Why three stacked heavy turrets are a hard design problem

Can three large main-gun turrets be stacked in a superfiring arrangement?

It appears feasible with cruiser-calibre guns, but heavier weapons impose increasingly severe weight and firing-load costs for a limited tactical benefit.

Three levels of superfiring turrets appear feasible with cruiser-calibre weapons, with 8-inch and possibly 9.2-inch guns suggested as manageable cases. Raising heavy guns also raises the point at which their firing forces act on the ship. Designers must account for those forces alongside beam, metacentric height, and centre of gravity. Above cruiser calibres, the cost and complexity are judged likely to grow faster than the tactical benefit. Real ships also rarely need every turret to fire directly ahead at very low elevation. Angled firing and elevated guns reduce the disadvantage of layouts in which one turret cannot fire over both of the others.