Great Western Coffee Shop

Could be weeks apparently!

Urgent repairs to a bridge between Reading and Oxford means all lines are blocked. As a result of this, trains running between these stations may be cancelled, delayed or suspended. 
Disruption is expected until the end of the day.

Customer Advice:

CrossCountry
To assist with your journey, you may use your ticket on the following at no extra cost:
Avanti West Coast via any reasonable route
Chiltern Railways via any reasonable route
London Underground via any reasonable route
London Northwestern Railway via any reasonable route
South Western Railway between Bournemouth and London Waterloo

Oops!

Advice on Cross Country from National Rail:


Interesting that no cross-availability on GWR ... So if I have a Bounemouth to Oxford advanced ticket (are there such things?  I must travel Bournemouth to Southampton on an XC train, but I can then use SWR to Waterloo, tube to Marylebone, and Chiltern to Oxford.   Not allowed to use XC from Bournemouth as far as they are running and the GWR to Didcot and bus to Oxford.

Their is major freight through there too ...  diversion via Greenford, or via Cheltenham, or something else??

No doubt a more concrete plan will emerge once more details about the situation and longevity come clear.

The Oxford–Didcot railway line is likely to be closed for up to three weeks due to the failure of Nuneham Viaduct over the Thames. The speed limit was reduced to 20mph in January, 5mph last week, then closed entirely today, with the line said to be “sinking” into the ground.

One of the brick arches is understood to have undergone severe subsidence, causing a dip in the track. Monitoring equipment, installed recently, showed today that the line is no longer safe. All GWR and CrossCountry services between Oxford and Didcot/Reading have been cancelled.

Tickets are valid on Chiltern services from Oxford to London Marylebone, on Thames Travel X2/X32 buses, and on the Stagecoach S6 to Swindon. A reopening date has not been announced but mid/late April is being suggested informally. Full repairs are expected to take months.

From the 'Oxford Clarion' on Twitter:
https://twitter.com/OxfordClarion/status/1642904141495169024 (https://twitter.com/OxfordClarion/status/1642904141495169024)

Colas are sending their traffic via Bristol and Bromsgrove.  Not sure about DB yet.

Abingdon Lock to Culham Lock    Red Caution strong stream warning
Culham Lock to Clifton Lock    Red Caution strong stream warning

Strong stream warning board

When these red boards are displayed on lock gates, the Environment Agency advises users of all boats not to navigate. The strong flows make it difficult and dangerous.

Ah, the photo that stuving has found shows there’s a few more areas that might be the failure site. The aerial photos don’t really give you any idea that’s there still some brick arch viaduct in use.

Yes, on both sides, I think. You can get a bit more of a peek from below with Google Street View, which has the view from the Thames Path on it.

I find it hard to believe that the water table that close to the river has changed much.

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?

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.

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

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.

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.

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

The large pipe that looks to be 12-18" in diameter, mounted on the exterior upstream side of Nuneham Bridge. Anyone know what it carries? (Or carried, perhaps...)

Mark

On railforums this morning, there's quite the telephoto image. A thumbnail available and a somewhat larger version if logged in to the forum demonstrating why the bridge was starting to be referred to as a 'Ski jump'.

Also, some hints on Twitter that crossing this, from the perspective of someone driving trains, was a singular experience and even more singular should the arrival of a passenger train coincided with a freight train on the other line.

Having seen some photographs of the sides and underneath I can say that I am very much relieved it has now been closed, even if much of the damage wasn't structural!  Sadly I can't share those photos as they are marked 'Internal use only', so you'll have to take my word for it.

Update from Paul Clifton https://twitter.com/PaulCliftonBBC/status/1643986645233074176?cxt=HHwWgIDUyZjJztAtAAAA (https://twitter.com/PaulCliftonBBC/status/1643986645233074176?cxt=HHwWgIDUyZjJztAtAAAA)

* Am I the only one that wonders why this wasn't picked up into some sort of planned engineering more mearured than a PANIC!

We know they were monitoring the subsidence of that southern abutment, and no doubt working on a plan. One part of the planning would be to decide whether it's just the abutment that needs to be fixed, or whether the bridge spans have such a limited remaining life they should be replaced as well.

The timescale for this is based on its rate of sinking. So when it suddenly drops by a big extra amount in a short time, the planning process is instantly running late. And you can't keep sending in a stone-blower to hitch the track up for ever. The amount of extra ballast is getting embarrassing - a rough estimate says it's about 50 tonnes!

BBC South Today showed a couple of photographs from the bridge.  There was also a quote that an engineer could get his arm into the cracks.

The bridge was closed throughout yesterday (April 3) due to emergency repairs to a bridge.

Safety concerns were raised after monitoring equipment detected increasingly significant movements of the Nuneham Viaduct, which crosses the River Thames between Culham and Radley.

This is despite Network Rail doing stabilising works in recent weeks.

Detailed inspections of the bridge are now underway.

David Davidson, Network Rail’s interim Western route director, said: “We are sorry for the disruption this has caused for passengers and advise them to continue to check before they travel.

“Safety is our top priority and our engineers our now working round the clock to identify what can be done to make this viaduct safe for passenger and freight trains to run again.
“We are disappointed that the work we’ve done so far hasn’t been successful and our efforts haven’t been helped by the wettest March in over 30 years. 
“We will continue to provide updates as we work to reopen the line as quickly and as safely as possible.”
(https://www.oxfordmail.co.uk/resources/images/16631775.jpg?type=mds-article-620)

Looks to me that it had the 1909 bridge support, the blue engineering bricks, built on top of the original 1843 brickwork.  It looks like at some stage in the past its had a concrete added as foundation repair.   The Victorian engineers did use wooden piles to build structures on, wonder if this is the case here the wooden piles have failed 

Very interesting aspiration being voiced locally that the permanent bridge should have an extra deck for walking and cycling:

https://twitter.com/LeyNathan/status/1644006919328219137

Together with the new road bridge being built over the Thames, that would make a north-south traffic-free cycle route of some 40 miles, from Witney, Woodstock and Hanborough, via Oxford, to Culham, Didcot and Wantage. Perhaps Oxfordshire County Council should start thinking now about oozegonnapayforit...

If we are getting a longer delay, the new permanent structure MUST have walking/cycling provision ...........

[…]
If new piles are required for a conventional abutment at Nuneham then the bridge deck will need to be removed to give clear vertical space for the drilling rig.  But maybe clever NR bridge engineers have another way of installing a new abutment, eg drilling piles either side of the bridge deck and then casting a beam between them, as Ellendune suggests.   

and last year, unusual heat

have a designated safe cycling route from Didcot to Oxford?

Some thoughts from MarkA posts
earlier it was said that the geology was London Clay (?, but certainly clay). The British Geological Survey Regional Geology; London and Thames valley says, in relation to shrink swell effects of clay:

"Widespread structural damage from these causes occurred following the drought in the summer of 1976"

Somebody with civils experience will be able to say if this has any relevance to a river situation after the 2022 drought. (shoot me down if needed)

Alluvium is a general term for clay, silt, sand and gravel. It is the unconsolidated detrital material deposited by a river, stream or other body of running water as a sorted or semi-sorted sediment in the bed of the stream or on its floodplain or delta, or as a cone or fan at the base of a mountain slope. Synonym: alluvial deposits. Normally soft to firm consolidated, compressible silty clay, but can contain layers of silt, sand, peat and basal gravel. A stronger, desiccated surface zone may be present.

An informative short discussion and a couple of images from 11 months back here on Linkedin (which will try and persuade the visitor to create an account/log in etc...) & kindly flagged by Hamish Harvey on Twitter.

Some evidence that the bridge deck is/was managing to push the tops of the wing walls out - and then also the wing walls showing signs that the pier was sinking/moving.

Mark

https://www.linkedin.com/posts/simon-deakin-woods-718aa2107_xeiad-networkrail-isar3-activity-6934582807071506432-dl3M/

In short without borehole data I would not like to make a judgement about what is going on in the superficial layers (which might go quite deep). 

Does rather beg the question - how on Earth did Network Rail allow it to get into this state before action was taken given that the damage had already been noted and these pictures are almost a year old and even then showed some pretty dramatic issues?

I also saw Paul Clifton's pictures on Twitter - most alarming.

As discussed elsewhere (http://www.firstgreatwestern.info/coffeeshop/index.php?topic=27227.msg331373#msg331373) there are other (probably many other) structures that appear long overdue for maintenance. I wouldn’t want the job of trying to guess which one was going to cause problems next…

Here's the view from space............

Due to urgent repairs to a bridge between Didcot Parkway and Oxford the line is closed. Disruption is expected until the end of the day on 30/04/23.

This restriction is for initial works to be taken under the south railway arch prior to further bridge repairs, during the overall repair of the bridge abutment.

During this time there will be a restricted river under the southern arch of the railway bridge. Caution is to be taken by boat masters when travelling via northern arch route, as this will be two-way traffic, and masters must take note of any instructions given by staff as to navigation past this point.

A pontoon will be moved into position to enable works to be taken from beneath the railway bridge in the channel. This will completely obstruct the southern arch during works. Subsequently the pontoon will be removed to a safe mooring when work is finished.

This is what it looked like three weeks ago without distortion from above or foreshortening from a telephoto lens.  Rather less dramatic.

Engineers have spent the weekend examining the structure and, on Easter Monday morning, Network Rail announced: “Disruption between Reading and Oxford is expected until at least the end of the day on Wednesday 31 May.”

The Independent (https://www.independent.co.uk/travel/news-and-advice/reading-oxford-network-rail-bridge-b2317072.html)

Main rail line to close until June due to a wobbly bridge

Passengers between the north of England and the South Coast are being advised to travel via Bristol or London instead

Disruption between Reading and Oxford is expected until at least the end of the day on Friday 9 June.

National Rail Enquires now saying 9th June.

Only a matter of time before some “clever” journalist works out that covers Easter, the May Day bank holiday, the Coronation weekend and the late Spring bank holiday.   ;D

The Independent seems to have misunderstood what "a lot of movement" in the bridge means:

Given how long this line is going to be closed, surely it would be better to add some extra services from Southampton travelling up via the Trans Wilts line to Swindon and then along the line to Cheltenham. Expecting people to divert a long way west or east to Bristol and London, where there are huge numbers of travellers and very complex movements, is a recipe for ensuring they don't ever travel by train again.

Stations from Bournemouth to Reading as "normal" then Didcot, Swindon, Cheltenham Spa, Worcestershire Parkway, before resuming regular route at Birmingham New Street.

Customers travelling between Worcestershire Parkway / Pershore / Evesham and London should consider travelling via Bristol Parkway or Birmingham.

In order to connect with the service up from the South Coast that tuns to Didcot. By the tie the RRS reaches Oxford, the northbound leaves.

In addition I guess, to give context that XC see their service as a South Coast service, not just Oxford & north of

https://www.networkrailmediacentre.co.uk/news/network-rail-engineers-work-around-the-clock-to-repair-nuneham-viaduct-with-the-line-expected-to-be-closed-until-early-june (https://www.networkrailmediacentre.co.uk/news/network-rail-engineers-work-around-the-clock-to-repair-nuneham-viaduct-with-the-line-expected-to-be-closed-until-early-june)

Sounds like they are going to do it once and have done with it, as opposed to a temporary fix. Although I might have misunderstood it.

Engineers have been working around the clock since the line was closed and are now working to replace the southern support structure with a new one, which will provide a long-term fix and allow for both passenger and freight trains to run again between Didcot Parkway and Oxford by Saturday 10 June. The work to replace the support structure will be complex and challenging owing to ground conditions at the site, including the proximity to the River Thames and the heavy clay soil in which the new support will need to be secured.

That's my reading too. After a lot about how they knew what was going on all the time, honest squire, and tried squirting some kind of glue (polymers, I gather) under the abutment but it still suddenly dropped a whole load more, this is the plan:

Some of Paul Clifton's reports
https://www.bbc.co.uk/news/uk-england-oxfordshire-65249735 (https://www.bbc.co.uk/news/uk-england-oxfordshire-65249735)

Mr Hopwood said GWR was also "looking at whether we can run some more trains from Oxford into London with Great Western using the Chiltern Railway route".

Yes, that’s the only way to do it now the Wycombe Line connection at Old Oak isn’t available.

Hasn’t the Network Rail view for some while been that the full Crossrail timetable prevents regular use of the flat junction at West Ealing?  Is that not why the Greenford shuttle was removed from Paddington?

Paul

Maybe - but then the bridge failure is hardly "regular", is it?

It would liven up the Greenford signaller's day.

Piles will be required of course, though the number, diameter and depth will depend on the ground conditions.  Fairly standard civil engineering work.

If there is to be a “temporary” support for the deck in the short term it’ll be interesting to see what form it takes, but I would have thought that would need piles too.

Clay rather than gravels might be a bad thing

So maybe they do intend to did a big trench and have a look at exactly what is there, and if it's not what they like replace it.

Site investigations into ground conditions involve a specialist geotechnical company drilling down and collecting core samples.  Trench digging is not required, which is just as well because you could be going down 25 metres or more.  The cores are laid out and the materials are identified and logged to record the depths at which they occur.  The strength and other attributes of the materials found are analysed and noted. 

This information, along with the load to be supported, is used to design the piles.  It is not especially complicated and the conditions at Nuneham are unlikely to be abnormal for the Thames Valley.     

I was also puzzled by the comment about "heavy clay" making the work difficult. I'd have though that was the best sort of clay! Clay rather than gravels might be a bad thing, of course. So maybe they do intend to did a big trench and have a look at exactly what is there, and if it's not what they like replace it.

Lots of boreholes in the area, mostly less than 10m deep and to do with the RADLEY ASH DISPOSAL SCHEME for Didcot power station (?)

Another Network Rail brief on Twitter. Mentions they’re going to build a structure in the river to support the spans, and they expect to pile to a depth of 25 metres:
https://twitter.com/networkrailwest/status/1646540219959721987

I was also puzzled by the comment about "heavy clay" making the work difficult. I'd have though that was the best sort of clay! Clay rather than gravels might be a bad thing, of course.

Wasn’t that mentioned as the plan in the EA river closure notice was hich was referenced here earlier in the thread?

Another Network Rail brief on Twitter. Mentions they’re going to build a structure in the river to support the spans, and they expect to pile to a depth of 25 metres:
https://twitter.com/networkrailwest/status/1646540219959721987

Re watching this video, he states that a temporary "piled structure" will but in the "middle of the river" this will mean closing one of the channels the EA will agree to this the adverse PR would not be good.

In the video he does mention the permeant piles down to around 25 meters, that's not to far off of the 100 ft mentioned in other posts

The question in my mind - and it affects the nature of the temporary structure in the river and the equipment needed to build it - is whether it is merely to support the dead weight of the bridge while the abutment is rebuilt (my assumption) or whether it has to allow the bridge to reopen while the permanent abutment is built.   

Small piling rigs are widely available that can get inside buildings but I am not sure how suitable they would be for this application. 

Another option to move plant to site is to bring it as near as possible by rail and building a short haul road along the line of the railway. 

.. Yesterday's BBC piece showed showed some aggregate corraled in sheet piles as where the temporary support would go. So maybe piles are not involved there, unless it's just something for the piling engine to stand on...

Ah, I now have a mental image of the bridge span supported at its centre from the river bed, then the span raised slightly and on a turntable - and for a month or so a swing span joins the list of Thames bridge types as it frees up headroom for the work to the abutment.

There was a reasonably factual piece about this poor old bridge and the work it needs in today's Sunday Times.

Chiltern Railways has advised customers to expect busier trains than usual between Oxford and London Marylebone from Monday (April 17).

Great Western Railway (GWR) is unable to operate any trains between Oxford and Didcot Parkway until the June 10 at the earliest whilst urgent Network Rail repairs to a bridge are taking place. This means that Chiltern Railways will be the sole option for direct rail travel between Oxford and the capital.

I'm not keen on crowding on to a replacement bus at Didcot along with disgruntled Cross-Country travellers, and the X40 bus service from Reading offers a long-winded 90-minute journey. So possibly I'll take a taxi from Didcot, drive to a village or town(Wallingford) to pick up the X40, or use one of the Oxford park & rides. At least for the initial hospital visit I won't be having any tests that preclude driving.

Whereabouts are you travelling from? Given your username I would suggest Marlborough (nr. Swindon) in which case GWR advise - https://www.gwr.com/oxford-update - that Service S6 (Swindon - Oxford, via. Farringdon) has an acceptance in place for rail tickets. Nice trip tbh which takes about 1½ - 1¾hrs depending on the time of day and I prefer it to a train trip if time allows. Also the S6 between Swindon and Oxford runs more frequently than the Didcot - Oxford service. The S6 is currently not going into Oxford City Centre though due to the work on the rail bridge by Oxford station.

Dave

Whereabouts are you travelling from? Given your username I would suggest Marlborough (nr. Swindon) in which case GWR advise - https://www.gwr.com/oxford-update - that Service S6 (Swindon - Oxford, via. Farringdon) has an acceptance in place for rail tickets. Nice trip tbh which takes about 1½ - 1¾hrs depending on the time of day and I prefer it to a train trip if time allows. Also the S6 between Swindon and Oxford runs more frequently than the Didcot - Oxford service. The S6 is currently not going into Oxford City Centre though due to the work on the rail bridge by Oxford station.

Dave

Chiltern route blocked due to a failed freight train causing mayhem there.

East West Rail construction site I think, not too far from Quainton Road of the Buckinghamshire Railway Centre.

Another update from Network Rail…

https://twitter.com/networkrailwest/status/1649077107660652547?s=46&t=ah-SsHksqViJs35eOx7jsQ

Looking at the piles stacked up they look like the type and style used for OLE masts; I wonder if they are making use of the Didcot - Oxford electrification piles that were not driven into the ground before the electrification was stopped

I wonder if those piles are going to be used to temporarily support the spans while the abutment is repiled and rebuild. The temporary piles will not have to support any dynamic weight unlike the abutment.

How do you pile into the bed of a river anyway? It may be closed, but the water is still there, and I've seen no mention of a coffer dam. In this case, would you use very long piles (joined if need be) so the tops are above water - and have to cut them down to free the river for reopening? Or would you drive the piles flush with the river bed, using a suitable piling hammer (which I see are standard pieces of kit), and bolt on the trestle underwater?
 

Is there a season cheaper via High Wycombe only? If so, I imagine there are a lot more OXF-LON seasons.

According to BR Fares, no ... virtually everything is "any permitted". I suspect there may have been some sort of agreement as Chiltern were allowed to enter Oxford that they would not undercut GWR?

Paul Clifton’s piece for Rail magazine has a very intresting snippet.

GWR tell him that since the pandemic, there are just 112 season ticket holders from Oxford. And around just 1,500 peak passengers on most days.

Wouldn't that be illegal as anti-competitive behaviour.  I thought the whole idea of competing services was to introduce competition!

According to BR Fares, no ... virtually everything is "any permitted". I suspect there may have been some sort of agreement as Chiltern were allowed to enter Oxford that they would not undercut GWR?

Known as ‘JFDI’?…..

omphaloskeptic.

The uncaptioned chap from NR said:

"We'd normally spend 2 or 3 years in planning and designing and getting everything organised"

This situation is very abnormal for a number of reasons, but one can't help wondering if other projects could move forward quicker if there was a greater sense of urgency...

Well, yeah.

I have an engineering background (mechanical rather than civil) so I do understand that there is a lot more to these things than meets the eye of the lay observer. But even in the exciting new world of Project Speed (https://www.gov.uk/government/news/launch-of-project-speed-challenges-rail-industry-to-cut-time-and-costs-of-rail-upgrades), I can't help thinking that the general modus operandi is still far too omphaloskeptic.

Also, there must be someone in Network Rail just itching to take the opportunity, while that span is lifted off its bearings and free of ballast, for a full grit blast and application of fetching (and black) epoxy surface coating to Nuneham Bridge's rusting steel.

Mark

[...]

The naval gazing is generated by a whole load of "governance" place on NR by the the Treasury and the DfT and the ORR and some internal.  NR is a large "public" body that spends a lot of Tax payers money which means there will always be rules governing how it spends money; after all Contractors mainly have to look after their share holders interests.

[...]

...naval gazing...

I see no ships.

Something has gone wrong somewhere though, hasn't it? Bond Street (Elizabeth line) and Portway Park & Ride stations have little in common on the face of it, but both seem to have faced months of delay due to certification issues. I'm told that a couple of local reopenings have been delayed by a lack of awarenesss of certification requirements.

From what Stuart Calvert says at 1:18 I wonder if they are going to make openings in the bridge deck so they can insert the piles and drill down through the deck from above.

If this is so the deck will be jacked up slightly so the new abutment can then be constructed underneath it before the deck is lowered down on to its new bearings.

For the abutment, I can see that removing the embankment will allow them to put piles in just beyond the end of the bridge, and they can also put them beside the bearings. That could give enough support and keep the load through the piles vertical (which I think helps). The bearing for the middle girder is the difficult one to get under or all around. 

Here's the picture from Twitter:

(https://twitter.com/507stre/status/1655619283479560196/photo/1)

Well I tried.  Why can I only get that to work 50% of the time?

I was going to add that that is just as I imagined it would be done. 

Now the real work can start on the new abutment. 

600mm. Blimey. Impressive.

Is this the problem I describe at http://www.passenger.chat/27456 ?

[...]

Depends if anyone else can see the image which is the one that Red Squirrel posted

For those that can see that picture ... doesn't the platform the jacks are sitting on - piles, lattice girders and all - look massively over the top for the load they are carrying (which is about 120 tons total)? Even if it's rigidity that counts, rather than strength, that's still true.

Possibly, though the trusses are only supported at the ends so there is quite a long span. The loads may not be evenly distributed among all the jacks that support the deck or if there is some differential settlement in the piles. There will also need to be some allowance for accidental and construction loads on the bridge deck.  Finally they will be using what they had available in the yard at short notice. 

See last two pictures for an idea of how much of the embankment has been removed at this stage
https://www.tmsmaritime.co.uk/emergency-works-2/ (https://www.tmsmaritime.co.uk/emergency-works-2/)

I wouldn't have thought the embankment would be cut back further than absolutely necessary - to do otherwise would increase the cost and duration of the repair -  so somebody must surely have concluded there is an awful lot of unstable ground around the south abutment.

Moving earth around has got so quick and easy with modern machinery that I don't suppose it's a big issue any more. You have only to look at any building site, even a couple of houses, to see how much moving earth back and forth goes on and how few people it takes to do it.

So I think it looks like working space they are creating. I'm sure there will be very strict rules and restraints to prevent anyone working underneath that bridge of Damocles. Incidentally, I've seen no sign of anything holding that span in place, to prevent it moving on or off its bearings or the jacks. Surely that's essential in a case like this?

New Friday video from Network Rail Western.

https://twitter.com/networkrailwest/status/1657030370897055744

I'm no closer to understanding how that bridge's bearings work. We could do with a few close up quality photos of the, um, ends.

Mark

... this type of bridge where the load is transferred at the corners of each deck. 

... and in the middle of the ends, made more complicated by the skew and the resulting stagger between the two sides.

... and in the middle of the ends, made more complicated by the skew and the resulting stagger between the two sides.

Is it the case that this aspect of the steel spans at Nuneham is rather peculiar and possibly uncommon?

Mark

Interesting that the central beam appears to project further back into the the abutment than either of the side beams.

Is it the case that this aspect of the steel spans at Nuneham is rather peculiar and possibly uncommon?

Mark

If you draw a line between the ends of the two side beams that's true. I think the centre beam is longer than the side beams, so that each half deck ends at right angles to the bridge axis. You can see this, just about, in other parts of the video. How else would you do it?

Images from Network Rail on Twitter show the progress with the row of piles, they basically line up with the ends of the three main girders, it looks like a small area of deck plating has been removed for vertical access:

https://twitter.com/networkrailwest/status/1658843943038009349

I’m surprised they’re saying it’s just starting today 17th, given the previous photos taken on the 15th…

Paul

Images from Network Rail on Twitter show the progress with the row of piles, they basically line up with the ends of the three main girders, it looks like a small area of deck plating has been removed for vertical access:

Exploiting the super-zoom facility of Flickr, you can see what they have done in one of yesterday's pictures. There are two longitudinal members under the deck on each side, resting on the crossbeams. Because of the skew (very clear in today's overhead view) they extend varying amounts beyond the last crossbeam. These stringers are made of short pieces joined by riveted plates, and it looks as if the end piece has been unriveted in each case. While it's hard to see, I think the end crossbeam meets the western (far) side girder right at its end, so part of this must have been unriveted as well. (Yes - that's visible in one of today's pictures.)

New parts, stringers, cross members may be being fabricated to match the new bearings,

That link doesn't work - it seems to have some '%' signs embedded.

Sorry - my mistake.

A note about dates: Stuart Calvert talks about the "1856 timber structure" - but the original timber bridge was built in 1843, and by inference its abutment was reused in 1856 and 1916 for the two iron bridges. The GWR magazine (posted earlier) only said it was "constructed under the Oxford Railway Act, 1843", and was "replaced in 1849-50". So who's right? I've been looking for old newspapers...

I have just found a piece in the Berkshire Chronicle of 11 November 1843 saying that the first Nuneham bridge started building "on Saturday, and will be completed in about five weeks." As the 11th was a Saturday, that start date was the 4th. I can't find completion recorded, but the line was opened on Wednesday June 12th 1844, and the "journey is performed in something under two hours and a half" (London-Oxford).

For the second bridge, there is a detailed report (Oxford Journal Saturday 20 September 1856) of the inquest into Henry Collett's death by drowning in the Thames. He was a labourer working on the new Nuneham bridge, and "late of Appleford", and several workmates gave evidence. He was last seen alive on Tuesday 9th September, and found under the new bridge on Monday 15th. We don't know from that how long the work took before and after, but those Victorians would likely not need all of a year for that job.

There was another inquest, into the death of a young lad working on the new bridge at Appleford, and that happened in July 1856. So it appears both bridges were rebuilt in wrought iron at the same time. If they were built the same way, at the same time, in the same river, it is pretty likely they both needed replacement together, and of course if the line has to be closed you'd rather do both within one closure.

Sorry - my mistake.

A note about dates: Stuart Calvert talks about the "1856 timber structure"

Attached is a classic example. The 1857 original timber bridge on the GWR Weymouth line was simply covered over when the line was doubled in the 1880s.

Then in the late 1980s it was rebuilt again, this time to provide clearance for the western arm of the Dorchester bypass(A37). I was called in by Dorset County Museum and was shown the site, after the line reopened, there is still timber buried there.

British Rail kindly gave the Museum and myself copied of the photographs they had taken, one of which is seen here

Think there's a couple of those fastenings lying spare on the deck and they may or may not be called 'Carriage bolts'.

Mark

07:10 Oxford to Didcot Parkway due 07:27

An additional train service has been planned to operate as shown 07:10 Oxford to Didcot Parkway due 07:27.

(https://cdn.prgloo.com/media/00432ebe66f147c08ca34afb2503c513.png?width=1135&height=960)
Friday 9 Jun 2023
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 Oxford and Didcot. A full timetable for all train operators is planned to resume from Saturday 10 June.

A major project

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*...

Notes to Editors

*From Saturday 29 July until the early hours of Monday 7 August Network Rail will be working to upgrade the track just north of Oxford Station - installing new high speed crossovers. To the south of the station,  Osney Lane footbridge will be modified, moving one of the piers to make way for track layout changes. Work will also be carried out to adjust the coping stones on platforms inside the station.

Did a return Didcot - Oxford today; noted that trains are running at reduced speed over the bridge.

50mph TSR.

Is that likely to be there just until they’ve completely demobilised from site?

Yes, I would imagine so.  A short 50mph restriction from a 90mph line speed won’t cause too many problems.

Yes, I would imagine so.  A short 50mph restriction from a 90mph line speed won’t cause too many problems.

Yes, I would imagine so.  A short 50mph restriction from a 90mph line speed won’t cause too many problems.