Mazagon Docks Ltd; (MDL) will soon hand over INS Kalvari to the Indian Navy—the first of six Scorpene submarines being built in India in collaboration with French shipbuilder, Naval Group (formerly DCNS). Though the dates are not confirmed yet, the first Scorpene submarine is likely to be commissioned by Prime Minister Narendra Modi—it will be a re-affirmation of India’s capability to build submarines and a major boost for the ‘Make in India’ programme of the government. With 30% indigenous components on board, the Made-in-India submarine is part of the ongoing project for the construction of six Scorpene-class submarines at MDL in Mumbai on transfer of technology from the French company.
Known as Project 75, in 2005 the Indian government awarded a contract to the French DCNS to build six Franco-Spanish Scorpene-class diesel attack submarines (with an option to build six more) on transfer of technology. Once the stealthiest diesel-electric attack submarine is in service, it will take the number of submarines in the Indian Navy to 14; the navy requires at least 26 submarines to effectively monitor the Indian Ocean region.
The Indian Navy was supposed to get all six submarines between 2012 and 2015, but delays have pushed induction five years behind schedule. INS Khanderi, the second Scorpene submarine, was launched in Mumbai in January 2017. It is currently undergoing trials and will likely be delivered in March 2018. The remaining four boats will be delivered at nine-month intervals.
This indigenously built stealth submarine will soon add potent underwater capability to the Indian Navy and is named after a deep-sea tiger shark. The 1,550-tonne Kalvari-class submarine is equipped with six 533-millimeter torpedo tubes for launching anti-ship torpedoes, anti-ship missiles, and sea mines. However, INS Kalvari is currently not fitted with an air-independent propulsion (AIP) system.This boat is constructed from special steel and it can withstand high yield stress. Since it possesses tensile strength, it can withstand hydrostatic force of high magnitude and dive deeper.
As reported by FE earlier, the Defence Research and Development Organisation (DRDO) is in the process of developing the ‘Air Independent Propulsion (AIP)’ technology that will enable future Indian-built submarines stay underwater for longer than a conventional submarine. The agency’s Ambernath-based Naval Material Research Laboratory (NMRL) is working on a technology demonstration project for “Development of land-based prototype for AIP” for submarine propulsion. With the AIP, the vulnerability of a submarine for detection by enemy warships can be reduced by increasing its underwater endurance in dived conditions. Normally, diesel electric generators are used by a conventional submarine to charge the batteries that provide propulsion power when the submarine is under water. To run the generators, the submarine has to surface for taking in air and throwing out the exhaust. Using the AIP system, a submarine can charge batteries without surfacing.
According to Navy chief Admiral Sunil Lanba, “We are making our own AIP indigenous system with DRDO. At present, project definition is going on. Prototypes based plant is being constructed and once it is ready, it will be fitted in the Kalvari-class submarines.”This class of submarine works in all settings including the tropics, wherein various means and communications are in place to ensure interoperability with various components of the naval task force.
The submarine is built according to the principle of modular construction, which involves dividing the submarine into a number of sections and building them parallely. The equipment was mounted onto cradles and then embarked into the sections. The complexity of the task increased exponentially as it involved laying of around 60 kms of cabling and 11 kms of piping in extremely congested and limited space inside the submarine.