Compartmentation

The fire spread rapidly after the building's compartmentation failed.

The reason for this compartmentation is FLAMETIGHT INTEGRITY. The purpose should be obvious: Propellent powder in flammable silk bags is always dangerous; compartmentation confines flame and explosive gas to the space in which it originates.

The Titanics compartmentation' did not stop water from entering rooms.

Compartmentation of the hull.—It has become the accepted practice in conventional rigid-airship construction to subdivide the buoyant gas into numerous independent containers[…]

Nevertheless the principles of compartmentation of information and need to know are essential to secrecy.