Napoléon: First purpose built Steam Battleship

[Brian James]

Napoléon was a 90-gun ship of the line of the French Navy, and the first purpose-built steam Battleship in the world. She is also considered the first true steam battleship, and the first screw Battleship. Launched in 1850, she was the lead ship of a class of nine battleships, all built over a period of ten years. This class of ship was designed by the famous naval designer Henri Dupuy de Lôme. Prior to the experimental adoption of the screw in warships in the 1840s, the only available steam technology was that of paddle wheels, which, due to their positioning on the side of the hull and the large machinery they required were not compatible with the broadside cannon layout of Battleships. Dupuy de Lôme conceived and carried out the bolder scheme of designing a full-powered screw liner, and in 1847 Le Napoléon was ordered. Her success made the steam reconstruction of the fleets of the world a necessity. She was launched in 1850 and trialed in 1852, and attained a speed of nearly 14 knots. During the Crimean War her performances attracted great attention, and the type she represented was largely increased in numbers. She was about 240 ft in length, 55 ft on the beam, and of 5,000 tons displacement, with two gun decks. The RN already had a few coastal units with screw/steam propulsion in the 1840s, called blockships, which were conversions of small traditional Battleships into floating batteries with a jury rig, with a medium 450 hp (340 kW) engine for speeds of 5.8 knots to 8.9 knots. The Royal Navy had also commissioned a number of steam Sloops, HMS Rattler being the first screw-propelled warship to be launched anywhere in the world in 1843. Both nations had also developed steam Frigates, the French Pomone launched in 1845, and the British Amphion a year later. However, Napoléon was the first regular steam Battleship to be launched...In 1847 Britain had designed a screw/steam Battleship named James Watt, but the project was much delayed and she did not enter service until 1854. Her sister ship, Agamemnon was ordered in 1849 and commissioned in January 1853. Another sailing Battleship, Sans Pareil was converted to steam on the stocks and launched in March 1851; she beat Agamemnon into service in November 1852. Britain’s reluctance to commit to the steam Battleship apparently stemmed from her commitment to long-distance, worldwide operation, for which, at that time, sail was still the most reliable mode of propulsion...In the end, France and Great Britain were the only two countries to develop fleets of wooden steam Battleships, although several other navies are known to have had at least one unit, built or converted with British technical support (Russia, Turkey, Sweden, Naples, Denmark and Austria). Altogether, France built 10 new wooden steam Battleships and converted 28 from older Battleship units, while Britain built 18 and converted 41.