The Barracuda class (or Suffren class) is a new nuclear attack submarine, designed by the French shipbuilder DCNS for the French Navy, replacing the Rubis-class submarines. Construction began in 2007 and the first unit will be commissioned in 2017. The Barracuda class nuclear reactor incorporates several improvements over that of the preceding Rubis. Notably, it extends the time between refuelling and complex overhauls (RCOHs) from 7 to 10 years, enabling higher at-sea availability.