Traditionally, a warship's armor system was designed both separately from, and after, the design layout. The design and location of various component subsystems (propulsion, steering, fuel storage & management, communications, range-finding, etc.) were laid out and designed in a manner that presented the most efficient and economical utilization of the hull's displacement. Then, armorers would attempt to design the application of barriers and deflectors which would protect vital areas of the hull, the superstructure, and its interior compartments from enemy shellfire, underwater mines, and torpedo attacks. There would also be attention paid to the limiting of sympathetic damage to hull compartments and spaces, caused as a consequence of primary damage to those hull compartments that directly received shellfire or underwater explosions.