Riachuelo-class submarine

In 2008, the Presidents of Brazil and France, Luiz Inácio Lula da Silva and Nicolas Sarkozy, signed a strategic partnership to the construction of four conventionally-powered submarines, and the support for the development of the first Brazilian nuclear submarine, in a program called PROSUB. The first stage of construction of the conventionally-powered Riachuelo took place in France, with the cutting of the first steel plates of the structure. At this point, technology transfer from French technicians to Brazilians began. The conventional Brazilian boats are larger in length, tonnage and cargo capacity compared to the French Scorpène class they are derived from. The Brazilian version are and 1,900 tons, compared to the original Scorpènes that are and 1,565 tons. ==Nuclear submarine==

As part of the program, a fifth submarine, named Álvaro Alberto, will be powered by nuclear propulsion. This unit has many similarities to its diesel powered predecessors of the Riachuelo class. The first Brazilian nuclear submarine will have a beam of to accommodate the pressurized water nuclear reactor (PWR). Its length and 6,000-ton displacement will be propelled by a fully-electric propulsion system. Once the vessel is completed no fuel imports are needed as all fuel required for the life cycle is included in the reactor. ==Boats==

The names of the conventional boats were selected to represent key Imperial Brazilian Navy's military operations during the Paraguayan War and the Platine War, and former Admiral Alfredo Karam. The nuclear boat honors the former Vice Admiral and scientist Álvaro Alberto da Motta e Silva. ==See also==