Why a cruiser hull is more than a large destroyer hull

Beyond scale, what distinguishes a cruiser hull from a destroyer or escort hull?

Its subdivision and machinery arrangement are fundamentally different, giving a cruiser more internal separation than an enlarged escort.

The response points first to internal subdivision rather than external size. Destroyer machinery spaces often occupy the full width of the hull, while a cruiser can divide machinery and other systems across more compartments. That difference affects resilience, arrangement, and the kinds of equipment the ship can support. On this definition, Long Beach remains the last US purpose-built cruiser rather than merely an oversized destroyer lineage.