Suggestions for Dawlish avoiding route(s)

[The Ham]

So you are suggesting we should deliberately cripple the railway today to force better upgrades in a few decades time?

No, I'm suggesting that we look to providing a reopened route which provides a diversion route for when there maybe problems at Dawlish. Then, when Dawlish needs to be abandoned we then provide a good fast well planned route which still has a possible diversion route.

Rather than build an avoiding line quickly and regret it in a few decades time when we could have had the justification for a faster rail service west of Exeter. Also, it leaves us with the risk that when the route through Dawlish has to be abandoned that we do not have a viable diversion as Okehampton has opened as a mostly single track route with low line speeds.

 

[47802]

Depends on how you view long term, are we thinking the next 20 to 40 years, or are we thinking the next 50 to 80 years?

Right, so lets say the DAL gets built (say with linespeeds of 90-100mph) in a hurry to just about cope with what is needed and then in 50 years time there is a proposal for a new HS line running to Exeter is proposed, then chances are the upgrades will stop at Exeter and the trains will then trundle onto Plymouth and Cornwall.

Conversely if the mainline is still routed through Dawlish, then there comes a big advantage in continuing the major upgrades to Plymouth (especially if there are closures of the line most winters by then) with linespeeds of over 140mph being a possibility and depending on how fragile the line through Dawlish is it could justify the new upgrades to occur sooner than they otherwise would have been. However in the meantime Plymouth has never been cut off from the network.

The big risk with the DAL is that will be it in terms of upgrades (other than electrification, maybe a bit of redoubling and a slow increase in the number of services) for services west of Exeter for a long time. Conversely the Okehampton reopening means that further upgrades will be required in the next 30-70 years, however by then there could be a lot more passengers (35 years of 2% growth doubles the numbers of passengers).

With double the passengers linespeed improvements become a lot higher value in terms of benefits. Therefore a HS tunnel between Exeter and Newton Abbot built in the next 50 to 60 years with a journey time of about 6 minutes, compared with the best current time of 18 minutes then becomes more likely. That would clearly be better than the DAL being built in the next 10 years with a journey time of about 15 minutes.

That is to most ridiculous load of nonsense I have ever come across to try and justify not building a replacement mainline route to Newton Abbot.
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No, I'm suggesting that we look to providing a reopened route which provides a diversion route for when there maybe problems at Dawlish. Then, when Dawlish needs to be abandoned we then provide a good fast well planned route which still has a possible diversion route.

Rather than build an avoiding line quickly and regret it in a few decades time when we could have had the justification for a faster rail service west of Exeter. Also, it leaves us with the risk that when the route through Dawlish has to be abandoned that we do not have a viable diversion as Okehampton has opened as a mostly single track route with low line speeds.

Again a most ridiculous load of nonsense, there no risk if the Dawlish line has to be abandoned if you have a new mainline route to Newton Abbot.

 

[LateThanNever]

Given that the route would not be required 99.9% of the time, such minimal expenditure would be relevant.

However, don't get carried away with single line being operated to double track capacity (as in Switzerland), or reversals done in 2 minutes (as in Switzerland). The UK railway has never been able to do either of these feats, and they are certainly not going to start now. What with probable 10 mph limits over Meldon Viaduct, likewise over the long rickety bridge at Bere Ferrers, climbing up to what was the highest point on the railway in southern England (at Meldon), and negotiating the Cowley Bridge floods TWICE on each trip, I reckon an extra hour on each journey. Of course, as you miss out half your potential traffic from Newton Abbot/Torbay, who presumably now have to drive to Exeter, there will be far less services required anyway.

Less of the 99.9% - this year so far it looks like 15%! Half the traffic coming from Newton Abbot or Torbay? How do you work that out?

 

[Trainbuff]

BTW, Did I read somewhere that NR were also considering a 'chord' route from Rewe on the GW mainline to link directly with the L&SW line near Crediton?

This was a report that came out on 14thFebruary last year. Google it on this search below and you will see the document. Very interesting.

https://www.google.co.uk/search?q=+...hannel=sb&gws_rd=cr&ei=KaUUU5ugHKiS7Ablq4GQDQ

A year old but fascinating.
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[Taunton]

Very good. So we'll miss Exeter as well, nowhere more than a jumped-up village between Taunton and Plymouth, where we arrive facing the wrong way and then needing to backtrack several miles. That is, unless we're going to build a chord at St Budeaux as well, straight over to Saltash and not a station in Devon at all.......

 

[yorksrob]

So you are suggesting we should deliberately cripple the railway today to force better upgrades in a few decades time?

Given the amount of investment NR are putting into the main line as we speak, I don't think anyone is "deliberately crippling" it.
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Given that the route would not be required 99.9% of the time, such minimal expenditure would be relevant.

That's simply not true. Tavistock, Okehampton, the National Park and the rest of the surrounding area need links all year round.
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However, don't get carried away with single line being operated to double track capacity (as in Switzerland), or reversals done in 2 minutes (as in Switzerland). The UK railway has never been able to do either of these feats, and they are certainly not going to start now. What with probable 10 mph limits over Meldon Viaduct, likewise over the long rickety bridge at Bere Ferrers, climbing up to what was the highest point on the railway in southern England (at Meldon), and negotiating the Cowley Bridge floods TWICE on each trip, I reckon an extra hour on each journey. Of course, as you miss out half your potential traffic from Newton Abbot/Torbay, who presumably now have to drive to Exeter, there will be far less services required anyway.

I'm really not convinced these viaducts are so decrepit as those with an agenda like to portray. We were told Ribblehead was on its last legs, yet it was brought back from the brink for a lot less cost than originally stated.

 

[ironstone11]

Yet another report into avoiding lines at:-

http://lordsoftheblog.net/wp-conten...mic-development-West-Country-rail-network.doc

 

[jmc100]

Very good. So we'll miss Exeter as well, nowhere more than a jumped-up village between Taunton and Plymouth, where we arrive facing the wrong way and then needing to backtrack several miles. That is, unless we're going to build a chord at St Budeaux as well, straight over to Saltash and not a station in Devon at all.......

That's the reason why I said a high-speed tunnel is the answer in the long term but something has to be done in the short term that's for sure.
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yorksrob, I think you are probably correct about the twin viaducts at Meldon. Strengthening work to the metal structures was carried out in the past, especially during 1944 when concrete strengthening was carried out in order to allow the viaducts to bear much heavier loads during WW2 and to prevent uplift. The viaducts are probably much stronger now than when they were originally constructed so trains would be able to pass over them at speeds before closure of the line.

 

[The Ham]

That is to most ridiculous load of nonsense I have ever come across to try and justify not building a replacement mainline route to Newton Abbot.

I am not suggesting that we do not build a replacement mainline route, rather we build it later when we have had chance to look at it in detail and do a good job rather than build it quickly so that the politicians can say that they have done something. If we are going to build a route quickly it is better one that for the most part doesn't matter if there are constraints to it, and has the advantage of providing new rail opportunities.

By building the new mainline later it has the advantage that passenger numbers will have grown meaning any time saving benefit would be larger, meaning that more can be done to reduce the journey time.

Again a most ridiculous load of nonsense, there no risk if the Dawlish line has to be abandoned if you have a new mainline route to Newton Abbot.

I'm am sorry I didn't realise that this new mainline will not need maintenance, will not be subject to freak weather events, nor will never have any other form of incident that will close it for any length of time. Therefore I agree we should build it and not worry about any form of diversion route.

 

[tsr]

...or reversals done in 2 minutes (as in Switzerland). The UK railway has never been able to do either of these feats, and they are certainly not going to start now.

Some FGW Turbo-operated workings have 3 minute turnarounds specified which involve reversals, and it is possible to stick to these, although it can help if they arrive early, of course. Nonetheless, that is very reasonable. Whilst traffic over the Dawlish route (and many others) does not currently consist of Turbos in any way, and long distance services won't, local services could no doubt achieve similar, should a proper plan be developed to use station capacity appropriately.

 

[The Ham]

Yet another report into avoiding lines at:-

http://lordsoftheblog.net/wp-conten...mic-development-West-Country-rail-network.doc

One interesting point in the report a 40 minute saving is valued at £6 per passenger. If that is the case (assuming 12,000 per day between Plymouth and Exeter, when the total entry/exits for Plymouth is about 7,000) the benefit of about 13 minutes of time saving (which is likely to be more than could be achieved between Exeter and Newton Abbot given the current fastest journey time of 18 minutes) works out at about £24,000 per day, or £8,736,000 per year (364 days per year), or £349m over 40 years. That is likely to be short of the cost of any form of new line.

If the journey time saving was about 7 minutes (a more realistic journey time saving) then the benefit would be about half that (i.e. about £175m). Yes there are other benefits (i.e. more passenger due to faster journey times), but then a route through Okehampton would have other benefits as well (i.e. passengers from the towns newly connected, new park & rail opportunities into Plymouth and Exeter, possible new routes from the SE to the SW in the for of the extension of the SWT's service to Exeter).

Therefore, if anything were to be done, it is likely to be an almost (plus or minus about £100m to £200m) straight race based on whichever is cheaper with the possibility that whichever could be done faster having a slight advantage.

 

[47802]

I am not suggesting that we do not build a replacement mainline route, rather we build it later when we have had chance to look at it in detail and do a good job rather than build it quickly so that the politicians can say that they have done something. If we are going to build a route quickly it is better one that for the most part doesn't matter if there are constraints to it, and has the advantage of providing new rail opportunities.

By building the new mainline later it has the advantage that passenger numbers will have grown meaning any time saving benefit would be larger, meaning that more can be done to reduce the journey time.

So the sensible solution to me would for Network Rail to look at a options which they are doing, and then make some recommendations regarding the ways forward.


But if I understand you correctly what we should be doing according to you is reopen the Okehampton route regardless because it will be quick (debatable), cheap (debatable), and Okehampton and Tavistock must have a train service, and then when that's done we can look at a new route for the mainline at some point in the future.

And you propose to get the Government who clearly don't want to spend much on the southwest, to spend £400 to £500 million on Okehampton and then a whole load more money at a later date.

I'm am sorry I didn't realise that this new mainline will not need maintenance, will not be subject to freak weather events, nor will never have any other form of incident that will close it for any length of time. Therefore I agree we should build it and not worry about any form of diversion route.

The new Mainline will eliminate the sea wall issue which is meant to be the main issue, regarding other weather events will have a similar risk to any other mainline, and trying justify Okehampton purely on that basis isn't going to work as there are many more mainlines which don't really have a realistic diversionary route in that situation.

Of course if money was no object yes perhaps we should use Okehampton to build a new fast alternate route into Cornwall following the route of the A30, but realisticly that's not going to happen is it certainly not in my lifetime.

 

[yorksrob]

The new Mainline will eliminate the sea wall issue which is meant to be the main issue, regarding other weather events will have a similar risk to any other mainline, and trying justify Okehampton purely on that basis isn't going to work as there are many more mainlines which don't really have a realistic diversionary route in that situation.

Of course if money was no object yes perhaps we should use Okehampton to build a new fast alternate route into Cornwall following the route of the A30, but realisticly that's not going to happen is it certainly not in my lifetime.

It won't get rid of the sea wall issue, because it will still need to be maintained for the service to local stations. From that point of view, a pure DAL won't save any expenditure on its maintenance.

If it comes to the point when we need to abandon Dawlish completely, it will be generations away, by which time the decision to invest in reopening the Okehampton route will seem as distant as the Beeching era that closed it is to us now. This will be when we need a Dawlish avoider from Newton Abbott, and the reopening of Okehampton (in the then dim and distant past) will have little or no bearing on a decision to reroute the main line.

In the meantime, the Dawlish route will continue to be maintained as the mainline, ideally with Okehampton reinstated as back up.

 

[47802]

It won't get rid of the sea wall issue, because it will still need to be maintained for the service to local stations. From that point of view, a pure DAL won't save any expenditure on its maintenance.

If it comes to the point when we need to abandon Dawlish completely, it will be generations away, by which time the decision to invest in reopening the Okehampton route will seem as distant as the Beeching era that closed it is to us now. This will be when we need a Dawlish avoider from Newton Abbott, and the reopening of Okehampton (in the then dim and distant past) will have little or no bearing on a decision to reroute the main line.

In the meantime, the Dawlish route will continue to be maintained as the mainline, ideally with Okehampton reinstated as back up.

If some form of DAL is the new mainline then as far as the mainline is concerned it gets rid of the seawall issue, and frankly Dawlish, Okehampton, Tavistock etc. are of lesser importance in this debate,

Then if the Dawlish route has to be closed due to damage or for maintenance only local services are affected and mainline services carry on regardless, and if single tracking the sea wall section makes maintenance easier then it can be done once the mainline has gone.

 

[TheKnightWho]

If some form of DAL is the new mainline then as far as the mainline is concerned it gets rid of the seawall issue, and frankly Dawlish, Okehampton, Tavistock etc. are of lesser importance in this debate,

Then if the Dawlish route has to be closed due to damage or for maintenance only local services are affected and mainline services carry on regardless, and if single tracking the sea wall section makes maintenance easier then it can be done once the mainline has gone.

Do you live in Torbay, by any chance? You seem awfully keen to make sure they'll always have a service, but seem fine with thousands of others losing a train service.

Fact: the Dawlish sea wall will not be abandoned to the sea even if your precious DAL is built because of the wider social good it achieves.. Another fact: this will hurt the DAL's business case.

 

[47802]

Do you live in Torbay, by any chance? You seem awfully keen to make sure they'll always have a service, but seem fine with thousands of others losing a train service.

Fact: the Dawlish sea wall will not be abandoned to the sea even if your precious DAL is built because of the wider social good it achieves.. Another fact: this will hurt the DAL's business case.

No I don't live in Torbay but

Fact: The population of Newton Abbot and Torbay is far bigger than Okehampton and Tavistock, and Dawlish for that matter.

Fact: DAL provides a more resilient mainline route to both Torbay, Plymouth and Cornwall.

Fact: In the summer there are many long distance Holiday trains to Torbay, bringing benefit to the Devon economy, while to Okehampton there are err None.


and yes Dawlish probably wont be abandoned sea defence wise, but it may be easier to do it without having to maintain a mainline railway as well.

 

[TheKnightWho]

No I don't live in Torbay but

Fact: The population of Newton Abbot and Torbay is far bigger than Okehampton and Tavistock.

Fact: In the summer there are many long distance Holiday trains to Torbay, while to Okehampton there are err None.


and yes Dawlish probably wont be abandoned sea defence wise, but it may be easier to do it without having to maintain a mainline railway as well.

Except the Dawlish line won't ever be abandoned either! It serves too many people to be worth it, and NR will still have to take care of the wall even if they don't run a railway over it.

And who cares if the population is larger? The point is that it's not acceptable for either of them to be without a train service. The DAL only solves part of the problem, as you very well know. You make this out like it's an either/or thing, but as has been pointed out that really isn't the case if we look at the long-term.

 

[jmc100]

To provide an alternative to the Cowley Junction issue I think in the long term NR will build a 'chord' from Rewe to Sweetham to link up with the former LSW route if they consider the Okehampton route a working proposition.

Does any member have any idea of how long it would take to reinstate the Okehampton an alternative route compared to how long it would take to construct a tunnel between Exeter and Newton Abbot?

 

[HSTEd]

If the DAL exists there is absolutely no reason to complete the entire ex-Southern route.
Branch lines to Okehampton and Tavistock are far cheaper than a through route.

 

[47802]

Except the Dawlish line won't ever be abandoned either! It serves too many people to be worth it, and NR will still have to take care of the wall even if they don't run a railway over it.

And who cares if the population is larger? The point is that it's not acceptable for either of them to be without a train service. The DAL only solves part of the problem, as you very well know. You make this out like it's an either/or thing, but as has been pointed out that really isn't the case if we look at the long-term.

At the end of the day there is no perfect solution to this problem but in my view a DAL is the best solution out of those available and provides the least amount of disruption in the event of the Dawlish route being closed. I'm not saying that we should abandon the Dawlish route either but I am saying it may be easier to maintain as a single track branch over the sea wall section, but at some point in the future it might become too difficult and expensive to maintain.

As for Okehampton and Tavistock if there is enough justification to reopen them as branches then that's fine, but they shouldn't be significantly part of the argument about what's best for the mainline route.

Overall I would like to see what conclusions the Network Rail study come up with.

 

[LateThanNever]

To provide an alternative to the Cowley Junction issue I think in the long term NR will build a 'chord' from Rewe to Sweetham to link up with the former LSW route if they consider the Okehampton route a working proposition.

Does any member have any idea of how long it would take to reinstate the Okehampton an alternative route compared to how long it would take to construct a tunnel between Exeter and Newton Abbot?

Cannot see it would be sensible to construct anything to specifically avoid serving Exeter, Newton Abbot and Torbay. The Cowley Bridge solution will have to be something else!
It is also doubtful if construction time would be the major stumbling block. In the UK it is generally the planning that takes the time. We backers of the Okehampton route hope as it is a line that is half built already that would speed it on its way!

 

[TheKnightWho]

Cannot see it would be sensible to construct anything to specifically avoid serving Exeter, Newton Abbot and Torbay. The Cowley Bridge solution will have to be something else!
It is also doubtful if construction time would be the major stumbling block. In the UK it is generally the planning that takes the time. We backers of the Okehampton route hope as it is a line that is half built already that would speed it on its way!

How about a reversal loop at some point just past Exeter? I don't see why an avoiding curve is necessary.

 

[starrymarkb]

Cannot see it would be sensible to construct anything to specifically avoid serving Exeter, Newton Abbot and Torbay. The Cowley Bridge solution will have to be something else!
It is also doubtful if construction time would be the major stumbling block. In the UK it is generally the planning that takes the time. We backers of the Okehampton route hope as it is a line that is half built already that would speed it on its way!

Crossrail tunneling seems to be pretty quick - it's the stations that are taking the time!

 

[PHILIPE]

It states on the "Dawlish Seawall Collapse" thread that the route will re-open on 4th April. We will then be able to put this thread to bed because diversionary routes will then be forgotten about.

 

[Xenophon PCDGS]

It states on the "Dawlish Seawall Collapsw" thread that the roue will re-open on 4th April. .

Have you ever seen the dictionary definition of "roué"....

 

[LateThanNever]

It states on the "Dawlish Seawall Collapse" thread that the route will re-open on 4th April. We will then be able to put this thread to bed because diversionary routes will then be forgotten about.

No it won't!
Because however good a job the restoration is - and it does seem to be thorough, the route will still be closed because in rough weather the odd rock, stray boat, beach hut and so on get thrown onto to the line by the waves. So even if the sea wall is not breached Plymouth, Torbay and Cornwall are still cut off!

 

[Goatboy]

No it won't!
Because however good a job the restoration is - and it does seem to be thorough, the route will still be closed because in rough weather the odd rock, stray boat, beach hut and so on get thrown onto to the line by the waves. So even if the sea wall is not breached Plymouth, Torbay and Cornwall are still cut off!

It is rarely ever closed.

 

[yorksrob]

It is rarely ever closed.

I'm sure like all main lines, it's closed quite regularly.
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Fact: DAL provides a more resilient mainline route to both Torbay, Plymouth and Cornwall.

I don't know how you work that out.

The Okehampton route would be available for scheduled and unscheduled closures between Newton Abbott and Exeter just as the DAL would. However, it would also be available for scheduled and unscheduled closures between Plymouth and Newton Abbott, whereas the DAL would make no difference, therefore the Okehampton route would provide a more resilient route for Plymouth and Cornwall.
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I'm not saying that we should abandon the Dawlish route either but I am saying it may be easier to maintain as a single track branch over the sea wall section, but at some point in the future it might become too difficult and expensive to maintain.

But for the time being, NR will be rebuilding and reinforcing it as a double track route, so the extremely marginal maintenance gains of converting it to a single route, don't really enter in to it.

 

[47802]

I'm sure like all main lines, it's closed quite regularly.
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I don't know how you work that out.

The Okehampton route would be available for scheduled and unscheduled closures between Newton Abbott and Exeter just as the DAL would. However, it would also be available for scheduled and unscheduled closures between Plymouth and Newton Abbott, whereas the DAL would make no difference, therefore the Okehampton route would provide a more resilient route for Plymouth and Cornwall.
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But for the time being, NR will be rebuilding and reinforcing it as a double track route, so the extremely marginal maintenance gains of converting it to a single route, don't really enter in to it.

Probably the fact I mentioned Torbay in there for which Okehampton would be useless. Yes there are + and - on both options, yes the Okehampton would provide an complete alternative between Exeter and Plymouth which the DAL, would not, but if we are talking about the primary reason for building an alternate route ie Dawlish closure, then the DAL causes the least disruption, Okehampton is no good to Torbay and even scheduled services to Plymouth and Cormwall are likely to be reduced with a longer journey time if diverted via Okehampton unless its built as a double track mainline.

At the end of the day we just keep making the same points again and again and we are clearly never going to agree on this, Dawlish will reopen hopefully on April 4th, and then lets see what happens with the Network Rail report.

 

[jmc100]

It states on the "Dawlish Seawall Collapse" thread that the route will re-open on 4th April. We will then be able to put this thread to bed because diversionary routes will then be forgotten about.

I think you'll find the concerns about providing an alternative route will rattle on which is a good thing. There's no doubt an alternative route is required in the short term for many other reasons besides the weather problems that seem to be damaging the Dawlish sea wall more often. Track repairs, maintenance of signalling equipment and clearing vegetation, just to mention a few.

The best idea would be a 7.5 mile tunnel. Network Rail could save their organisation millions of pound as they would not have to purchase any land under the tunnel. The only expense would be the acquisition of land up to the tunnel portals. The only problem is that building a tunnel is a much slower process compared with routing a line overland.