Iowa gun shock and missile fits

A weapon can be incompatible with a ship because of the shock produced by another weapon already aboard. The Iowa class illustrates why proposals for Aegis or a vertical-launch-system conversion involve protecting electronics and launch equipment from the battleship's own 16-inch gunfire. Hardening Aegis against such gunfire had not been a development priority. Later proposals therefore faced doubts about whether the conversion was sensible. The class carried Tomahawk missiles in canister launchers, where localized shock protection was more practical. Gun shock also helps explain the distribution of equipment around the ship.