SENSUIKAN!

© 2001-2017 Bob Hackett & Sander Kingsepp
Revision 2

1 May 1943:
Laid down at Kure Navy Yard as Submarine No. 655, the first unit of the planned class of the "Sen-ho" avgas tanker/supply submarines.

22 December 1943:
Renumbered I-351 and provisionally attached to Kure Naval District.

24 February 1944:
Launched and officially attached to Kure Naval District.

25 August 1944:
Cdr (later Captain) Tagami Meiji (51)(currently serving at the submarine section of Kure Navy Yard) is appointed the Chief Equipping Officer (CEO) as additional duty.

10 October 1944:
LtCdr (later Rear Admiral, JMSDF) Nanbu Nobukiyo (61)(former CO of I-362) is appointed the CEO.

11 December 1944:
LtCdr (Cdr, posthumously) Okayama Noboru (64)(former CO of I-361) is appointed the CEO.

28 January 1945:
I-351 is completed and commissioned in the IJN. 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. Assigned to SubRon 11 for working-up. LtCdr Okayama Noboru is the Commanding Officer.

Late January-early April 1945:
Works up in Iyo Nada, Inland Sea.

4 April 1945:
Assigned to SubDiv 15, Sixth Fleet. Continues battle training in Inland Sea until mid-April.

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:
Departs Singapore, carrying 132,000 gallons of aviation gasoline.

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. Most of the fuel she carried is later used for kamikaze training. Vice Admiral Daigo Tadashige, CinC, Sixth Fleet (Submarines), receives a special commendation from Vice Admiral Ozawa Jisaburo, CinC, Combined Fleet, for 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, embarks 132,100 gallons of aviation gasoline.

7-10 July 1945:
Dry-docked at Singapore.

11 July 1945:
Departs Singapore for Sasebo, carrying 42 flyers 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 I-class submarine and dives. At 0211 Campbell launches four Mk.18-2 torpedoes in two spreads in 05-36N, 109-37E. The first two 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 Mk.14-3A torpedoes at a range of 1,850 yds and scores 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. [1]

31 July 1945:
I-351 is presumed lost with all hands in the South China Sea.

15 September 1945:
Removed from the Navy List.

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Authors' Notes:
[1] USS BLUEFISH recovered three survivors who identified her 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. All three survivors were thrown clear and rendered unconscious. They came to in the water and swam for four hours before being rescued.

Thanks go to Dr. Higuchi Tatsuhiro of Japan and to John Whitman of the USA. Special thanks go to Hans Mcilveen of the Netherlands for info on FRUMEL intercepts.

– Bob Hackett and Sander Kingsepp.

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