IJN Submarine I-351: Tabular Record of
© 2001-2014 Bob Hackett & Sander Kingsepp
23 April 1944:
8 November 1943:
Laid down at Kure Navy Yard as Submarine No. 655, the first of the planned class of the "Sen-ho" avgas tanker/supply submarines.
10 October 1944:
LtCdr (later Rear Admiral, JMSDF) Nanbu Nobukiyo (61)(former CO of I-362) is appointed Chief Equipping Officer.
10 December 1944:
LtCdr (Cdr, posthumously) Okayama Noboru (64)(former CO of I-361) is appointed Chief Equipping Officer.
28 January 1945:
I-351 is completed, commissioned in the IJN and attached to Kure Naval District. She is equipped with a Type 22 surface-search radar and E27 Type 3 radar detectors. A Type 13 air-search radar is installed after the initial tests. LtCdr Okayama is the Commanding Officer. Assigned to SubRon 11 for working-up.
4 April 1945:
Assigned to SubDiv 15, Sixth Fleet.
1 May 1945:
The I-351 departs Kure for Singapore carrying clothing, ammunition and aircraft parts.
15 May 1945:
Arrives at Singapore.
18 May 1945:
On that day, the USN Fleet Radio Unit, Melbourne, Australia (FRUMEL) decodes the following message from I-351, timed 171026: "Arrived Singapore on 15th. Entered dock on 17th. Will change ballast and undock on 20th. Due to leave on 21st after loading aviation spirit and..."
20 May 1945:
31 May 1945:
On that day, FRUMEL provides the following information: "Submarine I-351, on passage from Singapore to Sasebo expects to arrive at 1300 on 3rd June. Her noon position on 2nd will be 31-00N, 126-00E."
3 June 1945
I-351 arrives at Sasebo carrying 132,000 gallons of gasoline. Most of the fuel is used for kamikaze training. Vice Admiral Daigo Tadashige (former CO of ASHIGARA), CINC, Sixth Fleet (Submarines), receives a special commendation from Vice Admiral Ozawa Jisaburo (former CO of HARUNA), CINC, Combined Fleet, for the I-351's successful mission.
14 June 1945:
On that day, CincPac's ULTRA Bulletin provides the following information: "Sub I-351 scheduled depart Sasebo about 19 June en route Singapore transporting AA ammo and cryptographic publications. Estimate will transport Avgas and other strategic materials on return trip to Japan."
22 June 1945:
At 1400, departs Sasebo on her second supply run to Singapore, carrying the Japanese commanding personnel for ex-Kriegsmarine submarines U-181 and U-862 (renamed I-501 and I-502), as well as a total of 60 boxes of new code books for the Tenth Area Fleet. That same day, CincPac's ULTRA Bulletin provides the following information: "I-351 departed Sasebo 221400 for Singapore. May be off China Coast 28-20N at noon 25th."
5 July 1945:
I-351's Type 13 air-search radar breaks down.
6 July 1945:
Arrives at Singapore.
7-10 July 1945:
Dry-docked at Singapore.
11 July 1945:
Departs Singapore for Sasebo carrying 42 flyers and the CO of the 936th Kokutai (E13A1 "Jakes"), an ASW and convoy patrol unit of the 13th Air Fleet.
14 July 1945:
South China Sea, ENE of Natuna Besar, Borneo. At 2356, I-351, zig-zagging on base course 035 at 14 kts, is picked up on radar by LtCdr J. H. Campbell's USS BLOWER (SS-325).
15 July 1945:
At 0030, BLOWER picks up radar impulses from the Japanese submarine and dives. At 0211 Campbell launches four torpedoes in two spreads in 05-36N, 109-37E. The first two probably hit the target, but do not explode. I-351 dives away and Campbell alerts the nearby USS BLUEFISH (SS-222).
100 miles ENE of Natuna Besar. At 0314, I-351, running on the surface, is picked up on radar by Cdr George W. Forbes, Jr.'s BLUEFISH. Forbes tracks and closes on the target for almost an hour. At 0411 he fires four torpedoes at a range of 1,850 yds and gets two hits. I-351 explodes and breaks in two, then sinks by the stern at 04-30N, 110-00E.
In the morning, BLUEFISH picks up three survivors. A total of 110 sailors and flyers are KIA. 
31 July 1945:
The IJN presumes the I-351 is lost with all hands in the South China Sea.
15 September 1945:
Removed from the Navy List.
 The USN recovered three survivors who identified target as I-351. They stated the submarine left Singapore of 12 July [actually 11 July] and on 15 July were torpedoed while the submarine was proceeding on surface at a speed of about 10 knots. All three prisoners were lookouts at the time. One of them saw four torpedoes approaching, one was wide of the target forward, one was aft and the other two struck; one amidship and the other aft. One survivor claimed it happened too quickly for him to give warning. One torpedo struck the aviation gasoline tank and a tremendous explosion followed. Prisoners were thrown clear and rendered unconscious. They came to in the water and swam for four hours before being rescued.
Special thanks go to Hans Mcilveen of the Netherlands for info on FRUMEL intercepts.Thanks also go to Dr. Higuchi Tatsuhiro of Japan and to John Whitman of the USA.
Hackett and Sander Kingsepp.
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