Major Engineering Work Planned at Clifton (Cumbria) to Replace WestCoast Mainline Bridge Over M6 - Jan 2026

[Justin Smith]

Probably 100 years at a time where they thought that post tensioned structures would last that long.

So they knew at the time it'd need replacing in 100 years.
But it hasn't lasted 100 years, did they get a warranty !?!

It'd be interesting to know what the figures would be re : cost of the additional finance over 60 years needed to build a bridge which would have lasted longer v the cost of having to pay for another bridge.

Last point, bearing in mind the railway was there first, I assume it's Highways England who are paying for this, not Network Rail ?

 

[stuu]

So they knew at the time it'd need replacing in 100 years.
But it hasn't lasted 100 years, did they get a warranty !?!

From who? No construction company, or any other commercial entity is going to guarantee anything for 70 years or more. The company who built it doesn't even exist as a construction company any more

Do we know what the expected tonnage of trains per year was when it was designed? Has the weather changed? Has it been maintained as the designers expected? There's too many factors after this length of time

 

[Bald Rick]

Last point, bearing in mind the railway was there first, I assume it's Highways England who are paying for this, not Network Rail ?

Depends on the deal done at the time it built between two publicly funded bodies.

 

[swt_passenger]

Last point, bearing in mind the railway was there first, I assume it's Highways England who are paying for this, not Network Rail ?

No, see the explanation in post #6. Similar with the recent M62 bridge, in that case the planning application even explained that it started out as split responsibility, but a lump sum was transferred to BR in the 1970s to take on full maintenance liability. But that would just be swallowed up into the total renewals budget, and would probably never have been ring fenced.

 

[chiltern trev]

The Clifton rail bridge is not the only M6 Cumbria bridge requiring major works.

https://nationalhighways.co.uk/iconic-m6-lune-gorge-bridges-set-for-major-facelift/

National Highways is planning to replace eight bridge deck structures along the spectacular six-mile section of the M6 through Lune Gorge in Cumbria, between junction 37 and junction 38 of the motorway at Tebay.


Seven of the bridges carry the M6 itself as it snakes through the gorge while an eighth carries the local A685 road over the motorway near Roundthwaite. The huge bridges range from 46 metres to 142 metres in length with heights of between 5 metres and 17 metres.


The Lune Gorge section of the motorway celebrated its 50th birthday in 2020 but the bridges are now showing their age and a major refurbishment programme is being planned.


National Highways is looking to carry out some preparation work next year before main construction work gets under way in 2027. It will also be staging a series of ‘meet the team’ events in 2025 to keep local people informed about the project – building on months of work which has already taken place to engage with local communities, including parish councils.


Khalid El-Rayes, National Highways’ Senior Project Manager, said:


“The bridges that carry the M6 and A685 over the Lune Gorge in Cumbria are rapidly reaching the end of their serviceable life. When this section of the M6 was opened in 1970 no-one could have predicted the huge rise in domestic and commercial traffic, with thousands of cars, coaches, vans and HGVs now pounding the motorway daily.


“That huge volume of traffic has taken its toll, but this project will ensure this section of the M6 plays a key role in connecting businesses and communities across the north and beyond for decades to come.”


A bridge deck is the surface of a bridge where vehicles travel and a key structural element of the bridge itself.


Future-proofing the M6 now will enhance safety for motorway users and reduce the cost and disruption of unplanned maintenance and emergency repairs as the bridges wear and tear and further deteriorate.


National Highways has already appointed a lead contractor, Kier, to deliver the work and deliver designs focusing on minimising inconvenience to motorway users and people living alongside the motorway.


Staff have already been out and about carrying out ground investigations and other surveys to help prepare for the work and design a project programme with the aim of keeping drivers on the move while the repairs take place, while also minimising the impact on local communities.


Mr El-Rayes said:


“Our delivery partners including Kier, RPS, Aecom, and Tony Gee, bring decades of experience in engineering and design, ensuring that we can deliver this project efficiently and safely.


“We’ve been working with them to develop design solutions to reduce the length of roadworks and number of closures. By using specialist equipment we’ll be able to replace the bridge decks safely and more quickly than traditional construction methods. This will mean less disruption for motorists and surrounding communities.”


It is likely that traffic management will involve using a contraflow system on one carriageway, using the hard shoulder, to run two lanes of traffic in each direction. This will free up the opposite carriageway and will allow work on all the structures simultaneously – significantly shortening the project timescale. A Cumbria Local Enterprise Partnership study published in the summer has already concluded a contraflow system is likely to have a negligible impact on congestion, the logistics sector and tourism trade.


As well as discussing the project and local people’s concerns, the project team has been delivering social value projects which will continue until the refurbishment has been completed in winter 2030 /2031.


The social value work has included a £10,000 donation to Bendrigg Trust in Kendal to help improve their outdoor space for disabled service users including customers with particularly complex needs. It also includes a further £10,000 donation for a ‘Sharing Shed’ building at Shap Primary School to store food and other donations for the local community.


Anyone with an interest in the scheme is being urged to sign up for regular email updates via the dedicated scheme website. Alternatively, they can follow the project on Facebook (National Highways: North-West) or on X (@HighwaysNWEST). Anyone with specific questions can also email the project team at [email protected]

 

[Justin Smith]

So they knew at the time it'd need replacing in 100 years.
But it hasn't lasted 100 years, did they get a warranty !?!

From who? No construction company, or any other commercial entity is going to guarantee anything for 70 years or more. The company who built it doesn't even exist as a construction company any more

Do we know what the expected tonnage of trains per year was when it was designed? Has the weather changed? Has it been maintained as the designers expected? There's too many factors after this length of time

I was being slightly tongue in cheek, but I have to say if the construction company said the bridge would last 100 years and it only lasted 60 why should they get away with it ?

No, see the explanation in post #6. Similar with the recent M62 bridge, in that case the planning application even explained that it started out as split responsibility, but a lump sum was transferred to BR in the 1970s to take on full maintenance liability. But that would just be swallowed up into the total renewals budget, and would probably never have been ring fenced.

I don't understand why it was ever a split responsibility. The railway was there first and, I assume, owned the land.
If Highways England (or their equivalent) wanted to put a bridge under the railway they should be 100% responsible for it, surely ?
The only way that may not apply is if they paid BR a shed load of money at the time to take on the responsibility.

 

[The Planner]

I was being slightly tongue in cheek, but I have to say if the construction company said the bridge would last 100 years and it only lasted 60 why should they get away with it ?

https://ukmotorwayarchive.ciht.org.uk/motorways-by-region/m6/the-m6-through-westmorland-j35-to-j40/

Suggests Laing and others were contractors, good luck with proving any liability 60 years down the line.

I don't understand why it was ever a split responsibility. The railway was there first and, I assume, owned the land.
If Highways England (or their equivalent) wanted to put a bridge under the railway they should be 100% responsible for it, surely ?
The only way that may not apply is if they paid BR a shed load of money at the time to take on the responsibility.

Which @SWTCommuter suugests happened with the M62 bridge at Castleton?

 

[AndrewE]

as has been said upthread, both client organisations were effectively government departments, and I suspect both would have had significant input to the design as they looked at buildability and the implications for the operating railway.
They might also have influenced the design (i.e. cost) in the light of their current finances or budget too. BR always went too far in falling in with government wishes!

(BR should have had millions out of the salt/brine pumping compensation scheme to keep Sandbach embankment fully useable. When I asked why not I was told that it would have been just an internal govt transfer as ICI paid most into it at that time and BR just copped the costs.)

 

[Bald Rick]

The only way that may not apply is if they paid BR a shed load of money at the time to take on the responsibility.

Which they did!

 

[Justin Smith]

as has been said upthread, both client organisations were effectively government departments

This, I think, explains a lot.

 

[swt_passenger]

Which @SWTCommuter suugests happened with the M62 bridge at Castleton?

All I know is what I read in the planning application for that job at the time. For the context see post #42 in the thread linked below and its replies. The text as written stated that the commuted sum was paid to Network Rail in the 1970s, but of course NR wasn’t around in the year noted, as was quickly pointed out. I think it’s a reasonable assumption that BR should have been stated in the document.

Castleton South Junction Renewal and M62 bridge replacement

The 2040 transport strategy plan for greater manchester.

www.railforums.co.uk

 

[GRALISTAIR]

We were discussing this at work. The problem may be that these infrastructure projects are usually paid for (directly or indirectly) by the government who are only really interested in what will happen during their tenure, which will usually be an absolute maximum of about 15 years and usually less. So cost, and how quickly it can be finished (so they get the credit and not the other lot....), becomes the over riding concern But, of course, when I say cost I mean short term cost.

Cynical but absolutely true imho.

----- Problem is a lot of this infrastructure was built around the same time (meaning a lot of of it is becoming life expired around the same time) and we became allergic to investing in infrastructure and/or slashed the budgets of organisations that are now dealing with these assets don't have the financial capacity to replace them in good time meaning that disruptive closures occur --------

The people building this stuff in the 1950s, 60s and 70s knew what they were building and knew how long it should last. But we just stopped investing in the 80s onwards and then slashed everyone's budgets even further in the 2010s. Hence why things are beginning to collapse around our ears.

Again infuriating but true.

It is why a rolling programme of electrification (or any other project you care to mention) is best. Nice and steady over many years. When maintenance/renewal is due in my grand children's lifetime, it will not all come due at once. Rolling stock and locomotives/units the same. Electrify, cascade, some new. Rinse and repeat.

Infrastructure and rebuilds need to happen on a nice steady rolling basis.

It is amazing what can be achieved if politicians and others stop worrying about who gets the credit.

 

[themiller]

From photos that I’ve seen, it looks like the Clifton bridge is suffering from spalling of the concrete where the rebar isn’t covered by sufficient depth of concrete. This allows water to get to the rebar which rusts and in doing so expands and blows the concrete. I’ve seen it many times so I wonder if it wasn’t known about when the bridge was designed or a lack of Quality Control.

 

[DelW]

From photos that I’ve seen, it looks like the Clifton bridge is suffering from spalling of the concrete where the rebar isn’t covered by sufficient depth of concrete. This allows water to get to the rebar which rusts and in doing so expands and blows the concrete. I’ve seen it many times so I wonder if it wasn’t known about when the bridge was designed or a lack of Quality Control.

The importance of correct cover to the reinforcement was certainly well known when I started on site building reinforced and prestressed concrete bridges in 1973. In those days roads and bridges were mostly designed in-house by public bodies, either regional Road Construction Units or County Councils. They would have directly employed Resident Engineers and Clerks of Works permanently based on site, who inspected and signed off every pour before concrete was placed. So although it's always possible that something slipped through the net, there would certainly have been a strict quality control system in place.

I suspect it's more likely that either (a) there was inadequate compaction of the concrete in places, particularly a problem if there's a high density of reinforcement, or (b) there's been a failure of the deck waterproofing, allowing water to penetrate through from above. As you say, once water and air can get to the rebar it corrodes and expands, and unless dealt with, the problem quickly becomes worse.

 

[AndyPJG]

The importance of correct cover to the reinforcement was certainly well known when I started on site building reinforced and prestressed concrete bridges in 1973. In those days roads and bridges were mostly designed in-house by public bodies, either regional Road Construction Units or County Councils. They would have directly employed Resident Engineers and Clerks of Works permanently based on site, who inspected and signed off every pour before concrete was placed. So although it's always possible that something slipped through the net, there would certainly have been a strict quality control system in place.

I suspect it's more likely that either (a) there was inadequate compaction of the concrete in places, particularly a problem if there's a high density of reinforcement, or (b) there's been a failure of the deck waterproofing, allowing water to penetrate through from above. As you say, once water and air can get to the rebar it corrodes and expands, and unless dealt with, the problem quickly becomes worse.

We were taught* at uni (1971-4) that RC should have minimum cover of 2"/50mm, and up to 4"/100mm in a marine environment.
Imagine my surprise when building RC structures in the next year (on contractor's side) that motorway bridges designed by the local RCU were specified with 45mm cover on the parapets, but only 35mm on the deck sides and a mere 25mm on the deck soffit (bottom).
I'm sure most of you have experienced rain swept roads after they've been salted, and the salt laden spray from trucks right up to overhead bridges.

* our structural design lecturer also gave us a tip....when in doubt, use 6" nails!

 

[DelW]

We were taught* at uni (1971-4) that RC should have minimum cover of 2"/50mm, and up to 4"/100mm in a marine environment.
Imagine my surprise when building RC structures in the next year (on contractor's side) that motorway bridges designed by the local RCU were specified with 45mm cover on the parapets, but only 35mm on the deck sides and a mere 25mm on the deck soffit (bottom).

I've been trying to remember what the soffit cover was on our bridges. I can visualise the grey concrete spacers we used, which gave different cover dimensions depending which way round they were, but not what the value was.

I clearly remember the stainless steel tying wire we had to use on bridge decks, as I acquired a roll of it at the end of one job, and it's come in handy for odd jobs ever since. Now 40+ years old, and last used a couple of days ago!

 

[furnessvale]

I'm hoping that the replacement will be a suspension bridge...

Suspension bridges and railways, especially high speed, are not normally good bedfellows.

 

[AndrewE]

Suspension bridges and railways, especially high speed, are not normally good bedfellows.

see post #53 onwards...

 

[Class 170101]

Also do the rates of usage affect the life of structures? When the M6 and various other structures around it were built I doubt it they were built with the amount of usage in mind they now receive.

 

[themiller]

We were taught* at uni (1971-4) that RC should have minimum cover of 2"/50mm, and up to 4"/100mm in a marine environment.
Imagine my surprise when building RC structures in the next year (on contractor's side) that motorway bridges designed by the local RCU were specified with 45mm cover on the parapets, but only 35mm on the deck sides and a mere 25mm on the deck soffit (bottom).
I'm sure most of you have experienced rain swept roads after they've been salted, and the salt laden spray from trucks right up to overhead bridges.

* our structural design lecturer also gave us a tip....when in doubt, use 6" nails!

Many years ago, I worked in industrial inspection and we were contracted to carry out radiographic inspection on the elevated section supports of the motorway around the M5/6 junction near Birmingham. This followed a spate of blown concrete and the depth of rebar was suspected to be below specifications in the area.

 

[Justin Smith]

I've been trying to remember what the soffit cover was on our bridges. I can visualise the grey concrete spacers we used, which gave different cover dimensions depending which way round they were, but not what the value was.

I clearly remember the stainless steel tying wire we had to use on bridge decks, as I acquired a roll of it at the end of one job, and it's come in handy for odd jobs ever since. Now 40+ years old, and last used a couple of days ago!

How much more expensive would stainless reinforcing bar have been ? ! ?
And the other question, why is rebar not galvanised ? Hot dip galvanising (though not pre galv so much...) is really effective and it would not have cost much to do that....

 

[DelW]

How much more expensive would stainless reinforcing bar have been ? ! ?
And the other question, why is rebar not galvanised ? Hot dip galvanising (though not pre galv so much...) is really effective and it would not have cost much to do that....

I've come across stainless steel dowels in movement joints, but I've never heard of stainless being used for normal reinforcement. It may have unsuitable mechanical properties (e.g. too brittle) or it may simply be too expensive, even considered against the possible cost of replacing the structure sixty years on. There are a lot of sixty year old bridges that haven't needed rebuilding.

I think I recall galvanised reinforcement being used in bridge copings (which are heavily exposed to salt spray), but I may be misremembering. I don't know why it isn't used more widely, but I wasn't involved in design or specification, we just built what was on the drawings.

 

[31160]

Sorry if this has already been said but I assume there will be buses put on vs diversions via the S&C

 

[themiller]

I've come across stainless steel dowels in movement joints, but I've never heard of stainless being used for normal reinforcement. It may have unsuitable mechanical properties (e.g. too brittle) or it may simply be too expensive, even considered against the possible cost of replacing the structure sixty years on. There are a lot of sixty year old bridges that haven't needed rebuilding.

I think I recall galvanised reinforcement being used in bridge copings (which are heavily exposed to salt spray), but I may be misremembering. I don't know why it isn't used more widely, but I wasn't involved in design or specification, we just built what was on the drawings.

I may be mid-remembering but, some years ago during a tour of Durham cathedral ‘basement’ the guide said that the tie rods which were installed to stabilise the masonry are stainless steel and that they had to be coated to isolate them chemically from the stone/mortar/cement grout but I can’t remember the reason.

 

[Peter Mugridge]

I may be mid-remembering but, some years ago during a tour of Durham cathedral ‘basement’ the guide said that the tie rods which were installed to stabilise the masonry are stainless steel and that they had to be coated to isolate them chemically from the stone/mortar/cement grout but I can’t remember the reason.

Lime mortar will react with stainless steel to cause corrosion.

I suspect limestone will do the same?

 

[themiller]

Lime mortar will react with stainless steel to cause corrosion.

I suspect limestone will do the same?

Thanks for that answer. I’d thought it’d be that but couldn’t remember for certain and I suspected that someone on the forum would know.

 

[Justin Smith]

Lime mortar will react with stainless steel to cause corrosion.

I suspect limestone will do the same?

Are you saying lime mortar causes corrosion in stainless steel but not in mild normal steel ? ! ?
What about zinc (as used in galvanising) ?

I have to say we have been told by more than one person that "using stainless V bolts [as opposed to plated one assumes] to bolt alloy poles to galavanised brackets will cause corrosion", so back in 2020 we set up two tests :

1 - An A2 stainless N&B through a section of alloy pole in salt water
2 - A plated N&B through a section of alloy pole in salt water

Other than salt deposits collecting around the interface there is no corrosion on either the stainless N&B or the alloy pole.
In the other test the plated N&B is starting to show signs of rust, as one would expect.

 

[AndrewE]

Are you saying lime mortar causes corrosion in stainless steel but not in mild normal steel ? ! ?
What about zinc (as used in galvanising) ?

I have to say we have been told by more than one person that "using stainless V bolts [as opposed to plated one assumes] to bolt alloy poles to galavanised brackets will cause corrosion", so back in 2020 we set up two tests :

1 - An A2 stainless N&B through a section of alloy pole in salt water
2 - A plated N&B through a section of alloy pole in salt water

Other than salt deposits collecting around the interface there is no corrosion on either the stainless N&B or the alloy pole.
In the other test the plated N&B is starting to show signs of rust, as one would expect.

"Stainless" isn't immune to corrosion. The French term "Inoxydable" is better (for the earliest sorts of stainess anyway.) It resists oxidation (rusting) in air, but is vulnerable in an alkaline environment, like in cement paste! You can get special alkali-resistant types of stainless, also [sea]salt-resistant stainless, but in an alkaline envirnment mild steel is passivated anyway. The trouble is that as concrete ages it will stop being alkaline!

(And I remember being taught that zinc was amphoteric, i.e. it will react with both acids and alkalis - so galvanising rebar is probably a waste of money...)

 

[Justin Smith]

(And I remember being taught that zinc was amphoteric, i.e. it will react with both acids and alkalis - so galvanising rebar is probably a waste of money...)

Is salt water acid or alkaline or neither ?

"Stainless" isn't immune to corrosion. The French term "Inoxydable" is better (for the earliest sorts of stainess anyway.) It resists oxidation (rusting) in air, but is vulnerable in an alkaline environment, like in cement paste! You can get special alkali-resistant types of stainless, also [sea]salt-resistant stainless,

Are you talking A4 "marine grade" stainless (as opposed to A2) ?
One does sometimes see corrosion on stainless steel, even marine grade.
I have a price of A4 plate which I use as a "load spreader" on a post I have installed on my decking, and that has annoying specks of rust on it !
One theory I heard is that when stainless has been cut (or filed) specs of the tool used to do the job embed themselves in the stainless and it is that that has corroded. I have shortened some A4 V bolts and noticed a small amount of corrosion on the cut ends, but only on the cut ends, and that theory would explain that.

 

[AndrewE]

Is salt water acid or alkaline or neither ?

It's roughly neutral - but it is full of chloride which reacts with whatever component it is that makes conventional stainless resistant to rusting.

Are you talking A4 "marine grade" stainless (as opposed to A2) ?
One does sometimes see corrosion on stainless steel, even marine grade.
I have a price of A4 plate which I use as a "load spreader" on a post I have installed on my decking, and that has annoying specks of rust on it !
One theory I heard is that when stainless has been cut (or filed) specs of the tool used to do the job embed themselves in the stainless and it is that that has corroded. I have shortened some A4 V bolts and noticed a small amount of corrosion on the cut ends, but only on the cut ends, and that theory would explain that.

There are hundreds of types of stainless now, https://steelprogroup.com/stainless-steel/properties/ talks about corrosion about half way down the page.
It could be that tool wear debris shows up as rust on stainless, especially as it will be the faster-corroding of the 2 components in a galvanic cell.