Forums Forums Wirral Information Ask - Wiki Wirral What are they doing at four bridges?

What's going on at four bridges? A massive crane has appeared and a large steel assemble painted yellow and the area around the old pumping station is alive with workers.

The Skylift 3 and the large yellow thing appear to be something to do with the Gladston Dock gate replacement, this is the first commission for the Skylift 3 and when it was heading to Liverpool it was carrying disassembled parts of that yellow thing.

https://www.heavyliftnews.com/ravesteins-skylift-3-400t-floating-crane-sets-off-for-first-project/

I suppose the big yellow thing could be a sluice. Presumably it will be buried?

Whoops:- the Gladstone Dock gates were completed in May 2023.

Skylift is back but its Skylift 2 in order to replace the dock gates between Alfred Dock and East Float https://www.facebook.com/groups/manchestercanal/permalink/8371255809665099/

Still none the wiser what the yellow thing is.

I've worked out what the big yellow thing is. It is the sill at the bottom of the new gates. The clue was the two tall columns rising from each end. These are the hinge pins for the gates. Anyway, its disappeared now and is presumably underwater waiting for the gates to be hung.

It looked hollow but the steel used was probably thick enough to give it slight negative buoyancy so it could be accurately maneuvered. I expect it would be filled with concrete once in place.

I was wrong about the big yellow thing at four bridges. It was not the sill for the gates.

Rather it was a diving bell for the construction of a concrete sill. Sunk into position, it would be sealed and pumped dry and men would go down and construct formwork which would subsequently be filled with concrete to form the sill.

That's my best guess anyway, although I am happy to be proved wrong with a better explanation.