Spanish Navy’s S-82 ‘Narciso Monturiol’ Submarine Completes Key Electrical Test

The S-82 ‘Narciso Monturiol’ submarine, the second in a series of four being built by Navantia for the Spanish Navy, has completed its first safety milestone with the successful "power up" of its electrical systems.

The "power up" involves activating the main and emergency electrical distribution networks, allowing onboard equipment to be safely powered. This step is part of the Safety Milestones Management Plan under the S-80 Program, which aims to ensure low-risk construction and testing processes for the submarines.

In addition to the electrical milestone, the first Harbor Acceptance Tests have also begun for the S-82 submarine. These tests are part of a program involving more than 1,500 verification procedures, including builder and acceptance tests.

Navantia reported in November 2024 that it completed the first installation of an AIP system on the third S-80-class submarine, Cosme Garcia (S-83).

The Spanish Navy awarded Navantia a contract for four S-80 submarines in 2004, with construction beginning at the company’s Cartagena facilities in 2007. After delays, the first submarine was unveiled in 2021 and conducted its maiden voyage in May 2022.

The S-82 submarine is scheduled to launch next summer, following the first S-80 series submarine already in service with the Spanish Navy. The S-80 class submarines measure 80.8 meters in length, 7.3 meters in diameter, and have a submerged displacement of approximately 3,000 tons.

A key feature of the S-80 class is the anaerobic propulsion system, known as BEST-AIP, which allows the submarine to generate electrical power using fuel cells at any depth. This air-independent propulsion (AIP) system, developed by Navantia, enables the vessel to stay submerged for weeks without surfacing, enhancing its stealth capabilities.

The BEST (Bio-Ethanol Stealth Technology) system recharges the submarine’s batteries while submerged by reforming bioethanol, a renewable energy source derived from organic materials. This process produces a hydrogen-rich stream that, when combined with oxygen, powers fuel cells to generate electricity silently. Unlike previous AIP systems used by other navies, this technology does not require storing hydrogen, improving both safety and operational autonomy.

The S-80 class is designed for various missions, including sea-to-land attacks, intelligence gathering, surveillance, reconnaissance, anti-surface warfare, and anti-submarine warfare. It is armed with DM2A4 heavyweight torpedoes, UGM-84 Sub-Harpoon anti-ship missiles, and SAES seabed mines. It is capable of launching UGM-109 Tomahawk land-attack cruise missiles.

Each submarine operates with a crew of 32 and can accommodate eight additional personnel. It can reach speeds exceeding 19 knots while submerged and dive to depths of more than 300 meters.