Prime Minister Narendra Modi inducted the largest-ever warship built in India till now, the 6,800-tonne destroyer INS Kolkata, at Mumbai on Saturday without its main air defence weapon which means the INS Kolkata is vulnerable to attacks from enemy missiles.The largest indigenously-built warship went into construction in 2003, but 11 years later, it is still not battle-worthy. One of its important weapons, a long-range Israel-built surface-to-air missile (LR-SAM) called the Barak 8 is still being developed and is expected to complete its trials in September and would then be available for being deployed on board the warship INS Kolkata.