The Yankee Boomer with the nose job!

There have been many unusual Soviet submarine modifications, and the modified Yankee class “Big Nose” Project 09780 Akson-2 was one of them!

Kazan ca. 1996-2000. Credit: АО «Центр судоремонта „Звёздочка“», Attribution, via Wikimedia Commons

K-403 began life as a Project 667A “boomer” SSBN Nuclear-powered Ballistic Missile Submarine, which received the NATO designation “Yankee class”. These were the first Russian missile boats with a conventional layout of missile tubes behind the sail – 16 SS-N-6 SLBMs. They were roughly contemporary to the USN “Forty-one for Freedom” classes, and, as Russian boats go, they looked downright normal – very similar to their Polaris-armed adversaries serving in the USN and Royal Navy.

K-219, another Yankee class boat, on the surface, after having been damaged by a missile propellant fire October 1986. Out of a class of 34 boats, this was the only loss. NARA: 330-CFD-DN-ST-87-00760

K-403 Kazan was commissioned in 1971, and would be modified several times. The website RussianShips.Info gives a summary of these modifications. During the early 1980s, K-403 was modified to a Project 667AK Akson or NATO “Yankee Pod” configuration, with the missile compartment removed and a towed sonar housing atop the rudder, which looked like what wound up installed on Oscar II class SSGNs. A decade later came the Project 09780 Akson-2 “Big Nose” conversion – a distinctive swollen bow section to house the large Irtysh spherical sonar prototype. At some point, K-403 was fully disarmed, with the bow torpedo tubes also removed.

Identification of K-403 based on wikipedia article on Yankee Class, which lists this boat as dismantled in the nearby drydock, in 2010. This boat was in multiple Severodvinsk captures 2004-2010.

The Kazan then served as the test-bed for the Irtysh/Amfora sonar system. THe trials must have been successful, as the system is fitted to current Project 885M (NATO Yasen-M) Nuclear Cruise Missile/Attack boats. K-403 was reportedly decommissioned around 2004 and scrapped at Severodvinsk in 2010. K-403 and K-411 (another oddity-a heavily modified, stretched mothership) were the last of the Yankees known to exist.