Napoléon class ship of the line

The Napoléon class was a late type of 90-gun ships of the line of the French Navy, and the first type of ship of the line designed from the start to incorporate a steam engine.

Designed by Henri Dupuy de Lôme, the prototype Napoléon displayed such outstanding performances during her trials that a production series was immediately ordered, yielding the Algésiras sub-class. Furthermore, construction of the two Bretagne class 130-gun ships was interrupted: Desaix, whose construction had only just started, was cancelled altogether and replaced with Arcole, while Bretagne was dismantled and entirely rebuilt on principled heralded by Napoléon. Further improvements to the Algésiras type yielded the Ville de Nantes sub-class.

The "swift ships of the line" of the Napoléon class were initially considered of the 3rd rank, behind the 120-gun first rank ships of the Océan class and Valmy and the 2nd rank 100-gun ships of the Hercule-class, and on par with the 90-gun Suffren class; however, in practice, most of the ships of the Hercule and Suffren classes had been transformed for steam and sail, losing ten guns in the operation, which made them steam ships of the line of 90 and 80 guns respectively. The Napoléon class was thus quickly promoted to 2nd-rank ships, also reflecting the status provided by their nautical performances.