Key Takeaways

India excels in complex nuclear submarines like Arihant-class and upcoming SSNs, with timely progress and commissions.
Simpler conventional SSKs under P-75 and P-75I face decades-long delays due to bureaucracy, not technology.
DRDO weapons like SLCM and ATGMs exemplify systemic struggles in less complex systems.
Reforms in decision-making and accountability are essential for balancing capabilities.

India has demonstrated remarkable proficiency in constructing advanced nuclear-powered submarines, with the recent commissioning of INS Aridhaman, the third vessel in the Arihant-class, expected around April or May 2026, marking a significant milestone in its sea-based nuclear deterrence capabilities.

This 7,000-ton submarine, also known as S-4, has completed critical sea trials, systems validation, and weapon integration, featuring enhanced capabilities such as the K-4 missile with a 3,000-kilometre range alongside K-15 missiles, thereby bolstering strike capability and survivability in line with India's nuclear doctrine.

The Arihant-class programme, encompassing INS Arihant and INS Arighat, showcases India's ability to indigenously build nuclear-powered ballistic missile submarines (SSBNs), with construction handled at the Shipbuilding Centre (SBC) in Visakhapatnam under the Ministry of Defence.

Further evidencing this ease, the Cabinet Committee on Security (CCS) cleared the construction of the first two Project 77-class nuclear-powered attack submarines (SSNs) in October 2024, with a displacement of 9,800 tons powered by a 200 MWe-rated nuclear reactor; preliminary design was completed by February 2020, constructions set to commence by 2023-24, and first unit entry into service projected for 2032.

Admiral Dinesh K Tripathi, the Indian Navy Chief, confirmed government approval for two indigenous SSNs, with design taking 4-5 years and construction another 5 years, leading to delivery of the first by 2036-37 and the second by 2038-39.

To augment expertise, India leased a Russian Akula-class SSN named Chakra in 2012, though it was returned in June 2021 due to powerplant and maintenance issues; a third lease, originally for 2025, is now delayed to 2027-28 owing to Russian supply-chain disruptions and Ukraine war-related sanctions.

In stark contrast, India struggles significantly with less complex conventional diesel-electric submarines (SSKs), as exemplified by Project 75 (P-75), initiated in 2007 to build six Scorpene-class SSKs with air-independent propulsion (AIP) and land-attack capabilities at Mazagon Dock Shipbuilders Limited (MDL) in collaboration with France's Naval Group.

Despite being conceptually simpler than nuclear submarines, P-75 faced protracted delays, with the lead boat INS Kalvari commissioned only in 2017—well beyond the original 2017 completion target—and the program stretching into 2025, leaving the Navy with critically low submarine numbers as ageing Sindhughosh-class vessels approach 40-45 years of service.

The successor Project 75I (P-75I), aimed at acquiring six advanced AIP-equipped SSKs worth ₹43,000-70,000 crore under 'Make in India', remains stalled nearly two decades after conceptualisation in 1998-1999, mired in protracted negotiations between MDL and Germany's ThyssenKrupp Marine Systems (TKMS), with contract expected only in March 2026 and first delivery in the mid-2030s.

Delays in P-75I stem not from technical complexity but organisational shortcomings: fragmented decision-making, rigid rule-bound procurement culture lacking accountability, high indigenisation demands (minimum 45% rising to 60%), unproven AIP systems, post-COVID inflation, and disqualifications like L&T-Navantia's in January 2025 for non-sea-proven AIP.

Past scandals, including procedural irregularities in submarine acquisitions that paralysed the SSK-building ecosystem, disrupted programme continuity, left MDL without orders, and deterred private sector participation, exacerbating the conventional fleet shortfall, as noted by retired submariners.

Even stopgap measures like Project 75(AS) for three additional modified Kalvari-class submarines at MDL remain in limbo, failing to materialise by March 2025 despite expectations.

This pattern extends beyond submarines to other less complex weapons, where Defence Research and Development Organisation (DRDO) projects suffer persistent delays due to systemic failures rather than technological hurdles.

For instance, the Nirbhay-based Submarine-Launched Cruise Missile (SLCM), designed for 533 mm torpedo tubes with 1,000-1,500 km range, faces extended timelines beyond 2030 despite tests like a 402-km flight in November 2024, due to integration challenges and shortfall from full specifications, clashing with P-75I induction around 2031.

DRDO's third-generation Anti-Tank Guided Missiles (ATGMs), promised after cancellations of imports in 2009 and 2018, lack even a basic prototype, repeatedly blocking procurement despite Army needs.

Broader issues include unrealistic specifications demanding perfection on first attempt, lingering distrust from INSAS rifle failures tainting indigenous small arms, deep-rooted import culture with foreign OEM incentives, and intolerance for initial imperfections unlike practices in the US, Israel, or China.

The original 1999 plan for 24 conventional submarines by 2030 has inducted only five Scorpene boats, with the sixth pending, highlighting glacial procurement and inadequate planning. Nuclear programs benefit from strategic priority, political will, dedicated facilities like SBC Visakhapatnam, and international leases for expertise transfer, enabling relative ease despite complexity.

Conversely, conventional projects and DRDO weapons suffer from bureaucratic red tape, corporate competitiveness deficits, and accountability voids, leading to intense criticism and operational readiness gaps.

A key foreign partner's role—such as Russia's in nuclear leases or Germany's in P-75I—is integral, yet negotiations falter on commercial and technical grounds in simpler programmes.

As of April 2026, with INS Aridhaman's commissioning imminent, India's nuclear submarine prowess contrasts sharply with stalled conventional fleet expansion and weapon indigenisation, underscoring the need for procurement reforms.

IDN (With Agency Inputs)