Source : Financial Express

Germany offers AIP equipped Dolphin-II submarine for Indian Navy Project-75I submarine program
Germany is offering next-generation submarines to India to jointly build six conventional submarines. While there is no official confirmation, the talks over the submarine which took place during Chancellor Olaf Scholz’s visit to India, are at the final stage, it is learnt.
Germany’s offer to India is a significant change from its earlier approach where Germany sought clarification on the joint manufacturing of submarines.
Germany operates HDW Class Dolphin submarines which is equipped with Air Independent Propulsion (AIP) system. The HDW Class Dolphin submarine provides high operational value as it is integrated with a fuel cell AIP system.
The AIP is marine propulsion technology that allows a non-nuclear submarine to operate without access to atmospheric oxygen (by surfacing or using a snorkel).
The fuel cell AIP system significantly increases submerged endurances while it is also loaded with a state-of-the-art combat system. Dolphin submarine in its compact size carries a weapon expulsion system, torpedoes, missiles, and mines which can be launched from the weapon tube set. Besides the high firepower, this class of submarine provides a very high automation degree of the controls for the propulsion plant, navigation and handling of the boat.
The AIP system for the P-75I submarine
In 2021, the Ministry of Defence (MoD) issued Request for Proposal (RFP) for the first acquisition programme under the Strategic Partnership model for the construction of six conventional submarines named Project 75(India) [P-75(I)] for the Indian Navy. The key element of the strategic partnership is based on the specific technology—the AIP.
Germany’s ThyssenKrupp Marine Systems (TKMS) is one of two international bidders for the proposed submarine project.
The ambitious Project-75(I) also proposes the plan for the indigenous construction of six conventional submarines, including associated shore support, engineering support package, training and spares package with contemporary equipment, weapons & sensors. Apart from the AIP Systems, the P-75 (I) must have advanced missile systems and torpedoes.
HDW fuel cell system delivers a unique AIP solution for direct integration into non-nuclear submarines. Fuel cells are energy converters that transform chemical energy directly to electrical energy without noise or combustion. Low noise and infrared signatures, high efficiency and low maintenance requirements make HDW fuel cell plants the ideal AIP solution for new non-nuclear submarines.
At the same time, India’s Defence Research and Development Organisation (DRDO) has also developed its AIP systems for the submarines of the Indian Navy. In an interaction with Financial Express, Samir V Kamat, Secretary Department of Defence R&D and Chairman DRDO confirmed that the indigenous AIP propulsion system developed by DRDO is a modular system that can be easily configured for any conventional submarine platform. Fuel Cell based air-independent propulsion (AIP) system crossed important milestones of user-specific tests. It is one of the most advanced AIP Systems in the world, where Fuel Cell Technology is used to generate onboard power.
The AIP can augment or replace the diesel-electric propulsion system of non-nuclear vessels.
What remains is the lengthy timeline for the rigorous trials to be certified and fitted into the Scorpene-class submarine.
The Indo- German collaboration may fill the gaps as the delay over the submarine project is also posing a serious challenge for the Indian navy to address China’s constant maritime expansionism in the IOR. Besides, the collaboration will also help DRDO to embrace the next-generation systems with combat capabilities in terms of the overall design and development of the futuristic submarine under P-75I. Besides, the collaboration will also help DRDO to embrace the next-generation systems with combat India’s growing Military power