Things are happening quickly now, with three sites on the go and good weather.
Firstly, our bridge engineer has had a look under the deck of bridge 1 to get a record of the damage for his files. His pictures are quite striking:

Damage to two rail bearers.

These two pictures show rust damage to the rail bearers under the deck at Broadway (caused by water dripping through the holes that show daylight), and the lower one shows additional buckling due to impact damage from a lorry strike. There's going to have to be a bit of welding here!

A strange phenomenon

And here is a picture of a really unusual corrosion phenomenon where a combination of erosion and corrosion, combined with capillary action, has packed a gap between two plates with dense scale which has expanded and pushed the main beam flange into a curve. Powerful forces were at work.

Updates, bridge by bridge

Bridge 1

Blast cleaning of the entire structure is virtually complete, and with the change in weather forecast for the weekend it was decided to apply an undercoat to the main girders.  Consequently much of the structure now has the primer coat applied. In addition, part of the upper surface of the deck plate has had a pre- waterproofing primer applied

The first layer of paint goes on at Broadway

 This primer is a protective coat (the deck excepted) to preserve the bridge while the patch repairs are carried out. Looks good ! This is what your money is buying, shareholders !

Bridge 4
This is the least damaged bridge, but has nonetheless had a series of patches fitted to the deck:

Bridge deck repairs at Peasebrook Farm.

 If we stop the water dripping through to the girders underneath, the main cause of the corrosion is removed.

Bridge 5
Extensive repairs continue on this bridge. On Wednesday, further excavation took place behind the abutments:

Further corrosion was then found behind the girder end plates:

Girder end plate removed.

The removal of the brick ballast walls exposed the fact that there were no holding down bolts attaching the steel to the tops of the abutment, and, following shotblasting revealed that the 4 end plates of the 2 main outer girders were left with rather interesting “lace curtain” patterns (see photo below). These have been cut out and new plates are to be welded in. The removal of the “lace curtains” has revealed further corrosion (see photo) and the shotblaster will return first thing on Monday to clean away the scale and rust ready for welding.

 

The 'lace curtain'

All of the outer web stiffeners to the two outer girders have had steel plates inserted where corrosion had eaten them away.

All the original repairs identified have been completed. This includes cutting out holed and corroded deck plates and welding in of 10 mm thick steel patch replacements, which have to have a full perimeter weld to create a totally waterproof deck. 9 holes were cut and filled on the downside and 5 on the upside requiring a total of 15.5M of perimeter weld to be used.

New bolt anchor brackets have been manufactured and will be fitted on Monday to the new end plates, mentioned above, which should then complete the steelwork on bridge 5. New holding down bolts will be cast into the concrete strengthening, in due course.

Rail bearers below the deck which had corroded due to deck holes allowing water through have been repaired.