The first steam battleship
Henri Dupuy de Lôme lived at 374 Rue Saint-Honoré
in Paris, from 1857 until his death in 1885 (detail of his commemorative plate on the right).
After his return from England, Dupuy de Lôme started work at the arsenal in Toulon. At the time the only armed steamships in the French Navy were propelled by paddle-wheels, and there was great opposition to the introduction of steam power into line-of-battle ships. The paddle-wheel was seen to be unsuited to such large fighting vessels, and there was no confidence in the screw; while the great majority of naval officers in France, as well as in England, were averse to any decrease in sail spread.
Dupuy de Lôme had carefully studied the details of the Great Britain, which he had seen being built at Bristol, and was convinced that full steam power should be used on line-of-battle ships. He held fast to this idea; as early as 1845 he addressed a report to the Minister of Marine suggesting the construction of a screw-driven frigate, to be built with an iron hull, and protected by a belt of armour formed by several thicknesses of iron plating. This report alone would justify his claim to be considered the leading naval architect of that time; such a ship was not built for several years, but the idea of the "classic" iron battleship was clearly stated in this report.
Dupuy de Lome's Napoléon
, the first steam battleship.
Dupuy de Lôme did not stand alone in the feeling that radical changes in the construction and propulsion of ships were imminent. His colleagues in the Génie Maritime (naval engineering) were impressed with the same idea: and in England, about this date, the earliest screw liners — converted "block ships" — were ordered. This action on the British part decided the French also to begin the conversion of their sailing line-of-battle ships into vessels with auxiliary steam power.
Dupuy de Lôme continued work on the idea, and was rewarded in 1847 with the ordering of Le Napoléon, which would become the first steam-powered battleship as well as the first screw battleship ever built. She was 77.8 m (240 ft) in length, 17 m (55 ft) in breadth, and of 5,000 tons displacement, with two gun decks. She was launched in 1850, tried in 1852, and attained a speed of nearly 14 knots (26 km/h). During the Crimean War her performance attracted great attention, and soon there were plans to introduce steam power to fleets around the world.