Steam frigates and the smaller steam corvettes were steam-powered warships.
The first vessel that can be considered a steam frigate was the Demologos which was launched in 1815 for the United States Navy.[1]
By the 1830s many navies were experimenting with steam-powered warships. This first generation of steam warships, termed 'paddle frigates', used paddlewheels mounted on either the sides or in the center. The ships were equipped with large guns mounted on one deck. Paddlewheels were less efficient than the propellers and more vulnerable to damage, and in the 1850s navies converted over to propellers.
From the mid-1840s frigates which more closely resembled the traditional sailing frigate were built with steam engines and screw propeller for locomotion. The ships retained a full sail-plan however, partly due to conservatism, and partly to conserve coal, the last being an especially important consideration for frigates, which often operated independently on the far side of the world. These 'screw frigates', built first of wood and later of iron, continued to perform the traditional role of the frigate until late in the 19th century. France and the United Kingdom were the only two countries to develop fleets of wooden steam screw battleships, and both navies built numbers of screw frigates.
From 1859, armour was added to ships based on existing frigate and ship of the line designs. The additional weight of the armour on these first ironclad warships meant that they could have only one gun deck, and they were technically frigates, even though they were more powerful than existing ships-of-the-line and occupied the same strategic role. The phrase 'armoured frigate' remained in use for some time to denote a sail-equipped, broadside-firing type of ironclad. For a time was the most powerful type of vessel afloat.
Towards the end of the 19th century, the term 'frigate' fell out of use. Armoured vessels were designated as either 'battleships' or 'armoured cruisers', while unarmoured vessels including frigates and sloops were classified as 'unprotected cruisers'.
The only surviving screw frigate is the Danish Jylland.