What work is required for Portishead to reopen?

[jazzy]

I’ve had a look at various Portishead threads and can’t see detail of what work is required to restore the passenger service? Clearly line will need to be laid from the junction with the line to Portbury Docks at Pill and of course a new station at Portishead but is there also work required on the existing line from Temple Meads to Pill to bring it up to standard for passenger use? I assume if the line is good enough for heavy freight then it’s good enough for passengers but maybe I’m being naive?

 

[John R]

It's a very good question. Work is indeed required through the Avon Gorge, with some realignments necessary IIRC. The speed limit for existing freight traffic is a somewhat leisurely 30mph, as you can see from the attached extract from the Sectional Appendix.

The problem is that the Avon Gorge is very constrained in terms of space, and also very sensitive environmentally - an issue that caused considerable delay in getting the Development Consent Order approved, as some very rare trees will have to be felled. Without that delay I suspect the work would be well underway, and at considerably lower cost, due to construction inflation in the meantime.

I don't believe any work is envisaged between Temple Meads and Parson St. Certainly any thought of reinstated the second southbound line as part of the project disappeared very early on.

 

[507020]

I’m aware that at least the *engineering* issues (political issues aside) revolve around the need to redouble through the environmentally sensitive Avon gorge, as the existing single track is insufficient to carry the passenger service. It isn’t just a case of laying the track from Pill to Portishead and building platforms, as much as that needs doing.

I don’t understand why the currently proposed scope of the project doesn’t include proper redoubling of Parson Street Junction, or a very busy station at Ashton Gate, but those would be possible later.

some very rare trees will have to be felled

Can cuttings, seed samples etc be taken to mitigate this?

 

[Snow1964]

It isn’t just a case of laying the track from Pill to Portishead and building platforms, as much as that needs doing.

The junction was plain lined few years ago, but only done on a quick and easy basis in sense the point blades are still there on site, sitting a few metres away (within the reach of a road-railer machine), and I believe the longer junction sleepers are still in situ allowing it to be be quickly put back (not that it has happened for few years).

Once past the short gap at the junction, I am fairly sure rusting track (probably now with weeds) covers fair chunk of the route. No idea if it needs replacing as worn out or just weed removal.

 

[John R]

I’m aware that at least the *engineering* issues (political issues aside) revolve around the need to redouble through the environmentally sensitive Avon gorge, as the existing single track is insufficient to carry the passenger service. It isn’t just a case of laying the track from Pill to Portishead and building platforms, as much as that needs doing.

I don’t understand why the currently proposed scope of the project doesn’t include proper redoubling of Parson Street Junction, or a very busy station at Ashton Gate, but those would be possible later.

Can cuttings, seed samples etc be taken to mitigate this?

There is no redoubling proposed through the Avon Gorge, just some realignment.

As for the trees, the proposal is to replace those felled with previously grown saplings. It is likely that some of those to be felled would have to be anyway, as Network Rail claimed they would soon become a danger to the line anyway. The problem was that the initial submission was not detailed enough to the Inspector's satisfaction given the representations. What surprised me is that usually these things are ironed out during the consultation process, but in this case apparently not.

 

[paul1609]

Ive walked along the cycle track thats next to the disused line from Junction 19 of the M5 to Pill Junction. Although the track is ostensibly still there, the line needs completely rebuilding- in many places its a ditch full of water. Certainly doesnt have any operational drainage and is largely completely overgrown.

 

[John R]

Once past the short gap at the junction, I am fairly sure rusting track (probably now with weeds) covers fair chunk of the route. No idea if it needs replacing as worn out or just weed removal.

Completely replaced. Some of it has already gone to the Avon Valley Railway.

I don’t understand why the currently proposed scope of the project doesn’t include proper redoubling of Parson Street Junction, or a very busy station at Ashton Gate, but those would be possible later.

It's called cost. Obviously the view is that it is not needed, which for an initial 1tph service is hardly surprising.

As for a very busy station at Ashton Gate, who knows. it's a moot point whether it would be suitable for events at the stadium, as the service would not be remotely adequate to cope with numbers, particularly after events finish. So even if built it might be closed when events are on.

 

[507020]

There is no redoubling proposed through the Avon Gorge, just some realignment.

As for the trees, the proposal is to replace those felled with previously grown saplings. It is likely that some of those to be felled would have to be anyway, as Network Rail claimed they would soon become a danger to the line anyway. The problem was that the initial submission was not detailed enough to the Inspector's satisfaction given the representations. What surprised me is that usually these things are ironed out during the consultation process, but in this case apparently not.

The plans I saw were for parallel single tracks i.e. Crediton - Yeoford or Bare Lane - Morecambe between Parson Street and Pill, rather than proper redoubling. Not sure why this is viable anywhere with the capacity constraint it introduces, for the sake of one crossover.

Are you saying that if there were no plans to reopen to Portishead at all, then removing the same trees over the existing goods line wouldn’t be an issue, but that as they are, they can be used as an excuse? Work could start, although with access only by road, at the Portishead, especially on the station while awaiting environmental surveys for the Avon gorge section.

It's called cost. Obviously the view is that it is not needed, which for an initial 1tph service is hardly surprising.

As for a very busy station at Ashton Gate, who knows. it's a moot point whether it would be suitable for events at the stadium, as the service would not be remotely adequate to cope with numbers, particularly after events finish. So even if built it might be closed when events are on.

Obviously Ashton Gate station would have to be built to cope with events, but they could use the Avonmouth/Severn Beach setup. 1tph to Portishead and 2tph as far as Ashton Gate. You wouldn’t just dump all stadium traffic onto Portishead shuttles. You could even do Portishead - Severn Beach on top of Ashton Gate - Avonmouth.

 

[John R]

The plans I saw were for parallel single tracks i.e. Crediton - Yeoford or Bare Lane - Morecambe between Parson Street and Pill, rather than proper redoubling. Not sure why this is viable anywhere with the capacity constraint it introduces, for the sake of one crossover.

Around 800m through Pill will be parallel single tracks prior to the divergence to Portishead, but the line through the gorge will remain single track.

Obviously Ashton Gate station would have to be built to cope with events,

It's not obvious at all. Parson St is less than a mile away, and is much better placed to cope with matchday traffic.

Work could start, although with access only by road, at the Portishead, especially on the station while awaiting environmental surveys for the Avon gorge section.

There is no issue with the trees now. The plan was agreed prior to the DCO sign off. It just added another 6 months to the sign off process. The issue now is that the government needs to agree to its (not inconsiderable) share of the funding of the project before any work can start. As a North Somerset Council taxpayer, I certainly don't want a penny spent on a project for which there is no guarantee that it can be completed if the govt walks away from it.

 

[jazzy]

Around 800m through Pill will be parallel single tracks prior to the divergence to Portishead, but the line through the gorge will remain single track.

Can you explain how parallel single tracks differ to double tracks?

 

[snowball]

Can you explain how parallel single tracks differ to double tracks?

Parallel single tracks means two tracks side-by side that look to the casual observer like double track, but at some point they separate and go to two different destinations. Instead of being an up line and a down line, each line is two-way, to and from its respective destination, with no access to/from the other. Post #8 mentions two other places on the network where this arrangement exists.

 

[DynamicSpirit]

The plans I saw were for parallel single tracks i.e. Crediton - Yeoford or Bare Lane - Morecambe between Parson Street and Pill, rather than proper redoubling. Not sure why this is viable anywhere with the capacity constraint it introduces, for the sake of one crossover.

It does indeed seem very short-sighted to do that kind of arrangement where a relatively small additional expense would give so much extra capacity. To be fair though, the issue can be, more than one crossover. As an example for Crediton-Yeoford, proper redoubling would also require work to rebuild/reopen the 2nd platform at Yeoford, plus I believe increasing the linespeed on the current Okehampton track to match that on the Barnstaple track if you don't want redoubling to cause slowing down of Barnstaple trains. I don't know whether there are any comparable issues for Portishead.

 

[John R]

It does indeed seem very short-sighted to do that kind of arrangement where a relatively small additional expense would give so much extra capacity. To be fair though, the issue can be, more than one crossover. As an example for Crediton-Yeoford, proper redoubling would also require work to rebuild/reopen the 2nd platform at Yeoford, plus I believe increasing the linespeed on the current Okehampton track to match that on the Barnstaple track if you don't want redoubling to cause slowing down of Barnstaple trains. I don't know whether there are any comparable issues for Portishead.

It’s only in respect of the last 800m before the lines diverge.

 

[DynamicSpirit]

Parallel single tracks means two tracks side-by side that look to the casual observer like double track, but at some point they separate and go to two different destinations. Instead of being an up line and a down line, each line is two-way, to and from its respective destination, with no access to/from the other. Post #8 mentions two other places on the network where this arrangement exists.

Yep, that's it. Although the Morecambe arrangement has the curiosity that both lines actually go to the same destination (Morecambe) so you literally have two parallel and independent single tracks to Bare Lane and Morecambe. It's just that only one of the two tracks allows the odd one train a day to carry on to Heysham.

 

[507020]

It does indeed seem very short-sighted to do that kind of arrangement where a relatively small additional expense would give so much extra capacity. To be fair though, the issue can be, more than one crossover. As an example for Crediton-Yeoford, proper redoubling would also require work to rebuild/reopen the 2nd platform at Yeoford, plus I believe increasing the linespeed on the current Okehampton track to match that on the Barnstaple track if you don't want redoubling to cause slowing down of Barnstaple trains. I don't know whether there are any comparable issues for Portishead.

I believe it’s the other way round, with the newer up and down Okehampton track being faster, but in this example, even doing no other work, installing a single crossover to allow Barnstaple trains to call at the platform at Yeoford in both directions, but with proper left hand running double track from there to Crediton would still provide a very cheap capacity increase, which I’m sure could absorb the difference of trains running faster in one direction than the other.

It’s only in respect of the last 800m before the lines diverge.

Yep, that's it. Although the Morecambe arrangement has the curiosity that both lines actually go to the same destination (Morecambe) so you literally have two parallel and independent single tracks to Bare Lane and Morecambe. It's just that only one of the two tracks allows the odd one train a day to carry on to Heysham.

But could you do something interesting with respect to this. For the immense cost of doing any construction work in the Avon gorge with full environmental mitigations, could you redouble more for relatively little cost increase, but a higher capacity railway and would both tracks necessarily need access to the docks as well as Portishead?

 

[zwk500]

Obviously Ashton Gate station would have to be built to cope with events, but they could use the Avonmouth/Severn Beach setup. 1tph to Portishead and 2tph as far as Ashton Gate.

Completely the opposite is true. The current shuttle bus system works perfectly well from Temple Meads and P&R sites, and any reopened Ashton Gate station would probably not have space for event crowds to queue. Buses can keep the queue moving at a steady pace (25K capacity is not massive in the scheme of football grounds) rather than 10- or 15-minute intervals of 1-200 people cramming onto a DMU. If Ashton Gate station did reopen, it'd likely close for a couple of hours either side of events for crowd safety.

Can you explain how parallel single tracks differ to double tracks?

Think of them as single lines that have a really gentle diverge.

But could you do something interesting with respect to this. For the immense cost of doing any construction work in the Avon gorge with full environmental mitigations, could you redouble more for relatively little cost increase, but a higher capacity railway and would both tracks necessarily need access to the docks as well as Portishead?

Anything to do with a loop at Pill will add costs to the project - exactly what it doesn't need when the BCR is so finely balanced. Far better to get it in and running at 1tph and then use permitted development rights to add in a loop at Pill later when the service goes to 2tph.

 

[John R]

But could you do something interesting with respect to this. For the immense cost of doing any construction work in the Avon gorge with full environmental mitigations, could you redouble more for relatively little cost increase, but a higher capacity railway and would both tracks necessarily need access to the docks as well as Portishead?

It’s an “interesting” suggestion on a scheme that has seen its cost multiply , partly due to the challenges of working within the gorge, to the point where it is on a knife edge as to whether it will proceed.

Are you actually familiar with the gorge? The idea that you could double the track through it is fanciful.

 

[JKF]

It’s an “interesting” suggestion on a scheme that has seen its cost multiply , partly due to the challenges of working within the gorge, to the point where it is on a knife edge as to whether it will proceed.

Are you actually familiar with the gorge? The idea that you could double the track through it is fanciful.

Sections of the gorge were built for double track, certainly the tunnel beneath the suspension bridge, but other infrastructure is definitely single. I’m not aware of any plans for doubling, though I think at one time there was talk of a passing loop in the gorge to allow half-hourly services (Pill and Parson Street don’t really work for this as too close to the respective ends of the service).

There have been extensive works in the gorge over the last year or so, with steel mesh netting installed to prevent rockfalls, particularly around the tunnel mouths - picture attached of one location. I guess this had been done outside of the cost of the passenger scheme, but I think there might have been one eye on preparing for this rather than to serve the more or less non-existent freight traffic. In places they have carefully cut the mesh around Bristol Whitebeam trees (a species native only to the gorge) while many other trees have been felled. There is already an area set out for planting replacement trees which I think is related to the proposed passenger scheme.

Regarding other costs, there will be station construction in Portishead and a lot of work required at Pill station. For the latter, the current track through the station was relaid towards the centre away from the platform when it was reopened for freight, so will need slewing back as well as installation of a second track. I think the proposed loop also commences on or before Pill viaduct where the track also currently still sits in the centre. Since the dock branch is off to the right, the proposal is to reopen the former down platform at Pill for passengers with freight staying on the up. This will need a lift tower and/or stairs to access from the road above.

The former up platform has level access at the north end, where there is also the former goods yard which could be used as a small car park and would be a better option for access, but I guess the cost of building and maintaining a lift tower works out less than the cost of making a loop or flat crossing with associated signalling at Pill for freight to use the up platform.

There are currently no plans to reopen Ashton Gate station, which is a shame as there is quite a lot of employment in that area and a decent cycleway linking to Hotwells/Clifton. Reportedly rejected due to potential football crowds.

Portishead station will be quite a distance from the high street and seafront, which isn’t going to make it very attractive for incoming visitors, so traffic will mostly be one-way in the peaks. The original station was right in the heart of the town, but since we aren’t allowed new level crossings it has to terminate 500 metres short.

 

[zwk500]

Sections of the gorge were built for double track, certainly the tunnel beneath the suspension bridge, but other infrastructure is definitely single. I’m not aware of any plans for doubling, though I think at one time there was talk of a passing loop in the gorge to allow half-hourly services (Pill and Parson Street don’t really work for this as too close to the respective ends of the service).

I think a 45-minute frequency is theoretically possible without a loop, so Pill likely would work although freight would probably then be restricted to certain hours as a 2tph service requires a 12 minute journey time between Ashton Jn and Pill or thereabouts). Ashton Jn to Pill is 6 miles, so a 12 minute transit would require an average speed of 30mph, hence the moderate uplifts needed as part of the scheme (obviously at points the speed will be below 30mph accelerating/braking so a speed above 30mph is required to average that figure). To get a freight in you would need a slightly higher speed or mid-section signals to allow freight to be 'flighted' behind the passenger service to maximise line capacity, increasing costs even further.

Gettting the line built is key, because once it's there, the pressure to make best use of it will grow. A 1tph or 1tp0.75h service will establish some data for usage and patterns, and amending an existing line is far more straightforward than building a new/restoring an old one.

There are currently no plans to reopen Ashton Gate station, which is a shame as there is quite a lot of employment in that area and a decent cycleway linking to Hotwells/Clifton. Reportedly rejected due to potential football crowds.

Not quite accurate - Ashton Gate remains a long-term intention, however it's been deferred from the current scheme to improve the overall scheme (i.e. it was costing more to fit it in than it was worth).

Portishead station will be quite a distance from the high street and seafront, which isn’t going to make it very attractive for incoming visitors, so traffic will mostly be one-way in the peaks. The original station was right in the heart of the town, but since we aren’t allowed new level crossings it has to terminate 500 metres short.

Portishead was always going to be about commuters in the peaks, visitor traffic won't be when the roads are most congested.

The original station was alongside the dock, so hardly much better than the existing site for the western half of the town. The 1954 Station is now under supermarkets, so you'd still have been 100m short. Cutting Quays avenue in two wouldn't exactly be great for traffic in the town centre even if you built a replacement further east using the Sheepway. However I wouldn't be surprised if many people looked at getting an E-Bike or E-Scooter for commuting from the far side of town, or even used the WestLink DRT service in the mornings.

 

[JKF]

The original station was alongside the dock, so hardly much better than the existing site for the western half of the town. The 1954 Station is now under supermarkets, so you'd still have been 100m short. Cutting Quays avenue in two wouldn't exactly be great for traffic in the town centre even if you built a replacement further east using the Sheepway. However I wouldn't be surprised if many people looked at getting an E-Bike or E-Scooter for commuting from the far side of town, or even used the WestLink DRT service in the mornings.

I did mean the ‘54 station! The building was used as the kiosk for the petrol station but was then demolished and the petrol station rebuilt around 30 years ago. I recall the proposed site was only slightly south of this, around the Waitrose car park area I think (although looking at the map maybe nearer Lidl).

A shame about the Quays Avenue crossing, I think the developer of the dockside housing was on the hook for this originally but they went bust with the 2008 recession (or rather the part of the company set up for this development did) so it was never done, and then after several high profile crossing incidents NR said no more crossings unless exceptional circumstances. I can’t really see it having been a big risk here given the likely speed of trains in proximity to the station, but thems the rules, and the station sits 400m south of where it should be as a result.

I’m hoping they improve pedestrian routes towards the west following the station opening as they’re not great at the moment. I think the run-down industrial estate to the west is highly likely to be redeveloped which will allow this, it’ll certainly be a high value site for housing with a station nearby.

 

[HSTEd]

I do worry that this project will end up leading to the "Hope Valley syndrome", where we end up with two parallel railways a few hundred metres apart - neither of which are able to offer a truly compelling service proposition.

I understand why reopening via Ashton Gate is the option that has been taken forward, but I can't help feeling that we will regret not building a bridge west of the gorge and adding another passing loop to the Severn Beach branch instead.
But I must admit that this project seems to have dragged on rather longer than we might have anticipated, with nothing happening.

 

[zwk500]

I’m hoping they improve pedestrian routes towards the west following the station opening as they’re not great at the moment. I think the run-down industrial estate to the west is highly likely to be redeveloped which will allow this, it’ll certainly be a high value site for housing with a station nearby.

Yes, there's a lot of scope to increase the permeability of access to foot/bicycle etc.

I do worry that this project will end up leading to the "Hope Valley syndrome", where we end up with two parallel railways a few hundred metres apart - neither of which are able to offer a truly compelling service proposition.

The Severn Beach line on it's own is well used, if a little light off-peak as you'd expect.

I understand why reopening via Ashton Gate is the option that has been taken forward, but I can't help feeling that we will regret not building a bridge west of the gorge and adding another passing loop to the Severn Beach branch instead.
But I must admit that this project seems to have dragged on rather longer than we might have anticipated, with nothing happening.

Where exactly? Building a bridge across the Avon would have got dragged through the legal wringer every bit as much as the options actually taken forward. And given the tidal range (~12m) the minimum air draught below the deck will require stiff gradients from the eastern bank (the line is right by the river at times), even if only for relatively low pleasure boats.

 

[John R]

I do worry that this project will end up leading to the "Hope Valley syndrome", where we end up with two parallel railways a few hundred metres apart - neither of which are able to offer a truly compelling service proposition.

I understand why reopening via Ashton Gate is the option that has been taken forward, but I can't help feeling that we will regret not building a bridge west of the gorge and adding another passing loop to the Severn Beach branch instead.

You only have to cross the Avonmouth Bridge and see how far below Portway Park and Ride is to realise that there is no possibility of a bridge. (The bridge is 30m above mean high water.) The tides in the River Avon and the need to retain access to Bristol Harbourside for taller vessels means it's a pie in the sky proposition.

And as for the Severn Beach line not offering a compelling service proposition - it's every 30 mins from Avonmouth into the centre, and enjoys a very healthy patronage.

 

[Geoff DC]

An opening bridge like those that are common in Holland would work and probably rarely need to open.
Even if it had to open on every tide - IIRC the river is only navigable for about 2 hrs each tide.
The majority of motor (leisure) vessels would pass under the bridge, so opening would probably be more for maintenance than navigational use.

 

[zwk500]

An opening bridge like those that are common in Holland would work and probably rarely need to open.
Even if it had to open on every tide - IIRC the river is only navigable for about 2 hrs each tide.
The majority of motor (leisure) vessels would pass under the bridge, so opening would probably be more for maintenance than navigational use.

Massive cost to include a lifting/swinging mechanism for such a small amount of benefit (limited opening times). And not a particularly useful service to the western bank of the gorge as it takes ages to get to Temple Meads. However running a Portishead-Avonmouth via Temple Meads allows a much quicker journey to TM, with only 15mins further to Clifton Down.
There's also the question of capacity between Clifton Down and Narroways Hill Jn.

 

[DynamicSpirit]

Perhaps a silly question, but has anyone ever considered the possibility of a footbridge (or foot tunnel) from Pill to Shirehampton? As the crow flies, it's 600m from Shirehampton station to the centre of Pill, so with a decently located crossing, that could be less than 10 minute's walk. A foot crossing wouldn't be cheap, but would likely massively cheaper than the rail reopening. And though it wouldn't do anything for Portishead itself, it would therefore for all practical purposes provide Pill with a not-too-inconvenient rail service.

 

[zwk500]

Perhaps a silly question, but has anyone ever considered the possibility of a footbridge (or foot tunnel) from Pill to Shirehampton? As the crow flies, it's 600m from Shirehampton station to the centre of Pill, so with a decently located crossing, that could be less than 10 minute's walk. A foot crossing wouldn't be cheap, but would likely massively cheaper than the rail reopening. And though it wouldn't do anything for Portishead itself, it would therefore for all practical purposes provide Pill with a not-too-inconvenient rail service.

May as well provide everybody in Pill with a e-trike to go across the Avonmouth M5 bridge footpath.

 

[John R]

An opening bridge like those that are common in Holland would work and probably rarely need to open.
Even if it had to open on every tide - IIRC the river is only navigable for about 2 hrs each tide.
The majority of motor (leisure) vessels would pass under the bridge, so opening would probably be more for maintenance than navigational use.

Yes, let’s make it a vastly more expensive project, with increased maintenance costs too, and as a result give Portishead a slower service into Bristol. Perfect!

 

[The exile]

I do worry that this project will end up leading to the "Hope Valley syndrome", where we end up with two parallel railways a few hundred metres apart - neither of which are able to offer a truly compelling service provision.

Given the fact that there is to all intents and purposes an uncrossable barrier between them (between the Suspension bridge and Avonmouth), it doesn’t matter whether the two lines are 60 feet apart or 60 miles.

 

[Doctor Fegg]

An opening bridge like those that are common in Holland would work and probably rarely need to open.

Keadby and Trowse show exactly how problematic these can be.