USS Threadfin (SS-410)

Built by the Portsmouth Navy Yard, the USS Threadfin (SS-410) was commissioned on 30 August 1944. On 25 December, the Threadfin left Hawaii for her first war patrol, arriving in her patrol area off Kyushu soon afterward. On 30 January 1945, she let a large enemy patrol pass overhead while she lay in wait to attack the vulnerable merchant vessels. That day she scored a torpedo hit on an enemy freighter and most likely sank the vessel.

During her second war patrol, she operated as a part of several wolf packs. On 28 March, the Threadfin achieved the unconfirmed destruction of a Japanese destroyer escort. Enemy depth charges, however, denied her the opportunity to confirm the kill. That same day, she engaged in a surface naval gun battle, damaging six enemy vessels, including two trawlers, while suffering no damage herself. In April 1945, the Threadfin and other submarines were stationed outside the entrance to the Japanese Inland Sea to provide warning to the Allied fleet as enemy vessels sortied during the assault on Okinawa. The submarines sent a timely warning, which allowed Task Force 58 to engage and sink the super battleship Yamato and most of her escorting vessels.

Operating out of the Yellow and East China Seas, the Threadfin’s third patrol opened with the successful sinking of an enemy schooner in a surface attack using her 5-inch deck gun. After rescuing nine enemy crewmen, she sank two more schooners, and on 20 May 1945, she scored two torpedo hits on an enemy ship during a night radar attack. Soon afterward, the Threadfin joined with the USS Sea Robin (SS-407). The two submarines destroyed four enemy cargo vessels.

Following the Japanese surrender, the submarine served as a training platform in New London and was decommissioned in December 1952, at which time she was modernized under the Guppy IA conversion program and recommissioned on 7 August 1953. She spent the remainder of her years operating off the Atlantic coast and in the Caribbean. On 18 August 1972, she was decommissioned and transferred to the Turkish Navy. She was sold to Turkey in August 1973, where she remained in service until 1998 as the Birinci Inönü.