Dawlish Diversion Route

[lightengine]

Or no days a year!  Just because there are no trains, the seawall will still have to be maintained to stop Dawlish being flooded...

Even though the present 'failed area' is being strengthened as it is rebuilt I guess the remaining sea wall length contains much walling that will potentially be susceptible to future weather and storms.

People have suggested offshore reefs or suchlike to reduce wave action prior to hitting the sea wall, but to protect the sea wall it would cost a few bob.

[lightengine]

They did give us Clapotis Wave Pattern

[Captain Kernow]

They did give us Clapotis Wave Pattern

I assume that this is some kind of avant-garde art form....?

 

 

 

 

 

 

Only kidding, I know that it's really a recipe for a kind of cheese cake...  

[Captain Kernow]

Even though the present 'failed area' is being strengthened as it is rebuilt I guess the remaining sea wall length contains much walling that will potentially be susceptible to future weather and storms.

People have suggested offshore reefs or suchlike to reduce wave action prior to hitting the sea wall, but to protect the sea wall it would cost a few bob.

Potentially, perhaps, but virtually all of the rest of it has actually survived pretty well (parapet wall sections excepted). This is all down to the historical common mode of failure, which was from the foundations upwards.

 

No foundations failed during these most recent storms...

[Glorious NSE]

Only kidding, I know that it's really a recipe for a kind of cheese cake...  

 

I thought it was something requiring a course of antibiotics...

[Adrian Wintle]

Potentially, perhaps, but virtually all of the rest of it has actually survived pretty well (parapet wall sections excepted).

 

Presumably this has a lot to do with the fact that the rest of it has the extra protection of the high level walkway, so even if the parapet failed the outflowing water wasn't able to pull away more of the wall. I'm guessing that the failure at the breach started with the parapet but was then enlarged by outflow scouring (pulling more of the wall apart) until it had managed to scour out enough of the backing fill to leave the wall unsupported (at which time wave impact could also do damage). 

 

Adrian

[Captain Kernow]

Presumably this has a lot to do with the fact that the rest of it has the extra protection of the high level walkway, so even if the parapet failed the outflowing water wasn't able to pull away more of the wall. I'm guessing that the failure at the breach started with the parapet but was then enlarged by outflow scouring (pulling more of the wall apart) until it had managed to scour out enough of the backing fill to leave the wall unsupported (at which time wave impact could also do damage). 

 

Adrian

Well put, Adrian, and in my personal view (pending the outcome of official investigations, of course) pretty much correct.

[Siberian Snooper]

SS, when you say that a slower diversionary route would be a longer and bigger pain than it is already, are you meaning for the operators or the passengers?

 

If I were a passenger on a train arriving at Exeter and en-route to Plymouth, and had to choose between remaining in my seat and the train proceeding at a leisurely pace around the fringes of Dartmoor; or collecting all my luggage, getting up and off the train walking down the platform and outside to a connecting bus which may or may not be there, discovering that there are too many of us for one bus and so maybe having to wait for a second to turn up, then getting all my luggage on board and finding a seat, then waiting until the bus has filled up, followed by a journey down the A38 with congestion at both the Exeter and Plymouth end, and probably an intermediate stop at Newton Abbot, I know which I option would choose and it would not involve the bus.

Traveling from the Taunton direction the rail replacement buses usually start at Tiverton Parkway for Plymouth and are usually a quicker between there and Plymouth than the train and visa versa. Every time that I have had to use the rail replacement services there has been more than enough coaches to carry the passengers. Whether this holds true for passengers for Newton and Torbay I can't say, as I don't travel to there from that direction. Yes it is a bit of a pain transfering from train to bus, but if I've been away all I want fo do is get home and the quicker the better.

 

As has been mentioned by others it isn't much fun on the sleeper and if travelling on that I wouldn't be to bothered if it took an hour or so longer, but for normal daytime travel speed is of the essence usually. I recently went to Exeter to collect an order I had placed with Dave at the Exeter Model Shop, I usually go by train and have a couple of beers up there for a change but this time I used me car which is a pain but less so than the RRB service as it was door to door.

 

SS

[lightengine]

I assume that this is some kind of avant-garde art form....?

 

 

 

 

 

 

Only kidding, I know that it's really a recipe for a kind of cheese cake...

Good try captain but as I know that you know perfectly well what it is there is no need to explain it further.

 

 

 

 

p.s. it was commented on in Washout at Dawlish (1633).

[lightengine]

Potentially, perhaps, but virtually all of the rest of it has actually survived pretty well (parapet wall sections excepted). This is all down to the historical common mode of failure, which was from the foundations upwards.

 

No foundations failed during these most recent storms...

Clapotis Wave Pattern as explained in (Washout at Dawlish (1633)) suggests that hidden damage cannot be seen. The avant garde art form sounds a better theory though.

 

Great photos posted by you today. You seem to be the only source of information. With the closure of Colyton beach the Dawlishians have no beach left to walk on, so it's good to see what is taking place.

 

On the day after the storm when hundreds of people were walking along that stretch of sea wall at Dawlish admiring the dangling track and cavernous hole, I was stopped from walking along Teignmouth promenade where a low garden brick wall had fallen over and lay partially obstructing the promenade.

[Ramblin Rich]

I would definitely favour the 'Dawlish Avoiding Line' to give a faster link to Plymouth and the capacity to improve the local traffic as detailed above. Depending on the start point the 'DAL' would possibly run quite close to our home so it would be interesting to see if it came about! I wonder if there could be some linkup with the Barnstaple line, which could then be marketed as the Tarka DAL....

Regarding the bus replacements, running from Tiverton to Plymouth makes a great deal of sense as the buses can be onto the M5 then A38 with no bother. If they ran from Exeter they would be stuck in the crawl out from St David's through the city centre & then out to M5/A38 which can easily take 40 minutes or more; add on the train journey time from Tiverton & it could be an hour after leaving Tiverton before getting onto the trunk roads - by which time the bus which started from Tivvy is probably already past Ashburton.... THe 'DAL would defintely improve journey times to Plymouth, especially if electrification was to happen eventually.

The road through Dawlish & Teignmouth is very slow & I don't envy the folks who've had to tolerate rail replacement buses from Teignmouth. The train journey to St Davids is around 20 minutes, where again it can take an hour or so by bus. The normal bus I use has also been very crowded, to the point that a single deck bus around 7:30 am has not been able to pick up in Exminster. There's a lot of oflks who will be very glad when the railway reopens; any future expansion can only be a good thing.

[lightengine]

 

The road through Dawlish & Teignmouth is very slow & I don't envy the folks who've had to tolerate rail replacement buses from Teignmouth. The train journey to St Davids is around 20 minutes, where again it can take an hour or so by bus. The normal bus I use has also been very crowded, to the point that a single deck bus around 7:30 am has not been able to pick up in Exminster. There's a lot of oflks who will be very glad when the railway reopens; any future expansion can only be a good thing.[/quote

 

When I asked at Teignmouth about the rail bus times at the start of the service the staff member told me that they had timetabled it 8 minutes from Newton to Teignmouth station. Even on a good day with wind assistance, the roads having been straightened and Stirling Moss at the wheel ...............................

 

I do like the Tarka DAL

[10800]

If Tiverton Parkway is used more routinely for train-bus transfers they need to have a much bigger footbridge from the down platform to the exit!  When we collected our son from there on Christmas Eve it took longer for the train load of passengers to cross the bridge than it had for us to drive from Teignmouth.

[Glorious NSE]

When I asked at Teignmouth about the rail bus times at the start of the service the staff member told me that they had timetabled it 8 minutes from Newton to Teignmouth station.

 

That's hilarious!

[The Stationmaster]

If Tiverton Parkway is used more routinely for train-bus transfers they need to have a much bigger footbridge from the down platform to the exit!  When we collected our son from there on Christmas Eve it took longer for the train load of passengers to cross the bridge than it had for us to drive from Teignmouth.

It is a problem but as Rich has pointed out it is massively quicker than doing the transfer at St Davids - I reckon you're probably past Hemerdon on the coach from Tivvy Parkway before you'd even be clear of the city environs if it ran from St Davids and from experience of it in the past I know the coach/'bus drivers greatly prefer the Tiverton Parkway option.

[Dunsignalling]

My own opinion is that, unless there is another breach further down the line next winter, the whole thing will get kicked into the long grass. 

 

However, my conclusions on the stated options if anything were to be done are as follows:

 

1. Teign Valley is a non-starter for various reasons, much of the trackbed has been lost to development and it was only ever single track anyway. Land aquisition for widening, rerouting and/or retrieval of original line of route where unavoidable would be time consuming, unpopular and expensive.  

 

2. Any of the inland 'bypasses' would be very expensive in terms of land acquisition and civil engineering. They would also reduce journey times, resulting in the coastal line becoming a de facto secondary route. That, combined with the level of expenditure required would make it very difficult to justify any future major repairs to the seawall route comparable to those that are currently nearing completion. To spell it out, any recurrence of this winter's events further along the line would seal its fate.

 

3. If one wants to keep the seawall route, the Dartmoor option is the most likely to ensure that. If it is restored, it is unlikely to be done as a high speed route so would not compete with the (frankly sluggish) journey times via Newton Abbot on a day-to-day basis. Despite the need for a new viaduct at Meldon and as-yet unquantified repairs to  others, it is likely to be by far the cheapest option. When not required for diversions, it would provide local/semi-fast services to settlements that have grown since closure. It might attract some non-time-sensitive travellers between Plymouth and Exeter who fancy a scenic ride over the moor despite it taking 20 or 30 minutes longer but would be unlikely to impact FGW's long-distance clientele. Unlike the other options, the line of route is relatively intact so very little compulsory purchase of developed land would be required. That would make it less controversial and therefore make it achievable in a much shorter timescale.

 

John

[brushman47544]

Tarka DAL....

 

For some reason that made me think of curried otter... :-)

[The Stationmaster]

My own opinion is that, unless there is another breach further down the line next winter, the whole thing will get kicked into the long grass. 

 

However, my conclusions on the stated options if anything were to be done are as follows:

 

1. Teign Valley is a non-starter for various reasons, much of the trackbed has been lost to development and it was only ever single track anyway. Land aquisition for widening, rerouting and/or retrieval of original line of route where unavoidable would be time consuming, unpopular and expensive.  

 

2. Any of the inland 'bypasses' would be very expensive in terms of land acquisition and civil engineering. They would also reduce journey times, resulting in the coastal line becoming a de facto secondary route. That, combined with the level of expenditure required would make it very difficult to justify any future major repairs to the seawall route comparable to those that are currently nearing completion. To spell it out, any recurrence of this winter's events further along the line would seal its fate.

 

3. If one wants to keep the seawall route, the Dartmoor option is the most likely to ensure that. If it is restored, it is unlikely to be done as a high speed route so would not compete with the (frankly sluggish) journey times via Newton Abbot on a day-to-day basis. Despite the need for a new viaduct at Meldon and as-yet unquantified repairs to  others, it is likely to be by far the cheapest option. When not required for diversions, it would provide local/semi-fast services to settlements that have grown since closure. It might attract some non-time-sensitive travellers between Plymouth and Exeter who fancy a scenic ride over the moor despite it taking 20 or 30 minutes longer but would be unlikely to impact FGW's long-distance clientele. Unlike the other options, the line of route is relatively intact so very little compulsory purchase of developed land would be required. That would make it less controversial and therefore make it achievable in a much shorter timescale.

 

John

Maybe so - but it's also a route to, effectively, nowhere with virtually no commercial originating revenue plus miles of maintenance at a cost to be borne by someone and - quite frankly - a resource hungry and operationally inconvenient route for diversions with the costs of maintaining route knowledge, the extra train resources it would need to maintain anything like a normal service level either side of it and so on.  Plus it puts at risk Torbay revenue by sending a 'we're not interested in you when things go wrong' message.  Glorious waste of money just to appease the 'Beeching was wrong' camp.

 

It would possibly be cheaper than the 'Dawlish diversion' option but then it offers far, far less because at least the diversion would have a recognisable rate of return with potentially increased revenue and reduced operating costs.  And it would provide increasingly needed capacity relief to the coastal route by effectively providing quadruple track track over some 18 miles of it

 

But the coast route cannot be anything but retained because it best serves various communities enroute so it won't go whatever happens in the next few decades - the decision will I suspect be quite simple 'we have to retain the coast route for a variety of reasons and that will mean a major programme to improve its resilience so will providing an alternative as well as that have any nett revenue and cost benefits?'  In the end the decision will be based on economics and business cases, not on sentiment.

[Dunsignalling]

Maybe so - but it's also a route to, effectively, nowhere with virtually no commercial originating revenue plus miles of maintenance at a cost to be borne by someone and - quite frankly - a resource hungry and operationally inconvenient route for diversions with the costs of maintaining route knowledge, the extra train resources it would need to maintain anything like a normal service level either side of it and so on.  Plus it puts at risk Torbay revenue by sending a 'we're not interested in you when things go wrong' message.  Glorious waste of money just to appease the 'Beeching was wrong' camp.

 

It would possibly be cheaper than the 'Dawlish diversion' option but then it offers far, far less because at least the diversion would have a recognisable rate of return with potentially increased revenue and reduced operating costs.  And it would provide increasingly needed capacity relief to the coastal route by effectively providing quadruple track track over some 18 miles of it

 

But the coast route cannot be anything but retained because it best serves various communities enroute so it won't go whatever happens in the next few decades - the decision will I suspect be quite simple 'we have to retain the coast route for a variety of reasons and that will mean a major programme to improve its resilience so will providing an alternative as well as that have any nett revenue and cost benefits?'  In the end the decision will be based on economics and business cases, not on sentiment.

The combined population of Dawlish and Teignmouth is 28,300, that of Tavistock and Okehampton, 18,400, so the difference isn't that huge and Tavistock is growing fast.

 

By comparison, two towns situated on the main line but (currently) without stations, Wellington and Cullompton, muster 38,000 between them but their residents have to travel to Tiverton Parkway or Taunton (comparable to the distance BETWEEN Dawlish and Teignmouth) if they wish to use rail services. 

 

If NR spend a billion or so on an inland bypass which shaves 10 or 15 minutes off the Exeter-Plymouth journey, the coast route will inevitably end up as a sprinter/pacer only branch outside the holiday season with, at best, half the expresses in the main summer period. If electrification ever came to pass, the exposed coastal route would become something of an embarrassment.    

 

Any of the bypass routes, with a higher line speed and in-cab signalling (though the existing line will get the latter eventually) permitting closer headways, would have more capacity than the existing line.  Rising sea level (even if it happens at only half the rate predicted) mean that NR will be forever chasing a moving target on the sea wall. The current political climate is fairly pro-railway but there is no guarantee that will last. The most likely result of a major sea wall outage in the future, would be that Dawlish and Teignmouth would get to share a nice new Parkway station on the inland route.

 

If I were a resident of either town, I'd be very wary what I wished for.

 

 

John

[Adrian Wintle]

The combined population of Dawlish and Teignmouth is 28,300, that of Tavistock and Okehampton, 18,400, so the difference isn't that huge and Tavistock is growing fast.

 

 

But the Tavistock/Okehampton route doesn't serve Newton Abbot, Totnes, or Torbay, so you really need to include that population in your comparison. (~160K more people)

 

Adrian

[Dunsignalling]

But the Tavistock/Okehampton route doesn't serve Newton Abbot, Totnes, or Torbay, so you really need to include that population in your comparison. (~160K more people)

 

Adrian

I quite agree but that wasn't the point I was trying to make which was, that if one of the inland bypass routes were built, the small towns it cuts off would become (in railway terms) much more vulnerable than if the SR route were reopened. Torbay, including Newton Abbot and (to a lesser extent) Totnes obviously carry a lot more weight.

 

However, as I said in my first post, I don't believe any of the proposed routes will be built unless there is a repeat of this year's chaos within two years. The only other trigger would be electrification, in which case one of the bypass lines would become essential and the entire line currently running along the coast would be relegated to the status of a diesel-worked branch until the wall got breached again, when it would become two diesel-worked branches!

 

John  

[lightengine]

The best option is a Dawlish diversionary route. Then a preservation group can take over and run a steam service from Newton to Teignmouth all year and Dawlish weather permitting. Problem solved.

Electrification, single line to Newton or north of Dartmoor can be fought out.

[lightengine]

The combined population of Dawlish and Teignmouth is 28,300, that of Tavistock and Okehampton, 18,400, so the difference isn't that huge and Tavistock is growing fast.

 

By comparison, two towns situated on the main line but (currently) without stations, Wellington and Cullompton, muster 38,000 between them but their residents have to travel to Tiverton Parkway or Taunton (comparable to the distance BETWEEN Dawlish and Teignmouth) if they wish to use rail services. 

 

If NR spend a billion or so on an inland bypass which shaves 10 or 15 minutes off the Exeter-Plymouth journey, the coast route will inevitably end up as a sprinter/pacer only branch outside the holiday season with, at best, half the expresses in the main summer period. If electrification ever came to pass, the exposed coastal route would become something of an embarrassment.    

 

Any of the bypass routes, with a higher line speed and in-cab signalling (though the existing line will get the latter eventually) permitting closer headways, would have more capacity than the existing line.  Rising sea level (even if it happens at only half the rate predicted) mean that NR will be forever chasing a moving target on the sea wall. The current political climate is fairly pro-railway but there is no guarantee that will last. The most likely result of a major sea wall outage in the future, would be that Dawlish and Teignmouth would get to share a nice new Parkway station on the inland route.

 

If I were a resident of either town, I'd be very wary what I wished for.

 

 

John

That could be likely John, and having lived in Wellington aeons ago I appreciate the need for re-instatement of the station there. Particularly as the Exmouth line has a brand new station, Newcourt.

But railway or no railway on the coast the sea wall still has to be maintained surely or Dawlish will start disappearing like Hallsands did.

[Fenman]

But railway or no railway on the coast the sea wall still has to be maintained surely or Dawlish will start disappearing like Hallsands did.

 

The Environment Agency stated last year at a public forum in Cromer (admittedly a smaller population: 7,700, to Dawlish's 12,800) that people should not necessarily expect the town to be permanently defendable against the sea.

 

Paul

[The Stationmaster]

The combined population of Dawlish and Teignmouth is 28,300, that of Tavistock and Okehampton, 18,400, so the difference isn't that huge and Tavistock is growing fast.

 

By comparison, two towns situated on the main line but (currently) without stations, Wellington and Cullompton, muster 38,000 between them but their residents have to travel to Tiverton Parkway or Taunton (comparable to the distance BETWEEN Dawlish and Teignmouth) if they wish to use rail services. 

 

If NR spend a billion or so on an inland bypass which shaves 10 or 15 minutes off the Exeter-Plymouth journey, the coast route will inevitably end up as a sprinter/pacer only branch outside the holiday season with, at best, half the expresses in the main summer period. If electrification ever came to pass, the exposed coastal route would become something of an embarrassment.    

 

Any of the bypass routes, with a higher line speed and in-cab signalling (though the existing line will get the latter eventually) permitting closer headways, would have more capacity than the existing line.  Rising sea level (even if it happens at only half the rate predicted) mean that NR will be forever chasing a moving target on the sea wall. The current political climate is fairly pro-railway but there is no guarantee that will last. The most likely result of a major sea wall outage in the future, would be that Dawlish and Teignmouth would get to share a nice new Parkway station on the inland route.

 

If I were a resident of either town, I'd be very wary what I wished for.

 

 

John

Interestingly I understand that Teignmouth & Dawlish between contribute =18% of the Plymouth/Cornwall - London revenues and if Okehampton was reinstated as the principal route beyond Exeter it has been estimated that 41% of the Plymouth/Cornwall - London route revenue would be lost.

 

Now I realise you are not proposing the north Dartmoor scenic tour route as an alternative to the coast route but as a diversionary route but where is the money to come from to pay for that?  It's not just the capital cost (which in itself could vary considerably depending on the amount of double tracking with track alone coming in at £1million+ per mile) but the consequent maintenance of that truck and the necessary resources to enable it to be of any use for diversions.  For instance I don't know how many Drivers would need to learn it but there would certainly be a need to involve Laira men who have little other need to be involved in mainline HST working and knowledge would also have to be maintained for Exeter, and possibly even Penzance men - and I can tell you from experience that maintaining Driver's Route Knowledge over routes which they don't normally work is not a cheap business, apart from actually providing trains or whatever to enable them to do it.

 

Line capacity along the LSW route would inevitably be very limited unless massive amounts of money were to be spent on doubling and signalling - again for little or no use in the normal course of events.

 

And yes - if the Dawlish Diversion does come about then the coastal route  would see little beyond local services and no doubt some seasonal long distance services.  But isn't that what increasing emphasis on Devon Metro might find ideal?  Apart from conflictions at the ends there would be far more reliable capacity avallable for a higher intensity local service if that is what the County should decide it needs.  And that is probably the only way capacity can really be created because while chucking in extra signal sections on the coast route would have some effect it will never have space for the looping/overtaking opportunities that speed and stopping pattern differentials demand - at some time it will run out of capacity, just like any other double line piece of railway.