The Indian Navy, hunting for acquisition of submarines to augment its underwater strength, will be offered a new technology that Indian giant Larsen & Toubro (L&T) and Spanish shipbuilder Navantia have unveiled this week. According to Navantia, the integration of bio-ethanol stealth technology (BEST) on the Spanish Navy’s S-80 submarine series, completed at Navantia’s Cartagena shipyard in Spain, marks a major milestone in advancing submarine capabilities, enabling vessels to remain submerged for significantly longer duration (three weeks) compared to conventional diesel-electric submarines.
The AIP (Air-Independent Propulsion) system, commercially branded as BEST by Navantia, leverages a bio-ethanol reforming process to generate hydrogen on demand, eliminating the need for stored hydrogen. The hydrogen-rich stream, combined with pure oxygen, powers a fuel cell to stealthily recharge the submarine’s batteries while submerged. This third-generation technology offers strategic advantages by enhancing tactical safety, crew protection, and operational autonomy.
Unlike older AIP systems that require specialized hydrogen refueling infrastructure, Navantia’s bio-ethanol based system allows for refueling at standard ports, making it highly adaptable and safer, Navantia has claimed. With over 50,000 hours of testing, the AIP system demonstrates technological advancements that place Navantia at the forefront of the global market for conventional submarines, the company added.
L&T, with its stellar record in contributing in building India’s strategic submarines, and Navantia had signed a teaming agreement in July last year to jointly bid for the Indian Navy’s Project 75 (India), which involves the acquisition of six advanced diesel-electric submarines equipped with AIP systems. This collaboration seeks to address the Navy’s urgent need to modernize its submarine fleet while meeting indigenization goals outlined by the government.
The S-80 program, currently operational with the Spanish Navy, highlights Navantia’s technological prowess. An India-based media team visited Navantia’s shipyard this week to witness the End of Shipment Ceremony of the AIP System of the S80 Submarine Program.
Navantia officials have stated their willingness to provide a full transfer of technology for the AIP system to India, which is working on developing its own AIP technology. They emphasized that the submarine being offered to India is identical to the one ordered by the Spanish Navy and not a downgraded export version.
Submarines of this class measure 80.8 meters in length, have a diameter of 7.3 meters, and possess a submerged displacement of approximately 3,000 tonnes, Navantia informed the media team.
The Indian Navy’s Project 75 (I) deal is expected to proceed following a government review, with the L&T-Navantia partnership positioned as one of the strongest contenders in the bid to deliver cutting-edge submarines to India.
(The reporter, Neelanjana Banerjee, visited the Navantia facility in Cartagena at the invitation of the Spanish firm)
