A screw frigate is a naval steam-powered frigate using a screw propeller for locomotion.
The first generation of steam warships, during the first half of the 19th century, used paddlewheels mounted on either the sides or in the center, but these were less efficient than propellors, and in the 1850s navies converted over. 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.
The only surviving screw frigate is the Danish Jylland.
