Black Bridge, Nuneham: southern abutment failure

[whole diary]

[grahame]

Moderators - can I suggest that the Nuneham/Culham viaduct problem merits its own thread, rather than being split between two general delay threads as at present?

Now 3 weeks according to JourneyCheck

Cancellations to services between Didcot Parkway and Oxford
Due to urgent repairs to a bridge between Didcot Parkway and Oxford the line is closed. Disruption is expected until 23:59 23/04.

If another of the mod team can sort this out as suggested - THANK YOU.  My connection keeps dropping and is very laggy ...

[grahame]

Noting Euston to Milton Keynes closed over Easter too. Southampton to Birmingham, Derby, etc., passenger might do better via Bristol?

[Mark A]

(It might not be easy to pull posts from at least two other threads into this one - if that's doable, other mods, please kill this one.)

Nuneham Bridge, the third bridge on the site, is a two span steel bowstring carried on two abutments and a central pier in the river, dating from 1907. On the north approach, the line is carried on several brick arches, on the south, an embankment.

The southern abutment has subsided over a period of months if not longer, additional ballast has been used to keep the line useable albeit with a speed restriction. At the start of April the abutment's subsidence continued to worsen and it was necessary to close the line completely. As of April 4th, a date at which it can be reopened has not been announced.

Mark

(Edited to correct the date that the current bowstring spans replaced much of the previous bridge. Wikipedia had this as 1929 so, corrected Wikipedia too...)

[Mark A]

I've launched a new thread in the appropriate forum topic. If that doesn't help, mods, please do delete it.

Mark

Edit - You can find that thread ((here)) - grahame.

If I have decent connectivity during tonight, I'll back up databases and see if I can do some splitting and merging while the forum is quiet, but if the connectivity is poor I may have to leave it until back on dry land.

[oxviem]

Updated now to be after easter

https://www.networkrailmediacentre.co.uk/news/passengers-advised-to-check-before-travelling-as-railway-between-didcot-parkway-and-oxford-to-remain-closed-until-after-easter

Though GWR^▸ (Great Western Railway) is still quoting the end of the day

[Mark A]

Paul Clifton has posted two good aerial photos to Twitter. Do they perhaps show that at the south abutment, the ballast in an indication that the abutment continues to subside, is retreating beneath the track?

In another, he says "...privately I’m hearing the closure will be months, not weeks."

Mark

https://twitter.com/PaulCliftonBBC/status/1643216802032353281

[ray951]

NR^» (Network Rail - home page) saying shuttle services are to be run Oxford -  Radley and Didcot - Culham.

Shame they can't run up to the bridge, where we can walk across and get on another train on the other side; that would be quicker than taking the bus 

And yes I understand all the issues about why that wouldn't happen.

According to Google would take 26 minutes to cycle between those two stations!

[Mark A]

On the bright side, the Environment Agency's not yet closed the river navigation beneath the bridge.

Paul Clifton's images are quite stark: the first actually shows that at the abutment, the ballast is retreating beneath the track, in a short time it looks to have dropped by about a sleeper's depth.

Adding some straight lines to his second photo just about starts to reveal the extent to which the southern span has subsided. The weight of the additional ballast added to the span can't be helping at this point. One of the yellow lines tracks a railhead, the other, the ends of the floor beams of the northern span projected across the southern span.

Mark

[Richard Fairhurst]

I've launched a new thread in the appropriate forum topic. If that doesn't help, mods, please do delete it.

I've merged the three (!) separate discussions on this.

Some of the interim topic names are still around and I can't see a way of changing them in bulk. grahame, if you have a moment (and the connectivity!) to do an UPDATE later, that would be the cherry on the cake.

[bobm]

Some of the interim topic names are still around and I can't see a way of changing them in bulk. grahame, if you have a moment (and the connectivity!) to do an UPDATE later, that would be the cherry on the cake.

Done  (that was the easy bit!)

[Mark A]

I have found one newspaper reference to the rebuilding of the viaduct, and that's from a "last year's work" summary in January 1931, and is as curt as: "the north end of Nuneham viaduct, Culham, [has been] reconstructed".

From the Thames Path, you can see that the arches piercing the pier on the north bank were filled in when that work was done. But there is no sign on distress in the pier itself, nor what little you can see of the arch attached to it. So maybe that isn't quite so likely as an explanation. You can also see the bearings of the bridge, which are not exactly sophisticated, and how the skew on the bridge complicates the one on the left (west) side.

Thanks for this. The Culham Ticket Office site's copy of the article from the 1908 GWR^▸ (Great Western Railway) Magazine's photo of the then new bowstring arches (both of which are good and level)

https://culhamticketoffice.co.uk/bits/hidden-pages/nuneham-bridge.html

That photo also shows what looks to be a couple of remaining spans from the previous viaduct still in use on northern approach - if that work was finally replaced around 1929, that date of '1931' combined with 'Last year's work' might be the origin for the erroneus 1929 date for the bowstring spans as given in the likes of https://www.thames.me.uk/s01530.htm

Mark

[stuving]

That photo also shows what looks to be a couple of remaining spans from the previous viaduct still in use on northern approach - if that work was finally replaced around 1929, that date of '1931' combined with 'Last year's work' might be the origin for the erroneus 1929 date for the bowstring spans as given in the likes of https://www.thames.me.uk/s01530.htm

Mark

I think that sentence on thames.me.uk (which also says the new bridge in 1929 had one span) has been misplaced, and should be on the Appleford bridge page. The two bridges (or viaducts) are near-identical twin sisters, in each of their three incarnations.

The Culham Ticket Office site also has a GWR^▸ (Great Western Railway) magazine page about Appleford, which explains that the work was meant to start in 1927, but was delayed until 1928 by guess what - flooding!. It was completed in 1929, suggesting that the more recently something like this is done, the longer it takes.

There are subtle differences in the design and working method, as well, though in both cases the bridge spans were rivetted together on site, with the girders placed on the piers first and then the cross members added in situ. At Nuneham, the outer girders fitted on the ends of the piers, and I think the middle one went in the gap between the two original one-track bridges (which may explain its different design). One track was closed and demolished and the replacing half assembled, then the other half was done. At Appleford, where the three girders are the same, they built the piers and the first half just to one side, with both tracks still in use. Then they demolished just one old bridge of the pair and finished the new one, still with two lines in use. So the track at each end has moved sideways, though I can't see any trace on the satellite views of that now.

[Mark A]

Ah, that's another find, thanks for this.

Mark

[grahame]

Big THANK YOU to Rchard for doing the lion's share of reforming this thread from disparate others which had content on the topic in them, and to Bob for icing the cake by fixing topic names.

Other topics include
http://www.passenger.chat/14689 - Infrastructure problems in Thames Valley causing disruption elsewhere - ongoing, since Oct 2014
where posts on other infrastructure problems still "belong?

[TaplowGreen]

Now updated to "at least" 23 April.


Cancellations to services between Reading/Didcot Parkway and Oxford until at least Sunday 23 April
Following a safety inspection of a railway viaduct between Didcot Parkway and Oxford the railway has been closed to allow emergency repairs to take place. We are expecting this work to continue until at least Sunday 23 April.