Spain commissioned its first S-80 Plus-class submarine, the Isaac Peral, on 30 November 2023. This next-generation class brings promising capabilities to the Armada Española and enhances Spain’s potential maritime contribution to the North Atlantic Treaty Organization (NATO) .
The S-80Ps’ introduction follows years of setbacks, including multiple delays, redesigns, and budget shortfalls that significantly altered original plans and delivery dates. Conceived in the late 1980s and early 1990s as relatively large submarines, S-80s were optimized for longer-range missions and would mature to become the first Spanish boats fitted with air-independent propulsion (AIP) for extended underwater endurance.
Construction of four submarines was authorized in 2003, with deliveries expected to begin around 2015. The namesake boat, the Isaac Peral, was laid down in 2007 at Navantia’s Cartagena shipyard. After more than five years of work, excessive weight issues necessitated reexamining the overall design. In 2013, U.S. submarine manufacturer General Dynamics Electric Boat was brought in to provide technical assistance, helping Navantia get the program back on track. Eventually, the design was enlarged, and the planned 233-foot submarines increased in length to 266 feet. Surfaced displacement grew from about 2,200 tons to 2,695 tons, while submerged displacement increased from a planned 2,465 tons to the current 2,965 tons.
Delays plagued the program during the redesign, affecting not just the first boat, but three planned sisters as well. Second in the class, the Narciso Monturiol, is now planned for delivery in 2024, while the Cosme Garcia is expected in 2026. The fourth and final unit, the Mateo Garcia de los Reyes, will join the fleet in 2028. The revamped Isaac Peral was launched 7 May 2021. Sea trials began in 2022 and continued through 2023, culminating this past October when she successfully conducted a dive to her maximum operational test depth. As commissioned, the submarine has a beam of 38 feet and a draft of 21 feet.
Numbered S-81, the Isaac Peral is named for a pioneering late 19th-century Spanish submarine designer and naval officer. The class’s diesel-electric propulsion incorporates three 1,200-kilowatt diesel generators, providing a top speed of more than 19 knots submerged or 12 knots on the surface. The innovative Bio-Ethanol Stealth Technology (BEST) AIP system, based on fuel cells, will be installed beginning with the third and fourth submarines. The first two boats are built without AIP systems but will receive them during initial major overhauls. Once operational, the AIP on the S-80Ps will reportedly permit quiet underwater cruising for three weeks at 4 knots.
The class operates with a crew of 32 and has additional accommodations for 8 special operations service members. The combat system incorporates active and passive sonars, including a towed array, and numerous other sensors. The submarines are armed with six 21-inch bow torpedo tubes and can carry heavyweight torpedoes, mines, and Harpoon antiship missiles. As the four boats become operational, the S-80 Plus design is expected to generate significant interest on the export market.
