The test was carried out in the southern area of Itacuruçá Island, about 4 nautical miles from the Itaguaí Naval Complex, in Sepetiba Bay, where a buoy was installed on the sea bottom to which the submarine remained tied until her return to the surface.
Static immersion of the “Riachuelo” consisted of the controlled intake of water into the submarine's ballast tanks until she completely submerged, without the use of its propulsion. The procedure was designed to ensure not only the sealing and longitudinal and transverse stability of the submarine when submerged, but also to record the volume of water that was admitted to the internal trim and trim tanks. These values were used to accurately determine the water displacement of Riachuelo when submerged.
O “Riachuelo”, primeiro dos quatro submarinos de propulsão diesel-elétrica em construção no âmbito do #PROSUB, foi submetido com sucesso ao teste de Imersão Estática, procedimento decisivo na avaliação de sua estabilidade no mar. O teste ocorreu na Baía de Sepetiba. pic.twitter.com/XOOEeaEaPL— Marinha do Brasil (@marmilbr) November 21, 2019
Static immersion was the first in a series of sea acceptance tests, which will be conducted from December this year. The purpose of the assessments is to verify the performance of the submarine's platform, equipment and systems, both on and offshore, to be conducted by the receiving crew, under the supervision of the Nuclear Propulsion Submarine Development Program General Coordination and the responsibility of Itaguaí Construções Navais (ICN) / Naval Group.
The final step will be the launch of F21 torpedoes and SM-39 submarine-launched anti-ship missiles to test the effectiveness of the combat system.
Riachuelo's operational environment tests represent another relevant step for the advancement of PROSUB, a program that adheres to the National Defense Strategy. By contributing to the strengthening of the Brazilian naval power, PROSUB stimulates the development of the national industrial park, also asserting the high technological capacity absorbed by the Navy and ICN in the construction of high technology submarines.