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NavSource Online: Amphibious Photo Archive

USS LSM-275
USS Portunus (ARC-1)

International Radio Call Sign:
November - Victor - Golf - Lima
Awards, Citations and Campaign Ribbons


Precedence of awards is from top to bottom, left to right
Top Row - American Campaign Medal - Asiatic-Pacific Campaign Medal (1)
Bottom Row - World War II Victory Medal - Navy Occupation Service Medal (with Asia clasp) - National Defense Service Medal

USS Portunus (ARC-1) was transferred to Portugal and renamed NRP Medusa (A5214)
LSM-1 Class Landing Ship Medium:
  • Laid down, 1 August 1944, at Federal Shipbuilding and Drydock Co., Newark, N.J.
  • Launched, 11 September 1944
  • Commissioned USS LSM-275, 6 October 1944, LT. Daniel D McLoed, USNR in command
  • During World War II USS LSM-275 was assigned to the Asiatic-Pacific Theater and participated in the:
  • Decommissioned, 21 April 1947, at Terminal Island Navy Yard, San Pedro, CA.
  • Laid up in the Pacific Reserve Fleet
  • Redesignated a Cable Repair Ship, 14 December 1951
  • Converted at Mare Island Naval Shipyard, Vallejo, CA., between 15 January and 18 August 1952
  • Recommissioned, USS Portunus (ARC-1), 2 July 1952
  • Decommissioned, 30 April 1959, at New York
  • Struck from the Naval Register, 1 May 1959
  • Transferred, 16 November 1959, under the Military Assistance Program, to Portugal
  • Commissioned into the Portuguese Navy, 18 November 1959 as NRP Medusa (A5214)
  • Final Disposition, disposed of by Portugal in 1976
  • USS LSM-275 earned one battle star for World War II service
    LSM Specifications:
    Displacement 520 t.(light), 743 t. (landing) 1,095 t.(fully loaded)
    Length 203' 6" oa
    Beam 34' 6"
    Draft light, 3' 6" forward, 7' 8" aft, fully loaded, 6' 4" forward, 8' 3" aft
    Speed 13.2 kts. (max.), (928 tons displacement)
    Complement 5 officers, 54 enlisted
    Armament one single bow mounted 40mm gun, four single 20mm gun mounts
    Vehicle/Boat Capacity 5 medium or 3 heavy tanks, or 6 LVT's, or 9 DUKW's
    Troop Capacity 2 officers, 46 enlisted
    Armor 10-lb. STS splinter shield to gun mounts, pilot house and conning station
    Propulsion two General Motors (non-reversible with airflex clutch) diesels. Direct drive with 1,440 BHP each @ 720rpm, twin screws
    Endurance 4,900 miles @ 12kts.(928 tons displacement)
    Click On Image
    For Full Size Image    		 Size Image Description Contributed
    By
    USS LSM-275
    LSM-167 76k USS LSM-275 and USS LSM-167 beached at Okinawa, 7 April 1945. Note USS LSM-167 off loading onto a pontoon causeway. Raymond Massel to the USS LSM / LSMR Association
    LSM-275 186k USS LSM-275 beached at Okinawa, April 1945. Note the dead Japanese suicide swimmer in the foreground on the small craft ramp. George Coughlin to the USS LSM / LSMR Association
    LSM-275 69k USS LSM-275 at anchor, date and location unknown. Note USS LSM-275 is painted Camouflage Measure 31, Design 10L. Richard Kruse in memory of his
    grandfather Robert Yates USS LSM-275
    LSM-275 56k USS LSM-275 moored in a nest with other LSMs, date and location unknown. USS LSM / LSMR Association
    LSM-275 62k USS LSM-275 underway, date and location unknown. Wilson Corrum to the USS LSM / LSMR Association
    LSM-275 74k USS LSM-275 underway, departing San Diego Bay, date unknown.
    A Ted Stone photo.    		 USS LSM / LSMR Association
    USS Portunus (ARC-1)
    LSM-275 108k Plan view amidships of USS Portunus (ARC-1) during conversion at Mare Island Naval Shipyard, 28 June 1952. Photo shows how the LSM's tank deck was converted to undersea cable wells and the increased size of the ship's bridge structure.
    US Naval Shipyard Mare Island photo # NY9-13506-6-52.    		 USS LSM / LSMR Association
    LSM-275 100k Plan view forward of USS Portunus (ARC-1) during conversion at Mare Island Naval Shipyard, 28 June 1952. Photo shows the LSMs forward tank deck reconfigured for storage of undersea cables and the new fo'c'sle.
    US Naval Shipyard Mare Island photo.    		 USS LSM / LSMR Association
    LSM-275 58k USS Portunus (ARC-1) underway in San Francisco Bay in 22 August 1952.
    US Naval Shipyard Mare Island photo    		 USS LSM / LSMR Association
    LSM-275 79k USS Portunus (ARC-1) underway in 1954, location unknown. USS LSM / LSMR Association
    View the USS LSM-275 / USS Portunus (ARC-1)
    DANFS history entry located at the US Naval Historical Center
    Crew Contact And Reunion Information
    U.S. Navy Memorial Foundation - Navy Log
    Fleet Reserve Association
    Additional Resources and Web Sites of Interest
    Robert Yates and the LSM-275
    Back To The Navsource Photo Archives Main Page Back To The Amphibious Ship Type Index Back To The Service Force Ship Type Index Back To The Landing Ship Medium (LSM) Photo Index Back To The Cable Repairing or Laying Ship Medium (ARC) Photo Index
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    This page is created and maintained by Gary P. Priolo
    © 2005 Gary P. Priolo © 1996 - 2009 NavSource Naval History. All Rights Reserved.
    Last Updated 15 February 2008