Raising Brick and Masonry Railway Bridges for increased clearances

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Bridge lift to increase clearances​

28 October 2016

The Railway Gazette published this item in 2016 "Bridge lift to increase clearances. UK: An innovative process to raise arched masonry bridges to increase clearances for electrification was successfully demonstrated in Buckinghamshire on October 26." This was also reported in Modern Railways. It involved jacking up both sides of the bridge simultaneously using computers to give millimetre accuracy of lift so as not to disturb the mortar. Did the firm get any contracts following the demo? (I can't read their name on the banner over the arch.)

 

[zwk500]

Here's the company's site: https://freyssinet.co.uk/masonry-arch-lifting-elevarch/

They don't appear to have got any further work. There's a lot of issues with this kind of lift for the relatively small benefit of preserving a brick arch bridge, which are many and often up and down the country on rail, road and canals.

 

[yorksrob]

It's a shame it hasn't received more interest really. It seemed quite a quick process.

 

[hwl]

If memory serves it also is only suitable for a sub-set of better constructed arch bridges (probably all with Portland cement too).

 

[InOban]

And bridges which don't carry services （water, power, telephone etc ）That's most of the reason it takes so long to carry out the work.

 

[yorksrob]

If memory serves it also is only suitable for a sub-set of better constructed arch bridges (probably all with Portland cement too).

That could be quite problematic. I'm guessing a lot of bridges built during the main construction phase of the railways will have used mortar.

 

[swt_passenger]

If memory serves it also is only suitable for a sub-set of better constructed arch bridges (probably all with Portland cement too).

I think on the demonstration they basically rebuilt the entire infill in reinforced concrete before starting anyway. I suspect this demonstration shows there is a last resort solution if some particularly obstructive local authority insists an old bridge cannot be altered, but we‘re unlikely to see it normally.

 

[EbbwJunction1]

Something tells me that one of the bridges between Newport and Cardiff (or Severn Tunnel Junction and Newport) was raised rather than replaced during the electrification works, but I can't remember any details (or even if I'm right!).

 

[edwin_m]

Something tells me that one of the bridges between Newport and Cardiff (or Severn Tunnel Junction and Newport) was raised rather than replaced during the electrification works, but I can't remember any details (or even if I'm right!).

It might have been a beam rather than an arch bridge. That would be easier to raise, as the beam is solid from end to end whereas with an arch there's a risk of masonry breaking up.

 

[EbbwJunction1]

It might have been a beam rather than an arch bridge. That would be easier to raise, as the beam is solid from end to end whereas with an arch there's a risk of masonry breaking up.

Ah, you could well be right, thanks; I did say that my memory was a little vague on it!

 

[bassmike]

Sounds hardly worth the trouble?

 

[edwin_m]

If the extra height is needed for structure gauge enhancement rather than electrification then an arch could have to be raised quite a way to achieve the necessary clearance at the corners where containers are larger than traditional trains. Replacing it with a beam bridge might allow the road to stay at or near the same level, reducing the work needed to re-profile the approaches.