Bridge Collapse at Barrow on Soar 2nd Aug 2016

[222007]

I assume that stock could be moved via Coalville if the line was expected to be closed for longer than a couple of days.

Something i had mentioned via facebook. I used to live on this line so one im very familiar with

 

[Philip Phlopp]

Do you have prima facie knowledge to that effect?

Yes..

 

[Robertj21a]

I think that the key concern of most people is simply that the parapet came down rather quickly and 'easily' once NR started working on it.

I doubt that NR expected the parapet to collapse so, presumably, it was in a worse condition than they had expected - in turn, that must surely bring into question the scale of previous examinations of the structure ?

 

[DarloRich]

I think that the key concern of most people is simply that the parapet came down rather quickly and 'easily' once NR started working on it.

I doubt that NR expected the parapet to collapse so, presumably, it was in a worse condition than they had expected - in turn, that must surely bring into question the scale of previous examinations of the structure ?

lots of leaps there! However I am sure you know best...........

( i will wait for an official report before making any judgement )

 

[Robertj21a]

lots of leaps there! However I am sure you know best...........

( i will wait for an official report before making any judgement )

Yes, accept there are a lot of 'leaps'. It does, however, tie in with what NR themselves have said publicly. I was also there yesterday and spoke to some of those involved.

In any event, all lines are now open again and trains are stopping at Loughborough - due credit to all concerned.

 

[Philip Phlopp]

Yes, accept there are a lot of 'leaps'. It does, however, tie in with what NR themselves have said publicly.

It really doesn't. The level of supposition on your part is staggering, frankly.

 

[Robertj21a]

It really doesn't. The level of supposition on your part is staggering, frankly.

Fair enough, I recognise that you will have far more real facts. Perhaps it may be advisable to suggest that the NR teams at Barrow should keep more to themselves in future.

 

[DarloRich]

Fair enough, I recognise that you will have far more real facts. Perhaps it may be advisable to suggest that the NR teams at Barrow should keep more to themselves in future.

There is a little bit of a difference between centrally approved comms and having a quick chat with some bloke on the site

 

[hwl]

BBC now have a quote from an Institute of Structural Engineers spokesman:

Bill Harvey, from the Institution of Structural Engineers, said it was probably a combination of factors that had "caused trouble."
"It looks as though over recent months or years there's been water leaking from the main - Severn Trent don't think that's the case, but the hollows from the footpath shown in the photographs that I've seen look like that to me. So, water would have been washing down... That may then have caused the thing to be that little bit more fragile when they started with a digger - and away it went."

http://www.bbc.co.uk/news/uk-england-leicestershire-36961840

And all 4 tracks now open.

 

[Robertj21a]

There is a little bit of a difference between centrally approved comms and having a quick chat with some bloke on the site

I'm not going to say any more other than you have assumed rather too much. In any event, a further visit to the site this afternoon revealed hardly any Network Rail guys (as expected), but rather a lot of National Grid gas vans, and their chaps busily working away.
I'm going to be very interested in the official findings in this case.

 

[Flying Phil]

In view of the MML electrification, I wonder if the hope was that the bridge would last until replacement in a few months, as it doesn't look as if there would have been enough clearance for the wires under that bridge?
But all credit to those concerned getting the rails cleared and normal service resumed.

 

[DarloRich]

I'm not going to say any more other than you have assumed rather too much. In any event, a further visit to the site this afternoon revealed hardly any Network Rail guys (as expected), but rather a lot of National Grid gas vans, and their chaps busily working away.
I'm going to be very interested in the official findings in this case.

I am not assuming anything ( and was trying to agree with you!) other than that there is always a difference in style and frankness between the horses mouth and the horses owners mouth so to speak. Central comms are always bland and carefully crafted to avoid saying anything that could be remotely interesting, controversial or judgmental!

 

[najaB]

In view of the MML electrification, I wonder if the hope was that the bridge would last until replacement in a few months, as it doesn't look as if there would have been enough clearance for the wires under that bridge?

I'm sure that you didn't mean to make it sound that way, but I'm pretty sure that NR doesn't manage their infrastructure on a 'hope' basis.

 

[LowLevel]

Apparently the running lines are open now, subject to any further work required, but Barrow station remains closed as the access has been declared unsafe on inspection this morning.

 

[Philip Phlopp]

I'm sure that you didn't mean to make it sound that way, but I'm pretty sure that NR doesn't manage their infrastructure on a 'hope' basis.

The way some people have gone on, you would think we've got Mystic Meg doing our inspections.

Electrification clearance of the bridge was acceptable and it wasn't scheduled for replacement or for the deck to be lifted (having been surveyed for the new clearances).

It needed the parapets raised to 1800mm as normal but that work hadn't been scheduled. There would also have been discussions with the local highways department about replacing the parapets with reinforced parapets meeting H4a standard, or providing a restraint system on the bridge other than by parapets.

 

[HowardGWR]

The way some people have gone on, you would think we've got Mystic Meg doing our inspections.

Electrification clearance of the bridge was acceptable and it wasn't scheduled for replacement or for the deck to be lifted (having been surveyed for the new clearances).

It needed the parapets raised to 1800mm as normal but that work hadn't been scheduled. There would also have been discussions with the local highways department about replacing the parapets with reinforced parapets meeting H4a standard, or providing a restraint system on the bridge other than by parapets.

That's very helpful. As I wrote earlier in the thread, eyeballing, it looked high enough above the rails not to need rebuilding for electrification. What is the minimum height above the rails, if you know that, please?

 

[daikilo]

Does anyone have a photo of what the failed earthwork and parapet protections look like now? I am intrigued as to how it could have been stabilised so quickly to allow reopening. That said. the failed earth seems to have sheered at an angle which could suggest a design feature.

 

[Flying Phil]

The way some people have gone on, you would think we've got Mystic Meg doing our inspections.

Electrification clearance of the bridge was acceptable and it wasn't scheduled for replacement or for the deck to be lifted (having been surveyed for the new clearances).

It needed the parapets raised to 1800mm as normal but that work hadn't been scheduled. There would also have been discussions with the local highways department about replacing the parapets with reinforced parapets meeting H4a standard, or providing a restraint system on the bridge other than by parapets.

Thank you for that detailed response - and for your many other informative posts.
In my initial post I did use the word "hope" but I should have been more specific and said "professional judgement bearing in mind the many factors known, little known and the totally unforseeable".

 

[eastwestdivide]

Does anyone have a photo of what the failed earthwork and parapet protections look like now? I am intrigued as to how it could have been stabilised so quickly to allow reopening. That said. the failed earth seems to have sheered at an angle which could suggest a design feature.

No photo, but when I passed on the train at slow speed yesterday afternoon, the stuff holding back the earthworks and parapet remains looked like industrial strength chicken wire held in place by rock anchors. Only got a quick glimpse though.

 

[QueensCurve]

No photo, but when I passed on the train at slow speed yesterday afternoon, the stuff holding back the earthworks and parapet remains looked like industrial strength chicken wire held in place by rock anchors. Only got a quick glimpse though.

I too would be interested in knowing what work has been done to make it safe for trains to pass without demolition.

 

[Philip Phlopp]

That's very helpful. As I wrote earlier in the thread, eyeballing, it looked high enough above the rails not to need rebuilding for electrification. What is the minimum height above the rails, if you know that, please?

There's no single value, but 5100mm is the value you want if you don't want the contact wire height (but not catenary wire height) varying across the route, which makes for a more reliable contact system. It's the value being used on the MML.

4690mm to the contact wire from rail head + 370mm air gap down to the top of contact wire gives 5060mm and another 40mm leeway doesn't go amiss particularly with older structures which might not be consistent.

I did some calculations for a bridge a poster here measured - can't remember which thread, possibly the Blackpool electrification thread or the MML one.

The contact wire height can be decreased down to whatever you can get away with for the proposed stock, say 3950mm, but that becomes problematic as discussed in the Blackpool thread as when stock is platformed, it brings the closest energised part of the contact system inside the minimum 3500mm distance now required to the platform edge.

 

[Karl]

Does anyone have a photo of what the failed earthwork and parapet protections look like now? I am intrigued as to how it could have been stabilised so quickly to allow reopening. That said. the failed earth seems to have sheered at an angle which could suggest a design feature.

Quite a good photo appeared on my Flickr feed yesterday from loose_grip_99 which was taken from a passing train on the slow lines. It's worth downloading the original 4059 x 2695 to get a detailed view.

https://www.flickr.com/photos/loose_grip_99/28651701442/in/photostream/

 

[nickleics]

Quite a good photo appeared on my Flickr feed yesterday from loose_grip_99 which was taken from a passing train on the slow lines. It's worth downloading the original 4059 x 2695 to get a detailed view.

https://www.flickr.com/photos/loose_grip_99/28651701442/in/photostream/

Great shot, and interesting to see how they are approaching the (presumably temporary) repair - mesh pinned to the original structure. I wonder how much of the displaced brickwork has been cleared from the site since this photo was taken, and what the long-term plans are for the bridge.

 

[snowball]

Since the actual arch looks undamaged, and since the info on here is that the headroom was OK, I'd guess that they'll build a new spandrel wall and parapet.

 

[Hophead]

roadworks.org is showing a road closure till 10 February 2017 - obviously there'll be some leeway there, but it doesn't look like it's going to be a quick job.

 

[HowardGWR]

roadworks.org is showing a road closure till 10 February 2017 - obviously there'll be some leeway there, but it doesn't look like it's going to be a quick job.

It will be an expensive one of course. I presume that NR has a contingency fund as part of its 5 year bid, since these events are bound to happen. The last few years (Dawlish, Dover, S and C, to name a few) has seen a fair number of major collapses.

The alternative would be insurance, but for a Victorian infrastructure outfit like NR, the premiums would be horrendous.

What do we reckon for Barrow upon Soar - £2m?

 

[Flying Phil]

Purely uninformed speculation but the GCR bridge over the MML at Loughborough is scheduled for completion by end of Dec 2016, with prep work due to start in Aug (Now??). The plan was to have the line possession during the Christmas shutdown.... so could they do the main repair work on the Barrow on Soar bridge during the same time to have it finished by Feb 2017?

 

[edwin_m]

Purely uninformed speculation but the GCR bridge over the MML at Loughborough is scheduled for completion by end of Dec 2016, with prep work due to start in Aug (Now??). The plan was to have the line possession during the Christmas shutdown.... so could they do the main repair work on the Barrow on Soar bridge during the same time to have it finished by Feb 2017?

IF they are replacing the entire bridge it will be a big job, especially because it no doubt carries lots of services as well as the water main that may (or may not) have been part of the reason for collapse. I guess just replacing the fallen wall would be easier if the rest of the structure is sound, given that we seem to have established that the bridge already provides electrification clearance. The bridge is narrow but wide enough for the one-way traffic it is supposed to carry, the rest of the road isn't much wider and the residents probably wouldn't want it widened for two-way traffic, so there may not be any reason to provide a wider bridge.

Possibly they will spray it with concrete to prevent what appears to be just earth from eroding out of the fallen section and risking further collapse. The "industrial strength chicken wire" could serve as reinforcement?

 

[philthetube]

It will be an expensive one of course. I presume that NR has a contingency fund as part of its 5 year bid, since these events are bound to happen. The last few years (Dawlish, Dover, S and C, to name a few) has seen a fair number of major collapses.

The alternative would be insurance, but for a Victorian infrastructure outfit like NR, the premiums would be horrendous.

What do we reckon for Barrow upon Soar - £2m?

If it is proven to have been caused by a burst water main then will the Water authority be liable?

 

[GRALISTAIR]

If it is proven to have been caused by a burst water main then will the Water authority be liable?

Not if someone other than water authority contractors did the damage surely?