YUSOSEN!

(Standard 2AT Tanker KENJO MARU by Ueda Kihachiro)

OTSUSAN MARU
Tabular Record of Movement

© 2011 Bob Hackett

E 1943:
Koyagishima. Laid down at the Kawaminami Kogyo K.K. shipyard as a 6,857-ton Type 2A Standard Cargo Ship for Mitsui Sempaku K.K., Tokyo.

1944:
Converted to a Standard 2AT Tanker while on the ways.

1944:
Launched and named OTSUSAN MARU

6 October 1944:
Completed.

3 November 1944:
At 1000, OTSUSAN MARU departs Moji for Miri, Borneo in convoy MI-25 also consisting of KACHAOSAN, ATAGO, NIKKO, DAIRETSU, DAIA, DAITO, RYUSHO, GYOSHIN, AKAGISAN, OTSUSAN, NICHIYO, KENSEI, HINAGA, YAMAMURA, TATSUTAMA, DAISHU, DAIEI and SHOEI MARUs and YUZAN MARU No. 2 and three unidentified ships escorted by kaibokan CD-23, CD-33, CD-51, CD-52 and CD-130.

8 November 1944:
OTSUSAN, KACHAOSAN and NIKKO MARUs and the three unidentified ships are detached for Takao. [2]

27 December 1944:
OTSUSAN MARU departs Takao for Singapore in convoy HI-85 also consisting of tankers SERIA, DAINAN, ENKEI, YAMAZAWA, ENGEN, ENCHO, DAIGYO, FUEI, OEI, SHINGI, SHINYU MARU and cargo ship TEIHOKU MARU (Ex-Vichy French PERSEE) escorted by light cruiser KASHII and kaibokan DAITO, TSUSHIMA, UKURU, CD-23, CD-27 and CD-51. Shortly after departure, DAINAN MARU breaks down and returns to Takao.

28 December 1944:
TSUSHIMA is detached from the convoy and makes for Yulin, Hainan Island. The remainder of convoy HI-85 heads for Cape St. Jacques via Qui Nhon Bay, Indochina. At some point, OTSUSAN and ENGEN MARUs are probably detached and head directly for Singapore.

29 December 1944:
OTSUSAN and ENGEN MARUs probably arrive at Singapore on this date. OTSUSAN MARU loads 7,100 tons of B grade oil, 1,250 tons of rubber, 400 tons of aviation gasoline, 100 tons of gasoline and 200 tons of crude oil. [3]

30 December 1944:
OTSUSAN MARU departs Singapore for Cape St. Jacques in a convoy also consisting of SAN LUIS, TATSUBATO, SHOEI, KYOKUUN, EIMAN, TATEBE, YOSHU and YUSEI MARUs and BANSHU MARU No. 63. [4]

4 January 1945:
The convoy arrives at Cape St. Jacques and awaits its escorts.

9 January 1945:
At 1200, OTSUSAN MARU departs Cape St. Jacques for Moji in convoy HI-86 also consisting of SAN LUIS MARU, KYOKUUN, TATSUBATO, SHOEI, EIMAN, TATEBE, YOSHU and YUSEI MARUs and BANSHU MARU No. 63 escorted by light cruiser KASHII, kaibokan DAITO, UKURU, CD-23, CD-27 and CD-51.

11 January 1945:
At 2120, the convoy anchors at Qui Nhon Bay.

12 January 1945: Operation "Gratitude"- Task Force 38's Strikes on Indochina:
Convoy HI-86 departs Qui Nhon. From 1100 to 1700, Curtiss SB2C "Helldiver" dive-bombers and Grumann TBF "Avenger" torpedo-bombers from Rear Admiral (later Admiral) Frederick T. Sherman's (USNA ‘10)(former CO of LEXINGTON, CV-2) Task Group 38.3's USS ESSEX (CV-9), TICONDEROGA (CV-14), LANGLEY (CVL-27) and SAN JACINTO (CVL-30) attack the convoy.

The planes sink light cruiser KASHII, CD-23, CD-51 and YOSHU and EIMAN MARUs and damage fleet tanker SAN LUIS MARU and kaibokan DAITO, UKURU and CD-27. Only three escorts survive the air attacks.

OTSUSAN, TATEBE, KYOKUUN, YUSEI and TATSUBATO MARUs and BANSHU MARU No. 63 are so damaged by bombs and fires they have to be beached and become constructive total losses. 28 of OTSUSAN MARU’s crewmen are KIA.

Author’s Notes:
[1] Also known as OTSUYAMA MARU and OTUSAN MARU.

[2] OTSUSAN MARU may have suffered a machinery breakdown and underwent protracted repairs at Takao.

[3] Accounts vary concerning convoy HI-85. It is known that OTSUSAN MARU arrived at Singapore where she loaded oil and gasoline, so she must have been detached from the convoy at some point.

[4] It is also known that HI-86’s four tankers and six freighters loaded cargo at Singapore and departed on 30 Dec ’44.

- Bob Hackett

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