Why capital-ship magazines are separated from machinery

What is the space between the forward and aft turret magazines used for?

It separates the magazines from hot machinery so ammunition temperatures remain safer and more consistent.

The apparent gaps around the Francesco Caracciolo class's magazines are deliberate protective spaces. Engines, boilers, and furnaces are concentrated away from ammunition stowage. Keeping propellant at a more even temperature reduces the risk of heat damage and inconsistent performance. The layout therefore connects internal subdivision to both safety and gunnery accuracy.