Patriotic Procurement & Precision Production: SAIL’s Steel Salvo

In a milestone achievement for India’s defence manufacturing drive, Steel Authority of India Limited has announced its role in supplying the entire requirement of special-grade steel used to construct the newly commissioned warship, INS Arnala. The vessel is the first in a new series of anti-submarine warfare shallow water crafts, ASW-SWC, designed for coastal operations and constructed by Garden Reach Shipbuilders & Engineers.

Commissioned into the Indian Navy on June 18, 2025, INS Arnala symbolises India’s naval modernisation efforts & exemplifies the ambitions of Make in India and Atmanirbhar Bharat, especially in strategic sectors like defence production, where domestic inputs are increasingly being prioritised over foreign imports.

Subsurface Superiority & Shallow-Water Sophistication: INS Arnala’s Arsenal

As the first vessel in the ASW-SWC class, INS Arnala is purpose-built for shallow-water deployment. It is optimised for operations such as subsurface surveillance, search & rescue, and low-intensity coastal combat, particularly in India's vast littoral zones. Designed with compact hull geometry and low acoustic signatures, the ship incorporates the latest sonar and navigation systems, enhancing detection capabilities against hostile submarines and underwater drones.

Armed with lightweight torpedoes, close-in weapon systems, and advanced combat management suites, INS Arnala is an essential asset for safeguarding India’s near-shore strategic interests.

Nationalistic Navalcraft & Native Alloys: Inside the Steel That Built INS Arnala

The steel used in INS Arnala is not ordinary structural alloy, it belongs to a specialised category of high-strength, low-alloy and corrosion-resistant steel grades developed specifically for naval warfare platforms. These include:

• DMR-249A & DMR-249B grades, known for their high toughness, superior weldability, and resistance to sea-water corrosion

• DMR-249C, a higher strength version used for submarine hulls & key structural components

• High-impact quenched & tempered steels, used in the vessel’s critical load-bearing and blast-resilient areas

These steels are produced in SAIL’s Bhilai, Rourkela, Bokaro, and Durgapur steel plants, where state-of-the-art processing facilities ensure strict adherence to naval quality standards specified by the Indian Navy’s Directorate of Naval Design. In some instances, the steels are further refined through vacuum degassing, tempering, and micro-alloying with vanadium, niobium, and chromium for enhanced mechanical performance.

Metallurgical Milestones & Maritime Mastery: SAIL’s Expanding Defence Role

This is not SAIL’s first contribution to India’s naval steel inventory. The company has become an indispensable supplier to the Ministry of Defence over the past two decades, having previously delivered critical steel components to:

• INS Vikrant, India’s first indigenously-built aircraft carrier, where DMR-249A steel was used for the hull and flight deck

• INS Nilgiri and INS Vindyagiri, under Project 17A stealth frigate class

• INS Surat, a Project 15B guided-missile destroyer, which incorporated advanced blast-resistant steel plates

According to senior SAIL officials, the company has consistently met stringent naval steel certification standards involving ultrasonic testing, Charpy impact testing at -40°C, and corrosion-fatigue resistance benchmarks. Its ability to mass-produce high-grade military steel has reduced India’s historical reliance on European and Russian steel suppliers.

Indigenisation Imperative & Industrial Ingenuity: From Mines to Maritime Might

SAIL’s contribution is a textbook case of vertical integration in India’s defence production. From mining raw iron ore in Jharkhand & Odisha to final rolling in modernised plants, the entire steel value chain has remained within national boundaries, a crucial strategic advantage in times of geopolitical volatility or wartime sanctions.

The success of INS Arnala’s steel supply also reflects years of R&D investments through collaborations between SAIL’s Centre for Engineering & Technology and the Defence Metallurgical Research Laboratory. The innovations from this partnership have now enabled mass production of high-performance naval-grade steel entirely within India.

Strategic Seamanship & Sovereign Strength: Boosting India’s Blue-Water Aspirations

The inclusion of INS Arnala into active naval service significantly boosts India’s ability to police its 7,500-kilometre coastline, especially against asymmetrical underwater threats. With shallow water combat capabilities, these vessels act as an effective deterrent against enemy mini-submarines or unmanned undersea vehicles attempting stealth infiltration.

Naval analysts see the ASW-SWC class as a crucial layer in India’s maritime doctrine, offering operational flexibility, faster deployment near shorelines, and a complementary shield to larger destroyers and frigates in deeper waters. More ships in this series are expected to follow, reinforcing India's tiered maritime defence.

Public Sector Prowess & Production Partnerships: GRSE & SAIL Synergy

The collaboration between SAIL and GRSE reflects a harmonious blend of material science & marine engineering, both accomplished under the stewardship of Indian public-sector undertakings. GRSE, which has delivered more than 100 warships since independence, completed construction of INS Arnala ahead of schedule, reinforcing confidence in India’s capacity to deliver defence-grade platforms autonomously.

The partnership serves as a scalable model for future ASW, patrol, and surface combatant programs. With private sector entry expanding in defence corridors, experts suggest that PSU-led ecosystems like SAIL–GRSE can remain the backbone of sovereign security supply chains.

Ceremonial Commissioning & Celebratory Confidence: Nation's Naval Pride

The ceremonial commissioning of INS Arnala was held under the aegis of the Indian Navy, drawing attendance from high-ranking defence officials, shipbuilders, and SAIL engineers. National flags fluttered as the warship was officially welcomed into operational command, evoking pride not just for the Navy but for Indian industry at large.

Defence Ministerial statements lauded the seamless execution of the steel supply chain. “This is not just a warship; it is a floating statement of Indian engineering,” remarked a senior Navy officer. For SAIL, the event also reaffirmed its identity as not merely a steelmaker, but a cornerstone in India’s quest for self-sufficient strategic autonomy.

Key Takeaways

• SAIL supplied 100% of the special-grade DMR-series steels used in constructing INS Arnala, including corrosion-resistant & blast-resistant naval-grade alloys.

• INS Arnala, commissioned on June 18, 2025, is the first ASW-SWC vessel built for shallow-water anti-submarine warfare, entirely manufactured in India.

• SAIL’s contribution reflects a robust, fully indigenous defence steel supply chain, supporting strategic autonomy under the Atmanirbhar Bharat initiative.