Napoleon's design allowed the screw to turn freely when disconnected from its shaft under sail, while British designers preferred a screw that could be lifted into a well. Britain's response, Agamemnon, needed a longer, fuller hull to accommodate steam machinery. Agamemnon was intended to perform well under both sail and steam, whereas Napoleon relied primarily on steam with sail as an auxiliary. Nominal machinery ratings do not settle which ship delivered more power to the propeller: D. K. Brown questioned the claim that Napoleon was faster. A possible weakness in Napoleon's shaft metallurgy is suggested as an explanation, rather than established as the cause.
Notable Point · 2:36:10-2:39:49
Napoleon and Agamemnon combine steam machinery with sail
French and British steam battleships used different propeller arrangements and placed different weight on sailing performance.