OVERVIEW: The P 831 *Sava* is a *Heroj*-class diesel-electric submarine operated by the former Yugoslavia. Built by Brodogradiliste specijalnih objekata (Special Objects Shipyard) in Split, the *Sava* represented a significant step in Yugoslav indigenous submarine design and construction. The vessel was commissioned in 1979.

DETAILS:
The *Heroj*-class submarines were developed in the late 1960s and 1970s as an improvement over the earlier *Sutjeska*-class. While the *Sutjeska* class represented a basic submarine design based on available foreign technology, the *Heroj*-class incorporated indigenous design elements and enhanced capabilities. The design philosophy centered on creating a relatively quiet and versatile submarine capable of operating in the shallow, confined waters of the Adriatic Sea. The *Sava*, along with its sister ships, was intended to provide a credible underwater deterrent and to contribute to the overall coastal defense strategy of Yugoslavia. The class emphasized improved sensor capabilities and enhanced crew comfort compared to its predecessors. Specific design features included an optimized hull form for reduced hydrodynamic noise and a more streamlined sail.

The primary role of the *Sava* was anti-surface warfare (ASuW), with a secondary capability in anti-submarine warfare (ASW). While not specifically designed for anti-aircraft warfare (AAW), its ability to operate undetected in littoral waters presented a potential threat to enemy surface combatants. The vessel's 533mm torpedo tubes were capable of launching a variety of torpedoes, allowing it to engage surface ships and submarines at varying ranges. The *Sava* could be deployed for reconnaissance missions, surveillance of enemy naval activities, and minelaying operations in strategic locations. The submarine's relatively shallow draft allowed it to operate effectively in coastal areas and navigate narrow straits.

The *Sava*'s sensor suite provided a comprehensive picture of the underwater environment. The Stop Light B [Nakat] likely served as a sonar intercept receiver, detecting and analyzing enemy sonar transmissions. The CSU 3-2 and IPS CSU 3 are believed to be active/passive sonar systems providing target detection and tracking capabilities. The Snoop Group, if related to radar systems, would provide surface search capability while surfaced. The PRS 3-4 likely offered improved passive ranging and detection. AN 407 represents another component of the overall sonar array. The generic submarine periscope and optical sensors allowed for visual observation of the surface and horizon, vital for navigation and target identification in periscope depth operations.

SPECIFICATION: Length: 55.7 m || Beam: 7.2 m || Draft: 5.1 m || Disp: 830 t

SENSORS: Stop Light B [Nakat] || CSU 3-2 || Snoop Group || PRS 3-4 || AN 407 || IPS CSU 3 || Generic Submarine Periscope, Optical

ARMAMENT: 533mm TT