I hadn't really thought before about such a thing as a 'one sided floating drydock', surely the objective of two sides is for capacity to flood down or raise while keeping on an even keel by having tanks in the two sides, whilst also supporting cranes etc.
But a pontoon such as Austin's requiring side access would also need to keep level, so was the water capacity for flooding entirely in the bottom section? If so, then that section would presumably need to be deeper than in a floating drydock with 2 sides, and that would work against the available draught for getting a ship on or off (unless it was in a deep hole!!).
Answers on 2 sides (or maybe 1) please .....

I have never really thought about this either, but . . .

In its raised position (ie with a ship in it) all the buoyancy must be provided by the base of the dock, not the sides. In the submerged position the bottom will need to be flooded, but do the sides? Do the sides just remain open to the water so that they do not provide buoyancy. Therefore are the sides only there to support cranes and hold the pumping machinery. Also help to keep the ship in place although the ship's main weight would be supported by the keel blocks.

That small dry-dock was in use in the early 1980s and I think it was the coaster LEE SHORE I saw occupying the dock circa 1984.

See new topic: FLOATING DOCK - viewtopic.php?f=149&t=4830

Ron

Going back to the main photo again, there are "arms" connecting the dock to the quay. Where the further dock has been removed, these "arms" can be seen sticking out. On the nearer dock the arms are attached to the dock and seem to pivot on the quay wall and extend further on to the quay. There couldn't have been pistons (or something) on the other ends of the arms could there?