Yankee Notch-class

The Yankee Notch, designated Project 667AT Grusha, is a modified variant of the Soviet Project 667A nuclear-powered submarine. The conversion program began in the 1980s, with the first unit entering service in 1987. Three submarines were completed to this specification, while four additional units remained unfinished.

Design characteristics of the Yankee Notch involved structural alterations to the baseline Project 667A hull. The modification process required lengthening the vessel and installing additional torpedo tubes in the waist area. These changes shifted the submarine's classification from a ballistic missile carrier to a guided missile submarine (SSGN) or attack submarine (SSN). The primary armament for this variant was the RK-55 Granat cruise missile, identified by the NATO reporting name SS-N-21 Sampson.

The operational history of the Yankee Notch followed the deployment patterns of the broader Yankee class, which maintained a presence in the Atlantic, Pacific, and Arctic Oceans. These vessels were part of the Soviet naval force until the implementation of international arms control agreements. Under the terms of the SALT I, START I, and START II treaties, the Yankee Notch units were disarmed and decommissioned. All completed vessels were subsequently transferred to nuclear ship scrapyards for disposal.