Around six months to completion, even with the steel shortages, very impressive. I wonder how they will increase the vehicle clearances below.

Maybe they will do something similar to what was done to the infamous 11 foot 8 bridge here in Durham - I thought they rebuilt it with "shorter" girders to create more clearance, but maybe they just raised it up?

TAN:YouTube movies show that the abutments were made higher. I'm not sure if the old girders were reused.

I believe the current A60 bridge is posted at 14' 3" clearance, so I would think that having the new bridge decks of a shallower design and by modifying the abutments before the new decks are put in place they would be able to gain at least 6" more clearance which at least would enable normal height double deck buses to run underneath it (which they can't at the moment). One of the two parts of the bridge is used by the connecting line - on a gradient - that joins the former GC line to the Midland Main Line, so that will have a bearing on any height alterations made to the trackbed.
The standard minimum height for new bridges over roadways here now is 5.03m (16' 6") but that would not be achievable in this location.
Hopefully the drawings of the new decks will appear in a more readable form at some stage, along with more information on the project. The next GCR Friends Main Line magazine is due out at the beginning of June, so that should have more about the operation in it.

What about lowering the road underneath? Or would that be troublesome due to traffic disruption and cost?

There is a river, brick construction river bridge and floodplain to throw into the equation as well, so lowering the road is a non-starter - Otherwise they would have done that years ago!
You can have a virtual drive along the road in question to the bridge on Google Maps...
https://www.google.com/maps/@52.7801744 ... 384!8i8192

This video says it is occasionally hit by lorries (semi-trucks probably) though 14'6" should clear those, in the US I believe you need a permit for anything above 13', not sure what is allowed in the area of the bridge: https://www.youtube.com/watch?v=Lk8EvtFG7Xk

The second paragraph of the article refers to "U decks" - I presume that is British terminology for a type of bridge superstructure design in which the main structural beams are alongside the tracks instead of directly underneath the tracks. The cross section of the bridge looks somewhat like a 'U', hence the name. The design provides more clearance underneath the bridge because the superstructure under the track isn't as thick (since the main beams are alongside the track, not under it.)

I think the design is patented and that's why it is not that commonly used in the US (most publicly funded infrastructure programs cannot pay for patented designs and proprietary materials.)

The cross-section of a U-deck bridge and a picture of it being lifted into place - note how the bridge is less than 10 inches thick below the track/ballast:
These illustrations are part of the article Innovative Composite Precast Prestressed Precambered U-shaped Concrete Deck for Belgium's High Speed Railway Trains [PDF] that was published in the November-December 2004 issue of the Precast/Prestressed Concrete Institute's PCI Journal.

I did actually find some images online today - after a bit of digging about - which enable the meaurements (in mm) for the A60 bridge to be read, more or less.

This is a cross section of the single track u-deck...

The pair of decks together....

Thickness of the bridge deck is just over 17" (420 mm), which is more than the example mentioned in the previous post.
The uprights of the U shape seem remarkably thin though - 210 mm is about 8.25"...!

Demolition work on the old A60 bridge (referred to above) took place at the weekend with a brand new structure - albeit using parts of the old bridge abutments - being erected in the coming weeks.
Six minutes worth of Video of the demolition....
https://www.youtube.com/watch?v=zqlVmobISGI
If you are really desperate, there is another video online lasting just under 5 hours that covers it all in real time!

It is amazing what is possible in a country that gives a s*it about its history.

In Durham NC the NS raised the Gregson St. 11 foot 8 bridge to 12 foot 4 by putting four 2 inch plates under each corner, then raising the approaches to match.

Trucks still hit it, or actually most of them hit a bright yellow beam ahead of the bridge, but not as often.

Here's how: http://11foot8.com/raising-11foot8/

Phil Mulligan

This has me musing about something. Has anyone calculated the failure modes of lateral impact against the bottom 'web' of one of these U-bridges, specifically the part where the stresses taken by the side beams go into the actual support of the track and ballast?

Perhaps I've been watching too many videos from Florida and Tesas about bridge failure modes, but I see some potential failure modes with the detail design and construction...

CVSR’s bridge over Memorial Parkway in Akron, OH was a truck magnet at 12’10” clearance, knocking it out of alignment a quite few times. They raised it to 15’6” clearance in 2013 with a new deck girder bridge and abutments. That was something like $1.7 mil to do that. I don’t think it’s been hit since…