Network Rail plan to close Tan Hill crossing and replace it with a footbridge

[whole diary]

[GBM]

There was a guy with a drone doing video too.

Justin?

[stuving]

There was a guy with a drone doing video too.

Justin?

No - he trades as Wokingham Aerial Photography. They have some photos and a video (with very annoying music) on his Facebook/Reels. There's a top view of the Ikea self-assembly junction kit too. I thought I found more videos on Instagram earlier, but can't find that now (or it may have been just photos).

[stuving]

Saturday was quite a spectacle, in the sense that it's not every decade you get a socking great mobile crane working at the corner of the street. It was also frustrating, with long waits with nothing happening except huddles of orange rainsuits debating (presumably) how to proceed. Then with no warning, something happens - often quickly. And as it was by then after dusk it was hard to see upwards, into a barrage of bright lights, or at the installation site, under limited site lighting, from the car park.

But I have a backlog of pictures. I'll start with the dramatis machinae:
A bridge of two halves
A toy train to take it down to where you can see one of the piers by the line
A Big Crane (Liebherr LTM1300 6.2)
... and a couple of these things (AC-55, I think). This one is going on-track, which makes a loud clunk noise.

[stuving]

Act one was setting up the crane for the lift (also in the first video above). This involves building pads for the outriggers, out of a combination of sandbags, planks, expanded polystyrene sheets, and a steel plate on top (better seen in the video at 8:40). This stuff comes on three artics (plus a trailer), together with the sections of the counterweight and the big spreader beam (p1).

This crane stacks its own ballast weights on a fixed platform in the middle of the vehicle body (p2). Two big lumps are slotted onto each side of this - 10t each bit. It picks up this stack, 96t of steel, with jacks on the back of the crane cab that lock into the ballast baseplate (p3). Only then can it fully extend the jib.

[stuving]

Act two was assembling the sling. In this case it has a massive beam to spread the strops in length, and two smaller ones to spread again in width. The big one was bolted together in the road (p1), I guess because that is flatter and stronger than the crossing. (p2)

Act three was attaching the sling to a bridge span. This took ages, as the plan was changed for some reason. The steel I-beams fixed under each end crosswise had had small extensions bolted to them on arrival, and the strops attached to the ends. This was tried (p3), but in the end the strops ran round the main tube at each side of the deck instead. This involved a rigger splitting the strop at the top so it could be fed along its new path.

[stuving]

And then, finally, the main event: the lift. The highest obstruction was the Vodafone mast by the station wall, so when lifted the span went round away from that, also avoiding the public footbridge (by then closed). It was lowered beside the signal box, onto the train of engineers' trailers (p1). For the second lift, onto the piers, two rail cranes operated in tandem (p2). One was on the tongue of land the centre span of the bridge crosses, the other on the track.

For the second span that crane moved to the other end, perhaps in the siding (I missed that - dinner time!). Obviously attaching the second span was much quicker, and in any case overlapped the work at the bridge site. This time the train of trailers didn't move into place until the span was in place (p3).

And by Sunday Morning, there is a new view up the line from the footbridge by the level crossing (p4).

[paul7575]

Great set of photos thanks. 

Always useful to explain how complex these sort of jobs are, I think there were suggestions ‘elsewhere’ it should have been done at the same time as the resignalling and junction relaying, but that was clearly impossible...

Paul

[Electric train]

Great set of photos thanks. 

I agree

Always useful to explain how complex these sort of jobs are, I think there were suggestions ‘elsewhere’ it should have been done at the same time as the resignalling and junction relaying, but that was clearly impossible...

Paul

Only by armchair engineers 

[stuving]

Now that bit is in place,. what about the bridge itself? The design of the bridge itself got little attention at planning, what with all the shouting about (the lack of) ramps. But it is a bit odd, compared with what we are used to.

The width is quite generous, at 4m overall and 3.1m for the footway. The sloping sides are really quite high, as struck me when I saw a rigger using a stepladder to reach the top. The plans say 1.878m vertically, and it's faced internally with a "brushed stainless steel perforated panel". The centre span does not have this panel now, but I think it will be fitted. The drawing suggests, and the photo agrees, that the panel is more perforated at the top.

So it looks as if the views I was recording from the old bridges will not be coming back - not as clearly, and perhaps not at all. Now, is there a good reason for that obstruction? Even if this is meant as a standard design for all railways, including those with OLE^▸ (Overhead Line Equipment, more often "OHLE"), it does seem excessive. And as for the small kids who like to look at the trains ...

The stays preventing a "pack of cards" collapse look temporary, so I guess the stairs will be expected to hold it rigid finally.

[paul7575]

The nearest concrete plinth looks odd, you’d expect it to be parallel to the legs? I suppose they had a reason to build it at an angle, but it looks weird…

Paul

[Mark A]

Good lord. They've taken a perfectly good bridge and given it anxiety.

Mark

[stuving]

The nearest concrete plinth looks odd, you’d expect it to be parallel to the legs? I suppose they had a reason to build it at an angle, but it looks weird…

Paul

Yes, while the staircase at the far side is in line with the bridge, this one has to be angled to avoid the car park (from which the picture was taken). Before the car park was built, there was a vague aspiration to continue the route from the footbridge on the level to, and through or around, the car park and on a walkway to the new Carnival Hub [sic]. That never made it into concrete, or even into a concrete plan.

[stuving]

When are they going to complete the new bridge? Or is that the purpose of the latest planned closure?

When that question was raised, I had been wondering the same thing. I'd noticed all the machinery and people had left well before the end of March, having put in some foundations for the steps (at the one end I can see). I had not been to look for a couple of weeks, and wanted to check if work had restarted before replying (but in fact didn't get there until yesterday).

A search pulled up a WBC update e-mail which said that they had been promised completion by the end of April (and which has now vanished). Now, in their planning application, NR^» (Network Rail - home page) had played the "we must spend our money by April 1st" card to stop all the whingeing about ramps for accessibility and get it approved PDQ. So I wondered if they had spent all that, and needed to beg for a little bit more in CP7 just to finish it. But no, that wasn't it.

This week, a local news item appears passing on an Xtweet from WBC:

Tan House footbridge completion is delayed due to Network Rail's contractor appointed to build the steps going into adminstration.

Discussions are taking place and we will provide a further update once received.

Wokingham Today has more from NR:

Bridge completion still months away

Residents took to social media to express their frustrations on being unable to use what one described as an important connection to the town centre.

In response to a request from Wokingham Today, a spokesperson for Network Rail said: “Balfour Beatty, who are working with Network Rail on the construction of Tanhouse Bridge, are in the process of terminating existing contracts with the previous bridge fabrication contractor, due to them entering administration.

“They have now acquired the necessary certificates, materials and design information to continue the project and, where necessary, re-contract the work to another fabricator.

I could be worse - and even might be. The north end of the bridge links to the newly-built "civic hub", with leisure centre, library, car park, bowling alley (and amusements arcade). There is also some housing in the development, but that got half built and then the contractor went bust. A new one was found, but almost immediately they went bust too. Third time ...

[eightonedee]

If Balfour Beatty are under a contract to complete the works, the insolvency of their sub-contractor will be their problem to resolve. Provided that there are other bridge fabrication suppliers out there who can fulfil the order this should just be a delay, not the end of the project. The worst case might be that a revised design will have to go through all the requisite approval processes.

[CyclingSid]

Possibly not the end of the story

https://www.bbc.co.uk/news/articles/cj9njwx30rpo

Get the impression there might be some mud-slinging over who was to blame.