GCR Bridge Project

[DCSA]

It is a pair of decks side by side, so typical GCR design.

No it isnt. Its a single continuos deck made using hobsons method of shallow iron archs and concrete. You didnt write the report did you? The author seemingly also didnt know what they were looking at.

 

[Flying Phil]

No it isnt. Its a single continuos deck made using hobsons method of shallow iron archs and concrete. You didnt write the report did you? The author seemingly also didnt know what they were looking at.

Hi and welcome DCSA
I was going by what can be seen from the train ie lattice girders, and thought it was just a very short version of other such bridges on the GCR ie the replaced Quorn bridge and refurbished Canal Bridge. I thought the Hobsons method was only used for the road overbridges as at Quorn and Loughborough etc. I'm happy to be corrected though.

 

[Almyle503]

"I think it'd be nice". If only railway extensions could be funded and built on this basis!

While I'm fully aware that railway construction isn't based on how I feel, I don't think there's any harm mentioning it. Do you?

 

[matrix24]

While I'm fully aware that railway construction isn't based on how I feel, I don't think there's any harm mentioning it. Do you?

Always a first in anything and a private funded extension on a new track bed for heritage or mainline railway will happen one day.

 

[AndrewE]

Always a first in anything and a private funded extension on a new track bed for heritage or mainline railway will happen one day.

The Dduallt spiral and tunnel on the Ffestiniog?

 

[Flying Phil]

Always a first in anything and a private funded extension on a new track bed for heritage or mainline railway will happen one day.

As there are individuals who have funded several steam locomotives and indeed, on the GCR, David Clarke largely funded much of the double track, it would be quite feasible for a bridge or part of trackbed to be the "Smith Bridge" or "Jones Embankment" rather than Bridge 342. After all doesn't the SVR have a Victoria Bridge (Not that she paid for it!)?

 

[Western Sunset]

My great, great, (great?) grandfather has a bridge over the Trent & Mersey canal named after the family.

 

[AndrewE]

My great, great, (great?) grandfather has a bridge over the Trent & Mersey canal named after the family.

That's a heritage to be proud of... I only had a red-painted sign on a wall in Torquay! Probably gone by now though.
A

 

[DCSA]

I was going by what can be seen from the train ie lattice girders, and thought it was just a very short version of other such bridges on the GCR

Thats half the problem. People guess instead of knowing but they dont say its a guess. They present it as fact and then other people who also dont know fornsure believe that is a fact and not just a guess.

And their arent any lattice girders on the preserved railway. Lattice parapets yeah but no girders.

 

[reddragon]

Thats half the problem. People guess instead of knowing but they dont say its a guess. They present it as fact and then other people who also dont know fornsure believe that is a fact and not just a guess.

And their arent any lattice girders on the preserved railway. Lattice parapets yeah but no girders.

This is a very friendly discussion, please consider how you respond to others.

 

[Flying Phil]

Unfortunately Bridge 348 is very inaccessible and so I have not been able to see it in any detail or take any photographs. However it is described in "Main Line" as an "Occupation Bridge" of standard design. The replaced bridge North of Quorn (341) also described as an "Occupation Bridge" is shown here, together with its refurbished lattice - girders, sections, parapets or pilasters???
DCSA is quite right to correct my description though - it is indeed a single deck, but there do not appear to be the Hobson style arches between the steel girders( which go below the actual rails)?


I did go to Quorn last week to see if the old bridge 348 was anywhere to be seen, but there was nothing - apart from the completely resurfaced car park.

 

[DCSA]

Unfortunately Bridge 348 is very inaccessible and so I have not been able to see it in any detail or take any photographs. However it is described in "Main Line" as an "Occupation Bridge" of standard design. The replaced bridge North of Quorn (341) also described as an "Occupation Bridge" is shown here, together with its refurbished lattice - girders, sections, parapets or pilasters???
DCSA is quite right to correct my description though - it is indeed a single deck, but there do not appear to be the Hobson style arches between the steel girders( which go below the actual rails)?
View attachment 112490

I did go to Quorn last week to see if the old bridge 348 was anywhere to be seen, but there was nothing - apart from the completely resurfaced car park.

348 and 341 are diferent methods of construction. You could compare apples and pears but they wouldnt look the same if you looked at them properly. Just because theyre both occupation bridges why would they have the same construction?

Their are no rail bearer girders in 348 or any other Hobson deck on the GC because the loads are spread across the entire deck.

And you wont have seen 348 at Quorn because it was never removed.

This is a very friendly discussion, please consider how you respond to others.

Sorry chum. Im an engineer not a politician. Used to people stating facts not dressing up guesses. Its OK not to know something but people should make that clear if theyre not sure. No offence meant.

 

[reddragon]

Sorry chum. Im an engineer not a politician. Used to people stating facts not dressing up guesses. Its OK not to know something but people should make that clear if theyre not sure. No offence meant.

I am also an Engineer working on bridges with no ability to be like a politician.

I also know most people don't know the difference between a jack arch or jack daniels when it comes to specialised items on bridges, OLE or whatever. Very simple language is required & understanding.

Now if only I could find someone who could explain the load path on a twin fixed hanger support, yeah I get the top load but not the twin lower fixing! And how do I determine load distribution between the various hangers under load & thermal movement with significant deterioration?

 

[DCSA]

Now if only I could find someone who could explain the load path on a twin fixed hanger support, yeah I get the top load but not the twin lower fixing! And how do I determine load distribution between the various hangers under load & thermal movement with significant deterioration?

Ha you need an Engineer with a big E a degree and a charter for that question. I am only an engineer with a little e a diploma and a hammer.

 

[Flying Phil]

Well Bridge 348 has been repaired and I was told at the GCR today, by some of the workers involved, that it was a normal steel bridge with girders under the rails. Apparently the repair has involved extra steel plate and rods (rebar?) and than concrete poured around the existing girders to form a solid base. However I have not seen any photographs or the actual result, so am eager to see a more detailed description in due course......
...and I do have an engineering degree (Mechanical, Hons), most of my posts are factual and backed up with photographs. I do make a few reasonable interpretations based on years of experience and observation at the GCR and elsewhere. As I said before "I am happy to be corrected though".

 

[Up Main]

The Great Central Railway PLC’s Board are pleased to announce that they have today given approval for the work on the replacement of Bridge 326 crossing the A60 adjacent to the former Brush Works in Loughborough to commence with immediate effect.

A purchase order has now been placed with VolkerLaser who are the preferred main contractors. Fabrication of the two new steel and concrete U decks will commence as soon as the final design work is completed by HBPW Consulting of Retford and the steel (which has already been design-specified) arrives at the fabricators, Carver Steel in Harworth, Doncaster. Volker will be ready to demolish the old bridge deck and install the new twin decks from the 1st October, as well as making good the existing bridge abutments

This will enable both the track to the midland mainline chord and the future line from GCR south to pass over the newly-constructed bridge. Two tracks over the bridge are essential to secure a future connection with the mainline.

This project represents the next major step in the reunification of the Great Central Railway Loughborough with the northern section which leads to Ruddington in Nottinghamshire.

Full details - https://www.gcrailway.co.uk/2022/04...-the-go-ahead-for-1000000-bridge-replacement/

 

[Pinza-C55]

The Great Central Railway PLC’s Board are pleased to announce that they have today given approval for the work on the replacement of Bridge 326 crossing the A60 adjacent to the former Brush Works in Loughborough to commence with immediate effect.

A purchase order has now been placed with VolkerLaser who are the preferred main contractors. Fabrication of the two new steel and concrete U decks will commence as soon as the final design work is completed by HBPW Consulting of Retford and the steel (which has already been design-specified) arrives at the fabricators, Carver Steel in Harworth, Doncaster. Volker will be ready to demolish the old bridge deck and install the new twin decks from the 1st October, as well as making good the existing bridge abutments

This will enable both the track to the midland mainline chord and the future line from GCR south to pass over the newly-constructed bridge. Two tracks over the bridge are essential to secure a future connection with the mainline.

This project represents the next major step in the reunification of the Great Central Railway Loughborough with the northern section which leads to Ruddington in Nottinghamshire.

Full details - https://www.gcrailway.co.uk/2022/04...-the-go-ahead-for-1000000-bridge-replacement/

That's great news. Another bit of the once great railway network is restored for future generations to enjoy.

 

[AndyY1951]

Excellent news!

 

[Flying Phil]

Here is a picture of the repaired bridge 348 with its lattice parapet.


Also a picture of the A 60 bridge, which is to be replaced in October by a new bridge.

 

[Flying Phil]

There is a more detailed report on the repair to bridge 348 in the latest "Main Line #191" and it is described as "the original steel half barrel deck construction" which has had "new structural steel beams and steel reinforcement totally encased in concrete". So DCSA was quite correct and I have learnt about another variant of occupation bridges on the GCR. Although it would appear that in this case the "half barrels" run lengthwise across the abutments?
In other bridge news, I was told that there are signs up at the A60 bridge indicating that the worksite is being prepared. I expect that the track will be being lifted and ballast removed so that the old bridge decks can be lifted. Also the brick abutments will need repair/preparation work before the new decks go in. The actual lifts are scheduled for two dates in October.
The fundraising for the two "Factory Flyover sections is now around £1.2M and there is the desire to get something started sooner rather than later in view of the inflation affecting costs. Could this follow on relatively quickly from the A 60 bridge work??

 

[Teaboy1]

Is there to be any provision for an increase in clearance? Looks like plenty of battle scar damage from bridge strike.
Given that current UK standar clearance is 16 ft - 6 inch, its too low by some 2ft - 3 inch.
Its either raise the abutments or plane out the tarmac/hardcore to achive a extra 2 ft - 3in. Got to be worth it while the deck is being removed.

 

[zwk500]

Is there to be any provision for an increase in clearance? Looks like plenty of battle scar damage from bridge strike.
Given that current UK standar clearance is 16 ft - 6 inch, its too low by some 2ft - 3 inch.
Its either raise the abutments or plane out the tarmac/hardcore to achive a extra 2 ft - 3in. Got to be worth it while the deck is being removed.

2'3" is a hell of a lot of tarmac to plane out. If you saw a 70cm pothole in the road you'd stop your car. The railway will be constrained by cost, the abutment strength, the gradients either side and possibly planning concerns as the bridge would be casting different shadows. The road will be constrained by gradients either side, the risk of lorries grounding at the ends, services under the roads and local ground conditions. Even splitting the difference isn't going to be easy. And remember - the GCR will face almost the entire bill for both road and rail changes.

 

[Flying Phil]

As zkk 500 says the road conditions are limited by the surrounding ground and there is a nearby brook which will cause road flooding if the road is lowered any more. The rail level is limited by the gradient up from the Midland Main Line along the chord line. However the new bridge is being designed and built to give an increase in the clearance as much as is possible according to the latest Main Line article.

 

[Flying Phil]

There is work now on site at the A 60 bridge. Some container type building are being put on the old works compound site by the embankment North of the MML bridge.

 

[fgwrich]

There is work now on site at the A 60 bridge. Some container type building are being put on the old works compound site by the embankment North of the MML bridge.
View attachment 116947

That's great to see, thankfully it wont be long before the new bridge is in place and hopefully, British Gypsum & GBRf will be crossing it on their way to Rushcliffe again.

On a side note, the GCR produced another video to do with the A60 bridge this week. Here it is for those who haven't seen it yet:

 

[Flying Phil]

Driving under the A60 bridge today there were several people at work and some vegetation has already been cut down on the embankment.
There was also this lorry with concrete segments that looked as though it was waiting to go into the site.

 

[Flying Phil]

There has been more progress on the A60 site as the vegetation has been cut down on the embankment. There were a lot of those concrete segments being stored.


As there was work going on by the bridge, I had a look and the bottom of the embankment is being moved back to widen the roadway?


But I was told this was a Network Rail worksite.....Then I saw that work was happening on the brook by the Preci Spark car park. It looks like the brook is being diverted from under the main Midland Main Line. Could this be work being done on the steel girders over the brook?

 

[AndyY1951]

Very interesting - I hope that what is being done is consistent with the reunification plan!

 

[AndrewE]

Ummm, in the second picture aren't those concrete units supposed to interlock - if you put them in the correct way up?

I hope that is just a temporary retaining wall (not that they are designed for that) because if not, there will be some seriously heavy lumps of concrete being pushed out to fall into your roadway in a few years' time. Something like https://www.eliteprecast.co.uk/inte...rete-blocks/duo-interlocking-concrete-blocks/ are what is needed there - or just stand them upright!

 

[Flying Phil]

I'm sure it is Andy - in fact it must be easier to do this work now, before the little "missing" embankment is put back to the North of the GCR MML bridge.