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NavSource Online:
Submarine Chaser Photo Archive


Call sign:
Nan - William - Roger - Able


SC-646 served the Navies of the United States and the Soviet Union.

SC-497 Class Submarine Chaser:

  • Laid down 23 September 1941 by the Robinson Marine Construction Co., Benton Harbor, MI
  • Launched 21 May 1942
  • Commissioned USS PC-646, 1 July 1942
  • Reclassified SC-646 in April 1943
  • Transferred to the Soviet Union 26 May 1945 and reclassified BO-310
  • Placed in service 17 July 1945
  • Assigned to the Soviet Pacific Fleet 30 July 1945
  • Participated in the liberation of South Sakhalin Island, Japan in August 1945
  • Placed out of service 8 July 1950 and reclassified to a Raid boat, RK-1483
  • Reclassified 23 June 1951 as a Messenger Ship and named Irtek
  • Placed out of service 25 June 1956 and sunk in the Strait of Tartary off Sakhalin Island.


  • Displacement 148 t.
  • Length 110' 10"
  • Beam 17'
  • Draft 6' 6"
  • Speed 21 kts.
  • Complement 28
  • Armament: One 40mm gun mount, two .50 cal. machine guns, two depth charge projector "Y Gun," and two depth charge tracks
  • Propulsion: Two 1,540bhp General Motors (Electro-Motive Div.) 16-184A diesel engines, two shafts.
    Click on thumbnail
    for full size image
    Size Image Description Source
    SC-497 161k Exploded view of SC-497 class Subchaser. © 1997 Theodore R. Treadwell

    There is no DANFS history available for SC-646
    Additional Resources and Web Sites of Interest
    Patrol Craft Sailors Association
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    This page created by Joseph M. Radigan and maintained by Tom Bateman
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