Dawlish Diversion Route

[Southernman46]

Ah what a lot of waffle we all know that HS4 to Exeter & Penzance will cut inland across the South Devon hills through a series of tasteful tunnels & bridges before crossing the Tamar on an architecturally graceful sweeping viaduct.................................................

[Siberian Snooper]

Ah what a lot of waffle we all know that HS4 to Exeter & Penzance will cut inland across the South Devon hills through a series of tasteful tunnels & bridges before crossing the Tamar on an architecturally graceful sweeping viaduct.................................................

I think that it's nearly time to wake up from yout little kip zzzzzzzz

[Captain Kernow]

The PM has been on the box today to announce that there is a few quid to be spent on upgrading the kipper and signaling in this neck of the woods and that nothing had been ruled in or out with reguard to Dawlish avoiding routes.

And I'm considering building a huge new sausage factory in the Midlands, no doubt creating thousands and thousands of jobs and a major new network of sharply curved goods-only lines worked by new-build 0-4-0 Pecketts, nothing has been ruled in or out. I'm just waiting for a report to tell me how much it will really cost...   

[PhilJ W]

And I'm considering building a huge new sausage factory in the Midlands, no doubt creating thousands and thousands of jobs and a major new network of sharply curved goods-only lines worked by new-build 0-4-0 Pecketts, nothing has been ruled in or out. I'm just waiting for a report to tell me how much it will really cost...   

What about the pasties?

[Captain Kernow]

What about the pasties?

I couldn't possibly presume to be capable of making better pasties than those already on offer in The Noble Realm...

[The Stationmaster]

And I'm considering building a huge new sausage factory in the Midlands, no doubt creating thousands and thousands of jobs and a major new network of sharply curved goods-only lines worked by new-build 0-4-0 Pecketts, nothing has been ruled in or out. I'm just waiting for a report to tell me how much it will really cost...   

I would have thought the answer was obvious - the medja said last year it would cost 3/10d so it's now bound to come in a several million and that's all down to the Halle Orchestra (which is well known for its fiddles).

 

I couldn't possibly presume to be capable of making better pasties than those already on offer in The Noble Realm...

You really must visit Ivor's establishment and try some proper pasties  (I rate them almost as highly as Mrs Stationmaster's)

 

http://www.ivordewdney.co.uk/

[mewstone]

I realise that we all need to await the official report, before any meaningful discussion can be made. I do, however, wonder why the comment was made on Spotlight that 2 of the proposals have to quote their report "been shunted into a siding" that is the reinstatement of the former Southern line across the Moor and the original GWR Teign valley route. The Teign valley is more obvious to me in that it was single track and a winding route which has part of the A38 built upon it and includes a partly collapsed tunnel. The former Southern main line, however is far more intact. The only obstacles on this might be the condition of Meldon viaduct and development around Tavistock. Much of the trackbed is no longer Network Rail property and I can understand that if you live in some of the beautiful former stations along the route, then to lose some of their land is not pleasant, but is this a good enough reason to abandon such a scheme. Reopening would provide an alternative route inland and would serve Okehampton and Tavistock as well. I am sure if would never have been closed in todays railway world, just like the Settle and Carlisle route has survived. Just my opinion though?

[The Stationmaster]

I realise that we all need to await the official report, before any meaningful discussion can be made. I do, however, wonder why the comment was made on Spotlight that 2 of the proposals have to quote their report "been shunted into a siding" that is the reinstatement of the former Southern line across the Moor and the original GWR Teign valley route. The Teign valley is more obvious to me in that it was single track and a winding route which has part of the A38 built upon it and includes a partly collapsed tunnel. The former Southern main line, however is far more intact. The only obstacles on this might be the condition of Meldon viaduct and development around Tavistock. Much of the trackbed is no longer Network Rail property and I can understand that if you live in some of the beautiful former stations along the route, then to lose some of their land is not pleasant, but is this a good enough reason to abandon such a scheme. Reopening would provide an alternative route inland and would serve Okehampton and Tavistock as well. I am sure if would never have been closed in todays railway world, just like the Settle and Carlisle route has survived. Just my opinion though?

We probably can't comment too far without the report and its details but I suspect the main reason is because it was blindingly obvious to anyone who cared to spend time thinking about it that both were clearly non-starters (for reasons which have already been well ventilated on here).  And equally obviously (to me at any rate) they were not only included to make up the numbers but also to allow them to be dismissed as non-starters with the backing of meaningful numbers.  Don't forget that with any route intended more or less solely for diversions it's will never be just a question of building it but also of maintaining it and doing such mundane (and expensive) things as keeping up traincrew knowledge - they are costs which cannot be avoided.

 

And of course we won't know what the numbers, and other details, are until we get to see the report.  However in view of the emotive nature of the Okehampton/Tavistock route I have little doubt that it will have been examined very objectively, and in as much - if not more - detail as some of the alternatives.

[Gwiwer]

[mode=tinhat]Of course if we were in Scotland we might be discussing the Waverley route of which the more populous northern section is already well on the way to reopening.  The southern part, through virtually unpopulated open countryside, is another matter however and is only being spoken of in terms of a diversionary route ..... [/mode]

[mewstone]

Thanks for your responses. I realise that there are a lot of factors that need to be taken into account when considering any reopening, cost, centres of population etc. I am just genuinely surprised that the former Southern Railway main line did not rank stronger. I know I am only basing this on the BBC Spotlight news item and not the detailed findings which have yet to be finalised and published. Like others have said on this thread I would have thought it was relatively easy to reinstate it. After all, in many ways it is a comparatively short section that is missing from this route, although there are obstacles such as infrastructure condition and Council Office's built on a part of the formation. It just seems to me that the sea wall is always going to be vulnerable to the effects of storm and maybe climate change as well. If things do go wrong the economic cost for the region are quoted as being very large indeed. A diversionary route around Dawlish seems to me to be incredibly expensive, whilst I thought that reopening across the Moor could be achieved for a far lower cost. Also it could offer customers an alternative beyond Exeter to (First) Great Western services. Perhaps a bit in the same way as Marylebone to Birmingham with Chiltern Trains  does for the Midlands and this of course is before HS2, or maybe I am just being too sentimental for the old days!

[Gwiwer]

 

 

I would have thought it was relatively easy to reinstate it.

 

As has been discussed extensively here in the past that is not the case.  Very significant engineering works are required, land which has been sold would need to be re-purchased or another route found and there would be a loss of amenity in the increasingly popular walking / cycling trails which now occupy significant parts of the old route.

 

As a diversionary route there would be no business case at all to rebuild it.  It would have to be based upon a sound case for local passenger traffic first.  That may only exist between Tavistock and Plymouth though we shall have to await the detail o the latest report to be certain.  Okehampton - Exeter is smaller market altogether and there is unlikely to be a huge (i.e. large enough) shift from the private car by transferring to train at Okehampton by those living within reasonable driving distance.  As I posted above it would be quicker to drive through to Exeter in most instances.  

 

There seldom ever was and is not likely to be now sufficient local traffic over the Okehampton - Tavistock section to really justify its existence.  Although I might be accused of comparing oranges with lemons the local bus route over that section which has been improved several times in recent years in attempts to win traffic has failed to do so and has itself recently been scaled back again.

[brushman47544]

We probably can't comment too far without the report and its details but I suspect the main reason is because it was blindingly obvious to anyone who cared to spend time thinking about it that both were clearly non-starters (for reasons which have already been well ventilated on here).  And equally obviously (to me at any rate) they were not only included to make up the numbers but also to allow them to be dismissed as non-starters with the backing of meaningful numbers.  Don't forget that with any route intended more or less solely for diversions it's will never be just a question of building it but also of maintaining it and doing such mundane (and expensive) things as keeping up traincrew knowledge - they are costs which cannot be avoided.

 

And of course we won't know what the numbers, and other details, are until we get to see the report.  However in view of the emotive nature of the Okehampton/Tavistock route I have little doubt that it will have been examined very objectively, and in as much - if not more - detail as some of the alternatives.

 

Whilst I agree with you entirely, I will be interested to see how the Okehampton/Tavistock figures take into account the reinstatement costs of Plymouth-Tavistock. Since this is already proposed as a separate scheme that seems likely to go ahead anyway at some point, arguably they should not be included, or at least not be a determining factor.

 

For transparency, perhaps it should also be compulsory that no one who worked for either BR(WR) or BR(SR) took any part, to avoid complaints of historic partisanship.

 

I would have thought the answer was obvious - the medja said last year it would cost 3/10d so it's now bound to come in a several million and that's all down to the Halle Orchestra (which is well known for its fiddles).

 

You really must visit Ivor's establishment and try some proper pasties  (I rate them almost as highly as Mrs Stationmaster's)

 

http://www.ivordewdney.co.uk/

 

What has Ivor got against the Scots (or at least some of them)? Do the pasties suddenly go bad over the extra distance to Falkirk?

 

Pasties can be sent to anywhere in mainland England or Wales and anywhere south of a line drawn between Glasgow and Edinburgh in Scotland.

[The Stationmaster]

Whilst I agree with you entirely, I will be interested to see how the Okehampton/Tavistock figures take into account the reinstatement costs of Plymouth-Tavistock. Since this is already proposed as a separate scheme that seems likely to go ahead anyway at some point, arguably they should not be included, or at least not be a determining factor.

 

For transparency, perhaps it should also be compulsory that no one who worked for either BR(WR) or BR(SR) took any part, to avoid complaints of historic partisanship.

 

 

What has Ivor got against the Scots (or at least some of them)? Do the pasties suddenly go bad over the extra distance to Falkirk?

As far as your last (and perhaps most important point?) is concerned I think it's a matter of time and cost - the latter will become clearer (maybe?) if you look at their postal etc rates and others where posting to the Highlands and islands can get very expensive; the line might be bit too far south but it would probably be the most understandably convenient place to draw it.  And again time might be a factor as when we were in the shop recently they did say they like their product to arrange fresh and in good condition and extended transit before getting it into cold storage might not help there?

 

As far as Plymouth -Tavistock etc is concerned I did put some numbers for various sections of the old LSW route in the original thread but excluded the bridgeworks.  I arrived at my  numbers simply by using those already quoted for other rail restoration schemes of recent times (e.g. the Waverley route) converted to a cost per mile and then multiplied back up.  What is less easy to get at - hence my continued comment to wait until we see the detail in the report - is not only the potential bridgeworks (including those between Bere Alston & Plymouth if the route is required to carry heavier traffic) but also the cost of bringing up to standard any existing track.  A lot too depends on the speed adopted plus the frequency planned for - all of these things influence costs and quite honestly can only be guessed at until the detail is known.

 

And just for transparency's sake something over 20 years ago the initial S&T drawings for restoration of a link to Tavistock were shown to me for informal comment on the method of working and I did not demur from what was proposed except to enter a caveat that I would have hoped something which allowed a greater service frequency would in the end be adopted - so no (G)WR bias on my part.  Oh and that scheme plan was drawn up under the guidance of an ex SR chap. 

[Peter Bedding]

Further to the professional comments made (above) regarding the viability of reinstating Bridge 613 (aka the Meldon Viaducts). Quite simply, there is not a ghost of a chance. (And I was only a Chartered Mechanical Engineer for airworthiness of military aircraft.)

 

It may not be a bad time and place to illustrate the difficulty:

 

The first viaduct was erected (almost entirely from wrought iron) in 1874. A broadly similar structure was erected shortly after, with detail differences.

 

Already by the early 20th century, increasing train loads were too much for the original slender structure, and clever but still limited make-do-and-mend patch repairs were necessary. One of the defect modes was the tendency for the entire structure to rock from side to side, causing the inside piers to lift. The solution was to encase each of the pier legs (piles) in mass concrete. Apart from anything else all this would have to be completely undone to increase the compressive strength of each pile - that's four piles per pier, five piers per viaduct, two separate viaducts for the complete structure. And then there's the question of the rest of each pier.

 

The piles are made to "Hughes Patent", This provides for a hollow circular tube made up of flange quadrants, riveted along the length of each joint. And then there are six pairs of Warren CI trusses on top of the piers.

 

All of that lot would essentially need 100% inspection, non-destructive testing, and sample testing to destruction before any one would sign it off as fit for future purpose, and accept liability for any failure.

 

So, believe me chaps, that  is not going to happen. My favoured option would be a completely new structure alongside the old. Something like the Tamar bridges, in fact.

 

My pictures show the original 1874 structure, the later doubled version (and some earlier mass concrete stabilisation), and lastly Mrs PB giving a size comparison during a site survey back in the 1980s.

 

Hth

 

PB

 

 

[Ramblin Rich]

Wow, that first view of the single track looks very frail - more like a conveyor than a railway bridge!

[brianusa]

Like most forecasts, enquiries, trends, etc, they are usually based on current conditions.  Global warming, tides rising are real so what will it be like down the road?  When the lines were closed, traffic was minimal when compared with today.  Tavistock could be reached within half hour from Plymouth, Exeter just over an hour even before the freeway; I know I used to work in Crediton and commuted every day from Plymouth!   Imagine Dawlish with water over the lines and traffic worse than it is now, then this discussion will be repeated once again for the third time!

 

Brian.

[brianusa]

The PDSWJR didn't have the benefit of Mr Brunel to build their bridges!

 

Brian.

[Peter Bedding]

Hello Brianusa,

 

I rather agree with you on this one. Whichever choice Brunel might have selected from his design book, the odds are that it would have led to a better outcome. His timber viaducts reached the end of their life sufficiently early to be permanently replaced whilst the rest of the line was considered viable. In the case of Bridge 613, the line was owned by the Devon and Cornwall Railway, but the technical debate would have been the same.

[Captain Kernow]

In the case of Bridge 613, the line was owned by the Devon and Cornwall Railway, but the technical debate would have been the same.

Hi Peter,

 

Sorry to have left my Mr Pedantic hat on, but I believe that Meldon Viaduct itself was sold for a very small sum to Devon CC?

 

Certainly the line from Meldon Quarry to the former Coleford Jct is not actually owned by Dartmoor Railway (or Devon & Cornwall Railways, or their parent company BARS - British American Railway Services), but is still the property of Aggregate Industries, who own the quarry itself. It is still officially 'up for sale', albeit with no current buyers...

[Peter Bedding]

Hello CK

 

Many thanks for your comment on my careless use of tense. I had intended to imply that the viaduct was originally owned and constructed by the Devon and Cornwall Railway, in contrast to the later sections constructed by the Plymouth, Devonport and South Western Junction. Another Forum member had commented that the line and viaduct would have been more successful if constructed by IKB. To which I say yes, but sadly for history IKB had died before the construction of this particular work

[locoholic]

"the line and viaduct would have been more successful if constructed by IKB."

 

In view of his atmospheric choice further south, I wonder which mode of propulsion IKB would have chosen to go round the northern edge of Dartmoor - rubber bands, perhaps, or rocket power?

[Siberian Snooper]

According to tonights Spotlight the report is due out tomorrow, there is also another one due in the autumn.

[Siberian Snooper]

Well the reports out and it looks as if the status quo will be maintained. NR reckons that all the alternatives are not value for money using their points scoreing system. The most likely route might be a double tracking of the Teign Valley route as the best value still less than 1 though, but it is up to government to decide, which is due in the autumn.

 

SS

[Christopher125]

The Network Rail report is available here - West of Exeter Route Resilience Study (.pdf)

 

Chris

[Siberian Snooper]

That report is taking some reading, but from what I have read so far in is pretty in-depth and fairly enlightening as to what has happened to both the ex SR and Teign Valley routes over the years. A new Meldon Viaduct? wow.

 

I think that the Sea Wall options will win out overall.

 

SS