The Commission de Paris was a body of French naval engineers gathered in 1821 to design the future frigates and ships of the line of the French Navy for the post-Empire era. Presided by Jacques-Noël Sané, the Commission comprised Jean-Marguerite Tupinier, Pierre Rolland, Pierre Lair and Jean Lamorinière.
The works of the Commission led to the design of double-decked 24-pounder frigates, as well as to four ranks of ships of the line: the 120-gun (Valmy being the lone unit built to the design), the 100-gun Hercule class, the 90-gun Suffren class, and an 80-gun type whose only ship ever started, Tour d’Auvergne, was never launched.
These ships of the line featured straight sides instead of the traditional tumblehome design that had prevailed until then; this tended to heighten the ships' centre of gravity, but provided much more room for equipment in the upper decks. Stability issues were fixed with underwater stabilisers. However, they proved difficult to build in a tight financial context; the resulting lengthy construction limited the useful lifetime of the ships, compounded with their quick obsolescence caused by the introduction of the Paixhans gun, steam engines and armour plating.
