Navantia’s shipyard in Cartagena has begun installing the first air-independent propulsion (AIP) system on a Spanish Navy S-80 Plus-class diesel-electric submarine.
The Cosme Garcia (S-83) is the third of four boats in the S-80 class and the first to be equipped with the capability.
Two vessels — the Isaac Peral (S-81) and the Narciso Monturiol (S-82) — will be upgraded with the system during their first major overhaul.
The S-81 was commissioned in 2023 while the S-82 is expected to be commissioned in 2026. The S-83, meanwhile, is expected to be commissioned in 2028.
“This AIP system is capable of operating at any depth and in all operational conditions, allowing it to adapt to any navy mission and making it the most advanced AIP system on the market,” Infodefensa quoted the Spanish ship builder as saying while announcing the development.
Air-Independent Propulsion
An AIP system recharges the vessel’s batteries during immersion with a fuel cell, which “uses hydrogen produced by processing bioethanol and oxygen to generate electricity,” Navantia explains.
It enables the vessel to sail underwater for weeks, two-three times longer than conventional submarines.
Greater underwater endurance allows the boat to avoid the risk of radar and visual detection, which is possible when the vessel comes close to the surface and raises its snorkel head out of the water for air intake for the diesel engine.
S-80 Plus
The Spanish government signed the deal with IZAR to construct the S-80 class in 2004, with delivery in 7 years.
However, design flaws pushed the schedule back by over a decade, with the first ship delivery in 2023.
The redesigned vessel is about 10 meters (33 feet) longer at 81 meters (266 feet) and about 500 tons heavier at 3,000 tons.
It has an endurance of 50 days and a surface speed of 10 knots (19 kilometers per hour) and submerged speed of 19 (35 kilometers per hour) knots.
The submarine can accommodate a crew of 32 plus eight additional personnel and is equipped with six 21-inch (533 mm) bow torpedo tubes, capable of deploying torpedoes, mines, and Harpoon anti-ship missiles.
