Reduced service on West of England Line from 5th Sept

[Class172]

As I’m casually scrolling through my twitter feed just now, I come across a tweet stating that due to degradation that has been discovered along the track bed of the West of England Line west of Yeovil, it will be necessary to limit services from 5th Sept onwards.

Now I’ve never seen an announcement like this before, and it’s not been provided directly from SWR or NR that I have seen (the tweet provided no direct source). Therefore I’m interested if this tweet has any truth to it, and whether this is documented officially somewhere, as it’s quite the drastic intervention if that’s the case.

@swtrains_watch: “#BREAKING West of England services on SWR to be cut by up to 50% for an indefinite period from next Monday, 5th Sep. Extended journey times and significant disruption are to be expected. This is due to the degradation of the infrastructure and track bed. Yet another blow for pax.”

 

[vikingdriver]

Apparently hourly as far as Yeovil and 2 hourly through to Exeter with journey times extended considerably.

 

[yorksrob]

This is certainly bad news. I would expect some sort of plan/timetable for fixing the issue, as at Eden Brows or Dawlish in recent years.

 

[swt_passenger]

Of course it’s often worse, with various embankment failures or collapses in the last few years resulting in complete closure of routes until fixed. Was the last big one in Kent somewhere?

 

[brad465]

Of course it’s often worse, with various embankment failures or collapses in the last few years resulting in complete closure of routes until fixed. Was the last big one in Kent somewhere?

There have been 2 in Kent in recent years that come to mind, the most recent I recall was Edenbridge/Penshurst way in early 2020 that curtailed Redhill-Tonbridge services due to a landslip. The other was the sea wall collapse between Folkestone and Dover in 2016 that took 9 months to fix, after discovering an old wooden structure underneath that was completely rotten out, with a full reconstruction of the line and seawall, perhaps even more complex than Dawlish in 2014.

Apparently hourly as far as Yeovil and 2 hourly through to Exeter with journey times extended considerably.

Could this be because a significant speed restriction needs imposing that would greatly impact single-line running west of Yeovil?

 

[swt_passenger]

There have been 2 in Kent in recent years that come to mind, the most recent I recall was Edenbridge/Penshurst way that curtailed Redhill-Tonbridge services due to a landslip. The other was the sea wall collapse between Folkestone and Dover in 2016 that took 9 months to fix, after discovering an old wooden structure underneath that was completely rotten out, with a full reconstruction of the line and seawall, perhaps even more complex than Dawlish in 2014.

There was one quite near Salisbury early 2020 of course, but heading in the Southampton direction, that would probably have been noticed more widely if it had affected the Exeter route. That was a 6 week closure.

South of Botley - the singles line to Fareham also closed for embankment repairs for about 6 weeks, 2014.

I’m wondering if perhaps a reduced service with speed restrictions is actually the more unusual response?

 

[vikingdriver]

There have been 2 in Kent in recent years that come to mind, the most recent I recall was Edenbridge/Penshurst way in early 2020 that curtailed Redhill-Tonbridge services due to a landslip. The other was the sea wall collapse between Folkestone and Dover in 2016 that took 9 months to fix, after discovering an old wooden structure underneath that was completely rotten out, with a full reconstruction of the line and seawall, perhaps even more complex than Dawlish in 2014.


Could this be because a significant speed restriction needs imposing that would greatly impact single-line running west of Yeovil?

There are already a couple of speed restrictions west of Yeovil but this recent and very lengthy one is east of Yeovil between Tisbury and Gillingham.

 

[Ashley Hill]

Is it known what has (allegedly) degraded?

 

[Kite159]

Makes sense, the speed restrictions between Gillingham & Tisbury are causing delays to snowball throughout the day due to the tight timetable.

 

[Snow1964]

Is it known what has (allegedly) degraded?

The general area around Cranborne Chase is chalk, (mainly Portsdown chalk and Culver chalk to be precise). However there are a number of Karst features (dissolved soluble rocks) and alluvial runoff from last ice age) and clay towards the South.

The Salisbury and Yeovil railway was built in late 1850s (opened in stages 1859 & 1860, and doubling the single line taking place in early 1860s.

The very dry weather can change the embankments, where the clay was included in embankments (and generally in 1850s route was all dug by hand so they moved it minimum distance possible). Dried out clay shrinks, leaving voids.

What can then happen, (and clearly diesel trains vibrate, and line uses trains with engines under every vehicle), it shakes down the foundations, and can lead to dips in the track. It can be even worse if when it rains again, some of the alluvial material washes into the voids, as the expanding clay (when the moisture returns) mixes with this sandy alluvial washout and produces a sort of slurry. The slurry is obviously unstable as it is a semi liquid.

Add in the karst feature areas with its previously dissolved rocks, they will clearly change if dried out (ultimately will get a powder if completely dry). So not a great basis for a solid base.

The actual detail of each metre of line will vary, so the above should give you an idea, even if not precise.

 

[JamesT]

If there’s an issue with the track, why would the restrictions wait for a week? Wouldn’t normal practice be to introduce restrictions immediately to prevent things worsening until it’s fixed?

 

[Bletchleyite]

If there’s an issue with the track, why would the restrictions wait for a week? Wouldn’t normal practice be to introduce restrictions immediately to prevent things worsening until it’s fixed?

I suspect the speed restrictions will be immediate but the timetable will just be a mess in the meantime.

 

[70014IronDuke]

The general area around Cranborne Chase is chalk, (mainly Portsdown chalk and Culver chalk to be precise). However there are a number of Karst features (dissolved soluble rocks) and alluvial runoff from last ice age) and clay towards the South.

The Salisbury and Yeovil railway was built in late 1850s (opened in stages 1859 & 1860, and doubling the single line taking place in early 1860s.

The very dry weather can change the embankments, where the clay was included in embankments (and generally in 1850s route was all dug by hand so they moved it minimum distance possible). Dried out clay shrinks, leaving voids.

What can then happen, (and clearly diesel trains vibrate, and line uses trains with engines under every vehicle), it shakes down the foundations, and can lead to dips in the track. It can be even worse if when it rains again, some of the alluvial material washes into the voids, as the expanding clay (when the moisture returns) mixes with this sandy alluvial washout and produces a sort of slurry. The slurry is obviously unstable as it is a semi liquid.

Add in the karst feature areas with its previously dissolved rocks, they will clearly change if dried out (ultimately will get a powder if completely dry). So not a great basis for a solid base.

The actual detail of each metre of line will vary, so the above should give you an idea, even if not precise.

Thank you for the detailed explanation.

Clearly not a problem that can be solved by a quick question at Prime Minister's question time.

If there’s an issue with the track, why would the restrictions wait for a week? Wouldn’t normal practice be to introduce restrictions immediately to prevent things worsening until it’s fixed?

That is what's happened, as far as I can see.

The two-hourly timetable is a more sustainable and predictable later modification.

 

[Oliver]

Thank you for the detailed explanation.

Clearly not a problem that can be solved by a quick question at Prime Minister's question time.

That is what's happened, as far as I can see.

The two-hourly timetable is a more sustainable and predictable later modification.

Here is the SWT announcement:

https://s6.newzapp.co.uk/t/view/1558991473/122565627

Due to the exceptionally dry conditions recently experienced across the Southern region, we have been forced to introduce an Emergency Speed Restriction between Tisbury and Gillingham.

The extreme heat, combined with a lack of rain, has caused the clay soil in some of the railway embankments between these stations to dry out and shrink. This has in turn led to some track defects appearing which means we are unable to run trains at full line speed. Our engineers are closely monitoring the condition of the line and estimate that this speed restriction will need to stay in place for several weeks.

To ensure we can run trains as reliably as possible between Salisbury and Exeter St Davids, we are working closely with our colleagues at South Western Railway (SWR), who in the coming days will announce a temporary, revised timetable for the line.

Whilst the timetable has not yet been finalised, it is expected that there will be a train approximately every hour between Yeovil Junction and Salisbury and approximately every two hours between Salisbury and Exeter St Davids...

I understand that the temporary timetable is not finalised, and it's not yet public. The odd part is that the problem is between Tisbury and Gillingham while the reduction in service will be west of Yeovil Jnc. That's because delays caused to Down trains around Gillingham will delay Up trains further west at the passing places, so the line descends into the spiral of delays which afflicts this route.

 

[yorksrob]

If they're going to be doing some heavy work on the route, is the affected area double track, and if not, would it be worth redoubling it at the same time ?

 

[zwk500]

If they're going to be doing some heavy work on the route, is the affected area double track, and if not, would it be worth redoubling it at the same time ?

They won't have the money, equipment, people, or authority to make any changes to the signalling. The most they can do is return the railway to the condition as published in the Sectional Appendix. They might be able to nab a few TSRs in the works, but no improvement over what was there before the problems.

 

[Irascible]

Hmm, any changes to Axminster-Exeter services? if the through route is two-hourly there's room ( and presumably a few spare units - aren't they being serviced at Exeter TMD these days? ).

 

[Oliver]

On Thursday 22nd September Claire Mann (MD SWT) and Mark Killick (NR Route Manager) will be addressing the AGM of SERUG (Salisbury to Exeter Rail User Group). The meeting will be held at the Yeovil Railway Centre, close to Yeovil Junction station, and starts at 17:00. There will be plenty to talk about! More details on the SERUG website: https://sites.google.com/view/serug/home

 

[Snow1964]

Here is the SWT announcement: https://s6.newzapp.co.uk/t/view/1558991473/122565627 I understand that the temporary timetable is not finalised, and it's not yet public. The odd part is that the problem is between Tisbury and Gillingham while the reduction in service will be west of Yeovil Jnc. That's because delays caused to Down trains around Gillingham will delay Up trains further west at the passing places, so the line descends into the spiral of delays which afflicts this route.

That is true for the through trains, cannot reach the passing loops by the time they are scheduled to cross.

However it is rather a poor explanation for why the service west of Yeovil needs to be dropped to 2 hourly, and a shuttle cannot run in the hour between the through trains.

The number of times the service is curtailed at Basingstoke when there is a line problem at London end suggests through services during disruption are not deemed essential, so there is no obvious need to operate a through service that spirals into further delays, when shuttles are normally accepted.

 

[SeanG]

Is it known when the temporary timetable will be published?

 

[dk1]

Not surprised that an emergency timetable is being brought in & makes sense. It's been quite chaotic of late constantly playing catch up.

 

[D6130]

However it is rather a poor explanation for why the service west of Yeovil needs to be dropped to 2 hourly, and a shuttle cannot run in the hour between the through trains.

Could it be because the average distance between passing loops West of Yeovil is greater than to the East?....although the introduction of the Axminster dynamic loop must surely have alleviated matters to an extent.

 

[brad465]

Thank you for the detailed explanation.

Clearly not a problem that can be solved by a quick question at Prime Minister's question time.

That is what's happened, as far as I can see.

The two-hourly timetable is a more sustainable and predictable later modification.

Presumably this can also be approved quicker than a full line closure to fix the works. Will there be a long list of night and weekend closures to fix the problem?

 

[Snow1964]

There are already planned closures in Tisbury area Sat 3rd and Sunday 4th September (all weekend)

Monday 19 - Friday 23rd was going to be buses Axminster-Exeter

 

[Timetraveller]

Also there is speed restriction in the Crewkerne area as well, hence a 2 hourly service will run through Waterloo to Salisbury to Exeter. (It will take longer too). Waterloo to Salisbury service will run alternate hour to Yeovil Junction.
The Planned closure on 3rd & 4th Septenber will mean trains are diverted via Westbury

 

[yorksrob]

They won't have the money, equipment, people, or authority to make any changes to the signalling. The most they can do is return the railway to the condition as published in the Sectional Appendix. They might be able to nab a few TSRs in the works, but no improvement over what was there before the problems.

Shame really. The demand is there for a main line service.

 

[zwk500]

Shame really. The demand is there for a main line service.

Maybe, but then it can go through the proper process to ensure the design is safe, cost-effective and all the supporting resources are in place as required for the life of the assets.

Emergency Repairs are not the time to start changing things. It will only end in tears, quite probably the customers as their trains are delayed for much longer than necessary because somebody tried to fit a resignalling scheme on top of an emergency embankment rebuild.

 

[Nicholas Lewis]

This might not be as simple as topping up the ballast to restore top and line and may need embankments to be strengthened which will necessitate civil engineering works.

 

[Grecian 1998]

Proves what Network Rail said in the 2020 line study is true - that the current level of single track makes it impossible to deliver a reliable on time railway with a resilient timetable. The study is here: https://www.networkrail.co.uk/wp-co...udy-Continuous-Modular-Strategic-Planning.pdf

As others have said, the timetable has been up the creek recently so thinning it out to deliver achievable timings is sensible despite the frustration it brings. The Axminster loop allowed an hourly service, but with minimal contingency for when things go wrong. As trains have been losing 20 minutes between Gillingham and Tisbury over a normally 10 minute journey, that definitely counts as wrong. There are

Network Rail have identified a number of packages which would allow improvements. As always the question is who pays for them.

Also there is speed restriction in the Crewkerne area as well

A particularly bad place for one, as it's in the middle of a 17 mile single track section between Chard Junction and Yeovil Junction.

 

[Bletchleyite]

Maybe, but then it can go through the proper process to ensure the design is safe, cost-effective and all the supporting resources are in place as required for the life of the assets.

Emergency Repairs are not the time to start changing things. It will only end in tears, quite probably the customers as their trains are delayed for much longer than necessary because somebody tried to fit a resignalling scheme on top of an emergency embankment rebuild.

Though to most peoples' surprise the last "biannual" Conwy Valley rebuild managed to sneak in a load of resilience work (e.g. some massive rocks alongside the line and the new Dolwyddelan platform being a solid "proper" one and not a cheapo "staging" one), and as a result it appears, touch wood, not to have washed away for quite some time now.

(I've jinxed it now!)