Ruby Zurich | Building site diver

First, the four concrete walls of the drop shaft were poured.

These were then sunk into the really damp soil under the foundation slab.
A tributary of the Limmat had its bed here once. The groundwater still floods in more quickly here as elsewhere, e.g. in the neighbouring building.

Once the walls were in position in the mud …

… a diver took to the water …

… and laid the first reinforcement irons before then pouring the drop shaft’s concrete foundation slab.
In and of itself, that’s nothing new. But this time, our diver’s vision was next to zero.

And here’s what the finished shaft looked like once the water had been pumped out.