Take a look at this drawing again. Our innermost bladder does not necessarily need to be 0 bar. In fact, it can be pressurized to 1 atmosphere. In fact, it can be pressurized further to any pressure desired - ladies and gentleman, the premise of the onion-shell or onion shell pressure vessel -
… and yes, in addition to pressure vessels, this principle applies also to the submarine…
Our vessel doesn’t need to be almond or traditional shape. You can do it also with pipes and spirals, any shape you need.
