New railway line in Devon

[phil-b259]

From what has been posted on here the Marlow-esq solution outlined is the best you can do without significant expenditure on signalling - something the branch lacks in it entirety at present (A token operated ground frame doesn't really count as 'signaling' per say). On the plus side though if no signalling will be installed then should things change in the future at least there won't be anything needing extensive modifications

 

I imagine to get a hour hourly service on the branch which I reckon Tavistock could well support at peak times you need to install a passing loop at Bere Alston plus a terminating platform for the Gunnislake shuttle all controlled Plymouth box - or maybe the ROC at Didcot. None of this comes cheap although the Turo branch successfully had a passing loop installed and there is this 'modular' signalling kit which is supposed to be relatively inexpensive (in signalling terms that is - to everybody else its still bloody expensive).

 

Mind you until they actually get a transport and works act to start rebuilding the railway its all a bit pointless planning the service.

[phil-b259]

I was wondering about how the line might be operated. At the moment, it's simple, one unit (a 150 whenever I've been there) trundles up and down all day about every two hours. With a Y shaped line, I speculated whether it would be a case of run Plymouth to Tavistock as the 'main' line and operate Bere Alston to Gunnislake as a branch (as CK suggests 'they' are planning) or whether there'd be an hourly service Plymouth - BA and then trains alternate between going up to Gunnislake and Tavistock (with obvious disadvantages for Tavistock passengers). Trains have 20 minutes timetabled for BA to Gunnislake and 18 coming back (downhill), so allowing 10 minutes or so at each end, an hourly service would be entirely feasible. I did wonder whether FGW would look at using a 153

 

Remember 153s are longer (23m body shell) than the 150s (20m) and the Gunislake branch was bit as a light railway with very tight curves. While the door positions on a 153 might not be optimal its more likely that its simply a case of the tightness of the curves and the amount of flange wear / rail sequel makes them using them a non starter. On the other hand 153s could serve a reopened Tavistock as the 'main line' isn't that bad curve wise.

[Kris]

Although the line to Gunnislake is shorter than the line to Tavistock will be, the line speeds on the Gunnislake line are very low. Significantly higher line speeds on the line to Tavistock could allo for the longer run in a similar time.

[Gwiwer]

I believe 153s are not permitted Bere Alston - Gunnislake account the line curvature and platform-to-train gaps which would arise at Calstock.  As ever I'm willing to stand corrected by anyone who knows otherwise for certain.

 

Tavistock should support an hourly train service to Plymouth.  The question is whether is will get one.  It is over-optimistic to expect a single unit to make a round trip in the hour every hour reliably when there might be only 2 -3 minutes at each end.  That might work at Tavistock but probably not at Plymouth.   So if only a one-train service is possible then the best we might see is a 90-minute headway or something uneven as happens on the Looe and Newquay branches.

 

Gunnislake trains can be full and standing but only on the busier runs - into Plymouth in the morning and out again late afternoon.  They can also fill up on summer Sundays when the Dartmoor Rover scheme operates.  A lot of the traffic is to and from Bere Alston and might transfer to Tavistock trains but a 2-car sprinter into Plymouth for 8am might not be adequate once Tavistock traffic builds up.

 

The Plymouth - Tavistock main road supports three buses an hour as a commercial operation through the business day though these only serve Plymouth and Tavistock in common with the railway; there are no direct buses between Plymouth and Bere Alston nor Calstock or Gunnislake.  Currently there is competition between First and Plymouth Citybus (part of the Go-Ahead Group) on that route meaning five buses an hour are running.  Time will tell what traffic will actually support and whether all five will last any length of time but it suggests there is good potential for rail reinstatement.  

 

In terms of where the rolling stock might come from it's worth remembering that Reading - Basingstoke is to be electrified soon which will release the two units (nominally the pair of 3-car 150s) employed on the stopping trains.  Given the timeframe of both that project and a reopening to Tavistock you might, if you wish, put two and two together ..... 

Edited July 12, 2014 by Gwiwer

[brianusa]

This is  a bit like planning a model railway; a lot of hope and wishful thinking but that's part of the fun.   And like a model railway, it would be nice if it were to happen!

 

Brian

[Captain Kernow]

as CK suggests 'they' are planning

 

The 'they' is Devon County Council - they are now managing the whole process and have - AFAIK - officially adopted the scheme.

 

I'd be very careful about speculating about additional infrastructure right now - there's still a lot of water to flow under this particular bridge. The current business case won't support a signalled passing loop as things stand.

 

In terms of an hourly service, were this to be eventually agreed on by the sponsors as the way to go - whether just in the peaks or even throughout the day, the key factor is timings from the main line junction at St Budeaux to Tavistock, and I believe that hourly would be possible, with units crossing at St Budeaux Junction (although how that would affect the wider timetable would need to be looked into).

 

I think there's little doubt in everyone's minds that Tavistock will immediately become the 'main line', but much effort is (rightly) being put into ensuring that the Gunnislake service works as well as possible, in terms of connections to the Plymouth - Tavistock service. I'm not sure that all direct Plymouth - Gunnislake services (apart from start and finish of day) have necessarily been ruled out, anyway, but that would only seem possible at the expense of a Tavistock - Plymouth service, certainly if the latter was to be hourly.

Edited July 12, 2014 by Captain Kernow

[The White Rabbit]

In terms of an hourly service .....   the key factor is timings from the main line junction at St Budeaux to Tavistock, and I believe that hourly would be possible, with units crossing at St Budeaux Junction (although how that would affect the wider timetable would need to be looked into).

 

If that's the case, that could remove a major problem. I couldn't see how any extra infrastructure would be financially acceptable (as you confirm) but was struggling to see the line could be operated without it. 

 

Anyway, away from ifs, buts and maybes - some pictures of the area I didn't have time to add last night. 

Bere Ferrers - there's a small heritage site here - http://www.tamarbelle.co.uk/ to the rhs and behind this shot. If you walk down into the village, you can get views down the River Tavy and (very!) long distance shots of the Tavy Bridge. 

 

And five frames of Calstock. 

[The Stationmaster]

The 'they' is Devon County Council - they are now managing the whole process and have - AFAIK - officially adopted the scheme.

 

I'd be very careful about speculating about additional infrastructure right now - there's still a lot of water to flow under this particular bridge. The current business case won't support a signalled passing loop as things stand.

 

In terms of an hourly service, were this to be eventually agreed on by the sponsors as the way to go - whether just in the peaks or even throughout the day, the key factor is timings from the main line junction at St Budeaux to Tavistock, and I believe that hourly would be possible, with units crossing at St Budeaux Junction (although how that would affect the wider timetable would need to be looked into).

 

I think there's little doubt in everyone's minds that Tavistock will immediately become the 'main line', but much effort is (rightly) being put into ensuring that the Gunnislake service works as well as possible, in terms of connections to the Plymouth - Tavistock service. I'm not sure that all direct Plymouth - Gunnislake services (apart from start and finish of day) have necessarily been ruled out, anyway, but that would only seem possible at the expense of a Tavistock - Plymouth service, certainly if the latter was to be hourly.

There would be a way of doing it with trains splitting at Bere Alston by very careful siting of token section boundaries and signing of them but it would effectively mean running passenger trains without any sort of Clearing Point/Overlap and it does depend on how the layout is arranged (obviously).   However the problem isn't so much the splitting but putting two Plymouth bound trains back together - that would need a preparedness to think a bit outside the box. 

[Captain Kernow]

There would be a way of doing it with trains splitting at Bere Alston by very careful siting of token section boundaries and signing of them but it would effectively mean running passenger trains without any sort of Clearing Point/Overlap and it does depend on how the layout is arranged (obviously).   However the problem isn't so much the splitting but putting two Plymouth bound trains back together - that would need a preparedness to think a bit outside the box. 

Yes, I have been encouraging some innovative thinking...

[Siberian Snooper]

Yes, I have been encouraging some innovative thinking...

 

64xx and auto coaches?

 

Hat,Coat.....G...O....N.......E

[Gwiwer]

Nurse!!!  The screens!!!!! 

[Captain Kernow]

64xx and auto coaches?

 

 

Not on that particular line....  

[Gwiwer]

Correct.  An M7 and gate stock might be a tad more appropriate if we can't have green Mk1 or Bulleid stock

[The Stationmaster]

Last time I travelled from Plymouth to Tavistock it was behind a spamcan, an extremely filthy one at that.

[brianusa]

The last time I travelled from Plymouth to Tavistock was behind a Spamcan which was clean but that was in 1953! 

 

Incidentally referring to Gwiwer's comments, is there any gated stock anywhere these days?

 

Brian.

[Ogauge83A]

If anyone is wondering about 2 passenger trains being attached and detached, doesn't it happen at Salisbury with the 159s on the Exeter/Bristol to Waterloo trains?

Antony

[Gwiwer]

If anyone is wondering about 2 passenger trains being attached and detached, doesn't it happen at Salisbury with the 159s on the Exeter/Bristol to Waterloo trains?

Antony

 

Yes it does but the difference is that Salisbury ( and other locations where this happens) is fully signalled whereas we are talking no fixed signalling at Bere Alston.  In effect trains could be approaching from both Tavistock and Gunnislake (which is in opposite directions) resulting in a head-on collision.

[Not Captain Kernow]

It would need the Gunnislake portion to take the same time to make the return trip as the Tavistock portion to make the timetable work to an hourly pattern. 

[Not Captain Kernow]

An awful lot of on the cushions mileage, unless you can recruit a local crew happy to work Gunnislake to BA for ever!

[Dunsignalling]

It would need the Gunnislake portion to take the same time to make the return trip as the Tavistock portion to make the timetable work to an hourly pattern. 

Not necessarily the same time.

 

It would only need both the Bere Alston - Gunnislake and Bere Alston - Tavistock return trips to be achievable within an allowance sufficient to make return departures from Bere Alston to Plymouth fit into a clock-face template.

 

If one had to wait for the other in Bere Alston for a few minutes on the way back, it would actually be beneficial. Any and all procedures that can be devised to couple up units begin with one being at a stand. If the same one always arrives first, it ensures a consistent operating approach is applied to all trains.

 

John

Edited July 13, 2014 by Dunsignalling

[The Stationmaster]

The most obvious (to me, from years ago) but expensive, solution is to have the Gunnislake trains run into a seperate platform at Bere Alston and to couple up by coming on top of the rear of the  unit from Tavistock via a  connection at the Tavistock end of the station/

Problem then is that you have two trains in a token/One Train working section - not quite the the thing

[The Stationmaster]

Not necessarily the same time.

 

It would only need both the Bere Alston - Gunnislake and Bere Alston - Tavistock return trips to be achievable within an allowance sufficient to make return departures from Bere Alston to Plymouth fit into a clock-face template.

 

If one had to wait for the other in Bere Alston for a few minutes on the way back, it would actually be beneficial. Any and all procedures that can be devised to couple up units begin with one being at a stand. If the same one always arrives first, it ensures a consistent operating approach is applied to all trains.

 

John

It doesn't really matter which one arrives first - as long as it is consistent as you say - but that might need a bit of visible signalling to ensure it happens (but it can be automatic).  The problem arises with there being no equivalent of a Clearing Point/Overlap between two passenger trains approaching the same bit of railway and this is where some thinking outside the box has to come in (and having the connection from Gunnislake trail in towards Tavistock immediately rules out one relatively straightforward solution - and it means that arriving trains from the two 'twigs' of the branch are running in face-to-face).

 

I can think of a way of doing it but it would require some bending of some basic principles.  Of course the other problem is taht the running time to and from Tavistock might not allow an hourly interval if it also includes a need to split/join trains at Bere Alston.

[The Stationmaster]

I know, but I leave the technicalities to those who know better than I

Presumably you can have two sperate sections, one for Gunni and one for Tavistock?

That is a logical outcome but the arrangement of the junction poses complications and it doesn't solve the problem - as i noted (but haven't fully explained) above.

[Gwiwer]

The present Gunnislake service is roughly at 2-hour intervals which suffices for present traffic needs.  A suggested Tavistock service might run once every two hours initially or (as I suggested above) every 90 minutes.  But two trains to ether beyond St Budeaux Junction is a no-no however you look at it without some sort of additional protection.

 

There may be no means by which a train to either route can be "locked in" to the route beyond Bere Alston and as I understand  CK's comments there is no proposal and no money for such a safe working system to be included.

 

Therefore I am left to conclude that the "creative thinking" option is what remains.  Judicious use of STOP boards for example.  That still bends principles in that there is nothing other than a sign to prevent an over-run and one train running ahead and meeting the other coming in the opposite direction.  It might have been easier had the connection involved both trains approaching in the same direction (as happens at Salisbury to refer back to an earlier example offered).

 

I believe signalling complications was one reason cited for the Far North trains no longer splitting at Georgemas Junction.  They operate on RETB rather than a traditional token and one-train working but units from opposite directions would still have to be admitted to the same platform with nothing to precent a head-on collision.  As with Gunnislake traffic levels don't always support more than a 2-car train either though in summer they most certainly do.

 

If there is to be a Gunnislake bay at Bere Alston then rather than have the "branch" unit idle for all but 20 minutes of each 2-hour cycle it could precede a Tavistock working and take the bay before reversal.  This would require some sort of lock and release system to clear the "main" line for a following Tavy unit.  If suitably timetabled this might result in a near-hourly (though probably not clock-face) service for Bere Alston and Bere Ferrers to and from Plymouth.

[Not Captain Kernow]

Not necessarily the same time.

 

It would only need both the Bere Alston - Gunnislake and Bere Alston - Tavistock return trips to be achievable within an allowance sufficient to make return departures from Bere Alston to Plymouth fit into a clock-face template.

 

If one had to wait for the other in Bere Alston for a few minutes on the way back, it would actually be beneficial. Any and all procedures that can be devised to couple up units begin with one being at a stand. If the same one always arrives first, it ensures a consistent operating approach is applied to all trains.

Sorry, I don't think I made it clear enough what I meant.  What you say is of course correct, but at present the journey from Bere Alston to Gunnislake takes 18 minutes.  The planned journey time from Bere Alston to Tavistock is only projected to take 9 minutes.  You can get an hourly Tavistock service in (as confirmed by CK above with conditions) but you will not be able to get the unit from Bere Alston to Gunnislake and back in time to connect with this.  It won't even work for a 90 minute service.