INS Aridhaman

Source: TP

Subject: Security / Defence (Nuclear Deterrence)

Summary:

• Context: India has officially inducted INS Aridhaman, its third indigenous nuclear-powered ballistic missile submarine (SSBN), significantly strengthening its maritime nuclear deterrence.
• The Lineage: It is the third vessel of the Arihant-class, following INS Arihant (2016) and INS Arighaat (2024).
• Development: Built under the highly secretive Advanced Technology Vessel (ATV) project at the Ship Building Centre (SBC), Visakhapatnam.
• Strategic Role: Completes and solidifies India’s Nuclear Triad, providing a robust, survivable “Second-Strike” capability in line with the No First Use doctrine.
• Evolution: Compared to the lead ship (Arihant), Aridhaman is larger (~7,000 tonnes) and carries double the vertical launch tubes.

Background Concepts & Strategic Context

1. The Second-Strike Capability

In nuclear strategy, a “Second-Strike” is the ability to respond to a nuclear attack with a powerful retaliatory strike. Since land-based silos and airfields are vulnerable to a first strike, a stealthy SSBN hidden deep in the ocean is the most reliable way to ensure deterrence.

2. SSBN vs. SSN (The “Sentinel” vs. The “Hunter”)

• SSBN (Submersible Ship Ballistic Nuclear): Like INS Aridhaman, these carry long-range nuclear missiles (K-series). Their mission is to stay hidden and act as a deterrent.
• SSN (Submersible Ship Nuclear): These are nuclear-powered attack submarines. They carry conventional weapons (torpedoes/cruise missiles) to hunt enemy ships and other submarines. India currently has a program to develop indigenous SSNs and plans to lease one from Russia by 2027-28.

3. The “K” Series Missiles (Sagarika)

Named after Dr. APJ Abdul Kalam, these Submarine Launched Ballistic Missiles (SLBMs) are the primary teeth of the Arihant class.

• K-15: Short-range (approx. 750 km).
• K-4: Intermediate-range (approx. 3,500 km), allowing India to target strategic locations from a safe distance in the Indian Ocean.

Key Technical Evolution: Aridhaman vs. Arihant

Feature	INS Arihant	INS Aridhaman (S4)
Displacement	~6,000 Tonnes	~7,000 Tonnes (Larger hull)
Launch Tubes	4 Vertical Tubes	8 Vertical Tubes (Double firepower)
Missile Capacity	4 x K-4 or 12 x K-15	8 x K-4 or 24 x K-15
Propulsion	83 MW Nuclear Reactor	Upgraded 83 MW (Higher endurance)
Stealth	Basic Stealth	Advanced Indigenous Stealth Tech

Examination Focused MCQs

Q1. INS Aridhaman, the third indigenous submarine of its class, is categorized as a:

A) Diesel-Electric Attack Submarine (SSK)

B) Nuclear-Powered Attack Submarine (SSN)

C) Nuclear-Powered Ballistic Missile Submarine (SSBN)

D) Stealth Destroyer

Q2. The ‘K-4’ missile, which can be launched from INS Aridhaman, has an approximate strike range of:

A) 750 km

B) 1,500 km

C) 3,500 km

D) 5,000 km

Q3. Under which project was the Arihant-class of nuclear submarines developed?

A) Project 75I

B) Advanced Technology Vessel (ATV) Project

C) Project 17A

D) Mission Sagar

Q4. What is the primary strategic advantage of a nuclear-powered submarine (SSBN) over a diesel-electric one?

A) It is cheaper to build and maintain.

B) It can remain submerged almost indefinitely, limited only by crew supplies.

C) It can only operate in very shallow waters.

D) It does not require a crew to operate.

Q5. India’s “No First Use” (NFU) policy makes which leg of the nuclear triad the most critical for deterrence?

A) Land-based Agni missiles

B) Air-based Rafale/Mirage delivery

C) Sea-based SSBNs (for Second-Strike)

D) Space-based kinetic weapons

Answer Key:

1. C) Nuclear-Powered Ballistic Missile Submarine (SSBN) (Recognized by its ‘K’ series ballistic missiles).
2. C) 3,500 km (The K-15 is the one with the 750 km range).
3. B) Advanced Technology Vessel (ATV) Project.
4. B) It can remain submerged almost indefinitely… (Nuclear reactors don’t need oxygen, unlike diesel engines).
5. C) Sea-based SSBNs (for Second-Strike) (Because they are the hardest to detect and destroy in a first strike).