Science and Technology Notes 15

Ships and Submarines

A submarine is a watercraft capable of independent operation underwater. It is distinct from a submersible, which has more limited underwater capability. The development of modern submarines was a pivotal moment in naval warfare, a concept explored by figures like Cornelius Drebbel in the 17th century and brought to military fruition by inventors like John Philip Holland and Simon Lake in the late 19th century.

Classification based on Power Source:

1. Diesel-Electric Submarines (SSK): These are conventional submarines that use diesel engines for surface travel and for charging large batteries. When submerged, they run on electric motors powered by these batteries, as diesel engines require air for combustion.

• Historical Context & Indian Acquisitions:
  • Phase I (Soviet/Russian Imports): Post-independence, India initially relied on the UK for its naval fleet. The strategic shift towards the Soviet Union in the 1960s led to the induction of the first submarines. The Foxtrot-class submarines were the first, followed by the more advanced Kilo-class submarines (designated Sindhughosh-class in India) from the 1980s. Notable examples include INS Sindhughosh (S55), INS Sindhurashtra (S65), and INS Sindhuvijay (S62). These formed the backbone of India’s submarine fleet for decades.
  • Phase II (Project 75 - Indigenous Construction): To bolster its ageing fleet and promote indigenisation, the Indian Navy initiated the 30-Year Submarine Building Plan in 1999. Project 75 is a key component of this plan. A deal worth USD 3.75 billion was signed in 2005 between the French naval group DCNS (now Naval Group) and India’s Mazagon Dock Shipbuilders Limited (MDL) for the construction of six Scorpène-class submarines in India.
    • The six submarines under this project are: INS Kalvari (S21), INS Khanderi (S22), INS Karanj (S23), INS Vela (S24), INS Vagir (S25), and INS Vagsheer (S26).
    • Features: These are advanced attack submarines known for their stealth capabilities. They possess a very low acoustic signature (low noise), making them difficult to detect by enemy SONAR (Sound Navigation and Ranging) systems. They are equipped with tube-launched MBDA SM-39 Exocet anti-ship missiles and DRDO-developed Varunastra heavyweight torpedoes.
• Air-Independent Propulsion (AIP): A major limitation of conventional submarines is the need to surface or snorkel frequently to run diesel engines and recharge batteries, which increases their vulnerability. AIP technology allows a submarine to remain submerged for longer durations.
  • DRDO’s AIP System: India’s Defence Research and Development Organisation (DRDO) has developed an indigenous fuel cell-based AIP system. This system uses the electrolysis of water to generate hydrogen, which is then used in fuel cells to generate electricity, with water as the only by-product. This system is planned to be retrofitted onto the Kalvari-class submarines during their refits. This development is a significant step towards strategic autonomy, as noted by strategic affairs analyst Dr. C. Raja Mohan.

2. Nuclear-Powered Submarines: These submarines employ a nuclear reactor to generate heat, which creates high-pressure steam to spin turbines that power the propeller and generate electricity.

• Advantages:
  • Endurance: They can stay submerged for months, limited only by the crew’s food and supplies. They do not need to refuel for up to 25-30 years.
  • Speed and Performance: They can travel at high speeds for sustained periods, unlike diesel-electric submarines whose battery life depletes rapidly at high speeds.
• Indian Context:
  • INS Arihant (S2): India’s first indigenously developed nuclear-powered ballistic missile submarine (SSBN), launched in 2009 and commissioned in 2016. It is powered by an 83 MW pressurised water reactor (PWR). The successful development of INS Arihant was a landmark achievement for Indian science and engineering, placing India in an elite club of nations with this capability.
  • Nuclear Triad: The commissioning of INS Arihant, armed with nuclear-tipped Submarine Launched Ballistic Missiles (SLBMs) like the K-15 Sagarika and the longer-range K-4, completed India’s nuclear triad. A nuclear triad refers to the capability to launch nuclear weapons from land (e.g., Agni missiles), air (e.g., Sukhoi-30 MKI, Rafale), and sea (INS Arihant). This provides a credible second-strike capability, which is the cornerstone of India’s ‘No First Use’ nuclear doctrine, as it guarantees a devastating retaliatory strike even if the country’s land and air-based assets are destroyed in a first strike.
  • Other Nuclear Submarines: India has also leased nuclear-powered attack submarines (SSNs) from Russia to train crews and gain operational experience, such as INS Chakra (an Akula-class submarine).

Torpedoes

A torpedo is a self-propelled underwater weapon with an explosive warhead, designed to detonate on contact with or in proximity to a target.

• Varunastra: It is an indigenously designed and developed ship-launched, heavyweight, electrically-propelled anti-submarine torpedo. Developed by the Naval Science and Technological Laboratory (NSTL) of the DRDO for the Indian Navy, it is capable of targeting quiet submarines in both deep and shallow waters. It is a significant achievement under the ‘Make in India’ initiative.
• Maareech Advanced Torpedo Defence System (ATDS): This is an indigenous anti-torpedo system developed by DRDO’s NSTL and Bharat Electronics Limited (BEL). It is a ‘soft-kill’ system that detects, locates, and neutralises incoming torpedoes. The system employs towed and expendable decoys to divert the homing torpedoes away from the target ship. Its induction enhances the survivability of naval platforms against underwater attacks.

Ships

1. Destroyers: These are large, fast, and heavily armed warships designed for multi-mission roles, including anti-air, anti-submarine, and anti-surface warfare. They often serve as the primary escorts for larger vessels like aircraft carriers. * Project 15B (Visakhapatnam-class): These are stealth guided-missile destroyers built by Mazagon Dock Limited. They are a follow-on to the Kolkata-class (Project 15A). Ships in this class include INS Visakhapatnam, INS Mormugao, INS Imphal, and INS Surat. They are equipped with the Barak-8 surface-to-air missile and BrahMos supersonic cruise missile, making them one of the most potent warships in the world.

2. Frigates: Smaller and faster than destroyers, frigates are versatile warships used for escort duties, anti-submarine warfare, and patrolling. * Shivalik-class (Project 17): These are the first stealth frigates built in India. Examples include INS Shivalik, INS Satpura, and INS Sahyadri. * Talwar-class: These are modified Krivak III-class frigates built in Russia for the Indian Navy. Examples include INS Talwar, INS Trishul, and INS Tabar.

3. Corvettes: These are the smallest class of surface combatants in a naval fleet. They are agile and primarily used for coastal patrol, anti-submarine warfare in littoral zones, and escorting convoys. * Kamorta-class (Project 28): These are indigenous anti-submarine warfare (ASW) corvettes built by Garden Reach Shipbuilders & Engineers (GRSE), Kolkata. They have high indigenous content and significant stealth features. Examples include INS Kamorta, INS Kadmatt, INS Kiltan, and INS Kavaratti.

4. Aircraft Carriers: These are capital ships that serve as mobile airbases, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. As strategic analyst Ashley J. Tellis has argued, aircraft carriers are crucial for power projection and sea control. * INS Vikramaditya: A modified Kiev-class aircraft carrier acquired from Russia and commissioned in 2013. It is currently the Indian Navy’s flagship. * INS Vikrant (IAC-1): India’s first indigenously designed and built aircraft carrier, constructed by Cochin Shipyard Limited and commissioned in 2022. It is named after India’s first aircraft carrier, INS Vikrant (R11), which played a crucial role in the 1971 Indo-Pak war. * Specifications: 262 meters long, displacement of around 45,000 tonnes, top speed of 28 knots, and can operate an air wing of about 30 aircraft, including MiG-29K fighter jets and helicopters. It has over 75% indigenous content. * Aircraft Launch and Recovery Systems: * STOBAR (Short Take-Off But Arrested Recovery): Used on INS Vikrant and INS Vikramaditya. Aircraft take off using a ski-jump ramp at the front of the deck, which helps them gain altitude. For landing, they use an arrester wire system. * CATOBAR (Catapult Assisted Take-Off But Arrested Recovery): This system uses a catapult to launch aircraft, allowing them to take off with a heavier payload (more fuel and weapons). The catapult can be steam-powered or an advanced Electromagnetic Aircraft Launch System (EMALS), which is more efficient and powerful. Future Indian aircraft carriers are expected to incorporate EMALS. * Arrested Recovery: In both systems, landing aircraft use a tailhook to catch one of several high-strength steel wires stretched across the deck, bringing the aircraft to a rapid stop.

Stealth Technology

Stealth technology, also known as low-observable technology, is a sub-discipline of military tactics and electronic countermeasures which covers a range of methods used to make personnel and materiel less visible to radar, infrared, sonar, and other detection methods.

• Principles:
  • Radar: Radar works by transmitting electromagnetic waves and detecting the echoes that return from objects. The size, shape, and material of the object determine its Radar Cross-Section (RCS), or how “visible” it is to radar.
  • Sonar: Sonar operates on a similar principle but uses sound waves in water. The key is to reduce the acoustic signature (noise) of a vessel.
• Methods of Achieving Stealth:
  • Shaping: Designing the aircraft or ship with flat surfaces and sharp, angled edges (faceting) to reflect radar waves away from the radar receiver, rather than back to it. The iconic Lockheed F-117 Nighthawk (retired in 2008) was a prime example of this design philosophy.
  • Radar-Absorbent Materials (RAM): The surface of the vehicle is coated with special paints or materials made of ferromagnetic particles or crystalline structures that absorb the energy of radar waves, converting it into heat and minimizing reflection. The Northrop Grumman B-2 Spirit bomber combines both shaping and advanced RAM.
  • Electronic Jamming: Actively broadcasting radio signals to interfere with enemy radar systems. This ‘drowns out’ the reflected signal with noise, preventing the radar from obtaining a clear lock on the target.

Aircraft

Generations of Fighter Aircraft: The classification into generations is an unofficial framework popularised by aviation analysts since the 1990s to delineate major leaps in fighter jet technology.

Generation	Key Features	Examples
1st (1940s-50s)	Subsonic, cannons, unguided bombs	F-86 Sabre, MiG-15
2nd (1950s-60s)	Supersonic, early air-to-air missiles, basic radar	F-104 Starfighter, MiG-21
3rd (1960s-70s)	Advanced avionics, multirole capability, guided missiles	F-4 Phantom II, Mirage III
4th (1970s-2005)	Fly-by-wire, high maneuverability, look-down/shoot-down radar	F-16, Su-30, Mirage 2000, Rafale (4.5)
5th (2005-present)	All-aspect stealth, supercruise, advanced sensor fusion	F-22 Raptor, F-35 Lightning II

Combat Aircraft in the Indian Air Force (IAF):

• Russian Origin: Sukhoi Su-30MKI (air superiority fighter), MiG-29 (air defence), MiG-21 (interceptor, being phased out).
• French Origin: Dassault Mirage 2000 (multirole), Dassault Rafale (multirole, 4.5 generation).
• UK/European Origin: SEPECAT Jaguar (deep penetration strike aircraft).
• Indigenous:
  • HAL Tejas (LCA): A 4th-generation, single-engine, lightweight, supersonic, multirole fighter aircraft developed by the Aeronautical Development Agency (ADA) in collaboration with Hindustan Aeronautics Limited (HAL).
    • Features: It is one of the world’s smallest and lightest supersonic fighters. It incorporates a delta-wing design, fly-by-wire flight control, and composite materials for a lighter airframe. It can carry a range of air-to-air and air-to-surface precision-guided weapons. It possesses air-to-air refuelling capability, a maximum payload of 4,000 kg, and a top speed of approximately Mach 1.8.

Airborne Early Warning and Control System (AEW&C): An AEW&C system is a “force multiplier” that uses a powerful radar mounted on an aircraft to detect enemy aircraft, ships, and missiles at long ranges. It provides a 360-degree view of the battlespace and directs friendly fighter aircraft to intercept threats.

• Indian Systems:
  • Phalcon AWACS: Three systems using the Israeli EL/W-2090 radar mounted on a Russian Ilyushin Il-76 platform.
  • Netra AEW&C: An indigenous system developed by DRDO, using a radar mounted on a Brazilian Embraer ERJ 145 aircraft. Two are in service, with plans for more advanced versions on larger platforms.

Emerging Trends in Modern Warfare

1. Directed-Energy Weapons (DEW): DEWs damage targets using highly focused energy, such as lasers, microwaves, or particle beams, rather than a physical projectile.

• DRDO’s KALI (Kilo Ampere Linear Injector): An ongoing Indian project aimed at developing a linear electron accelerator. While often portrayed as a beam weapon, its primary stated purpose is for industrial and research applications, and potentially as a source for high-power microwaves that could be used to disable the electronic circuits of incoming missiles or aircraft. Its development remains classified.

2. Weaponization of Space: This involves placing weapons in outer space or creating weapons that transit through space to attack targets on Earth (e.g., Fractional Orbital Bombardment Systems), as well as developing anti-satellite (ASAT) weapons.

• International Law: The Outer Space Treaty of 1967 is the foundational legal framework. It prohibits placing nuclear weapons or other weapons of mass destruction in orbit or on celestial bodies. However, it does not explicitly ban conventional weapons in space or ground-based ASAT weapons.
• Recent Developments: The US, China, and Russia have all demonstrated ASAT capabilities. In 2019, India successfully tested its own ASAT missile under Mission Shakti, demonstrating its capability to protect its space assets. There is a growing international debate, with India advocating for new norms to prevent an arms race in outer space, emphasizing the need to update the 1967 treaty.

3. Hypersonic Vehicles: These are vehicles that travel at speeds of Mach 5 (five times the speed of sound) or faster within the atmosphere.

• Types:
  • Hypersonic Glide Vehicles (HGVs): Launched from a rocket before gliding to a target.
  • Hypersonic Cruise Missiles: Powered by air-breathing engines (scramjets) during their entire flight.
• Strategic Advantage: Their high speed and maneuverability make them extremely difficult for current missile defence systems to track and intercept.
• Challenges:
  • Atmospheric Drag: Intense friction requires a highly aerodynamic design.
  • Extreme Heat: Air friction generates temperatures exceeding 2,000°C, requiring advanced heat-resistant materials.
  • Propulsion: Requires advanced air-breathing engines like scramjets.
• Indian Efforts: DRDO has successfully tested its Hypersonic Technology Demonstrator Vehicle (HSTDV), powered by a scramjet engine, achieving a crucial milestone in this technology.

4. Air-Breathing Engines: These engines take in air from the atmosphere to use as an oxidizer for combustion, unlike rockets which carry their own oxidizer.

• Turbojet/Turbofan Engine: Uses a compressor (rotating blades) to compress incoming air before combustion. Efficient from zero speed up to Mach 3. Used in most conventional aircraft.
• Ramjet: A simpler design with no moving parts. It uses the vehicle’s high forward speed to “ram” and compress air. It cannot operate at zero speed and must be accelerated to supersonic speeds (around Mach 3) by another means (like a rocket booster) before it can function. It is efficient up to about Mach 6.
• Scramjet (Supersonic Combustion Ramjet): An evolution of the ramjet where airflow through the entire engine remains supersonic. By avoiding the need to slow the air to subsonic speeds for combustion, scramjets can operate efficiently at hypersonic speeds (theoretically up to Mach 15). This is the key technology for sustained hypersonic flight.

Prelims Pointers

• Submarine Types: Diesel-Electric (SSK) and Nuclear-Powered (SSN for attack, SSBN for ballistic missiles).
• Project 75: Construction of six Scorpène-class submarines by Mazagon Dock Limited (MDL) with French collaboration.
• Scorpène-class Submarines: INS Kalvari, Khanderi, Karanj, Vela, Vagir, Vagsheer.
• AIP Technology: Air-Independent Propulsion; allows non-nuclear submarines to stay submerged longer. DRDO has developed a fuel cell-based AIP system.
• INS Arihant: India’s first indigenous nuclear-powered ballistic missile submarine (SSBN).
• Nuclear Triad: The capability to launch nuclear weapons from Land, Air, and Sea.
• SONAR: Sound Navigation and Ranging.
• Varunastra: Indigenous heavyweight anti-submarine torpedo.
• Maareech: Indigenous Advanced Torpedo Defence System (ATDS).
• Project 15B: Visakhapatnam-class stealth guided-missile destroyers.
• Project 17: Shivalik-class indigenous stealth frigates.
• Project 28: Kamorta-class indigenous anti-submarine corvettes.
• Indigenous Aircraft Carrier: INS Vikrant (IAC-1).
• STOBAR: Short Take-Off But Arrested Recovery (uses a ski-jump). Used on INS Vikrant and Vikramaditya.
• CATOBAR: Catapult Assisted Take-Off But Arrested Recovery (uses a catapult, e.g., EMALS).
• LCA Tejas: Indigenous 4th-gen Light Combat Aircraft developed by HAL and ADA.
• AEW&C Systems:
  1. Phalcon: Israeli radar on a Russian IL-76 platform.
  2. Netra: Indigenous DRDO radar on a Brazilian Embraer platform.
• DEW: Directed-Energy Weapon. DRDO’s project is KALI (Kilo Ampere Linear Injector).
• Mission Shakti: India’s Anti-Satellite (ASAT) missile test conducted in 2019.
• Outer Space Treaty: Signed in 1967, it governs activities in space and prohibits WMDs in orbit.
• Hypersonic Speed: Mach 5 and above.
• Air-Breathing Engines:
  1. Ramjet: Needs initial supersonic speed to start; combustion is subsonic.
  2. Scramjet: Combustion occurs at supersonic speeds; for hypersonic flight.
• HSTDV: Hypersonic Technology Demonstrator Vehicle, developed by DRDO.

Mains Insights

1. Indigenisation of Defence Technology (GS Paper 3: Science & Technology, Security)

• Significance:
  • Strategic Autonomy: Reduces dependence on foreign suppliers, insulating India from geopolitical pressures and sanctions. The development of INS Arihant and INS Vikrant are prime examples.
  • Economic Benefits: Creates a domestic defence industrial base, fosters innovation, generates employment, and saves foreign exchange. It aligns with the ‘Atmanirbhar Bharat’ vision.
  • Customisation: Indigenous platforms can be tailored to meet India’s specific geographical and strategic requirements.
• Challenges:
  • Technological Gaps: Critical components like jet engines and advanced sensors are still largely imported.
  • Time and Cost Overruns: Projects like the LCA Tejas and Arjun MBT have faced significant delays and budget escalations, impacting military preparedness.
  • Lack of Private Sector Participation: While improving, the private sector’s role has historically been limited, slowing down innovation and production capacity.
  • Bureaucratic Hurdles: Complex procurement processes and lack of a long-term integrated perspective can hinder progress.
• Way Forward:
  • Encourage public-private partnerships (PPP) and streamline procurement processes through initiatives like the Defence Acquisition Procedure (DAP).
  • Invest heavily in R&D and create an ecosystem that nurtures defence start-ups and innovation.
  • Focus on developing critical technologies domestically through targeted missions.

2. India’s Nuclear Triad and Deterrence Policy (GS Paper 3: Security)

• Cause-Effect Relationship: India’s ‘No First Use’ (NFU) policy necessitates a credible and survivable second-strike capability. The sea-based leg of the triad, embodied by SSBNs like INS Arihant, is the most survivable element. It can remain hidden in the vastness of the ocean, ensuring that even if land and air-based assets are destroyed in a surprise attack, India can launch a devastating retaliatory strike.
• Strategic Importance:
  • Credible Minimum Deterrence: The triad enhances the credibility of India’s nuclear deterrent against nuclear-armed adversaries, particularly China and Pakistan.
  • Regional Stability: A stable and assured second-strike capability reduces the incentive for a pre-emptive nuclear strike by an adversary, thus contributing to strategic stability in a volatile region.
• Debate: Some strategic thinkers have occasionally questioned the rigidity of the NFU policy in the face of evolving threats. However, the official stance remains unchanged, and strengthening the triad, especially the sea-based leg, is seen as the most effective way to uphold the credibility of the NFU doctrine.

3. The Changing Character of Modern Warfare (GS Paper 3: Security)

• Emerging Domains: Modern warfare is no longer confined to land, sea, and air. Space and cyberspace have become critical domains. Furthermore, technologies like AI, hypersonic weapons, and DEWs are blurring the lines between conventional and unconventional conflict.
• Implications for India:
  • Vulnerability: India’s critical infrastructure, including communication and financial networks, is vulnerable to cyber-attacks. Its space assets are vital for communication, navigation (NavIC), and surveillance.
  • Need for Doctrinal Shift: India needs to develop integrated doctrines that account for these new technologies. The creation of the Defence Cyber Agency, Defence Space Agency, and a Chief of Defence Staff (CDS) are steps in the right direction.
  • Investment and Preparedness: A significant and sustained investment in R&D for hypersonic, DEWs, and cyber defence is crucial. India cannot afford to be left behind in this technological race. The success of Mission Shakti was a deterrent signal, but sustained efforts are needed to secure space assets.

4. Maritime Security and the Indian Navy’s Role (GS Paper 2: IR; GS Paper 3: Security)

• Geo-strategic Context: The Indian Ocean Region (IOR) is a hub of global trade and energy flows. China’s increasing naval presence in the IOR (the ‘String of Pearls’ strategy) and non-traditional threats like piracy and maritime terrorism pose significant challenges.
• Navy’s Role as a ‘Net Security Provider’: India envisions its navy as a provider of security for the entire region.
  • Power Projection: Aircraft carriers like INS Vikrant, supported by destroyers and frigates, are central to projecting power and ensuring sea control across the IOR.
  • Sea-Lane Protection: Naval assets are crucial for protecting vital Sea Lanes of Communication (SLOCs).
  • Diplomatic Tool: Naval exercises with friendly nations (e.g., MALABAR with Quad partners) and port calls are key instruments of India’s maritime and foreign policy. The SAGAR (Security and Growth for All in the Region) vision underscores this role.