Tonnant-class ship of the line
The Tonnant class was a series of eight 80-gun ships of the line designed in 1787 by Jacques-Noël Sané, whose plans for the prototype were approved on 29 September 1787. With sixteen gunports on the lower deck on each side these were the most effective two-deckers of their era. Their broadside of 1,102 livres equated to 1,190 British pounds weight, over 50% more than the standard British 74-gun ship, and even greater than that of a British 100-gun three-decker.
Five ships were ordered from 1787 to 1793, and all were completed during the 1790s; six more were ordered in January 1794 to be built to this design at Toulon, but only three of these were named and built. All but one of the eight ships were to be captured or destroyed by the British Navy, and four of these were to enjoy long careers in their new service. The prizes were highly regarded by British sea officers, but they proved costly and time-consuming to maintain.
From 1802 a new group of French 80-gun ships was begun of slightly modified design, of which more than 24 were begun.