The Swallow-class sloop was a 9-gun wooden screw sloop class of four ships built for the Royal Navy between 1854 and 1857. Design Built of a traditional wooden construction, the Swallow class were intended as "type of screw vessel below the ". The class were armed with a single 32-pounder gun (58 cwt) gun on a pivot mount and eight 32-pounder (25 cwt) carronades on the broadside. These guns were all smoothbore muzzle-loading, and were little changed from the standard guns of Nelson's era. Propulsion was provided by a two-cylinder horizontal single-expansion steam engine developing 60 nominal horsepower and an indicated horsepower of between and . Propulsion was applied through a single screw and at maximum power under steam, top speed was about . A barque rig of sails was carried, which meant the ships of the class had three masts with a square rig on the fore and main masts. Ships The first two ships were ordered on 5 July 1852, Ariel on 2 April 1853 and Lyra on 3 April 1854. Citations References Sloops of the Royal Navy Swallow Sloop classes