Salisbury - Exeter punctuality improvements?

[MarkyT]

delete

 

[BerkshireRails]

I don't think so, not to a worthwhile extent. That would have minimal impact on the delays incurred on the single line sections.

Oh, yeah, because Tisbury has two platforms and passing the looo extension would save 5 minutes on Down services on the route to Exeter.

 

[supervc-10]

That wouldn't be a bad idea to have one long dynamic loop.

How about one big dynamic loop all the way from Salisbury to Exeter, with a few crossover points?

In all seriousness- Tisbury absolutely needs doubling to the station. So frustrating sitting there in a field, waiting to get off an overheated 159 with non-functioning AC, having come all the way from London (I speak from experience! Worst was when having flown back from Chicago with a high fever and catching the train down.... grim, 0/10, do not recommend)

A rolling program of upgrades would be the most logical plan. Upgrading the pinch points one at a time to improve punctuality and resilience, but with a whole line plan. Passive provision for 25kV electrification should be designed in where possible too, given the current issues with extending 3rd rail. Where joining loops is possible, that would be ideal. I don't think that the route is ever going to get as quick or well used as the GWR option, but passenger numbers are growing across much of the south west, and it's already often pretty overcrowded.

 

[BerkshireRails]

How about one big dynamic loop all the way from Salisbury to Exeter, with a few crossover points?

In all seriousness- Tisbury absolutely needs doubling to the station. So frustrating sitting there in a field, waiting to get off an overheated 159 with non-functioning AC, having come all the way from London (I speak from experience! Worst was when having flown back from Chicago with a high fever and catching the train down.... grim, 0/10, do not recommend)

A rolling program of upgrades would be the most logical plan. Upgrading the pinch points one at a time to improve punctuality and resilience, but with a whole line plan. Passive provision for 25kV electrification should be designed in where possible too, given the current issues with extending 3rd rail. Where joining loops is possible, that would be ideal. I don't think that the route is ever going to get as quick or well used as the GWR option, but passenger numbers are growing across much of the south west, and it's already often pretty overcrowded.

Just sorting out Tisbury would save Five Minutes on Down services to Exeter, which could either be used for reliability or as a journey time saving or both.

 

[Brubulus]

Just sorting out Tisbury would save Five Minutes on Down services to Exeter, which could either be used for reliability or as a journey time saving or both.

Tisbury and new trains would likely enable substantial reliability and journey time improvements.

A loop at Cranbrook to enable 2tph between Exeter and Honiton and the line is sorted for the medium term.

I would hope there could be a standardised battery range for Project Churchward of 125 miles, which would enable full battery operation across the GWR network, with chargers on branches, OLE on Filton Bank, Penzance and a short OLE section between Taunton and Exeter.

This would then enable SWR services to run from Basingstoke to Exeter on a single charge.

 

[BerkshireRails]

Tisbury and new trains would likely enable substantial reliability and journey time improvements.

A loop at Cranbrook to enable 2tph between Exeter and Honiton and the line is sorted for the medium term.

I would hope there could be a standardised battery range for Project Churchward of 125 miles, which would enable full battery operation across the GWR network, with chargers on branches, OLE on Filton Bank, Penzance and a short OLE section between Taunton and Exeter.

This would then enable SWR services to run from Basingstoke to Exeter on a single charge.

That is some of the stuff Network Rail is suggesting on WofE interims of trackwork.

Network Rail suggests;
New 6km Loop at Cranbrook,
Honiton Country end Loop extension to 3.9km past the platforms,
Axminster London end Loop extension to 142 milepost,
Yeovil Junction double track extended by 1 mile at the Country end,
Tisbury Loop is extended by 5.5km in the country direction, which will see an extra platform at Tisbury on the Down Exeter, with the Up Exeter using the existing platform.

This is the full list of track work.

 

[Zomboid]

This would then enable SWR services to run from Basingstoke to Exeter on a single charge.

That might be cutting it a bit fine given that it's 124 miles.
If you meant 125 miles between 80% and 20% charge it might work, but there are a lot of other variables that will affect range (temperature, speed, gradients, heat/AC load...). And there would need to be sufficient turn round time at Exeter to get a pretty depleted battery back to a high state of charge.

 

[Haywain]

Just sorting out Tisbury would save Five Minutes on Down services to Exeter, which could either be used for reliability or as a journey time saving or both.

But the down train still has to meet the up trains at all the right points, so a time saving in one direction doesn't necessarily make much, if any, difference.

 

[Zomboid]

What it would do is provide 5 minutes of resilience in down trains, which would probably need to be "spent" before Yeovil Junction. I wouldn't expect just sorting Tisbury out to have much impact on the timetabled departures from Gillingham etc.

 

[BerkshireRails]

What it would do is provide 5 minutes of resilience in down trains, which would probably need to be "spent" before Yeovil Junction. I wouldn't expect just sorting Tisbury out to have much impact on the timetabled departures from Gillingham etc.

Network Rail does plan to extend the double tracking at Yeovil Junction by a mile.

That might be cutting it a bit fine given that it's 124 miles.
If you meant 125 miles between 80% and 20% charge it might work, but there are a lot of other variables that will affect range (temperature, speed, gradients, heat/AC load...). And there would need to be sufficient turn round time at Exeter to get a pretty depleted battery back to a high state of charge.

You could have fast chargers at Crediton and Eggseford to top up the battery on route as the train stands there for a few minutes to exchange tokens.

 

[Zomboid]

We'll see what happens when batteries are rolled out for real, but I don't think that is a great idea to have a mandatory dwell time for charging at stations, especially at an intermediate station on tightly scheduled single lines. Any disruption and you could find yourself snookered all day.

In the context of the Salisbury - Exeter route, electrification of Templecombe to Yeovil and a section at the Exeter end (maybe fast chargers at St David's and the reversal/ stabling sidings, or just electrification of Cranbrook to Exeter Central) combined with trains that can manage 100-120 miles between 80% and 20% charge on the route would be enough.

 

[BerkshireRails]

We'll see what happens when batteries are rolled out for real, but I don't think that is a great idea to have a mandatory dwell time for charging at stations, especially at an intermediate station on tightly scheduled single lines. Any disruption and you could find yourself snookered all day.

In the context of the Salisbury - Exeter route, electrification of Templecombe to Yeovil and a section at the Exeter end (maybe fast chargers at St David's and the reversal/ stabling sidings, or just electrification of Cranbrook to Exeter Central) combined with trains that can manage 100-120 miles between 80% and 20% charge on the route would be enough.

That is in ideal conditions, what happens when the train has to sit for a few hours in the middle of no where without any external power supply?

 

[DM352]

The big problem with rebuilding the bridge is that the next junction north on the M5 is miles away at Cullompton - the old A38 just wouldn't be able to cope if you closed the motorway entirely. It would have to be done by by alternately closing each carriageway.

There is an overbridge over a lightly used lane a little to the north which would take a second track and has been looked at, but there are houses on the Exeter side which would require demolition.

The existing bridge would take gauntleted track which would save on pointwork if not signalling.

I am not an engineer but from google street view of the M5 bridge, it could be done in two halves with traffic redirected to one side.

Wishful thinking but looking at all the nearby greenfield building, the developers could contribute something meaningful for infrastructure beyond the usually minimal viable roundabouts installed on arteries.

I am curious how they did the A38 with Trent Valley 4 tracking from the two track original bridge. If it was HS2 a precast bridge would be slid into place!

In terms of general improvements, the Cotswold line may have had similar issues and they bit most of the bullet to redouble two? long single sections with a couple of single remaining.

 

[Zomboid]

That is in ideal conditions, what happens when the train has to sit for a few hours in the middle of no where without any external power supply?

It doesn't use a lot of its power, the vast majority of the drain on the battery will be for traction.

However that's one of the reasons I suggested 100-120 miles for 80-20% depletion, when the actual gaps would be 65 miles Basingstoke to Templecombe and up to 50 between Yeovil and Exeter. Salisbury terminators would have to run 70 miles Basingstoke - Salisbury - Basingstoke, though if the depot remains in Salisbury then some some charging infrastructure will be needed there.

I haven't considered the Salisbury - Southampton or Westbury line services. I have also assumed that the 10 miles between Templecombe and Yeovil is enough to get the state of charge back up to ~80%, which it may not be.

 

[The Ham]

It doesn't use a lot of its power, the vast majority of the drain on the battery will be for traction.

However that's one of the reasons I suggested 100-120 miles for 80-20% depletion, when the actual gaps would be 65 miles Basingstoke to Templecombe and up to 50 between Yeovil and Exeter. Salisbury terminators would have to run 70 miles Basingstoke - Salisbury - Basingstoke, though if the depot remains in Salisbury then some some charging infrastructure will be needed there.

I haven't considered the Salisbury - Southampton or Westbury line services. I have also assumed that the 10 miles between Templecombe and Yeovil is enough to get the state of charge back up to ~80%, which it may not be.

Which is fine when everything works well, however personally I'd put wires up at Salisbury (gains you charge for GWR services as well as SWR services and removes some of the pressure on the third rail to charge the Salisbury/Southampton services).

Likewise, extend the wires from Exeter to as far east as it's viable, however at the very least to the junction for Exmouth (again provides the most capacity for GWR services to charge).

Both these areas have a reasonable number of services (I think both have at least 4tph) so are reasonable to have wires installed.

I am not an engineer but from google street view of the M5 bridge, it could be done in two halves with traffic redirected to one side.

Wishful thinking but looking at all the nearby greenfield building, the developers could contribute something meaningful for infrastructure beyond the usually minimal viable roundabouts installed on arteries.

I am curious how they did the A38 with Trent Valley 4 tracking from the two track original bridge. If it was HS2 a precast bridge would be slid into place!

In terms of general improvements, the Cotswold line may have had similar issues and they bit most of the bullet to redouble two? long single sections with a couple of single remaining.

The M5 isn't necessary much of an issue, even if there were 8 trains (4tph n each direction) you'd still have 7 minutes to thread them through, even if the single line was 3 miles long and the trains were running at 30mph that's still enough time.

Firstly I'd you could get that down to 1 mile and 45mph then that would be more robust, but then you could probably run 10 services fairly reliably (single live section would be cleared in 90 seconds, maybe 120 seconds from stopped with a further 4 minutes to get through in the 6 minute window before impacting on the next service)

However the point being is that to get to that point you'd be looking at needing to redouble under the M5 you could be running 5tph in each direction, which is far more than most people are talking about for the foreseeable future.

 

[The Ham]

Not sure if others picked up on it, but Green Signals had an interview with SWR towards the end of last year where they were talking about shifting to battery trains with new third rail to charge (about 80km over 15 islands, mostly at stations).

 

[BerkshireRails]

Not sure if others picked up on it, but Green Signals had an interview with SWR towards the end of last year where they were talking about shifting to battery trains with new third rail to charge (about 80km over 15 islands, mostly at stations).

I did see that however the DfT is calling for a Combined Chiltern, GWR & SWR fleet replacement which might have stopped the currently proposed battery plan as we well have to wait and see what the combined fleet specifications are. It could be we gain tri-mode units like the class 769s. With SWR gaining AC, DC and Diesel units. This could be helpful in improving reliability as units would gain an enhanced constant acceleration rate compared to now.

 

[The Ham]

I did see that however the DfT is calling for a Combined Chiltern, GWR & SWR fleet replacement which might have stopped the currently proposed battery plan as we well have to wait and see what the combined fleet specifications are. It could be we gain tri-mode units like the class 769s. With SWR gaining AC, DC and Diesel units. This could be helpful in improving reliability as units would gain an enhanced constant acceleration rate compared to now.

Interesting.

That if course doesn't exclude the possibility of battery trains as SWR fleet could be an option for extra units as a fallback if the battery trains don't work as expected and/or the costs are too high to deliver.

(Although it's possible that the costs are known and they're too high, hence the combined fleet order).

 

[Brubulus]

Interesting.

That if course doesn't exclude the possibility of battery trains as SWR fleet could be an option for extra units as a fallback if the battery trains don't work as expected and/or the costs are too high to deliver.

(Although it's possible that the costs are known and they're too high, hence the combined fleet order).

There is no plan for third rail charging islands between Basingstoke and Exeter. The plan, if there is one, is to buy trains with large enough batteries that they can run the route on a single charge.

 

[The Ham]

There is no plan for third rail charging islands between Basingstoke and Exeter. The plan, if there is one, is to buy trains with large enough batteries that they can run the route on a single charge.

I was only quoting what was said on Green Signals at the tail end of last year, obviously may have changed since then but that was what they were talking about at that time.

 

[Brubulus]

I was only quoting what was said on Green Signals at the tail end of last year, obviously may have changed since then but that was what they were talking about at that time.

It was an idea, they've changed their mind. DfT seems to be convinced (correctly for once) that battery trains can travel 100 miles + on a charge so they are the future and very minimal infrastructure is needed.

 

[Zomboid]

Basingstoke to Exeter is 125 miles.

Whilst a 250+ mile range might be possible, I'd be very surprised if no charging was provided at all.

 

[brad465]

Basingstoke to Exeter is 125 miles.

Whilst a 250+ mile range might be possible, I'd be very surprised if no charging was provided at all.

At a minimum charging in the sidings at Exeter would be essential, especially as services are booked to spend around 45 minutes at that end of the route; if journey time savings of 5-10 minutes were found along the whole route, this would further help. This would of course though need the punctuality improvements through increased double-tracking, so that there is more likely to be enough time for late trains to recharge enough to get back. I'd also expect an "recharge island" would need to exist somewhere in the middle to improve resilience, perhaps somewhere between Salisbury and Yeovil to cater for trains that go beyond Salisbury but don't go all the way to Exeter.

 

[Haywain]

At a minimum charging in the sidings at Exeter would be essential, especially as services are booked to spend around 45 minutes at that end of the route; if journey time savings of 5-10 minutes were found along the whole route, this would further help. This would of course though need the punctuality improvements through increased double-tracking, so that there is more likely to be enough time for late trains to recharge enough to get back. I'd also expect an "recharge island" would need to exist somewhere in the middle to improve resilience, perhaps somewhere between Salisbury and Yeovil to cater for trains that go beyond Salisbury but don't go all the way to Exeter.

I would have thought charging would be needed at both Salisbury (for the depot) and Yeovil (for stabling). It can't be assumed that units will always be able to get to the existing 3rd rail.

 

[Kite159]

Meanwhile, in the real world where so-called super battery trains which can do 100+ miles of stop/start work with high speed running in between station calls are a mere pipe-dream for the UK as well as the infrastructure required to charge the super battery trains away from the 3rd rail, the sprinter fleet continues to drop like flies with various faults. But still give it 10 years and a 450 with batteries might just cope, smashing up the network with the excessive weight of an already heavy train made heavier with lots of batteries.

Whereas pure battery trains might be 'nice' for an environmental point of view, the only solution is diesel trains, maybe with smaller batteries to allow the engines to be shut down at terminal stations (whilst still providing power for AC/lighting etc and to give a boost to acceleration. Something like a 197 (which has gangways to allow passengers to transfer between units for short platforms and for portion detachments) and would allow the high peak trains to/from London to be formed of 9 coaches and the extensions to Castle Cary to be 3 coaches (as well as the Romsey services). Would keep the ORR happy with no new charging rail being installed and introducing risks of 3rd rail to South West based Network Rail track staff.