Yankee Class Submarine - Variants

Variants

There were eight different versions of the Yankee subs (all no longer in service):

• Yankee I (Project 667A): The baseline configuration, these were ballistic missile submarines that first saw service in 1968; 34 were built. The subs carried 16 SS-N-6 missiles, had 6 torpedo tubes, and carried 18 Type 53 torpedoes. They were the first Soviet SSBNs to carry their ballistic missiles within the hull (as opposed to the sail).

• Yankee II (Project 667AM/Navaga M-class): A single-ship class, this was a Yankee I submarine (K-140) converted to carry 12 SS-N-17 missiles, which was the Soviet Navy's first solid-fuelled SLBM. The existence of this individual prototype led to several theories about the Yankee II having a unique role in the Soviet arsenal that justified maintaining a single ship with such a unique weapon. One theory suggested that it was designed to perform an emergency satellite-launching function. Subsequently, it was proposed that the SS-N-17 may have had a retargeting capability to allow strikes on aircraft carrier battle groups.

• Yankee Notch (Project 667AT/Grusha-class): These converted subs were attack submarines and first appeared in 1983; four Yankee I boats were rebuilt to this configuration. They incorporated a "notch waisted" center section, which replaced the old ballistic missile compartment, featuring eight 533 mm (21-inch) torpedo tubes for up to 40 SS-N-21 missiles or additional torpedoes. The forward torpedo tubes were retained as well, with some reports suggesting that the vessels may have also been able to fire 650 mm (26.5-inch) Type 65 torpedoes. The emphasis on additional SS-N-21 missile carriage suggested a tactical role for these submarines, or as second-strike nuclear submarines. Their configuration was a combination of SALT treaty limitations (which affected SLBMs but not cruise missiles) and a typical Soviet unwillingness to completely discard any military hardware that might still have some use. The conversion increased the overall length by 12 m (39.4 feet) to 141.5 m (464.2 feet), with a displacement of up to 11,500 tons submerged. While classed as SSNs (attack subs), these boats might also be considered SSGNs by virtue of their heavy missile armament.
• Yankee Sidecar (Project 667M/Andromeda-class) Also known as Yankee SSGN, this was another single-ship (in this case K-420) class, converted into an SSGN. It appeared in 1983, carrying 12 SS-NX-24 nuclear-tipped cruise missiles instead of the original ballistic missiles. The SS-NX-24 was an experimental cruise missile, with a supersonic flight regime and twin nuclear warheads. It was meant as a tri-service strategic weapon, and thus would have filled a rather different role than the tactically-oriented Oscar-class SSGNs of the same era. In the end, the missile was not adopted, and the K-420 became a weapon system without a weapon. It was fully 13,650 tons displacement (dived), and was even longer than the Yankee Notch to accommodate the massive cruise missiles; it was 153 m (501.8 feet) long overall.
• Yankee SSN 16 of this type were converted from the basic Yankee I specification. Some were not completely converted, although they cannot carry ballistic missiles, so they were called Yankee SSNX. They retained only their forward torpedo tubes, with the central missile sections having been removed. Some are being scrapped.
• Yankee Pod (Project 09774 "Akson") The Yankee Pod (also known as the Yankee SSAN) is a converted trials submarine K-403 "Kazan'", which was used for sonar equipment, with the namesake pod mounted atop the rudder (a la Victor III-class SSNs. It had other sensor systems incorporated as well, notably alongside the sail.
• Yankee Stretch (Project 09774) K-411, the Yankee Stretch conversion, is a "mothership" for Paltus-class mini-submarines. It is fully 160 m (525 feet) in length, making it the largest of the Yankee conversions. Like the Yankee Pod, it lacked missile armament. Its mission was believed to be a combination of oceanographic research, search and rescue, and underwater intelligence-gathering.

• Yankee Big Nose (project 09780 "Akson-2") is K-403 "Kazan'" modified again for trials of acoustic system for Russian submarines of the 4th generation: sonar system "Irtysh" with spherical antenna "Amfora", which occupies whole nose section of submarine. Modification of K-415 was started in 1987, but due to the end of the Cold War and lack of funds, this was never completed.