Original SJD-3 sonar on earlier Type 037 class submarine chaser is replaced by a 13 kHz (2 frequency ranges) French Thomson Sintra SS-12/DIP 12 hull mounted (HM)/variable depth sonar (VDS).
submarine | Gym Class Heroes | class action | class | Class A | working class | nuclear submarine | Anti-submarine warfare | DB Class 218 | Class War | British Rail Class 37 | The Chaser | Social class | British Rail Class 47 | Victorian Railways X class | GWR 3031 Class | Class D | British Rail Class 66 | anti-submarine warfare | World Class Championship Wrestling | Saved by the Bell: The New Class | Nimitz-class aircraft carrier | Middle Class Rut | Middle class | middle class | Mercedes-Benz G-Class | Master Class | master class | LNER Class A4 4468 Mallard | First class travel |
The first ship, BO-270, was built at Zelenodolsk in 1945-1947 and a total of 227 were built for Soviet Navy (175) and border guard until 1955.
Special Base Force (Surabaya), 2nd Southern Expeditionary Fleet, Southwest Area Fleet.