Humaitá (S 41) was formally signed over to the navy and commissioned during a 12 January ‘Cerimônia de Mostra de Armamento’ event at the Base de Submarinos da Ilha da Madeira (BSIM) in Itaguaí in the presence of defense minister José Mucio Monteiro. The Riachuelo class (also known as S-BR) is a customized variant of the generic Scorpène design developed by France’s Naval Group.
Building on a strategic defense agreement signed by the Brazilian and French governments in December 2008, Naval Group is delivering the PROSUB (Programa de Desenvolvimento de Submarinos) programme through the ICN joint venture established with Brazil’s Novonor. In December 2019, ICN was given authority to also undertake submarine maintenance, and to take on additional naval construction or manufacturing work outside of the scope of PROSUB.
The Brazilian government concluded detailed contractual terms with Naval Group in September 2009. The original scope of supply, involving eight separate contracts, encompassed three main components: a transfer of technology package for the in-country build of the four Scorpène S-BR boats; design and manufacturing services related to the non-nuclear elements of Brazil’s first SCPN (Submarino Convencionalmente Armado com Propulsão Nuclear) nuclear-powered submarine; and support for the design and construction of a new submarine build facility and naval base in Itaguaí.
Compared to earlier Scorpène variants, the S-BR version features a lengthened hull (increased from 66.4 m to 71.6 m) to meet the specific requirements of the Brazilian Navy for increased range, extended endurance, and accommodation for a larger crew. Displacing 1,870 tonnes submerged, the S-BR design is fitted with six 533 mm launch tubes for the discharge of Naval Group F21 heavyweight torpedoes, MBDA Exocet SM39 Block 2 Mod 2 missiles, and mines. Up to 18 weapons can be carried: 12 on racks in the weapon compartment plus six in the tubes.
Humaitá was launched in December 2020, and began an extensive program of sea trials in December 2022. This has included a deep dive and initial weapon firings with F21 exercise torpedoes. Naval News was told that the submarine is expected to be fully operational by the end of the first quarter of 2024.
First-of-class Riachuelo (S 40), commissioned in September 2022, was moored adjacent to Humaitá during the commissioning ceremony. The Niteroi class frigate Defensora was berthed on the opposite quay as guard ship.
The third and fourth S-BR submarines, to be named Tonelero (S 42) and Angostura (S 43), are both in the construction hall at Itaguaí. Launch of Tonelero is planned for March this year, with sea trials to start later in 2024 prior to handover next year. Angostura’s schedule is approximately 12-13 months behind: launch is planned for April 2025, with sea trials beginning later next year ahead of planned handover in 2026.
A new headquarters (Comando da Força de Submarinos) for the Brazilian Navy’s submarine force was also inaugurated at the BSIM facility on 12 January. The Marinha do Brasil’s submarine arm (Força de Submarinos) was previously headquartered at Mocanguê Island in Nitéroi.
Naval Group is providing support for the design and construction of the non-nuclear aspects of the SCPN, to be named Álvaro Alberto. The SCPN program transitioned into the main C phase of detailed design in 2022: Naval Group is currently contracted to provide design support for the project through to 2032.
The SCPN design will be approximately 100 meters in length and displace around 7,000 tonnes. Current planning envisages completion of Álvaro Alberto in the 2036-2037 timeframe; the navy cut the first steel plate of a qualification section in October 2023.
