Why wartime warship programs arrive late

USS Independence was ordered during the War of 1812 but entered service too late to affect the conflict. Even a wartime crash program tends to require roughly two years before useful hulls arrive. Material acquisition, machinery, construction, and the physical behavior of components impose delays that money and urgency cannot wholly remove. Later rapid programs such as the Flower and Hunt classes benefited because orders and long-lead work had begun before the Second World War.