Please report any broken links or trouble you might come across to the Webmaster. Please take a moment to let us know so that we can correct any problems and make your visit as enjoyable and as informative as possible.

NavSource Online: Mine Warfare Vessel Photo Archive


AM-478 was built for Portugal

AM-478 Class Fleet Minesweeper:

  • Laid down 26 August 1953 as AM-478 by the Bellingham Shipyards Co., Bellingham, WA
  • Launched and delivered 30 April 1954
  • Sponsored by Mrs. D. F. Smith
  • Reclassified by U. S. Navy as an Ocean Minesweeper, MSO-478, 7 February 1955
  • Completed 24 April 1955
  • Transferred to Portugal 26 April 1955 and named NRP São Jorge (M 478)
  • Reclassified M-415
  • Decommissioned 2 April 1973 and scrapped at Malaga, Spain.


  • Displacement 665 t.
  • Length 172'
  • Beam 35'
  • Draft 10'
  • Speed 13.5 kts.
  • Complement 39
  • Armament: One 40mm mount and two .50 cal. machine guns
  • Propulsion: General Motors 1,600shp diesel engines, two shafts.
    Click on thumbnail
    for full size image
    Size Image Description Source
    MSO-478 461k 30 April 1954
    Mr. and Mrs. David F. Smith, Bellingham Shipyards chief engineer and ships sponsor
    Fred Smith
    MSO-478 721k 30 April 1954
    Photo from a local Bellingham newspaper
    MSO-478 529k 30 April 1954
    After launching
    NRP São Jorge (M 478)
    MSO-478 341k c. 1956
    Portuguese Navy photo from Janes Fighting Ships
    Robert Hurst
    NRP São Jorge (M 415)
    MSO-478 72k David Wright
    MSO-478 64k c. 1960
    Portuguese Navy photo from the 1960/1961 edition of Janes Fighting Ships
    Robert Hurst
    MSO-478 157k c. 1970
    Portuguese Navy photo

    There is no DANFS history available for MSO-478
    Additional Resources and Web Sites of Interest
    102 Minesweepers (MSO) Oceangoing Minesweepers
    Naval Minewarfare Association
    Association of Minemen
    Back to the Main Photo Index Back to the Mine Warfare Ship Photo Index Back to the Ocean Minesweeper (MSO) Photo Index

    Comments, Suggestions, E-mail Webmaster

    This page created and maintained by Joseph M. Radigan
    All pages copyright NavSource Naval History