The project to build the six SSNs (nuclear-powered attack
submarines, usually without nuclear-tipped missiles), in turn, is to
be undertaken at the secretive ship-building centre (SBC) at Vizag.
India's first three SSBNs (nuclear-powered submarines
with nuclear ballistic missiles) are already being built at
the SBC to complete the country's nuclear weapons triad -
the capability to fire nukes from land, air and underwater.
The expertise gained in the construction of
the SSBNs will help the SSN project, said sources
.