I ended my last report by stating that we hoped by now to have removed the first 40 metres of our nemesis Big Pipe at phase 2 and perhaps to have completed the concreting beneath it. Well, I’m pleased to report that by the end of June we’d completed both.
So this update isn’t chronological order – it starts with the pipe removal.
Unfortunately, I didn’t take any photos of the actual pipe removal. I was focused on operating the digger and ensuring that the lift and pipe removal went smoothly. However, there were other people who recorded the event, and the photos in this article were taken by Paul Marshall.
It didn’t entirely go to plan, as we had to cut the collar/boss off one of the pipes in order to pull the adjacent pipe clear. But, once we got the first one out the rest were relatively easy to remove.
We hired in a telehandler and Adrian carried them off site to a storage area. They’ll eventually be picked up by a lorry-mounted Hiab for recycling and reuse elsewhere.
In preparation for the removal and to achieve the first milestone target, we all got pretty good at casting concrete slabs. We were doing just over seven linear metres per pour and got to the magical 85 metre mark by mid‑May. Sometimes additional volunteers managed a second pour on the third day.
When it rained, the tank flooded and we noticed that the concrete blocks were not entirely impermeable. So as a precaution, we tanked the walls with an epoxy resin.
Meanwhile, other work was being carried out at elsewhere on site
Dave was working on the incline wall that leads us down to towpath level, and Bob and Chris were topping off the reinforcing wall with blue bricks.
Once the pad was cast, the sheet piling was backfilled with spoil material and a sealant mastic was added to the pile clutches (the gap between). With the pipe gone, we had access to clear out under it and finish concreting the base.
The wharf extension wall and handrail is now finished – it’s quite a drop from the offside path. The spoil from under the pipe was used to backfill the wall.
The next section is already being worked on. We are building a headwall, where our nemesis pipe emerges from behind the sheet piling for a second time, so that this section of pipe can be removed in the future.
By early July, we had not only put the bund in place at 85m but also removed most of the temporary plastic pipe. The continuous flow of underground stream water comes out of the big pipe next to the bridge, but then flows back into the pipe at the end of the wharf wall. It may only give us a depth of 20cm at the moment, but by definition, we have a waterway here now.
Mike Babb
Workparty volunteer
This blog first appeared in Cut Both Ways, our members’ magazine, become a member to get your copy.
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