Vengeur-class ship of the line

The "Vengeur"-class ships of the line were a class of forty 74-gun third rates, designed for the Royal Navy as a joint effort between the Surveyors of the Navy at the time. The "Vengeur" Class, sometimes referred to as the Surveyors' class of third rates, amongst other names, was the most numerous class of ships of the line ever built for the Royal Navy - forty ships being completed to this design. Due to some dubious practices, primarily in the commercial dockyards used for construction, this class of ships earned itself the nickname of 'Forty Thieves.'
Between 1826 and 1832, ten of these ships were cut down by one deck ("raséed") to produce 50-gun "frigates". These were the "Barham", "Dublin", "Alfred", "Cornwall", "America", "Conquestador", "Rodney" (renamed "Greenwich"), "Vindictive", "Eagle" and "Gloucester". Planned similar conversions of the "Clarence" (renamed "Centurion") and "Cressy" around this time were cancelled, but the "Warspite" was additionally converted along the same lines in 1837–1840.
Around 1845 four of these ships were converted into 'blockships', the then-current term for floating batteries, equipped with a steam/screw propulsion system and re-armed with 60 guns. In this guise some of them saw action during the Crimean War. The four were the "Blenheim", "Ajax", "La Hogue" and "Edinburgh". About ten years later, a further batch of five ships was similarly converted - this included the "Russell", "Cornwallis" and "Pembroke" of this class (as well as the "Hawke" and "Hastings" of other designs).
Ships.
Further ships were ordered to this design, including HMS "Boscawen" on 6 January 1812 and HMS "Carnatic" on 30 September 1814, but none of these were completed to this design.
In fiction.
A fictitious member of this class of 74s, HMS "Worcester", features largely in "The Ionian Mission", one of the Aubrey-Maturin series of novels by Patrick O'Brian.