If we managed to dig a several hundred foot verticalshaft and the soil was feeling generous, not collapsing inward and waiting for us to build the wall, the challenge of casting this concrete would still be great.
Being simply a rotating horizontal shaft with a heavy vertical load on it, early locomotive axles suffered severe stress reversals in their outer skins with every rotation.
It had a circular elevator shaft for the round elevators that he believed would be the vertical transportation of the future, although it did not receive one that fit until a 1970s renovation.