Isis
History
United Kingdom
Ordered	10 September 1811 (as a two-decker)
Builder	Woolwich Dockyard.
Laid down	February 1816
Launched	5 October 1819
Completed	3 September 1823 at Chatham Dockyard
Fate	Coal depot at Sierra Leone in March 1861, then sold to purportedly be broken up there on 12 March 1867 at liquidation.
General characteristics
Tons burthen	1,29288⁄94 (as redesigned)
Length	164 ft 0 in (49.99 m)
Beam	41 ft 11 in (12.78 m)
Depth of hold	13 ft 3 in (4.04 m)
Propulsion	Sail
Complement	350
Armament	UD: Twenty-eight 24-pounder guns; QD & Fc twenty-eight 42-pounder carronades and two 24-pounder guns.

HMS Isis launched in 1819 was ordered in 1811 as a 50-gun two-decker of the fourth rate Salisbury class, but was redesigned while building, being lengthened on the stocks by 11 feet (3.4 m), and cut down by one deck to produce a spar-deck frigate, that is, to carry extra guns on the spar deck which linked the forecastle to the quarterdeck.

It was then intended for her to have carried 58 guns as shown in the table, but this weapon 'fit' was amended on 3 June 1823 to complete her as a 50-gun frigate with an unarmed spar deck, and she was later reduced in 1830 to a 44-gun frigate carrying twenty-six 32-pounder guns on the upper deck, twelve more 32-pounder guns on the quarterdeck, and two 32-pounder guns on the forecastle together with two 8-inch shell guns.

References

• David Lyon, The Sailing Navy List, Conway Maritime Press, London 1993. ISBN 0-85177-617-5.
• David Lyon and Rif Winfield, The Sail and Steam Navy List, Chatham Publishing, London 2004. ISBN 1-86176-032-9.