Melampus had a length at the gundeck of 151feet and 127feet at the keel. She had a beam of 40feet, a draught of 14feet and a depth of hold of 12feet. The ship's tonnage was 1088 tons burthen.[1] The modified Leda-class frigates were armed with twenty-eight 18-pounder cannon on her gundeck, fourteen 32-pounder carronades on her quarterdeck and a pair of 9-pounder cannon and two more 32-pounder carronades in forecastle. The ship had a crew of 315 officers and ratings.[2]
Melampus, the second ship of her name to serve in the Royal Navy,[3] was ordered on 1 May 1816, laid down in August 1817 at Pembroke Dockyard, Wales, and launched on 10 August 1820.[2] She was completed for ordinary at Plymouth Dockyard 2–23 September 1829 and was roofed over from the mainmast forward. The ship cost £23,007 to build and £7,072 to fit out for ordinary. She was fitted out for sea at a total cost of £9,156 from March to 18 May 1845.[1]
Melampuss first commission began on 12 March with Captain John Campbell in command and she was ready for sea on 18 May.[1]