The term “ring-magazine” refers to a design philosophy used in current-generation Imperial Navy capital ships, other than carriers, along with a number of the larger, quadruple-turreted cruiser classes.

To review, these types – unlike the smaller destroyers and frigates – share a common general plan dictated by the requirements of military starship design. The core of the vessel is a primary truss structure extending from the thrust frame at the stern to the bow, around which the habitable section is constructed. Above this, connected by the remaining structural trusses, the outer hull is a slender, rhombus-based pyramid, similar to the blade of a poniard, slightly flattened on the dorsal-ventral axis. This enables it to present a favorable glacis angle during engagements.

Current capital-ship design favors four primary mass driver turrets (secondary turrets if the class is outfitted with one or more spinal mounts), arranged one per face of the hull. In ring-magazine designs, rather than each turret feeding from its own dedicated magazine, a toroidal magazine is constructed surrounding the core of the ship and in close proximity to the hull at the turret access points, taking inspiration from the ring-main power feeds to both kinetic and laser turrets. Since standard mass driver ammunition contains no active explosive elements, there are no requirements for isolating magazines to prevent sympathetic or secondary detonations in the event that damage penetrates the magazine. Rather, damage-control concerns are limited to minor machinery, electrical, and fuel fires readily addressed by standard milspec compartmentalization.

While compartmented, this design permits a continuous ammunition-feed system to redistribute ammunition to any turret access point on demand; one which cannot be interrupted by single-point damage, since there are multiple feed routes to each turret (typically chained conveyors both fore and aft of the ammunition storage area).

Thus, ring-magazine design both enables capital ships to carry a greater total quantity of ammunition, and to use it with greater tactical flexibility, leading to its adoption as the present standard.

– Fíerí’s Starships of the Associated Worlds