The screw propeller was first used on a military vessel in 1852 by the French with the introduction of the Napoleon a 90-gun ship-of-the-line as part of the French Navy - becoming the very first screw-driven steam battleship in the world. Before the adoption of screw propulsion in warships during the 1850s, the technology of choice was steam used to drive a paddle wheel attached to the side of the warship. This arrangement formulated several distinct disadvantages. Firstly, the size of the wheel reduced the number of guns that could be mounted for a broadside along that particular side of the ship. Secondly, enemy cannon shot could easily render the wheel out of commission making it a vulnerable target in any attack. New technology was needed to place the driving force of a military warship out of harm's way. It was the invention of screw propulsion that finally made steam-powered warships practical. Cannon fire would not be obstructed and the underwater propeller would be well-protected from both shot and shell. The screw propeller was a radical leap forward and started one of the major arms races in naval history.
France and England were the two major sea powers of the day and were always trying to evolve a major naval technological advantage in an effort to gain sea-going superiority over the one another. Over the next decade, at least 100 wooden steam battleships were built in France and Britain alone. Launched in 1850, the Napoleon was the lead ship of a class of 9 battleships built over a 10 year period under the watchful eyes of naval designer Dupuy de Lome. She was 239ft (73m) in length and 55ft (17m) in breadth while displacing 5,120 tons. She was fitted with two gun decks and featured a 45-gun-strong broadside. The height of the battery above the waterline was 6ft 4in. Under full steam and sail, she could make 13 knots ( 8.089mph) across short distances with a sail area of 3,411 square yards. Napoleon's success made the fleets of the world turn completely to a steam screw, such was her revolutionary inception. She was launched in 1850 and, during the Crimean War in 1852, her design execution attracted world attention with the introduction of steam power and a large coal supply giving her longer range than her contemporaries. Her engine gearing created maintenance problems (common to most early geared-screw machinery) and new direct-drive engines were ultimately fitted. She was the only French ship-of-the-line with two funnels.
Warships made of wood and powered by steam engines were the dominate ship of the world's navies by the early 19th century. In the 1820s and 1830s, steam engines were first tried in tugs, gunboats and sloops. Larger engines were built by the 1840s, making them usable in medium-sized ships like frigates. In the 1850s, steam-powered wooden battleships combined their steam engines with a sailing rig, just in case the coal ran out. Many nations did not have worldwide coaling stations.
In the late 1830s the screw propeller attracted naval interest not only in Britain and France but also in American where experimentation was underway. The American USS Princeton was being built at the same time as the British HMS Rattler, both ships were sloops and their respective navy departments felt they performed their mission rather well. France jumped ahead in 1845 with the first screw steam-powered frigate - the Pomone. By the end of the decade, both Britain and France were building steam-powered versions of the ship-of-the-line, leaving America was somewhat behind.
In 1850, the British Admiralty decided that no more sailing warships would be built and the government committed 100,000 pounds for machinery for its new steam battle fleet. Most of the world's navies were essentially forced to follow suit. Britain converted 41 sail-only ships-of-the-line to steam and built 18 new ones. France fell behind by converting only 28 ships to steam and built an additional 10. Russia learned the hard way, losing her sailing fleet during the Crimean War and built just 9 steam-powered ship-of-the-line battle ships.