NEW DELHI: With India planning a larger fleet of nuclear-powered submarines, which can prowl underwater for several months at a time and let loose their nuclear-tipped missiles as and when required, the Navy has acquired a new advanced facility to communicate with the silent predators.The state-of-the-art very low frequency (VLF) transmitting station was commissioned at INS Kattabomman in Tirunelveli (Tamil Nadu) by Navy chief Admiral RK Dhowan on Thursday.“The new facility will boost our ability to communicate with submarines, which have trailing wire antenna to pick up the coded VLF radio waves, on an uninterrupted basis throughout the year," said an officer.Only a handful of nations have such a VLF capability, which is critical to pass coded orders to nuclear submarines on long-range deterrent patrols. Diesel-electric submarines have to surface every few days to get oxygen to recharge their batteries and have limited endurance due to fuel requirements.Nuclear-powered submarines, armed with nuclear-tipped missiles, in turn, are considered the most effective and difficult-to-detect nuke platform since they can operate underwater at long ranges for months at end.The submarine communication centre at INS Kattabomman.India is down to just 13 old diesel-electric submarines, barely half of which are operational at any given time, and a single nuclear-propelled submarine INS Chakra on lease from Russia without any long-range missiles.But India’s first three SSBNs (nuclear-powered submarines with nuclear ballistic missiles) are already being built at the secretive Ship-Building Centre at Vizag to complete the country’s nuclear weapons triad – the capability to fire nukes from land, air and underwater.The first, the 6,000-tonne INS Arihant, is slated to go for extensive sea trials soon after its miniature 83MW pressurized light-water reactor, which went “critical” in August last year, attains “full power” in the next couple of months. Moreover, there is an ongoing proposal to build six SSNs (nuclear-powered attack submarines, usually without ballistic missiles), as reported by TOI earlier.