Riachuelo Class Submarine (Scorpène)

Brazilian diesel-electric attack submarines based on French Scorpène design built under technology transfer at domestic shipyard — representing major capability upgrade and industrial development. Four submarines in class: Riachuelo, Humaitá, Tonelero, and Angostura (deliveries 2020-2024+). Part of PROSUB programme alongside nuclear submarine development. Displacement of 1,870 tonnes with length of 71.6 metres. Features Air Independent Propulsion (AIP) system providing extended submerged endurance (18+ days without snorkeling), six 533mm torpedo tubes for heavyweight F21 torpedoes and potentially Exocet anti-ship missiles, advanced SUBTICS combat management system, comprehensive sonar suite including flank arrays and towed array, periscope with thermal imaging and low-light TV, and modern electronics. Maximum submerged speed of 20 knots. Crew of 35. The submarines built with significant Brazilian content (approximately 60%) at Itaguaí Naval Complex with technology transfer enabling domestic submarine construction capability. Brazilian industry produces major hull sections, systems, and equipment. The construction programme developed Brazilian shipbuilding expertise directly applicable to nuclear submarine programme. Riachuelo-class provides capability for coastal defense, sea lane protection, intelligence gathering, and special forces deployment. Significantly more capable than Brazilian legacy submarines (Tupi-class based on 1980s German Type 209). Represents strategic investment in Brazilian Navy power projection and maritime domain awareness in South Atlantic.