Stromboli-class sloop
The "Stromboli" class was a group of two vessels designed by Sir William Symonds the Surveyor of the Navy. The design was approved on 29 August 1838. The vessels were of the design but were altered to the new draught derived from the . The ships were initially classified as Steam Vessels Second Class (SV2) and were later classified as First Class sloops. The ships were built in two Royal Dockyards (Portsmouth and Sheerness). Both ships were at the bombardment of Acre in 1840. Both were in the Black and Azov seas during the Russian War. They served  on various stations of the Empire. "Vesuvius" was sold in 1865 and "Stromboli" in 1866. Both were broken by White at East Cowes on the Isle of Wight. "Stromboli" was the only named vessel in the Royal Navy. "Vesuvius" was the eleventh named vessel (spelt "Vesuvius" or "Vesuve") since it was used for a 8-gun fireship, launched by Taylor of Cuckold's Point on 30 March 1691 and expended on 19 November 1693 at Saint-Malo. Design and specifications. Both vessels were ordered 12 March 1838 and laid down in September at Portsmouth and Sheerness. The vessels were launched  in July ("Vesuvius") and August ("Stromboli") 1839. The gundeck was with the keel length of reported for tonnage. The maximum beam was with reported for tonnage. The depth of hold was . The light draught forward was and aft. The builder's measure was calculated at 965 tons whereas the vessels displaced 1,283 tons. Robert Napier & Sons of Govan supplied the machinery for both vessels. They were equipped with two fire-tube rectangular boilers. The engines were 2-cylinder vertical single expansion (VSE) side-lever steam engines rated at 280 nominal horsepower (NHP). This gave the ships a speed under power  of about . Pictures show "Vesuvius" with a barque rig. All four ships were initially armed with two 10-inch 84 hundredweight (cwt) shell Millar's original guns on pivot mounts and two 68-pounder 64 cwt muzzle loading smooth bore (MLSB) carronades and two 42-pounder (22 cwt) MLSB carronades on broadside trucks. In 1856 the 10-inch guns were replaced with a Dundas 1853 68-pounder 84 cwt MLSB gun and the carronades were replaced with four 32-pounder 42 cwt MLSB guns on broadside trucks. In the 1860s the 68-pounder was replaced with an Armstrong 7-inch  rifled breech loader (RBL) gun. This weapon is also known as the 100/110-pounder gun depending on the weight of shell fired. They had a complement of approximately 149 men and grew to 160 men with the change in armament.