The Navy is set to commission indigenous stealth frigate Mahendragiri in the presence of Defence Minister Rajnath Singh at an event in Visakhapatnam on Saturday. Anti-submarine warfare vessel Malvan is slated for commissioning on July 22.Mahendragiri is the sixth of the seven-ship series of the INS Nilgiri Class, five of which have been commissioned. The Nilgiri class is the first class of warships to be built using a new, faster shipbuilding technique called ‘integrated construction’. These ships are modular, ergonomic and have been built within the envisaged timelines.Fitted with the latest weapons, sensors, attack missiles such as the BrahMos and air-defence missiles, Mahendragiri has the ability to stay at sea for extended periods, a capability referred to as a ‘blue-water’ capability in naval parlance.The seven ships of the Nilgiri class – named Project 17-A – are follow-on to the Shivalik class of frigates and represent a generational leap. The Naval Warship Design Bureau (NWDB) has incorporated indigenous design features, improved stealth, survivability and combat capability, along with reduced radar signatures, advanced surveillance radars and electronic warfare suites.The Nilgiri class displaces about 6,700 tonne, are 5 per cent larger than their predecessor, the Shivalik-class frigates, and yet incorporate a sleeker form, with a reduced radar cross section.They are powered by combined diesel or gas (CODOG) propulsion plants using diesel engines and gas turbines that drive controllable-pitch propellers and are managed through an integrated platform management system (IPMS). This enables higher speeds and improved fuel efficiency.The weapon suite includes supersonic surface-to-surface missiles, medium-range surface-to-air missiles, 76-mm MR Gun and a combination of 30-mm and 12.7-mm close-in weapon systems and the anti-submarine and underwater weapon systems.The Nilgiri class uses ‘integrated construction’ which entails making various parts of a ship, particularly its hull, superstructure, and internal systems in blocks of 250 tonnes each.These blocks are built with precision to allow cabling and piping to pass through when two set of blocks are welded together seamlessly. Artificial intelligence helps determine the sequence for assembling a warship, including sourcing of material and production timelines.Indian shipyards now build a ship in six years, down from the earlier period of 8-9 years.The Naval Warship Design Bureau has introduced the latest technology, adopted new design software, and used artificial intelligence and modern construction techniques. The design bureau uses a software to predict what would a ship be like. It predicts the turning radius, a ship’s sailing ability and its infra-red signature besides the ability to sustain in water and what sort of power it needs. The equipment, layout of machinery, fluid dynamics are predicted by a software.