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Scratch One Flagship

On January 24, 1944, a Japanese convoy consisting of the auxiliary submarine depot ship Yasukuni Maru and the former armed merchant cruisers Aikoku Maru and Akakgi Maru departed Yokosuka escorted by the destroyers Michishio, Shiratsuyu, and Ikazuchi. The group had been tasked to transport members of the IJN 149th Air Defense Party to Truk. The Yasukuni Maru was carrying submarine spare parts, torpedoes, and submarine technicians. Because of an acute shortage of vessels, the IJN had designated the Yasukuni Maru to replace the light cruiser Katori as Vice Admiral Takagi Takeo’s flagship at Truk. There she would also service IJN Sixth Fleet submarines. She was built in 1930 as a passenger liner for Nippon Yusen KK (11,933 GRT). In 1940, she was requisitioned to serve as a auxiliary submarine depot ship. She serviced the First and Third Submarine Squadrons before her Sixth Fleet assignment.

On January 8, 1944, the USS Trigger (SS-237), captained by Robert E. Dornin and his XO, Ned Beach, departed Pearl Harbor on her eighth war patrol. Her orders were to patrol in the Caroline Islands area between Truk and Guam. On January 31, at 0131 hours, Trigger spotted the Truk-bound convoy at 9° 50′ 0.000″ N, 147° 6′ 50.000″ E. From the bridge at 11,000 yards, Dornin could clearly see the contacts and described them as three large cargo or transport vessels with two Fubuki-class destroyers as escorts, one on each quarter. Over the ensuing two and a half hours, Trigger made four attacks on the convoy, with Ned Beach at the TBT on the bridge while Dornin tracked the contacts on radar. For most of the period, the destroyers did not spot Trigger. Dornin attributed this to Trigger’s new gray camouflage. In his first attack, Dornin said he saw two torpedoes hit one of the destroyers, which disappeared in a cloud of smoke and debris. In the last attack, Dornin fired five torpedoes at what he believed to be a “Large high speed oil fueled AP [transport].” He saw two torpedoes hit it, resulting in several heavy explosions and flames. He also observed the vessel sink. Back at Pearl Harbor, Dornin was credited for sinking a 10,000-ton naval auxiliary of an unknown class and a 1,850-ton Fubuki-class destroyer.

Japanese records do not substantiate Dornin’s claim for the Fubuki-class destroyer. None of the destroyers assigned as escorts for the convoy were sunk or damaged. In addition, none of them were Fubuki-class destroyers. The Michishio was a Asashio-class destroyer, the Shiratsuyu was a Shiratsuyu-class destroyer, and the Ikazuchi was a Akatsuki-class destroyer. However, the records do show that the 11,933-ton auxiliary submarine depot ship Yasukuni Maru was Trigger’s victim. She was hit by two torpedoes on January 31, 1944, at 0358 hours, at 9° 15′ 0.000″ N, 147° 13′ 0.000″ E, and sank five minutes later. About three hundred sailors and eight hundred and eighty-eight technical personnel were lost. The Shiratsuyu rescued forty-three people. Thus, Vice Admiral Takeo never got his new flagship.

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