Editing Propeller (section)

===Screw propellers===
Despite experimentation with screw propulsion before the 1830s, few of these inventions were pursued to the testing stage, and those that were proved unsatisfactory for one reason or another.<ref>{{cite book|author=Smith, Edgar C.|year=1905|title=A Short history of Naval and Marine Engineering|url= https://books.google.com/books?id=TSg7AAAAIAAJ|publisher=University Press | place = Cambridge|pages=66–67}}</ref>[[File:F. P. Smith's original 1836 screw propeller patent.jpg|thumb|right|Smith's original 1836 patent for a screw propeller of two full turns. He would later revise the patent, reducing the length to one turn.]]

In 1835, two inventors in Britain, [[John Ericsson]] and [[Francis Pettit Smith]], began working separately on the problem. Smith was first to take out a screw propeller patent on 31 May, while Ericsson, a gifted [[Sweden|Swedish]] engineer then working in Britain, filed his patent six weeks later.<ref name=bourne84>Bourne, p. 84.</ref> Smith quickly built a small model boat to test his invention, which was demonstrated first on a pond at his [[Hendon]] farm, and later at the Royal Adelaide Gallery of Practical Science in [[London]], where it was seen by the Secretary of the Navy, Sir William Barrow. Having secured the patronage of a London banker named Wright, Smith then built a {{convert|30|ft|m|adj=on}}, {{convert |6|hp|kW|adj=on|lk=in}} canal boat of six [[tons burthen]] called ''Francis Smith'', which was fitted with his wooden propeller and demonstrated on the [[Paddington Canal]] from November 1836 to September 1837. By a fortuitous accident, the wooden propeller of two turns was damaged during a voyage in February 1837, and to Smith's surprise the broken propeller, which now consisted of only a single turn, doubled the boat's previous speed, from about four miles an hour to eight.<ref name=bourne84/> Smith would subsequently file a revised patent in keeping with this accidental discovery.
[[File:EricssonCounterRotatingScrews.png|thumb|Ericsson's original patent for a contra-rotating screw propulsion.]]
In the meantime, Ericsson built a {{convert|45|ft|m|adj=on}} screw-propelled steamboat, ''Francis B. Ogden'' in 1837, and demonstrated his boat on the [[River Thames]] to senior members of the [[British Admiralty]], including [[Surveyor of the Navy]] [[Sir William Symonds]]. In spite of the boat achieving a speed of 10 miles an hour, comparable with that of existing [[paddle steamer]]s, Symonds and his entourage were unimpressed. The Admiralty maintained the view that screw propulsion would be ineffective in ocean-going service, while Symonds himself believed that screw propelled ships could not be steered efficiently.{{Efn | name=ogden_note | In the case of ''Francis B. Ogden'', Symonds was correct. Ericsson had made the mistake of placing the rudder forward of the propellers, which made the rudder ineffective. Symonds believed that Ericsson tried to disguise the problem by towing a barge during the test.}}  Following this rejection, Ericsson built a second, larger screw-propelled boat, ''Robert F. Stockton'', and had her sailed in 1839 to the United States, where he was soon to gain fame as the designer of the [[U.S. Navy]]'s first screw-propelled warship, {{USS|Princeton|1843|6}}.<ref name=bourne87-89>Bourne, pp. 87–89.</ref>

[[File:Illustrirte Zeitung (1843) 21 335 1 Archimedische Schraube des Dampfschiffes Archimedes.PNG|thumb|left|Screw propeller of {{SS|Archimedes}}]]
Apparently aware of the Royal Navy's view that screw propellers would prove unsuitable for seagoing service, Smith determined to prove this assumption wrong. In September 1837, he took his small vessel (now fitted with an iron propeller of a single turn) to sea, steaming from [[Blackwall, London]] to [[Hythe, Kent]], with stops at [[Ramsgate]], [[Dover]] and [[Folkestone]]. On the way back to London on the 25th, Smith's craft was observed making headway in stormy seas by officers of the Royal Navy. This revived Admiralty's interest and Smith was encouraged to build a full size ship to more conclusively demonstrate the technology.<ref name=bourne85>Bourne, p. 85.</ref>

[[File:Great Britain propeller and rudder wideshot.jpg|thumb|A replica of {{SS|Great Britain}}'s first propeller. A four-bladed model replaced the original in 1845. The ship was originally designed to have paddles, but plans changed after screw propellers were shown to be much more efficient.]]
{{SS|Archimedes}} was built in 1838 by [[Henry Wimshurst]] of London, as the world's first steamship{{Efn | The emphasis here is on ''ship''. There were a number of successful propeller-driven vessels prior to ''Archimedes'', including Smith's own ''Francis Smith'' and Ericsson's ''Francis B. Ogden'' and ''Robert F. Stockton''. However, these vessels were ''boats'' – designed for service on inland waterways – as opposed to ''ships'', built for seagoing service.}} to be driven by a [[#History of ship and submarine screw propellers|screw propeller]].<ref>"The type of screw propeller that now propels the vast majority of boats and ships was patented in 1836, first by the British engineer Francis Pettit Smith, then by the Swedish engineer John Ericsson. Smith used the design in the first successful screw-driven steamship, ''Archimedes'', which was launched in 1839."  Marshall Cavendish, p. 1335.</ref><ref>"The propeller was invented in 1836 by Francis Pettit Smith in Britain and John Ericsson in the United States. It first powered a seagoing ship, appropriately called ''Archimedes'', in 1839." Macauley and Ardley, p. 378.</ref><ref>"In 1839, the Messrs. Rennie constructed the engines, machinery and propeller, for the celebrated ''Archimedes'', from which may be said to date the introduction of the screw system of propulsion…" ''Mechanics Magazine'', p. 220.</ref><ref>"It was not until 1839 that the principle of propelling steamships by a screw blade was fairly brought before the world, and for this we are indebted, as almost every adult will remember, to Mr. F. P. Smith of London. He was the man who first made the screw propeller practically useful. Aided by spirited capitalists, he built a large steamer named the "Archimedes", and the results obtained from her at once arrested public attention." MacFarlane, p. 109.</ref>

The ''Archimedes'' had considerable influence on ship development, encouraging the adoption of screw propulsion by the [[Royal Navy]], in addition to her influence on commercial vessels. Trials with Smith's ''Archimedes'' led to a [[tug-of-war]] competition in 1845 between {{HMS|Rattler|1843|6}} and {{HMS|Alecto|1839|6}} with the screw-driven ''Rattler'' pulling the paddle steamer ''Alecto'' backward at {{convert |2.5|kn|kph}}.<ref>[https://bowcreektoanatahan.wordpress.com/propeller-versus-paddle-the-tug-of-war-between-hms-rattler-and-the-alecto/ Propeller versus Paddle: The Tug of War between HMS Rattler and the Alecto], Bow Creek to Anatahan.</ref>

The ''Archimedes'' also influenced the design of [[Isambard Kingdom Brunel]]'s {{SS|Great Britain}} in 1843, then the world's largest ship and the first screw-propelled steamship to cross the [[Atlantic Ocean]] in August 1845.

{{HMS|Terror|1813|6}} and {{HMS|Erebus|1826|6}} were both heavily modified to become the first Royal Navy ships to have steam-powered engines and screw propellers. Both participated in [[Franklin's lost expedition]], last seen in July 1845 near [[Baffin Bay]].

Screw propeller design stabilized in the 1880s.