Iowa is characterised as a South Dakota design stretched enough to provide substantially greater speed. Its armament changed from 16-inch/45 guns to 16-inch/50 guns. The ships were designed before the United States entered the war, but the prospect of conflict imposed pressure on the programme. Reusing an established design could save time and money compared with starting afresh. More radical Iowa alternatives existed, but the adopted approach illustrates how urgency can favour a practical enlargement over a new design.
Notable Point · 1:33:13-1:34:27
Iowa reused South Dakota's design to gain speed quickly
The Iowa comparison treats lengthening an existing battleship and fitting longer guns as a response to the pressure of approaching war.