**OVERVIEW:** The PLARK-667AT Yankee Notch [Grusha] is a Project 667AT *Grusha* (Yankee Notch class in NATO parlance) nuclear-powered attack submarine (SSN) operated by the Russian Navy. Commissioned in 1992, the vessel represents a significant upgrade to the earlier Project 667A (Yankee I) class, incorporating improved acoustic quieting measures and enhanced sensor suites.

**DETAILS:**
The Project 667AT *Grusha* submarines were developed in the 1980s as a direct response to the increasing sophistication of Western anti-submarine warfare (ASW) capabilities. The primary design goal was to reduce the acoustic signature of the original Project 667A vessels, making them more difficult to detect. This involved extensive modifications to the hull, machinery, and internal systems to dampen noise and vibration. The *Grusha* class also received upgrades to their sensor suites and fire control systems to improve their operational effectiveness. While externally similar to the Yankee I, the Yankee Notch incorporated a new anechoic coating and rafted machinery to significantly reduce its acoustic signature, rivaling that of contemporary Western SSNs.

The primary role of the Yankee Notch is anti-submarine warfare (ASW), tasked with hunting and eliminating enemy submarines, particularly ballistic missile submarines (SSBNs). It can also perform anti-surface warfare (ASuW) operations, targeting enemy surface combatants. The submarine’s improved acoustic signature allows it to operate closer to enemy coastlines and within contested waters, increasing its effectiveness in these roles. The installation of the Shark Teeth [MKG-100 Kerch] and Shark Fin [MKG-100 Kerch] sonar systems provides the vessel with a comprehensive underwater acoustic picture, facilitating target detection, classification, and tracking.

The PLARK-667AT’s sensor suite enables diverse operational capabilities. The Brick Pulp [MRP-21 Zaliv-P] radar provides surface search capabilities, while the Snoop Tray 2 [MRK-50 Kaskad] system likely functions as an electronic support measures (ESM) suite, intercepting and analyzing enemy radar signals. The Generic Acoustic Intercept system further enhances the vessel's ability to detect and classify targets based on their acoustic emissions. The inclusion of Generic Mine & Obstacle Avoidance sonar and a Generic Submarine Periscope allows for safe navigation in confined waters and covert intelligence gathering. The armament of 533mm torpedo tubes provides the submarine with the capability to launch a variety of torpedoes and anti-ship missiles, while the presence of a Signal Ejector suggests the ability to deploy decoys or communication buoys. The 533mm Single MT could refer to the ability to launch mines from the torpedo tubes.

**SPECIFICATION:** Length: 141.5 m || Beam: 11.7 m || Draft: 7.9 m || Disp: 9000 t

**SENSORS:** Shark Teeth [MKG-100 Kerch] || Shark Fin [MKG-100 Kerch] || Park Lamp || Brick Pulp [MRP-21 Zaliv-P] || Snoop Tray 2 [MRK-50 Kaskad] || Generic Acoustic Intercept || Generic Mine & Obstacle Avoidance || Generic Submarine Periscope, Optical

**ARMAMENT:** 533mm TT || 533mm TT || 533mm TT || Signal Ejector || 533mm Single MT