By Ajai Shukla
Cochin Shipyard, Kochi
Business Standard, 17th Aug 13
For more than a quarter of a century, the INS Vikrant had proudly symbolised the Indian Navy’s status as the only regional navy with an aircraft carrier, which could project power in a limited manner into the Indian Ocean. But by the late 1980s the Vikrant was getting long in the tooth and was undergoing a life-extension refit that would keep it in service till 1997. And a more muscular newcomer was grabbing the limelight --- the 28,700-tonne INS Viraat, formerly INS Hermes, which India had acquired from the Royal Navy in 1987 after it had led the Falklands sea campaign. For the first time, naval planners began discussing a successor to the Vikrant.
At first the navy considered leasing an aircraft carrier. London had already sold India two aircraft carriers and there was a comfort level with the Royal Navy. The alternative was a 65,000-tonne Admiral Kuznetsov-class Soviet Navy aircraft carrier, the Varyag, which had been launched in 1988 but was no longer wanted by a Soviet Union in economic and political free fall. Ironically, many years later, China’s People’s Liberation Army (Navy) bought the Varyag, restored it, and named it Liaoning, China’s first aircraft carrier.
But in New Delhi, the Directorate of Naval Design (DND) strongly opposed leasing. Buoyed by the confidence of designing and building the Delhi-class of destroyers, the DND made out a strong case for the Vikrant’s successor to be designed and built indigenously.
Commodore Saibal Sen, who heads Project 71, as the Vikrant programme is called, talked to me about that decision as we walked along the flight deck of the half-built INS Vikrant in Kochi. A trim, articulate officer who seems to know every detail about the warship he is building, Sen quietly affirms, “We had absolutely no doubt that we could build an aircraft carrier.”
And so, in 1989-90, the Indian Navy hired French warship builder, DCNS, as consultants to vet the design process based on the French experience of building carriers. A “Joint Concept Study” was carried out and DCNS gave the green light to the navy’s concept for building a 33,000-tonne vessel, large enough to field contemporary fighter aircraft --- which meant Boeing’s F/A-18 Hornet, and Dassault’s Rafale medium fighter, which the Indian Air Force (IAF) is now negotiating to buy.
That plan, like so many others, foundered on the rocks of defence cutbacks during what the navy calls the “Lost Decade” --- the economic restructuring of the 1990s when defence budgets were sharply constrained. With North Block scrimping on every penny, the idea of a large and expensive aircraft carrier was simply not saleable. But the navy did not give up; instead, it floated the concept of an “affordable aircraft carrier” --- a smaller, cheaper, 16,000-tonne vessel from which Sea Harrier vertical/short take off and landing (V/STOL) fighters could be flown. The navy produced a concept design; and the indigenous aircraft carrier was wheeled back from the morgue and placed on life support.
At that stage, the Defence R&D Organisation (DRDO) entered the fray, offering the Tejas Light Combat Aircraft (LCA), which it said could fly off a short deck carrier. That would make the “affordable aircraft carrier” more potent, but the vessel’s design had to undergo a major overhaul. Unlike the Sea Harrier, which could land vertically like a helicopter, the Tejas performed “arrested landings”, which required a longer deck with arrester wires laid out to drag the fighter to a halt.
Reorienting and lengthening the deck for the Tejas meant bulking up the vessel to 19,000 tonnes in the mid-1990s. And then it emerged that the Tejas required a longer runway to land on than originally envisaged. To accommodate that, the planned weight of the carrier went up to 24,000 tonnes.
In 1999, the Cabinet Committee on Security (CCS) sanctioned a 24,000 tonne indigenous aircraft carrier, to be designed by DND and built in Cochin Shipyard Ltd (CSL). CSL was an automatic choice since none of the three defence shipyards --- Mazagon Dock Ltd, Mumbai (MDL); Garden Reach Shipbuilders & Engineers, Kolkata (GRSE); and Goa Shipyard Ltd (GSL) --- had a dry dock large enough for an aircraft carrier. With a 244-metre-long “building dock”, and a 270-metre-long “repair dock”, CSL was the only realistic choice.
With the CCS sanction already obtained, the navy’s Air Wing took the process back to the start line. Instead of the obsolescent Sea Harrier, naval aviators wanted a new-generation Russian fighter that would give the indigenous aircraft carrier real punch. At exactly that time, Moscow and New Delhi were negotiating the transfer to India of the Admiral Gorshkov, a 45,000-tonne Kiev-class aircraft carrier that would operate frontline Russian fighters.
In contention as the Gorshkov’s air complement were the Sukhoi-33 and the MiG-29K, with the latter finally chosen because the Su-33 required a larger deck. In the minds of naval planners, it made perfect sense to have the same fighter operate off both the new aircraft carriers. Convinced of this logic, the MoD gave the green signal.
Choosing the larger, heavier, more powerful MiG-29K demanded that the indigenous aircraft carrier be designed afresh. Eventually, in November 2002, the CCS gave its sanction for a 37,500-tonne aircraft carrier. This was the final sanction on the basis of which INS Vikrant was built.
With a design finalised, the next challenge was to develop the “warship grade” steel needed for building the Vikrant. This challenging specialty metal needed to combine the contradictory qualities of hardness and toughness, just as a champion gymnast must be strong as well as flexible. It had to retain these qualities at temperatures of minus 60 degree Celsius, when normal metal plates shatter easily. In its maritime working environment, it should resist endless corrosion from seawater and air.
For long, India had relied on Russia, Poland, the UK and others for warship grade steel. But that exposed CSL to the danger of supply delays. And so the decision was taken to rely on the Steel Authority of India Ltd (SAIL), which had been working with DRDO since 1999 on mass-producing warship steel. With the engineering drawings ready and production scheduled to begin, SAIL finally mastered the process in 2004 and gave the green light to begin construction.
SAIL’s flagship plants at Bhilai, Rourkela, Bokaro and Durgapur have produced three special steels for the Vikrant, which will also be used for all subsequent Indian warships. These are DMR 249A for the hull and body; DMR 249B, a more resilient steel, for the flight deck that must take the repeated impact of 20-30 tonne fighter aircraft landing; and DMR Z25 for the floor of compartments that house engines and generators. This absorbs the compression and decompression from the heavy equipment. With expertise growing, SAIL is now developing DMR 292A, special steel for the hull of Indian submarines.
For CSL, there was now the challenge of translating drawings and steel slabs into an aircraft carrier. Commodore (Retired) K Subramaniam, the boss of CSL recounts a host of challenges that were faced and overcome.
“The first challenge was to work with the high tensile steel that SAIL had supplied. We had to develop special welding electrodes for this, which we did in-house with the DRDO’s Naval Materials Research Laboratory (NMRL). Then we had to train and qualify welders for the different welding processes in order to produce a high quality, and defect-free, warship. And, in order to weld together 18,000 tonnes of steel within four years, we developed a special automated welding process,” says Subramaniam.
This expert welding is evident when one looks at the Vikrant. It has a high quality finish, the surface entirely free of the ripples and undulations that often characterise large stretches of metal.
CSL officers also describe the difficulties of developing a “build strategy” for the ship, which involved breaking down the huge task of hull construction and outfitting into definite, manageable sequences.
“Making this especially creditable is the fact that CSL is building a warship for the first time,” explains Sen, the Project 71 director. “MDL and GRSE, which have built so many warships, have a well-established build technique. But CSL brought in a new approach and tackled a new set of challenges. They developed entirely new processes for welding the extra-thick steel of the Vikrant, which is thicker than the plates that go into frigates and destroyers.”
“We also had to tackle new, more demanding, more quality-conscious customers. The navy insisted on 100 per cent testing of all the butt joints --- welded joints that join together the large blocks that comprise the vessel. Every butt joint had to undergo radiographic and ultrasonic testing to check for welding defects. In commercial ships, only random checks are done,” explains M Murugaiah, General Manager, Shipbuilding.
Another challenge was the Vikrant’s propulsion system. It is driven by four General Electric LM 2500 gas turbines, which transmit power to the propellers at the rear of the warship through two giant shafts --- one over 100 metres long, the other one 50 metres. Since an Indian shipyard was handling such an engine-shaft configuration for the first time, the navy brought in Italian shipbuilder, Fincantieri, as a consultant to vet the design.
Consultancy was also essential for the aviation complex, which controls aircraft operations on a carrier. Since the MiG-29K was the primary fighter, Moscow provided this guidance.
What has been completed so far is only the Phase I of the Vikrant’s build, for which CSL was paid Rs 1,150 crore. The next phase, called outfitting, will see the installation of the vessel’s internal equipment, gas turbines, generating sets, air-conditioning equipment, etc. The MoD will negotiate a separate contract for that.
For Phase II, INS Vikrant will move to CSL’s Repair Dock, which is large enough for all the equipment that will be added. Suresh Babu, General Manager, Ship Repair, says that outfitting should be completed within a year. After that, INS Vikrant will begin an extensive set of trials --- harbour trials, sea trials, etc --- after which the vessel will join the Indian Navy fleet.
What the navy is most pleased about is the high level of indigenisation in the Vikrant. According to the DND, the “float” component of the vessel, which consists of the hull and superstructure, is 90 per cent Indian. The “move” component, which propels the vessel and includes the auxillary machinery like generators and air-conditioners, is 70 per cent indigenous. Only the LM 2500 gas turbines and the shafting was bought from abroad. And the “fight” component, which consists of weapons and sensors, is 35-40 per cent indigenous.
The icing on the cake, says Commodore Sen, is that a non-defence shipyard has produced a top-end warship, effectively adding to the navy’s options when it looks to build more in the future. Already reaching the decision stage is the successor to the Vikrant, so far referred to as indigenous aircraft carrier – 2. And when the time comes to decide who will build it, CSL will surely be on the list of options.