REALLY stupid question (turning big stuff)
Let's for one second set aside the safety aspect.
Something I've been thinking about - to turn a bowl, what do you need? A surface to mount a block of wood to, and a way to spin it, and preferably a way to vary the speed at which it turns.
Anyone ever seen someone have a machine shop mount a chuck or flange to a car hub (perfectly balanced, of course) and mount it to a properly jacked and blocked car? Remember "Commando" when the village was using an old Jeep pickup to turn their belt-driven water pump? At least I think it was "Commando".
You would then have almost infinitely variable speeds, especially the extremely slow speeds for large, not-yet-balanced blanks. No worries about not having enough room for the throw. Very heavy-duty, at least as far as lathes go.
This is not something anyone would ever try, but do you think it would even be possible?