The S-83 is the third submarine in the S-80 series. Navantia said the final tests began after completion of previous installation work on the equipment required for their execution.
The tests will allow the company to make the necessary adjustments to the system in its actual location. This will take place before the 12-metre-long, approximately 400-tonne section is joined to the rest of the submarine’s pressure hull.
The S-83 section carrying the AIP is located in a special test facility at the Cartagena shipyard known as IPS3. A multidisciplinary team from Navantia’s Submarine Business has carried out the checks required to begin testing.
Testing began with the first loading of liquid oxygen and bioethanol. The system uses these materials to produce hydrogen for its fuel cell and propel the submarine while submerged.
Navantia said the technology is a third-generation AIP system. This means it does not carry stored hydrogen, but generates it on demand from liquid fuel.
The company said this approach overcomes limitations of earlier generations currently in operation. Air-independent propulsion will allow S-80 submarines to remain submerged for weeks rather than days.
Navantia said this compares with the underwater endurance of current conventional submarines equipped with lead-acid batteries. The capability is intended to improve the submarines’ stealth and deterrence.
The AIP will undergo checks set out in the programme’s systems engineering manual. The work will take place on a test bench able to simulate the submarine’s bow and stern, as well as real operating conditions.
The simulated conditions include diving depth and the submarine’s forward speed. This will allow functional adjustments and demonstrations to be carried out before further testing.
The demonstrations will include power generation with the AIP under different operating conditions. Navantia said the process will help optimise the planned schedule for testing the system in harbour.
The testing process on board the S-83 section represents a new milestone for the AIP system. Navantia said the technology has a high level of national technological content.
The company said the milestone reflects progress in the S-80 programme. The S-82 is undergoing harbour trials, while the S-83 and S-84 are under construction at the Cartagena shipyard.
Navantia’s S-80 programme covers the construction of four next-generation submarines for the Spanish Navy. The AIP system allows the vessels to generate electrical power while submerged using oxygen and bioethanol stored on board.
This enables the submarines to operate for extended periods without surfacing or carrying out snorkelling manoeuvres. Navantia said the S-80 submarines also feature a high level of stealth, advanced combat systems and modern sensors.
The submarines are designed for long-duration operations. Navantia said the programme places Spain among the countries with the technological capability to develop this type of strategic platform.
