Nuneham Viaduct shut - Didcot- Oxford

[Bald Rick]

What they won't do is actually pay for a program of pro-active inspection and maintenance to avoid this kind of dangerous situation in the first place (and the expensive, disruptive work that goes with it)

Sorry, but this has to be called out.

There is a very robust proactive inspection and maintenance regime.

Specifically on Nuneham, it was being inspected frequently, and pro-active maintenance was underway. It was the people doing that work who put in place the line closure, as the bridge deteriorated very very quickly in a way that was not expected.

 

[jfowkes]

Sorry, but this has to be called out.

There is a very robust proactive inspection and maintenance regime.

Specifically on Nuneham, it was being inspected frequently, and pro-active maintenance was underway. It was the people doing that work who put in place the line closure, as the bridge deteriorated very very quickly in a way that was not expected.

True, I was too quick to post.

The context of my post was CP7 funding. It's clear (to me at least) that NR have been given the bare-minimum resources they need to maintain the network and that's about it. "Do more with less" is the motto here and I don't think that's a good thing for performance or safety.

 

[Annetts key]

Sorry, but this has to be called out.

There is a very robust proactive inspection and maintenance regime.

Specifically on Nuneham, it was being inspected frequently, and pro-active maintenance was underway. It was the people doing that work who put in place the line closure, as the bridge deteriorated very very quickly in a way that was not expected.

Yes, the engineers were monitoring it and closed the line. And yes, some work to try to stabilise it was taking place (which ultimately failed to help).

But where was the plan to proactively replace the bridge support and replace the affected part of the embankment? It’s not like the problem was not known about, it’s been ongoing for years.

The point is that trying to stabilise or extend the life of some infrastructure does not always work. But the railway does not always have sufficient money to be able to be proactive very often and therefore may not be able to replace said infrastructure before it gets to or near the point of line closure.

It can in some circumstances, but as funding for maintenance (as in maintaining the infrastructure for existing routes including renewals and replacement, not just ‘routine maintenance’) falls, the railway will have more and more dilemmas on which gets funding for large proactive engineering works, and which gets monitoring and cheaper ‘solutions’ to extend infrastructure life.

 

[Freightmaster]

Realtime trains is now showing freight to be back on 9th June, and passenger on 10th June. Great news!

Some Didcot to Oxford 'shuttles' have just appeared for tomorrow (Friday 9th):

Realtime Trains | Departures from Didcot North Jn between 0001 and 2359 on 09/06/2023

Train information at Didcot North Jn between 0001 and 2359 on 09/06/2023. From Realtime Trains, an independent source of train running info for Great Britain.

www.realtimetrains.co.uk

...if they run, that means the first passenger train since April 3rd should pass over the viaduct around 10.03 tomorrow.




MARK

 

[Xenophon PCDGS]

The affected running area from Oxford to Didcot is something more part of the national main-line picture than on some of the branch lines.

 

[reddragon]

Sorry, but this has to be called out.

There is a very robust proactive inspection and maintenance regime.

Specifically on Nuneham, it was being inspected frequently, and pro-active maintenance was underway. It was the people doing that work who put in place the line closure, as the bridge deteriorated very very quickly in a way that was not expected.

Pre works had also already been completed to divert the water main off the bridge due to movement a while ago. Imagine the consequences of it still being there?

 

[Bald Rick]

Yes, the engineers were monitoring it and closed the line. And yes, some work to try to stabilise it was taking place (which ultimately failed to help).

But where was the plan to proactively replace the bridge support and replace the affected part of the embankment? It’s not like the problem was not known about, it’s been ongoing for years.

Speaking to the people directly involved (one of whom is a long standing friend) - yes there was a plan. The issue is that the stabilisation works did not do what it was intended to - which is to put it mildly was unexpected.

 

[BrianW]

Yes, the engineers were monitoring it and closed the line. And yes, some work to try to stabilise it was taking place (which ultimately failed to help).

But where was the plan to proactively replace the bridge support and replace the affected part of the embankment? It’s not like the problem was not known about, it’s been ongoing for years.

The point is that trying to stabilise or extend the life of some infrastructure does not always work. But the railway does not always have sufficient money to be able to be proactive very often and therefore may not be able to replace said infrastructure before it gets to or near the point of line closure.

It can in some circumstances, but as funding for maintenance (as in maintaining the infrastructure for existing routes including renewals and replacement, not just ‘routine maintenance’) falls, the railway will have more and more dilemmas on which gets funding for large proactive engineering works, and which gets monitoring and cheaper ‘solutions’ to extend infrastructure life.

If I have read things right, there is 'incentive' to do emergency work as it avoids a lot of the delay and cost associated with paperwork/ approvals etc.

'A stitch in time' demands accurate assessment of timeliness, and inclination to do work ahead of when it might be necessary. That's a cost too, and leaves less in the budget for improvement works. Now where's that money tree?

BTW- credit to the 'orange army'; time for a Dawlish-esque photo-op; any Oxfordshire MPs in the Cabinet? MPs for Wantage and Maidenhead so 'yesterday'

 

[Benjwri]

Some Didcot to Oxford 'shuttles' have just appeared for tomorrow (Friday 9th):

Realtime Trains | Departures from Didcot North Jn between 0001 and 2359 on 09/06/2023

Train information at Didcot North Jn between 0001 and 2359 on 09/06/2023. From Realtime Trains, an independent source of train running info for Great Britain.

www.realtimetrains.co.uk

...if they run, that means the first passenger train since April 3rd should pass over the viaduct around 10.03 tomorrow.




MARK

Seems like they are still skeptical of them running though, not added to the timetable of the day yet.

 

[crablab]

not added to the timetable of the day yet.

Official reopening was said to be the 10th, so I imagine it's a case of "under promise, over deliver" in case there are delays handing back the possession or whatever.

 

[Sly Old Fox]

Chatting to a more senior driver who said there was a bump in the track there back when he signed the road in 1994.

Hopefully these works will help.

 

[father_jack]

An empty stock has run from Oxford to Didcot and back to Oxford this evening.

Realtime Trains | 5L99 1953 Oxford to Oxford | 08/06/2023

Real-time train running information for 5L99 1953 departure from Oxford to Oxford on 08/06/2023. From Realtime Trains, an independent source of train running info for Great Britain.

www.realtimetrains.co.uk

 

[Bald Rick]

Looks like the possession has been lifted…

 

[JN114]

An empty stock has run from Oxford to Didcot and back to Oxford this evening.

Realtime Trains | 5L99 1953 Oxford to Oxford | 08/06/2023

Real-time train running information for 5L99 1953 departure from Oxford to Oxford on 08/06/2023. From Realtime Trains, an independent source of train running info for Great Britain.

www.realtimetrains.co.uk

165124

 

[The Planner]

Possession handed back around 1900 apparently.

 

[Cowley]

Yes, the engineers were monitoring it and closed the line. And yes, some work to try to stabilise it was taking place (which ultimately failed to help).

But where was the plan to proactively replace the bridge support and replace the affected part of the embankment? It’s not like the problem was not known about, it’s been ongoing for years.

The point is that trying to stabilise or extend the life of some infrastructure does not always work. But the railway does not always have sufficient money to be able to be proactive very often and therefore may not be able to replace said infrastructure before it gets to or near the point of line closure.

It can in some circumstances, but as funding for maintenance (as in maintaining the infrastructure for existing routes including renewals and replacement, not just ‘routine maintenance’) falls, the railway will have more and more dilemmas on which gets funding for large proactive engineering works, and which gets monitoring and cheaper ‘solutions’ to extend infrastructure life.

Some of this is quite interesting so rather than me trying to pick the various posts apart I’ve started a separate thread on it which is here:

https://www.railforums.co.uk/threads/is-there-a-better-way-to-monitor-infrastructure-to-preemptively-catch-failures.249857/

If we could keep this thread on topic from here on that would be most appreciated.

Thanks.

 

[Snow1964]

It should also be remembered that although the line has now reopened, there is still lot of work to do under the span.

The temporary jacking platform needs to be removed, the temporary piles in the riverbed cut and removed (the affected span needs to be reopened to river navigation, so that boats can resume normal drive on the right).

Some of the worksite is also on the flood plain (although river has been low due to lack of rain), so probably need to build up some scour protection in front of the new piled abutment, and remove all temporary equipment, ahead of the autumn and winter high river season.

 

[Siemens Staines]

It look like 165128 worked the first passenger train to run through from Oxford to Didcot

Realtime Trains | 2L50 0710 Oxford to Didcot Parkway | 09/06/2023

Real-time train running information for 2L50 0710 departure from Oxford to Didcot Parkway on 09/06/2023. From Realtime Trains, an independent source of train running info for Great Britain.

www.realtimetrains.co.uk

 

[jimm]

Joint email just received from Network Rail Western, GWR and XC

You will know that we planned to re-open Nuneham Viaduct on the line between Oxford and Didcot Parkway for freight and passenger services from tomorrow (Saturday 10 June).

We have just had some very exciting news from the project team. All has gone well with the final testing and as a result GWR began operating passenger services over the viaduct this morning (Friday 9 June).

This is earlier than expected so full services, both GWR and CrossCountry, will resume tomorrow as planned, but we are really pleased that we have been able to deliver the earlier finish. Shuttle services will run throughout the day today between Oxford and Didcot Parkway.

Our Network Rail project team have worked very hard to make this happen. They understood the importance of re-opening as quickly as we could and everyone has been focused on meeting the 10 June opening date. It really is therefore fantastic to be reporting that not only is the viaduct opening on time, it’s opened early.

Thank you all for your help and support during the closure, please feel free to share the news of the opening to your networks (including footage at www.twitter.com/networkrailwest & www.gwr.com/gwrhelp) and let them know that while today services will be a shuttle from Oxford to Didcot, from tomorrow normal service is fully resumed.

 

[snowball]

Already a press release by 08:30 (may have been earlier)

Rail passengers on the move again through Nuneham as major project to replace 160-year-old viaduct support completes ahead of schedule

Engineers have worked around the clock to safely reopen Nuneham Viaduct, in Oxfordshire, a day early, on Friday 9 June, following an intensive ten-week programme of work.

www.networkrailmediacentre.co.uk

Rail passengers on the move again through Nuneham as major project to replace 160-year-old viaduct support completes ahead of schedule

Engineers have worked around the clock to safely reopen Nuneham Viaduct, in Oxfordshire, a day early, on Friday 9 June, following an intensive ten-week programme of work.

The railway between Didcot and Oxford was closed on Monday 3 April after significant movements in the viaduct were detected due to emerging structural issues with the south bank abutment (structure that supports the bridge). The abutment was built as part of the original viaduct in 1856.

The rail industry, including Great Western Railway (GWR), Chiltern Railways and CrossCountry, worked closely to keep passengers moving during the closure, whilst Network Rail’s engineers and contractors at Balfour Beatty carried out emergency repairs, which completed, ahead of schedule.

On Friday 9 June, the first passenger service to cross the viaduct in just under ten weeks was a GWR shuttle train between Didcot and Oxford. A full timetable for all train operators is planned to resume from Saturday 10 June.

Around 800 people have worked nearly 60,000 hours, to successfully install the new steel support, which will secure the future of this important rail link for generations to come.

In the final week of the major project, the 150-tonne bridge was lowered onto the new abutment, a new embankment built, before the railway tracks and cables were put back in place.

The repair of the viaduct has been complex, challenging and required some heavy engineering:

24 x 15m long steel piles were driven into the bed of the River Thames to create a solid platform for the temporary structure that held the weight of the viaduct while the abutment was demolished and rebuilt.
Eight more piles were driven up to 20m into the embankment to support the new structure.
A 750-tonne crane was used to lift the temporary structure into place.
4,500 tonnes of material removed from the old embankment
5,500 tonnes of material brought back in to build the new embankment

Engineers will remain on site for up to 12 weeks to finish works and demobilise the construction site, working outside of train operating hours, whilst track, signalling and station upgrades continue in Oxford city centre*.

 

[Nicholas Lewis]

Already a press release by 08:30 (may have been earlier)

Rail passengers on the move again through Nuneham as major project to replace 160-year-old viaduct support completes ahead of schedule

Engineers have worked around the clock to safely reopen Nuneham Viaduct, in Oxfordshire, a day early, on Friday 9 June, following an intensive ten-week programme of work.

www.networkrailmediacentre.co.uk

Good to see the industry can deliver extraordinary things when in crisis mode yet if you had tried to do this through normal channels probably would have needed a three year lead in and cost a lot more as @Bald Rick quoted above.

Perhaps there's an argument for just waiting for a crisis as long as it doesn't jeopardise safety to get things done.

 

[zwk500]

Perhaps there's an argument for just waiting for a crisis as long as it doesn't jeopardise safety to get things done.

Judging that is a fine and risky art. Better option would be to streamline the process for pre-emptive interventions so we don't have to risk the ground slipping under a train.

It's a busy line, if that embankment had given way while a 750m+ freight or 500+ passenger intercity train had been travelling over it the train could have ended up in a river that was basically in flood. It would have been catastrophic. The fact the TSR had gone down to effectively walking pace shows the risk was very real. Yes, this time all the warning systems worked and thank goodness they did. But do we want to run that risk again, or a similar risk to that at Hook?

 

[Benjwri]

Judging that is a fine and risky art. Better option would be to streamline the process for pre-emptive interventions so we don't have to risk the ground slipping under a train.

It's a busy line, if that embankment had given way while a 750m+ freight or 500+ passenger intercity train had been travelling over it the train could have ended up in a river that was basically in flood. It would have been catastrophic. The fact the TSR had gone down to effectively walking pace shows the risk was very real. Yes, this time all the warning systems worked and thank goodness they did. But do we want to run that risk again, or a similar risk to that at Hook?

Except this happened because of the liquefaction of the ground, something that isn't fully understood, and is risk anywhere. They were trying to intervene, and then the condition deteriorated suddenly, there wasn't really any preparing for that. If that kind of liquefaction happened under the majority of abutments on the network they would eventually collapse, should we close the entire network so we can pile ridiculously deep to avoid that?

 

[jfowkes]

Except this happened because of the liquefaction of the ground, something that isn't fully understood, and is risk anywhere. They were trying to intervene, and then the condition deteriorated suddenly, there wasn't really any preparing for that. If that kind of liquefaction happened under the majority of abutments on the network they would eventually collapse, should we close the entire network so we can pile ridiculously deep to avoid that?

It sounds like we need more money and resources to better understand the issue and precisely target interventions where necessary.

Climate change is going to make ground conditions harder to predict and control and hit extremes of moisture content more often.

 

[SynthD]

Is there a public map of all temporary speed restrictions or sites under special observation?

 

[quantinghome]

Except this happened because of the liquefaction of the ground, something that isn't fully understood, and is risk anywhere.

It's understood pretty well by specialist geotechnical engineers but it's usually initiated by seismic events so it's not a particularly common phenomenon in the UK. In fact I'm not convinced it's true liquefaction - it might be, but alternatively it may just be very low strength soil.

They were trying to intervene, and then the condition deteriorated suddenly, there wasn't really any preparing for that.

The odd thing in this case is that the weight of the abutment should have increased the strength of the ground over the long term as the pressure applied from the abutment compacts the soil. Quite what happened in this case will be of considerable interest to geotechnical engineers. Hopefully there will be a detailed forensic investigation so that lessons can be learned and applied.

If that kind of liquefaction happened under the majority of abutments on the network they would eventually collapse, should we close the entire network so we can pile ridiculously deep to avoid that?

Most ground is unlikely to be susceptible to this sort of failure. It needs to a particular type of ground - typically silt or sand, occasionally gravel. Rocks and clays are not at risk. The material also needs to be loose and located below the water table. So there will be certain locations which are susceptible but by no means all the network.

 

[railfan99]

Will there be a temporary speed restriction (how many miles/kms per hour limit) until the track 'settles'?

 

[Snow1964]

Except this happened because of the liquefaction of the ground, something that isn't fully understood, and is risk anywhere. They were trying to intervene, and then the condition deteriorated suddenly, there wasn't really any preparing for that. If that kind of liquefaction happened under the majority of abutments on the network they would eventually collapse, should we close the entire network so we can pile ridiculously deep to avoid that?

It's not just Network Rail that doesn't fully understand ground liquification, been problem elsewhere. Had been mudslides after earthquakes, and examples in past where some newly constructed dams couldn't be used because the weight of water causing liquification.

Its not new problem in UK, as an example the embankment near Sway on the 1880s Bournemouth direct line partly liquified and slumped during construction, had to be stabilised with rocks etc, and rebuilt, even today remains hundreds of feet wide at bottom.

My hunch is combination of two factors might have contributed, one is very high river this winter and early April saturating the ground, the other is diesel locomotives with fewer cylinders, so possibly vibrate more (or at lower frequency) than in past. It is known (but I don't think understood) that vibrations like earthquake tremors can contribute.

 

[Deepgreen]

165124

Shame it couldn't have been 769959!

 

[TurboMan]

Will there be a temporary speed restriction (how many miles/kms per hour limit) until the track 'settles'?

Yes, 50mph.