Steam vessels driven by propellers were differentiated from those driven by
paddle-wheels by referring to the ship's
screws (propellers). Other propeller-driven
warships included the heavier steam
corvette and the lighter gun vessel.
The United Kingdom Hecla in 1854 vs paddle sloop
Alecto in 1845 By 1833, the Royal Navy's vessels fell into three classes: • Rated ships and yachts, commanded by captains • Sloops and bomb vessels, commanded by commanders. • All other smaller vessels, commanded by lieutenants and inferior officers. At the time, sloops could be ships (with three masts) or brigs (with two masts) or be corvette-built (also with three masts) or otherwise. The term sloop referred to a sailing vessel. Small paddle steamers like
HMS Rhadamanthus,
Meteor, and
Firebrand were listed as 'steam vessels'. In 1840, the steam vessels of the Royal Navy were also divided into classes: • First class: commanded by captains, e.g.
HMS Cyclops and
HMS Gorgon • Second class: commanded by commanders, e.g.
HMS Rhadamanthus and the
Hydra-class sloop • Third class: commanded by lieutenants and masters, e.g.
Meteor and
Firebrand By 1845, the List of the Royal Navy referred to dozens of 'steam sloops'. Most of these were commanded by a commander, many others had a lieutenant commander.
Cyclops was still a steam frigate.
Gorgon was now a steam sloop commanded by a captain.
Hydra was a steam sloop.
Meteor was a steam vessel. In 1845, the first screw sloop appeared in the Royal Navy. The first four
Alecto-class sloops had been launched in 1839–1841. The fifth unit of this class,
Rattler, was reordered as a screw-propelled vessel. In spring 1845, comparative trials were held between
Rattler and
Alecto. The most famous of these was that in which the sloops towed stern to stern, with
Rattler towing
Alecto backwards at 2.8 knots.
In the USA In the 1860s American context, the general meaning of the word 'sloop' was a three-masted square-rigged ship with a full broadside on a single deck. In a looser sense, it could also refer to a three-masted vessel like
CSS Alabama, which was a
barque and lacked a full
broadside.
USS Princeton launched in September 1843, was the first world's screw steam vessel of war. She had been designed by
John Ericsson, who had previously applied the screw to commercial boats.
Princeton was also revolutionary because it had its engines under the waterline and had an armament that included a very high-caliber wrought-iron gun. This gun proved able to penetrate of armor. The success of
Princeton led the United States Navy to slowly shift to the propeller as means of propulsion. In 1857 the United States ordered 5 large screw sloops.
USS Hartford was a good example of these.
Brooklyn also belonged to this order that made the screw sloop popular. In 1858, seven smaller screw sloops were ordered.
USS Mohican and
Narragansett were examples of these seven. ==See also==