Our structures engineer John has visited the three current sites again, so that we can give you an up to the minute update of the progess of the works - as at 13.00 hrs today. Hot news indeed! Here we go:

Bridge 1 - Broadway

The shotblaster has moved back to Broadway this week, from bridge 5, as there was too much conflict over the working space required, with the excavation works going on behind the Cheltenham end abutment. He is continuing with blasting and priming at Broadway and is aiming to get a primer coat on all of the steel, and perhaps an undercoat on some parts. The steel fabricators and erectors are currently back at their factory manufacturing the 19 pieces of deck plate that are needed to patch the areas where corrosion has eaten right through the 3/8” thick plates – quite amazing what a bit of water can do!! They are also making the 2 No. 15” wide x ½” thick plates to fit on the bottom flange of the east main girder, which require almost 300 holes  x 24mm to be drilled (not ¾” that we mentioned before- there are only about 20 of them). In addition they will also be bringing back many other pieces of steel to repair minor areas, now that the corrosion has been removed. As usual the blast cleaning has exposed the very thin areas and enlarged the small holes that were there before. Consequently the sizes of the many small bits needed has increased somewhat. Below are a couple of typical shots of steel where corrosion has eaten the metal. Not easy things to repair!!

Outer girder stiffener.

Examples of corrosion at Broadway - outer girder bearing.

Bridge 4 - Peasebrook Farm 

The brickwork should all be completed by tonight (started 23^rd June – 10 weeks early ) and the site will be temporarily sealed off until one of the follow-up trades groups (blast cleaning, or steel repairs) becomes free. Photos of the 3 completed wing walls are shown below:

Down side, Cheltenham end.

Up side, Cheltenham end

Up side, Broadway end, pilaster cap stone still to go

Bridge 5 - Little Buckland

 

As can be seen from the photos below, the dig behind the Cheltenham end abutment is nearing completion, with about 50% of the short section behind the upside wing wall to be finished. This may be completed today. As can be seen the chasm created is getting to look more like the Grand Canyon every day. The contractor was waiting for trench sheets to be delivered to make the dig face safe, before they started drilling the brickwork to insert dowel bars to tie the brickwork and new concrete together. The horizontal white line marks the height of the first pour of concrete – app 80 Cu. Mtrs (app 160 tonnes). There is quite a lot of concrete work going on around Cheltenham at the moment, so getting large quantities of concrete delivered, and availability of the concrete pump, when we need it, is a bit touch and go. However we are hoping that the concrete will poured by the end of the day, this Friday.

The white line marks the limit of the first pour

The chasm - Cheltenham end. Dig now complete.

 The next picture shows a crack (app. 50mm wide) at the junction of the Cheltenham end abutment and the adjoining wing wall, which may account for the signs of movement and minor cracking on the face. 

 

Crack between Cheltenham abutment and wing wall.

A further picture below shows the original abutment foundations and those to the upside wing wall (barely visible).

Foundations - not very visible.

The final picture shows that the steelwork has been mostly blasted and primed, and the whole of the deck has had the pre-waterproofing primer applied.

After sand blasting the steelwork

 You can see that you don't want to be sand blasting a few feet away from where the digger was excavating behind the abutment here. A big concrete block is going to fill this hole, tied into the leaning abutment with dowel bars. There won't be any more movement here in the future!

If you scroll to the top of the page, you can see the Broadway end of the bridge on the Blog cover. This is how bad it was at Little Buckland. The wing wall completely detached, and the pilaster had vanished - we found it several yards down the trackbed.