Echo Class Submarine - Echo II Class

The Echo II class (Project 675 class) were built at Severodvinsk (18 vessels) and Komsomolsk (11 vessels) between 1962 and 1967 as anti-carrier missile submarines. The Echo II class carried eight P-6 (SS-N-3a "Shaddock") anti-ship cruise missiles mounted in pairs above the pressure hull.

To fire the missiles, the ship had to surface and the missile was elevated to about 25 to 30 degrees. The Echo II class also had fire control and guidance radar. The Echo II class could fire all eight missiles in 30 minutes, but would have to wait on the surface until the missile mid-course correction and final target selection had been sent unless guidance had been handed over to a third party.

From the mid-1970s, fourteen of the 29 Echo II class were converted during overhauls to carry the P-500 Bazalt (SS-N-12 "Sandbox") anti-ship cruise missile, with a range of 550 kilometres (340 mi). The conversions (Project 675M) could be distinguished by the fitting bulges either side of the sail.

Three of these modified units were further upgraded under Project 675MKV towards the end of the Cold War. The P-1000 Vulkan (GRAU 3M70) flies faster (Mach 2.3-2.5) than the P-500 and its range was extended to 700 kilometres (430 mi). It replaces steel components with titanium to reduce weight, and has an improved propulsion system. It appears to have used a similar fire-control system to the P-500, the Argon-KV and Argument radar. P-1000 was installed on three units of the Northern Fleet between 1987 and 1993; the conversion of two boats of the Pacific Fleet, the K-10 and K-34, was abandoned due to lack of funds.

The Echo II class were divided evenly between the Pacific and Northern Fleets. The boats were obsolete by the mid-1980s, and were deleted in 1989 and 1995.