Submarine Riachuelo Performs Static Immersion Test
(Source: Brazilian Navy; issued Nov. 21, 2019)
(Unofficial translation by
Riachuelo, the first of four Scorpène-class diesel-electric submarines being built for the Brazilian Navy, heads to sea from the Itaguaí Naval Complex for her first static immersion tests. (Brazil Navy photo)
The submarine Riachuelo, the first of four diesel-electric propulsion submarines under construction under the Submarine Development Program (PROSUB), was successfully subjected to a static immersion test on November 20, a decisive milestone for the assessment of her stability at sea.

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.

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.


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