Cartagena (Spain): Spanish shipyard Navantia has completed installation of its Hydrogen-based Air Independent Propulsion System (AIP) into its third S80 class submarine which will allow it to remain submerged underwater for nearly 21 days at a go.
The integration of the latest generation of the AIP system on Tuesday, which has undergone over 50,000 hours of testing, comes just months after the Indian Navy carried out a field evaluation trial (FET) of it.
The Indian Navy is pursuing Project 75 India (P75I) under which it aims to procure six new conventional diesel electric submarines with the AIP system.
This is because a normal conventional submarine has to resurface every two to three days to charge its batteries, making them susceptible to being spotted by enemy sonars and other anti-submarine warfare systems.
The Indian Navy has asked for an AIP with minimum 14 days of endurance so that the ship is able to operate with more stealth.
Navantia’s AIP will give the Spanish Navy the capability to remain underwater for three weeks or about 21 days.
It has tied up with India’s Larsen and Toubro (L&T) and is offering its latest generation S80 class of submarines—being built for the Spanish Navy.
Navantia, however, is in direct competition with German shipyard TKMS which has tied up with state-run MDL.
The P75I project is the first to be pursued under the Indian Defence Ministry’s strategic partnership programme that aims to bring in private players into big ticket programmes. It was first envisaged in 1998 and is part of the Navy’s 30-year submarine-building plan to build 24 submarines by 2030.
Speaking on the AIP system, Navantia officials said they were willing to hand over complete transfer of technology to India which is trying to build its own AIP system.
They also said what they were offering India was exactly the same submarine that the Spanish Navy had ordered for, and was not an export variant.
Incidentally, the Germans are offering an Indian version of the Type 214 submarine which is an export version of the Type 212 the German Navy operates.
Also read: Bharat Forge & defence ministry start contract negotiations for ATAGS. The journey so far
Advantages of bioethanol
Navantia calls its AIP the BEST—Bio Ethanol Stealth Technology. It uses bioethanol as fuel, making it both environmentally friendly and easy to refuel as bioethanol is easily available across the world.
Bioethanol’s availability makes it easy to refuel an AIP plant at any port without needing specialised hydrogen-refuelling systems—unlike previous generation AIP plants offered by TKMS—which require handling of pure hydrogen that comes with risks.
Navantia’s AIP plant is also relatively safe as hydrogen is produced on demand and not stored on board, unlike the other technology where hydrogen is stored and carried in the form of metal hydrides.
India as manufacturing hub
Meanwhile, sources said that Navantia was considering India as a second manufacturing base for its submarines to cater to possible Asian clients.
They said both Indonesia and Vietnam wanted to procure submarines from the company and were looking at smaller ones with around 1,500 tonnes displacement unlike the S-80, which is about 3,000 tonnes.
The plan is still at an exploratory stage and could be irrespective of the Indian submarine programme, they said.
Sources also said Navantia would have to set up a new company for Asia which would allow it to take production outside Spain. Navantia and L&T, which has been deeply involved with India’s strategic submarine programme, are in talks with each other for this venture.
(The reporter visited the Navantia facility in Cartagena at the invitation of the Spanish firm)
(Edited by Tikli Basu)
Also read: Indian Navy submarine & fishing vessel collide off Goa coast, search for 2 missing fishermen on