HMS Unicorn’s Progress Book shows that ‘building began’ in February 1822 in the Royal Dockyard at Chatham, Kent, but an earlier letter from the Navy Board dated 17 September 1820 directs the Dockyard to complete building HMS Diana on No 4 slip and to set up Unicorn’s frame in part on the same slip and to proceed with providing other materials for her.
HMS Unicorn was launched into the River Medway on 30th March 1824. The Commissioner of Chatham Dockyard reported to the Navy Board, “I have to acquaint you that His Majesty’s Ship Unicorn was launched to day from the 4th slip at this Yard.”
HMS Unicorn was built as a 46 guns frigate for the Royal Navy under the supervision of Sir Robert Seppings, the Surveyor of the Navy. She had taken two years and almost a thousand oak trees to build, and her hull cost £26,541, of which a modest £5,630 was charged to labour.
A sailing frigate was a powerful cruising vessel, heavily armed and fast, and HMS Unicorn would have been one of the elite ships of the fleet in her day.
For service at sea, HMS Unicorn would have been rigged with three towering masts and a bowsprit. The mainmast would have been 160 feet (50 metres) high and would have weighed 8 3/4 tons. Twenty three and a half miles of rope would have been used in the rigging, and the sails would have weighed six tons.
Although HMS Unicorn’s hull took two years to build, a small team of skilled riggers could have set up her rigging in just a few days.
But HMS Unicorn’s story took an unexpected turn: a roof was placed over her hull before she was launched, and she was placed straight into reserve or ‘Ordinary’…