Tuesday 28 October 2014

Gentlemen, your Tuesday bridge update is ready for inspection! It was a great, sunny warm day, and the contractors continue to be busy. Here is a little roundup of the work going on:

Bridge 2, Childswickham Road









After a return to base to manufacture to size the new pieces, there were 2 steelworkers on bridge 2 today, and they were completing the last of the larger (but not very large) repairs. The downside outer girder repair is now completed, as you can see in this picture.















Here we can see the underside of the same outer girder, where it has been reinforced to repair an old bridge strike.










These two pictures of two cross beam repairs show how the newly manufactured plate is provisionally attached to the beam on site, and then holes are drilled through in order to insert the bolts replacing the former rivets. The drill is an electro-magnetic one. Your scribe has never seen it used upside down though !
The same drill was used with a broach (hollow drill bit) to drill out the reluctant rivets from twisted plates on much struck Broadway bridge.

The steel workers hope to finish all of the steel this week. Three of the smaller deck plates have been welded in, but none of the larger ones. 

Bridge 4, Peasebrook farm

As you can see in this picture the deck has been completely cleared of concrete. What a strange construction, it does indeed look just like so much corrugated iron. Note the car in the corner - you can drive down there now, thanks to the completion of bridge 5. This time last year you could see Broadway goods shed in the distance from here, but since then the undergrowth has sprouted again. However, as you may have seen on the Lineside Clearance and PWay Flickr sites, work has started from Laverton to clear both lineside and trackbed. One helluva job - want to help them?
Underneath bridge 4, shotblasting has been completed and the voids between the corrugations filled in with brickwork. Looks tidy now. You can see here that the corrugated bed is not one big sheet, but a lot of channels riveted together. They don't make 'em like that any more.

Bridge 5, Little Buckland

This bridge is now virtually completed, as the two pictures below of the up and down sides show:
Looking west

Looking towards Buckland village.
Working on top of bridge 5 is the mini digger, spreading ballast over the protective sheet. This job was completed by the end of the day. It remains for the embankment to be raised to its final level. The one at the Broadway end will have to wait until work at bridge 4 is complete, as this point is used to access the trackbed to get to bridge 4.
 



Here you can see the mini digger spreading ballast around the Broadway end (leaving the above mentioned access possibility for bridge 4) and a bit more in the foreground, the brand new fencing. Nice job ! The new brickwork looks great too - remember that there is an enormous concrete infill right behind it.

Sunday 26 October 2014

Just to say that I have enabled 'Anonymous' comments. Previously it was Google account only, but there were very few comments.
But if you do use 'Anonymous' please tell us your name. You know mine :-).
Happy reading!

NB What do you think of this bridge's warning?

How clear is that ! And only 10ft clearance too. Nobody seems to have hit it yet.

Who can guess where it is? No prizes though, just fame !

Friday 24 October 2014

A dual report today - progress on the bridges to Broadway, and also a look at some of our other bridges along the line. We don't often talk about those, but they are not forgotten. Indeed, as you will see, we keep a very close eye on them.

So, on Broadway, here's a look at work on the three bridges currently being worked on:

Bridge 2, Childswickham Road
Further to our report on Wednesday showing the fabricators at work, we have three more shots of the corrosion damage and measures being taken to address it:
This is a shot of where we have had to enlarge a corrosion hole through a girder end to remove piles of muck, corrosion and who knows what about 150mm thick. This simply helps keep the steel wet, so encouraging faster rot! It has to be removed, and be replaced with proper drainage and access.
Corrosion of a main girder end




And finally, a very tricky repair to a track bearer end (Broadway side), including (just visible) the replacement of a section of the bottom flange plate. Not a lot left of our original bridge here...

Bridge 4, Peasebrook Farm

Here the concrete break out (it is weak concrete, and didn’t take much effort!) and removal is almost complete...
Exposing the troughing


Damage underneath the troughing - trains will have to rumble over this
... and a picture of the holes through the end – just to remind people why we are having to do this. The ends are the critical points where the weight of the trains is transferred onto the bearings, or not in the picture above! As reported earlier, a technical solution has been agreed, but no doubt at extra cost.

Bridge 5, Little Buckland

Below is a shot of the deck with the ballast boards all finished (before the off cuts & sawdust were cleared up of course). Unfortunately the gales on Tuesday severely displaced a lot of the neatly laid waterproofing protection mat. This will soon be straightened again, and covered with ballast.
In the picture, we are looking south. 800yds away is the railhead at Laverton :-)

Now, as they say on TV, ' in other news tonight'.....

Bridges 32 (Prescott Road) and Bridge 34 (our largest, Gotherington skew bridge)

Another activity on Bridges is the need to carry out inspections. We aim to try and inspect all major structures and as many minor (mainly culverts ) as we can, each year. This is done on a visual basis working from the ground or on the bridge, taking photos & writing reports.

In addition we then carry out Principal (detailed) Inspections, using the services of a Consulting Engineer, on a 6 year rolling programme basis. This involves hiring in a cherry picker so that we can see the critical areas on the tops of the abutments, where most corrosion arises. This happens due to the poor maintenance access availability, leading to heavy and extensive corrosion, which has created so many of the problems now being repaired on bridges 1 to 5.

Because of the narrow roads and the need for a cherry picker, we also have to provide traffic management, (lights, signs, cones, etc) to keep the operation safe for our men and the general public.

Below are shots of bridge 34 -Gotherington skew bridge (our largest) – note the lady assistant engineer, in yellow, and 32 – Prescott Road, almost our most hazardous. Both of these were done with traffic lights controlling a single lane system. Because of the safety distances required the lights are not visible in the photos.

We also did bridge 28 (Stanley Pontlarge) and in 10 days time will be doing a further 5, where access will be obtained from track level on our service road. Again a cherry picker will be involved.

Detailed reports will follow on the basis of which a priority list of repairs will be compiled - hopefully not too many.





Finally, here is a shot of one poor connection under the running line on bridge 34. It looks worse than it actually is because of the highly coloured corrosion.
Evil looking, but mostly surface corrosion (for now)
Money continues to dribble in on the share issue, but will it be enough to cover all the extra costs? Or even rails for the extension? One more week of the EIS scheme remains.