Spanish Navy’s First S-80 Plus Class Submarine Isaac Peral Completes Initial Sea Trials

Navantia conducted the initial sea trials of the first S-80 class submarine, Isaac Peral (S-81), in the Bay of Cartagena on May 27, 2022. Navantia is building four of the submarines at its Cartagena shipyard for the Spanish Navy. Spanish state-owned shipbuilding company Navantia announced the development through a Twitter post. The four-hour surface sailing marks the beginning of the Isaac Peral’s (S-81) sea trials. The submarine is a system of systems, and it is important to verify the correct functioning of all systems and their integration. This first cruise has confirmed the excellent level of integration and performance. The submarine will conduct the various port and sea trials scheduled in the calendar, including docking the submarine during the summer months.

During the mooring trials, the operation of the submarine’s propulsive line will be verified. This is conducted prior to the start of its sea ??trials.The boat completed start-up of its diesel engines in November 2021, marking a new safety milestone. The start-up was carried out as part of its port testing process. The submarine is powered by three bio-ethanol engines, a 3,500kW main electric engine, and a 300kW atmosphere-independent propulsion system. The S-80’s air-independent propulsion (AIP) system is based on a bioethanol-processor consisting of a reaction chamber and several intermediate Coprox reactors. Provided by Hynergreen from Abengoa, the system transforms the bioethanol (BioEtOH) into high purity hydrogen. The output feeds a series of fuel cells from UTC Power company.

The Isaac Peral (S-81), the first unit in the series, was launched by King Felipe VI and his daughter, Princess Leonor, heir to the throne, on April 22, 2021 at the Cartagena shipyards, with plans to enter service in 2023, after originally being targeted for 2011. The remaining three boats are slated to be delivered in 2025, 2027 and 2029. They are oceanic submarines of medium tonnage with the capacity to carry out long duration missions in scenarios far from their base, acting with a minimum level of indiscretion. They will have an integrated platform control system that allows operation with a reduced endowment and a high degree of automation with remote control.

The S-80’s air-independent propulsion (AIP) system is based on a bioethanol-processor consisting of a reaction chamber and several intermediate Coprox reactors. Provided by Hynergreen from Abengoa, the system transforms the bioethanol (BioEtOH) into high purity hydrogen. The output feeds a series of fuel cells from UTC Power company. The Reformator is fed with bioethanol as fuel and oxygen, generating hydrogen and carbon dioxide as subproducts. The produced hydrogen and more oxygen is fed to the fuel cells. The oxygen and fuel flow rates are directly determined by the demand for power. The AIP power in the S-80 submarine is at least 300 kW (400 hp). A permanent-magnet electric motor moves a fixed propeller of a special design, that doesn’t create cavitations at high speed.