New tech speeds up warship making

Ajay Banerjee

INDIA has accelerated its speed of making warships. Aided by technology, design software, modern construction techniques and helped by a growing domestic manufacturing base, the warship construction pace is almost matching that of the shipyards in Europe. More than 60 warships and submarines are currently being made across multiple shipyards in India. Significant are two classes of warships — the Nilgiri class stealth frigates and the Visakhapatnam class guided missile destroyers.

Excluding the INS Vikrant, the aircraft carrier commissioned in August last year, the Nilgiri class and the Visakhapatnam class are the biggest and most complex warships ever made in India. Both have an added focus on ‘Make in India’. It is not just the weapons these ships will carry, it is the pace of construction that needs to be noted.

The Ministry of Defence (MoD) opted to have ‘integrated construction’ on warships 10 to 12 years back. This entails various parts of a ship, particularly its hull, superstructure and internal systems, getting designed to be manufactured in separate blocks, which are aligned seamlessly to create the ship’s structure.

In the past five-six years, new infrastructure has been added at shipyards, supply lines established and artificial intelligence applied to arrive at the ‘sequencing’ of putting together a warship, including sourcing of material and production timelines.

Nilgiri class frigates

The first project using integrated construction is the ongoing construction of seven ships of the Nilgiri class stealth frigates. The technique has since being extended to make other ships. Four of the Nilgiri class warships are under construction at Mazagon Dock Shipbuilders (MDL), Mumbai, and three at the Garden Reach Shipbuilders & Engineers (GRSE), Kolkata. Both the shipbuilders are public sector enterprises under the MoD.

The Nilgiri class is a massively upgraded derivative of the Shivalik class frigates — three of these were commissioned into the Navy between 2010 and 2012. The build period of Shivalik class — from keel-laying, then launch at sea and finally to commissioning — was almost nine years for each of them.

The Shivalik class is seen as a turning point in ship-making as India started using its own steel, the DMR 249A. From then onwards, warships use the same steel. Before the DMR 249A, India had been importing steel from Russia. Now SAIL, Jindal and Essar make it.

In contrast to the Shivalik class, the first of the Nilgiri class — from keel-laying to commissioning — is expected to take about six years and six months and is targeted for commissioning in mid-2024. An official said, “As the design parameters and manufacturing process have settled down, the time taken for each ship is getting compressed.” The last four of the Nilgiri class ships are scheduled to take just about five years to make — from keel-laying to commissioning. Six of the Nilgiri class warships have been launched at sea. The Nilgiri and the Himgiri were launched in 2019 and 2020, respectively. Four warships — Udaygiri, Dunagiri, Taragiri and Vindhyagiri — have been launched at sea in the past 15 months. And the seventh and last ship, Mahendragiri, is set for launch in September — meaning five launches in just about 16 months. Six ships of the Nilgiri class are scheduled to be commissioned between 2025 and 2027.

Commodore PR Hari (retd), Chairman and Managing Director of GRSE, says, “We estimate a reduction in build period in the construction of the Nilgiri class. Reduction in manhours has been aided by the adoption of new technologies, improving efficiency.”

Integrated construction working

Ship designers at the Navy’s Warship Design Bureau, New Delhi, and the ship builders have worked out a formula to fit in maximum equipment before the warship is launched at sea and the outfitting of equipment gets done later. A ship has to be launched at sea to check its capacity in water. Secondly, an entire warship cannot be built on a dry dock as it would block the dry dock for a longer period.

As of now, 37 per cent of the warship is ready by the time it is launched at sea. The target is to get 40 per cent of the ship ready at launch, a functionary said. This includes the superstructure of the ship, its propeller, pumps, piping and cabling. Timelines are faster. Each block is about 250 tonnes. It is designed and built with precision to allow cabling and piping to pass through when two sets of blocks are welded together.

Design element

The Navy’s Warship Design Bureau uses a software to predict what a ship would be like. It suggests a reduction in radar signature, making it difficult for the enemy radars to track it mid-sea. The software predicts the turning radius, its zig-zag sailing ability and its infra-red signature, besides the ability to sustain in water, its capacity, what sort of power it needs.

The Bureau’s work starts from the concept, the design and till the entire project is completed — meaning, when all ships of a particular project are commissioned and are sailing. This would include the functional design; steering the project past the MoD and the Cabinet Committee on Security; monitoring of physical and financial progress; resolution of design issues; integration and support during trials.

Within the Bureau, the ‘forward design group’ looks at how feasible the design is, its hull and stealth features. Another group does a structural analysis — for strength, vibration and shock.

The Bureau tells about the equipment, layout of machinery, validates fluid systems, it steers system installation and the trials to prove equipment. A key part is crew comfort. The 2D and 3D drawings are used to design comfortable crew quarters and galley design for the food-making process.

Employing integrated construction, the Nilgiri class has significantly reduced ship construction timelines. Equipment installation, piping systems and outfitting of the hull have been undertaken in the block construction stage on a dry dock. This has enabled a higher percentage of the ship getting built prior to launch at sea, cutting down the time for readiness and for sea trials during the phase when it’s afloat before commissioning. Rear Admiral IB Uthaiah, Director General, Warship Design Bureau, Indian Navy

Local industry inputs

With stress on self-reliance, the Micro, Small and Medium Enterprises (MSME) sector has to play a key role. “About 65 per cent of the orders for equipment and systems of ships are placed from indigenous firms, including MSME enterprises. The MSME sector has to streamline supply chains to match ship construction timelines,” said a senior MoD official.

The Indian Naval Indigenisation Plan (INIP) 2015-2030 looks to develop various advanced systems for warships, submarines and planes. It lays down requirements of the Indian Navy and lists out the equipment which can be taken up for indigenisation in the coming years.

Modern facility for modular and integrated construction is akin to the best in the world. Integrated shipbuilding facility was created at GRSE, Kolkata, in 2013. Our dry dock is of 10,000 tonnes capacity and a Goliath crane with 250 tonnes capacity. Upgradation was done in 2019-2020 to the engineering complex, steel plate preparation shop and ship-building shop to cater to production requirements. Commodore PR Hari (retd), Chairman and Managing Director, GRSE

Speed up for other warships

Four ships of the Visakhapatnam class guided missile destroyers are a follow-on to the Kolkata class, three warships of which were commissioned between 2014 and 2016. Each ship took more than 10 years from keel-laying to commissioning.

The INS Visakhapatnam took eight years to make. The next ship of the class, INS Murmagao, was commissioned within seven years. The remaining two, Imphal and Surat, have both been launched at sea and are targeted to be commissioned within six years of keel-laying.

Commodore Nair says, “Integrated construction is being applied for Survey Vessel Large, and Anti-Submarine Shallow Water Crafts.” The next generation offshore patrol vessels will be executed with the same technology, he adds.

What the future holds

The Navy has set a target of completing the design in two-three years for new ships like the eight Next Generation Corvettes (NGCs), okayed by the Defence Acquisition Council at a cost of Rs 36,000 crore. The MoD, in June 2022, said: “NGCs would be constructed based on new in-house design of Indian Navy using latest technology of ship building.” The target to make an NGC from keel-laying to commissioning is four years.

This will bring the shipbuilding speed almost at par with China, South Korea and Japan. Probably another technology push is needed for the Indian shipyards.

US warns of China’s speed

• Even as India picks up speed, China is also racing. The ‘China Naval Modernisation: Implications for US Navy Capabilities — Background and Issues for US Congress’ report in May this year said, “China no longer relies on Russia or other countries for any significant naval ship systems.”
• It warns: “A majority of past foreign projections of the Chinese military and Chinese navy procurement scale and speed have been underestimated.” It expressed concern at the rapid pace of China’s naval shipbuilding effort.
• A report, ‘Military and Security Developments Involving the People’s Republic of China’, released by the Department of Defense, US, in November 2022 says, “China is the top ship-producing nation in the world and is increasing its shipbuilding capacity and capability for all naval classes.”
• It domestically produces naval gas turbine and diesel engines as well as almost all shipboard weapons and electronic systems for its shipbuilding sector, making the sector nearly self-sufficient for all shipbuilding needs.