Bridge wing wall collapse near Oxford 10/2/23. Debris hit by train.

[DelW]

Not saying it’s wrong, just surprised it took so long to do this, if this was the best option.

Compare the earlier photos with this recent one. Wing/retaining walls are erected/constructed for a reason. The interlocking sheet piles are not in the same place/same alignment as the brick wing/retaining wall was.

It takes time to decide on the best option, carry out the design and an independent check, source the chosen sheet piles, and mobilise a piling gang and equipment, before the work itself can be started. Having been in such situations many times (not on railways), I think they've managed it pretty quickly.

Wingwalls can be parallel to the railway, or parallel to the road, or at any angle in between - they carry out the same function whichever is chosen. Possibly in this case it's to avoid the buried part of the sheet piles clashing with the old wingwall's foundations. A rule of thumb for cantilever sheets is that the total length is between two and three times the exposed length, so the toes will be down below track level.

[Edit] looking at the photo on a proper-sized screen, these piles are anchored not cantilevered, but most of the above still applies.

 

[ainsworth74]

A short update from the RAIB laying out the scope of their investigation:

At around 18:40 hrs on Friday 10 February 2023, the driver of the 17:34 hrs Great Western Railway service from London Paddington to Hereford struck some brick rubble on the single line at Yarnton, between Oxford and Charlbury. This had fallen onto the track from a failed wingwall that was adjacent to the line, and which formed part of a bridge carrying a local road over the railway.


The train was travelling at around 55 mph (89 km/h) when the collision occurred. The train sustained damage but did not derail. There were no injuries reported to the traincrew or passengers on the service.


Although Network Rail initially reopened the line on Sunday 12 February, it was closed again after a few hours. It remained closed for a further nine days while an adjacent embankment was stabilised.


Our investigation will seek to identify the sequence of events which led to this accident. It will also consider:

• the history of this structure including modifications to the affected wingwall, and any repair work undertaken
• the findings of inspections undertaken of the structure and the responses to them
• a report of cracking in the road approaching the structure on the adjacent embankment which was made before the failure occurred
• any underlying management factors.

[Withdrawn] Train striking debris at Yarnton

Investigation into a train striking debris from a failed bridge wingwall at Yarnton, near Hanborough, Oxfordshire, 10 February 2023.

www.gov.uk

 

[jimm]

Masonry at bridges along the eastern end of the Cotswold Line appears to have been inspected in recent days. Brick-built ones, at least.

There is now a 20mph speed restriction under a bridge taking a private track over the line at Walcot, just north-west of Charlbury station.

Some work seems to be under way at the road overbridge near Burleigh Farm, to the west of the Yarnton Road bridge, but with no apparent speed restriction past the site. Picture of this bridge by Martin Loader is at http://www.hondawanderer.com/50036_Cassington_1984.htm

Contractor's plant was still in evidence yesterday on the piling-supported section of the road at Yarnton.

 

[Annetts key]

Picture of this bridge by Martin Loader is at http://www.hondawanderer.com/50036_Cassington_1984.htm

That 1984 photo does clearly show the normal/typical alignment of a wing wall. And despite the picture resolution not being great (for zooming in) it does look like this structure was in a good state of maintenance at the time. With mortar and bricks having been replaced/renewed at some time in the past. At that time BR did have a engineering department who’s main job was to maintain structures including bridges and tunnels.

 

[Purple Train]

A short update from the RAIB laying out the scope of their investigation:

[Withdrawn] Train striking debris at Yarnton

Investigation into a train striking debris from a failed bridge wingwall at Yarnton, near Hanborough, Oxfordshire, 10 February 2023.

www.gov.uk

I did have to chuckle at the slightly unfortunate wording in that:

At around 18:40 hrs on Friday 10 February 2023, the driver of the 17:34 hrs Great Western Railway service from London Paddington to Hereford struck some brick rubble on the single line at Yarnton, between Oxford and Charlbury.

I wonder why there wasn't a train accompanying the driver?

 

[AndrewE]

I did have to chuckle at the slightly unfortunate wording in that:

I wonder why there wasn't a train accompanying the driver?

Perhaps he was so cross at being delayed that he got out and kicked it?

 

[greyman42]

I did have to chuckle at the slightly unfortunate wording in that:

I wonder why there wasn't a train accompanying the driver?

Cutbacks?

 

[jimm]

The road over the bridge is now open to traffic again, with just a single lane, and temporary traffic lights in use.

No sign yet of any work to build a new wing wall for the bridge and reinstate the slope of the embankment to conceal the piling holding up the road.

 

[ainsworth74]

The RAIB have now published their report into this accident:

Summary​

Just after 18:35 hrs on Friday 10 February 2023, the driver of the 17:34 hrs Great Western Railway service from London Paddington to Hereford reported striking an object on the single line at Yarnton, between Oxford and Hanborough. The train had struck brick rubble from a collapsed wing wall, part of a bridge carrying a local road over the railway. The train was travelling at around 58 mph (93 km/h) when the collision occurred and sustained damage but did not derail. There were no injuries to the traincrew or passengers on the service.

The wing wall, adjacent to the railway, was known to be in poor condition and collapsed when it was no longer able to carry the load imposed by the embankment it was supporting. Action had not been taken to address risks associated with the wing wall’s deteriorating condition because effective control measures had not been put in place.

Recommendations​

RAIB has made four recommendations to Network Rail regarding improvements in the specification of repair work and the quality of information available for making safety- critical decisions relating to the stability of structural defects. They also address the need to improve the process of evaluating defects and improve asset knowledge of wing walls. RAIB has also identified four learning points for infrastructure managers and examination contractors regarding the ability to monitor structural movement, risk mitigation measures when remedial work is deferred, the importance of clearing vegetation to allow structural examinations to take place, and the value of including comparable photographs in examination reports.

Report 01/2024: Train striking debris at Yarnton

RAIB has today released its report into a train striking debris at Yarnton near Hanborough, Oxfordshire, 10 February 2023.

www.gov.uk

 

[snowball]

Almost a year after the event, the date in the thread title is a year out.

 

[BrianW]

The RAIB have now published their report into this accident:

Report 01/2024: Train striking debris at Yarnton

RAIB has today released its report into a train striking debris at Yarnton near Hanborough, Oxfordshire, 10 February 2023.

www.gov.uk

Another example of inadequate attention to maintenance, akin to matters leading to Fisherton, Culham, Carmont and back to Hatfield and the inadequacies of Railtrack. I note a number of associated organisations, each taking their 'slice', inadequacies of budgets and consequences of delay and deferals. Fortuitously no-one died or was seriously injured on this occasion- another time, or will ' lessons be learned'; no heads rolling , so opportunity for 'institutional memory' to be developed and retained, one may hope.

 

[Benjwri]

Another example of inadequate attention to maintenance, akin to matters leading to Fisherton, Culham, Carmont and back to Hatfield and the inadequacies of Railtrack. I note a number of associated organisations, each taking their 'slice', inadequacies of budgets and consequences of delay and deferals. Fortuitously no-one died or was seriously injured on this occasion- another time, or will ' lessons be learned'; no heads rolling , so opportunity for 'institutional memory' to be developed and retained, one may hope.

Although in this case the report does mention a significant contributing cause was the presence of a skin wall. Most of the decisions here were correct, if what the engineers thought was occurring was occurring. The real issues are with the lack of documentation of the wall, and the examinations which weren’t carried out but were documented to have been. That’s extremely significant as it gives false security as to the state of the wall, and assumptions that are being made.

 

[BRX]

An interesting commentary here (a little critical of the RAIB report) from a structural engineer with a special interest in old masonry structures.

156. Yarnton Road Bridge — Bill Harvey Associates Limited

Yarton Road Bridge suffered a wingwall collapse in February 2023. A train hit the debris, and the RAIB investigation report was published early February. This is a review of the report. There is a lot to think about.

www.billharveyassociates.com

 

[BrianW]

An interesting commentary here (a little critical of the RAIB report) from a structural engineer with a special interest in old masonry structures.

156. Yarnton Road Bridge — Bill Harvey Associates Limited

Yarton Road Bridge suffered a wingwall collapse in February 2023. A train hit the debris, and the RAIB investigation report was published early February. This is a review of the report. There is a lot to think about.

www.billharveyassociates.com

The author is right, as a professional and as a citizen to get 'hot under the collar'. IIUC, the RAIB has no power to compel higher standards, of inspection or of maintenance, only to investigate an accident and to report. Old railway structures, just like old buildings generally, conceal lots if incipient decay. Maintenance is not 'sexy' and is always cut, and cut again until something has clearly 'failed' and s--t hits then fan, when 'something must be done'. We do that with our homes- not fixing the roof when the sun's shining.

 

[Annetts key]

If I could have a £1 for every bush or tree growing out of a brick or stone railway structure, I would be rather rich by now. Alas, as long as trains are running, as said above, maintenance especially proper preventative maintenance is low or non priority.

If the railway lets its infrastructure degrade until either it fails or it becomes uneconomic to repair, that means completely replacing it. Which is often far more costly.

A simple 'weed' like a dandelion can grow deep into a brick mortar which will over time cause the mortar to fail and may result in the brick(s) moving. So you can imagine the damage bush and tree roots can do.

In my area, BR had an entire engineering department that maintained the railways stone, brick, concrete block and other structures (including overbridges, underbridges, tunnels, buildings etc. They did not just inspect, they would carry out repair work and arrange larger works, such as renewals. But now, in my area, these staff and their department are now just memories.

Its impossible for me, as an individual to know if in the long term, this has saved money or cost more. As when and where do you define the end time?

 

[BrianW]

If I could have a £1 for every bush or tree growing out of a brick or stone railway structure, I would be rather rich by now. Alas, as long as trains are running, as said above, maintenance especially proper preventative maintenance is low or non priority.

If the railway lets its infrastructure degrade until either it fails or it becomes uneconomic to repair, that means completely replacing it. Which is often far more costly.

A simple 'weed' like a dandelion can grow deep into a brick mortar which will over time cause the mortar to fail and may result in the brick(s) moving. So you can imagine the damage bush and tree roots can do.

In my area, BR had an entire engineering department that maintained the railways stone, brick, concrete block and other structures (including overbridges, underbridges, tunnels, buildings etc. They did not just inspect, they would carry out repair work and arrange larger works, such as renewals. But now, in my area, these staff and their department are now just memories.

Its impossible for me, as an individual to know if in the long term, this has saved money or cost more. As when and where do you define the end time?

How do you cost/value the costs of disruption- lost time, trips not taken, business lost to roads, planes, reputational value, deaths and injuries maybe ...?
vs Staff 'costs' 'saved'; passed to private sector 'mates'?

 

[BRX]

I find it sad to watch the 150-year old brick viaducts around me in south London get slowly prised apart by Buddleia roots. Now and again they come along and cut it all back and even replace a few bricks (badly) but it's just cosmetic and within months or weeks the plants are sprouting again.

 

[PupCuff]

An interesting commentary here (a little critical of the RAIB report) from a structural engineer with a special interest in old masonry structures.

156. Yarnton Road Bridge — Bill Harvey Associates Limited

Yarton Road Bridge suffered a wingwall collapse in February 2023. A train hit the debris, and the RAIB investigation report was published early February. This is a review of the report. There is a lot to think about.

www.billharveyassociates.com

I'm certainly happy to defer to their knowledge on structural engineering, but I do take some level of umbrage with their comments on safety investigations. Expecting the RAIB to also investigate generic structural issues which happen to occur on the railway infrastructure is unreasonable; the RAIB's remit is over the most serious of incidents which stand to have the biggest impact on the operational railway and they are resourced as appropriate to that.

"The best we can hope for in response to events like collapsing spandrel walls is an internal, unpublished investigation from an organisation with an overriding interest in repairing the damage and re-opening the railway" - There's no basis to the implication that (in this case NR) will compromise an internal safety investigation on the basis of their interest in getting the railway re-opened. They remark about it being unpublished, but Network Rail is subject to the Freedom of Information Act and there's nothing stopping anyone going on WhatDoTheyKnow and making a request for a copy (and that's before we even consider, does everyone really need to know the minutiae of every structural failure, or indeed other incident that happens? Most are dreadfully uninteresting). It feels like an implication that the railway industry is incapable of investigating safety incidents when actually, we're pretty well versed at it by now.

 

[Annetts key]

I'm certainly happy to defer to their knowledge on structural engineering, but I do take some level of umbrage with their comments on safety investigations. Expecting the RAIB to also investigate generic structural issues which happen to occur on the railway infrastructure is unreasonable; the RAIB's remit is over the most serious of incidents which stand to have the biggest impact on the operational railway and they are resourced as appropriate to that.

"The best we can hope for in response to events like collapsing spandrel walls is an internal, unpublished investigation from an organisation with an overriding interest in repairing the damage and re-opening the railway" - There's no basis to the implication that (in this case NR) will compromise an internal safety investigation on the basis of their interest in getting the railway re-opened. They remark about it being unpublished, but Network Rail is subject to the Freedom of Information Act and there's nothing stopping anyone going on WhatDoTheyKnow and making a request for a copy (and that's before we even consider, does everyone really need to know the minutiae of every structural failure, or indeed other incident that happens? Most are dreadfully uninteresting). It feels like an implication that the railway industry is incapable of investigating safety incidents when actually, we're pretty well versed at it by now.

If the current railway arrangements were any good at investigating the root causes, do you really think we would even be here discussing this? Network Rail is owned by the tax payer, so, why not publish "internal" reports as discussed above under Crown Copyright?

 

[CharlieSpotted]

An interesting commentary here (a little critical of the RAIB report) from a structural engineer with a special interest in old masonry structures.

156. Yarnton Road Bridge — Bill Harvey Associates Limited

Yarton Road Bridge suffered a wingwall collapse in February 2023. A train hit the debris, and the RAIB investigation report was published early February. This is a review of the report. There is a lot to think about.

www.billharveyassociates.com

Whilst the commentary here appears worthwhile, it's worth noting that it does not appear to be entirely impartial. There's a (brief) reference to a software tool they're developing which, of course, would be of use in this type of investigation...

 

[davetheguard]

any good at investigating the root causes

I like what you did there.