The HMS Ajax, third of the name, was launched in 1809, and was a 74-gun third-rate battleship.

She was converted to a blockship with screw propulsion for coastal defense (also called "steam-guard-ships") in 1846.

The conversion process involved removing her copper, removing the ballast and some of the bulkheads, and cutting her down in the shape of a blockship "Workmen are engaged in removing the housing over her, and preparing her for cutting down to a blockship for that port." (Times Newspaper, 30 October 1845) "29 October 1845: The Ajax, 72, intended for a block ship, was docked yesterday to have her copper stripped off and to be cut down."(Times Newspaper, 30 October 1845) 2 "November 1845: The Ajax, 72, was undocked yesterday at Portsmouth, having had her copper stripped off, ballast removed, and some of her bulkheads taken out. She will be towed to Cowes in a day or two for conversion to a blockship, by Mr. White." (Times Newspaper, 3 November 1845).

She was broken up in 1864.

Notes