Yes, more re-instatement of double track on the Salisbury - Exeter road, but put the route back to doing the job it was created for. No reversals required!

 

That does not imply downgrade to the coastal route at all. Noting the fact that passenger journeys today exceed those of the pre-Beeching network and every re-opening seems to generate far more traffic than projected, one might think of it as creating more capacity in the Plymouth and east market.  Such a move could deliver significant economic stimulus and route options (how about a Dartmoor Circular service?). 

 

Noting comments from the SW business community about the projected cost of lost business resulting from the current closure, the cost-benefit analysis in favour is being set out by the hour and this situation has a very high probability of being repeated in years to come.

 

Good luck to the NR team taking care of the immediate problem. Awful conditions to be carrying out the task in.      

       

On an earlier post I saw the concept of a bailey type bridge being dismissed as an option. However, I recently saw just such a solution in use on Austrian Railways where a remote area, significant stone-arch under-bridge had collapsed and a steel span had been placed over the gap, overstepping the abutment walls by some way. On a subsequent visit the whole lot had been replaced by a new reinforced concrete bridge.  

 

Also, many moons ago while gainfully employed by the DCE Wimbledon, I recall we had large stocks of military trestling in reserve for just such events. This kit played a role in doing rapid repairs to blitzed bridges in WWII and I believe, some of it was still in place and functioning in the 70's. Different scenario to that in Devon though.    

[PenrithBeacon]

I think the time has come to build the inland route which has been bruited so often. The  effects of climate change are here, now and it's not going to get better.

 

Regards

[AngryMeerkat]

I'd love to hear the thoughts of the Captain and any other civil engineers on here regarding an idea I've had......

 

Concrete is a pretty solid material, and when used as a sea defence is prone to the force of the waves and the scrubbing effect of the water and anything solid within the water. Spraying a resin over the outside face of the concrete, and injecting resin at intervals along the length of a sea wall, will give it some added semi-flexible protection from those things. The internal resin will allow the concrete an amount of flex to absorb the power of the waves instead of just reflecting them, and the external resin would prevent the scrubbing of the concrete that weakens it. Topping up the resin coat would be easier than maintaining concrete, and the resin coating would fill any cracks therefore continually adding to the structural integrity of the wall.

 

I've touched on something similar in the past, using a polymer to prevent water ingress through a porous wall and this worked very well, a coat of 20 microns thickness lasted over 3 years when exposed to mid-European weather on a test building.

 

Mark

[Edwin_m]

Today's loss of all three of the rail routes across Somerset suggests another problem for the use of Okehampton-Tavistock as a diversionary route.  Had it been reopened or never closed, how likely is it that the exceptionally poor weather across the region would have blocked it as well? 

 

While I wish all success to those campaigning for Okehampton-Tavistock reopening, I fear its benefit as an emergency diversionary route is limited whether assessed as part of a business case or in purely strategic terms.  As others have suggested, closures of the coast route rarely last long enough to bring in an unplanned diversion of this length, and diversion via Okehampton cannot provide a satisfactory service for the significant populations served by the intermediate stations on the main line or by the Paignton branch. 

 

Having read all this discussion it seems to me to boil down to three issues:

 

(1) In the short term the sea wall line must be reinstated and continue to be maintained both as a railway and as a sea defence.  Maximum commendation to CK and his Network Rail colleagues!  

 

(2) Some study is needed of whether this event is truly rare or whether the effects of climate change (more storms and higher sea levels) make it increasingly likely.  If disruption and damage is predicted to reach unacceptable freqencies then either the wall needs to be improved while still carrying the railway, or the railway needs to be rebuilt further inland so the wall can be rebuilt higher/wider/better without the constraint of having to accomodate the railway.  The inland route should if possible provide stations at the "back" of Dawlish and Teignmouth. 

 

(3) Any Okehampton-Tavistock reopening needs to stand on its own merits.  Justification would be based on the benefits of providing a service to the towns it passes through, plus perhaps some small benefit as a planned diversionary route during blockades especially between Totnes and Plymouth. 

[The Stationmaster]

That'l be all the signal cables, signalling power supply cables, location cabinets totally screwed then!

Soul destroying.............

Regrettably yes - the signals themselves might survive as they're on concrete foundations in many cases but the location cupboards have clearly had it as have some of the track circuit units.  And there could well be unseen damage to the formation which will only come to light when the water recedes - and unlike Dawlish my initial impression here is that little can be done until the water has receded, definitely not the right conditions for renewing S&T kit and no use at all for assessing damage to the track and formation.

 

All in all a very nasty situation and one which to my knowledge hasn't occurred before in that vicinity aIthough we used to get flooding much further east in the cuitting at Flax Bourton.

[Vanders]

There's a decent picture of the work that's been done to stabilise the washout on the BBC right now.

[Rods_of_Revolution]

I'd love to hear the thoughts of the Captain and any other civil engineers on here regarding an idea I've had......

 

Concrete is a pretty solid material, and when used as a sea defence is prone to the force of the waves and the scrubbing effect of the water and anything solid within the water. Spraying a resin over the outside face of the concrete, and injecting resin at intervals along the length of a sea wall, will give it some added semi-flexible protection from those things. The internal resin will allow the concrete an amount of flex to absorb the power of the waves instead of just reflecting them, and the external resin would prevent the scrubbing of the concrete that weakens it. Topping up the resin coat would be easier than maintaining concrete, and the resin coating would fill any cracks therefore continually adding to the structural integrity of the wall.

 

I've touched on something similar in the past, using a polymer to prevent water ingress through a porous wall and this worked very well, a coat of 20 microns thickness lasted over 3 years when exposed to mid-European weather on a test building.

 

Mark

 

The wall at Dawlish is of an old design, a modern sea wall would probably not be constructed in such a manner. I don't know the particulars of the Dawlish wall but it looks to be vertical without any piles, vertical walls allow clapotic waves (which move vertically rather than horizontally) to form and cause heavy erosion at the base of the wall. These waves allow the wall to be undermined and collapse. 

 

Modern sea walls are curved with protection at the base, this prevents the wall being undermined and better distributes the forces of wave impact; it also prevents overtopping (water going over and beyond). The ideal solution would be to replace the sea wall with modern design. Failing that, I think having a steel reinforced slab concrete track bed supported on piles behind the existing wall would mean even if the wall was breached the track would remain in place and repairs would be much quicker and cheaper.

 

I know more about quays than sea walls but I've picked up a bit working in a marine engineering design office.

 

Cheers,

 

Jack

[TheSignalEngineer]

No, FGW ends up with a route which it can use when bad weather makes the Dawlish route impassible. No one has suggested that FGW be required to route all Plymouth services via Okehampton. Now you might argue whether it is worth it for the perhaps one week a year that it might be needed for that purpose, but the passengers may well find it preferable for their train to reverse on those occaisions.

 

At the moment, not having that backup option is also making the M4-M5-A30/A38 very attractive.

Any diversionary route is only as good as the availability of drivers with route knowledge. I am reminded of a possession I had which blocked Small Heath to Snow Hill in the early days of privatisation. Centro trains ran into New St, but Chiltern services stopped short at Leamington because they couldn't provide drivers with route knowledge via Coventry or St Andrews. To make the Okehampton line a viable emergency diversionary route FGW would need to run regular services that way, as was done in the 1960s when Southern Region men worked a daily service via the Dawlish line and vice versa Edited February 9, 2014 by TheSignalEngineer

[The Stationmaster]

I remain puzzled by the assumed advantages offered the LSW route were it to reopen.  True it would (might - if sufficient money is spent?) allow freight traffic to continue but I suspect for the majority of passengers it would be second choice if they were offered a rail replacement coach service from Tiverton Parkway because from there the running time to Plymouth station is only an hour - the coach would probably be past Exeter by the time the train had reached StDavids and made its way back to Cowley Bridge.  The train then faces just over 50 miles to run to Plymouth and is anybody seriously suggesting that a lightly used diversionary route will be able to offer a nett running time of an hour for that distance - plus whatever ever might be needed in the way of crossing time in order to pass trains coming the other way?  

 

It might well suit some people not to have the inconvenience of detraining and crossing the bridge at Tiverton Parkway but on the occasions I've experienced it the arrangements have worked well with no waiting to join a road coach at either end although the stion is not the best of places to wait when there are a couple of trainloads of passengers waiting for their trains eastwards and northwards. 

 

To achieve that 50+ mph average speed the train is going to have to spend a lot of its time going much faster and that means higher initial outlay on the formation and higher maintenance costs  - which i suggest might not stand up too well against comparative road vehicle hire costs.   And we're not just talking about a putative gap between Okehampton and a hefty demolition exercise at Tavistock - the track, formation and drainage throughout would have to be brought up to spec for something heavier than a two car dmu, it's additional expenditure right the way through for what - several weeks or weekends per annum.

 

If that sort of money would be involved it is probably more than reasonable to consider spending some more and getting an inland route round the back of Teignmouth and Dawlish (yes, back to what could be done with the 1936 scheme which would not only be an all weather route but could offer higher line speeds than any alternative).  And like the GWR I wouldn't see that alternative as a replacement for the coastal line (which already has some pathing problems) but supplemental to it.

 

But both inland schemes are going to be compared with the costs of future proofing the existing line and both would undoubtedly be far more expensive so I think we can guess the outcome.

[Etched Pixels]

Only if the entire Dawlish - Teignmouth coast, to a width of (say) 100 yards disappeared into the sea, never to return, do I think that the inland route would attract a positive business case...!

 

In a sense there is probably a positive business case because already its an expensive piece of line to maintain, and global warming won't make it get any cheaper. There is also significant work going to be needed by the 2030s anyway. Viewed in the long term there is probably already a business case for moving the line inland (as opposed to via Tavistock) simply because that will cut the year on year repair bill, somewhat improve service reliability and lay the basis for electrification.

 

Pity we scrapped the 76's they'd have been good on the Devon banks ;-)

 

 

Alan

[Dunsignalling]

No, FGW ends up with a route which it can use when bad weather makes the Dawlish route impassible. No one has suggested that FGW be required to route all Plymouth services via Okehampton. Now you might argue whether it is worth it for the perhaps one week a year that it might be needed for that purpose, but the passengers may well find it preferable for their train to reverse on those occaisions.

 

At the moment, not having that backup option is also making the M4-M5-A30/A38 very attractive.

Almost inevitable given today's further developments!

 

It is absolutely vital that the alternative arrangements by FGW and SWT are dependable with all passengers kept properly informed. This all needs to be in place no later than Monday morning. Delays are unpleasant but unpredictability is what really puts people off.

 

If I wasn't confident, before setting out, that the railway could also get me back and offer a reasonable idea of how and when (assuming that nothing else goes wrong); I'd be taking the car, a long distance coach or deferring the trip altogether. 

 

John

Edited February 9, 2014 by Dunsignalling

[Dunsignalling]

Big assumption is that they would bother. We have perfectly good diversionary routes here that involve a reverse and some hassle so FGW runs buses instead of diverting their trains. If there was an Tavistock diversion I imagine FGW would run busses instead of using it. So to "fix" the problem you've also got to fix the train operators.

 

Alan

When I was still at the pointy end of things, I gave up ringing Swindon to point out available paths up the Southern for FGW HSTs stuck in Exeter.

 

Normally, by the time they made the decision and got it on the move, the opportunity had passed and the poor thing emerged at Castle Cary behind the first train through after the WR line had reopened! 

 

At least we knew where we were with XC, I imagine most of their drivers who formerly signed the route (on HSTs and 47s) are retired by now and I don't think there has ever been even a gauging trip by a Voyager.

 

Not really surprising. Most TOCs are owned by bus companies, after all. 

 

John

[Dunsignalling]

I remain puzzled by the assumed advantages offered the LSW route were it to reopen.  True it would (might - if sufficient money is spent?) allow freight traffic to continue but I suspect for the majority of passengers it would be second choice if they were offered a rail replacement coach service from Tiverton Parkway because from there the running time to Plymouth station is only an hour - the coach would probably be past Exeter by the time the train had reached StDavids and made its way back to Cowley Bridge.  The train then faces just over 50 miles to run to Plymouth and is anybody seriously suggesting that a lightly used diversionary route will be able to offer a nett running time of an hour for that distance - plus whatever ever might be needed in the way of crossing time in order to pass trains coming the other way?  

 

It might well suit some people not to have the inconvenience of detraining and crossing the bridge at Tiverton Parkway but on the occasions I've experienced it the arrangements have worked well with no waiting to join a road coach at either end although the stion is not the best of places to wait when there are a couple of trainloads of passengers waiting for their trains eastwards and northwards. 

 

To achieve that 50+ mph average speed the train is going to have to spend a lot of its time going much faster and that means higher initial outlay on the formation and higher maintenance costs  - which i suggest might not stand up too well against comparative road vehicle hire costs.   And we're not just talking about a putative gap between Okehampton and a hefty demolition exercise at Tavistock - the track, formation and drainage throughout would have to be brought up to spec for something heavier than a two car dmu, it's additional expenditure right the way through for what - several weeks or weekends per annum.

 

If that sort of money would be involved it is probably more than reasonable to consider spending some more and getting an inland route round the back of Teignmouth and Dawlish (yes, back to what could be done with the 1936 scheme which would not only be an all weather route but could offer higher line speeds than any alternative).  And like the GWR I wouldn't see that alternative as a replacement for the coastal line (which already has some pathing problems) but supplemental to it.

 

But both inland schemes are going to be compared with the costs of future proofing the existing line and both would undoubtedly be far more expensive so I think we can guess the outcome.

Even when trains are running normally, the schedule west of Exeter is such that a non-stop coach from Tiverton Parkway to Plymouth could beat an HST anyway.

 

John

[Gerald Henriksen]

So searching the web I found a couple of documents of interest.

 

First we have a Devon Metro document - http://www.devon.gov.uk/devon_metro_briefing.pdf - which mentions the very popular in this topic Tavistock to Okehampton line.  Quoting from page 4 we have "At the current time, re-opening plans for these lines is not considered viable because of the capital cost of re-opening and the revenue cost of the operation" - in other words, very expensive to rebuild and the ongoing subsidies would be too expensive (this was referring to Teign Valley, extensions from Barnstaple, and Okehampton to Tavistock).

 

We also have a paper authored by Devon, Cornwall, Somerset, Plymouth and Torbay outlining their concerns regarding the rail connections of the rest of the UK.  Page 8 figure 2 shows the population density of the area and the location of existing rail lines.  It is clearly shown that LSWR route from Tavistock to Exeter does not have the population to support a service.

 

In addition to the oft mentioned Meldon Viaduct, wikipedia http://en.wikipedia.org/wiki/Exeter_to_Plymouth_railway_of_the_LSWR says there are 9 viaducts on the old LSWR line that presumably would need various amounts of work, likely none cheap, to bring the line up to a standard where it could be used for HSTs and other mainline activities beyond a slow moving DMU (5 of them have likely not been looked at since abandonment 45 years ago).  In short, lots of money.

[Dunsignalling]

 

In addition to the oft mentioned Meldon Viaduct, wikipedia http://en.wikipedia.org/wiki/Exeter_to_Plymouth_railway_of_the_LSWR says there are 9 viaducts on the old LSWR line that presumably would need various amounts of work, likely none cheap, to bring the line up to a standard where it could be used for HSTs and other mainline activities beyond a slow moving DMU (5 of them have likely not been looked at since abandonment 45 years ago).  In short, lots of money.

Whilst they haven't carried any traffic nor earned a penny in revenue in that time, they will certainly have been inspected at as NR will still be responsible for the structural safety of any they haven't managed to offload onto new owners.

 

Incidentally, even the slowest of DMUs is capable of 75mph these days.

 

John

Edited February 9, 2014 by Dunsignalling

[Rods_of_Revolution]

You could completely replace the whole 4-5 mile open sea section of the sea wall with a modern design of sea wall for about £40 million or the whole sea wall for about £100 million. It's a far more viable option than opening or reopening other pieces of railway with a cost in the hundreds of millions. A new sea wall would reduce the on going maintenance costs to little more than a standard section of railway.

 

Regards,

 

Jack

[Gerald Henriksen]

Whilst they haven't carried any traffic nor earned a penny in revenue in that time, they will certainly have been inspected at as NR will still be responsible for the structural safety of any they haven't managed to offload onto new owners.

I should have been clearer.  My intent was that haven't been evaluated or maintained for rail use in 45 years, and there is a big difference between making sure a structure doesn't fall down while allowing people to walk on it and have it safely handle 130 tonne freight locomotives or 70 tonne HSTs at a reasonable speed.

 

Incidentally, even the slowest of DMUs is capable of 75mph these days.

 

I wasn't trying to imply that DMUs are slow, but rather there is a big difference between running a long, heavy HST or freight train vs a light (relatively) DMU that can obey a slow order because you are running a limited service on a branch line.  And yes, you could in theory run the HST at a slow speed, but that would then make the diversion even less useful given how slow the trains already are in Devon and Cornwall.

[MarkC]

Isn't it the case that the Bere Alston - Tavistock rebuilding only happening because of the new housing being built in Tavistock? The developers only got permission to build after they pledged a lot of money towards the reinstatement of the railway?

[Siberian Snooper]

Isn't it the case that the Bere Alston - Tavistock rebuilding only happening because of the new housing being built in Tavistock? The developers only got permission to build after they pledged a lot of money towards the reinstatement of the railway?

 

That is true, they only got the planning permission on the back of rail reinstatement because the A 386 is at virtual capacity, at peak times it can take 40 to 50 mins to drive from Plymouth to Tavistock or vis a versa on a good day and barring accidents.

 

SS

[Pete 75C]

High tide at Dawlish was around 1am. Does anyone in the South Devon area have any news about wind speed and wave height? From what I can gather, last night was a big worry but the weather is meant to improve slightly today with the winds easing tonight. Monday is looking good, but gales possible again on Tuesday. Apart from wondering when it will ever end, what's it like now?

[Oldddudders]

Whilst they haven't carried any traffic nor earned a penny in revenue in that time, they will certainly have been inspected at as NR will still be responsible for the structural safety of any they haven't managed to offload onto new owners.

 

Incidentally, even the slowest of DMUs is capable of 75mph these days.

 

John

I don't think NR owns any of that stuff beyond Okehampton. The 1.4.1994 split of BR was conducted on the basis of giving Railtrack operational lands and properties only. BR Property Board held onto the old and closed liabilities, including covenants on church rooves and village duckponds, extant since the railways were built. I suspect now BR Residuary has been wound down, the DoE may hold these lands etc?

[Mallard60022]

Caught up now...took me a good hour, including some reversals to the kitchen. I do hope all is well along the sea wall and in Somerset? Good luck to you all.

I am also so impressed with the discussion, however there is a little bit of going around in circles re diversionary routes. I am really sorry to say that I now understand that that will be way back on the prioity list, but see my comments below re electrification.

Anyway, I have not seen any mention of electrification for many, many pages. Was the line west of Exeter meant to get this eventually or was the plan to run diesel services of some kind from Bristol/Exeter all the way to Penzance?

Was it planned to run OHL as far as Plymouth and then Penzance would be a diesel 'branch line'? I really don't know what was planned so please don't suggest that I wake up; I have been awake for a couple of hours thanks, but have not read any planning reports yet.

What electrification, if it was a really serious plan, would surely need would be a 'safe route'. I have seen some pics of what I believe to be a Scottish line with OHL and seas breaking over trains on it; that looked pretty dodgy to me.

What is the situation with OHL lines and sea water trying to inundate it? 

If electrification was/is planned for this lovely piece of ex GWR railway, how would they do it with respect to what has just happened and the sort of 'violent' seas that have happened at Dawlish and area for decades?

Thanks.

P

Edited February 9, 2014 by Mallard60022