KOSAKUKAN!

© 2008 Bob Hackett, Sander Kingsepp and Peter Cundall

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21 May 1938:
Tamano. Laid down by Tama Zosensho as a 5,110-ton freighter for Itaya Shosen K. K., Tokyo.

12 November 1938:
Launched and named HAKKAI MARU. [1]

21 February 1939:
Completed and placed in service by Itaya Shosen K. K.

26 March 1941:
Requisitioned by the IJN. Registered in the Sasebo Naval District as an auxiliary salvage and repair vessel.

1 August 1942:
Assigned directly to the Combined Fleet.

12 August 1942:
Sasebo Naval Yard. Completes conversion to a repair ship.

1 September 1942:
Departs Sasebo.

1 October 1942:
Recalled Captain (later Rear Admiral) Yokoyama Tokujiro (36)(former CO of KAKO) assumes command.

27-31 October 1942:
Rabaul. Provides repairs for destroyer AKIZUKI damaged in her engineering spaces by a near-miss bomb off Guadalcanal on 25 Oct '42.

7-18 April 1943:
Rabaul. Provides repairs for destroyer KAZAGUMO that struck a mine in Kahili Bay, Bougainville on 3 Apr '43.

26 May 1943:
At 1700, HAKKAI MARU departs Truk by the north channel for Yokosuka in convoy No. 4526 consisting of fleet oiler NOTORO escorted by kaibokan OKI, minelayer TOKIWA and minesweeper W-8. After the convoy is at sea, W-8 returns to Truk and aircraft transport MOGAMIGAWA MARU joins the convoy.

29 May 1943:
Convoy No. 4526 departs Saipan escorted by subchaser CH-11.

3 June 1943:
In the late afternoon, LtCdr Nicholas J. Nicholas' USS SALMON (SS-182) attacks the convoy. He fires seven torpedoes and claims hits on HAKKAI and MOGAMIGAWA MARUs, but in reality his attacks are unsuccessful.

5 June 1943:
Arrives at Yokosuka. Fitted with defensive arnament and engine maintenance works undertaken. Electrically powered sounding sonar and searchlights and six 13mm AA guns are installed.

11 June 1943:
Enters dock.

14 June 1943:
Undocked.

15 June 1943:
Departs Yokosuka escorted by destroyer NAMIKAZE.

19 June 1943:
At 1900, arrives at Ominato.

20 June 1943:
Departs Ominato in an unnumbered convoy consisting of HAKKAI, TERUKAWA and AKASHISAN MARUs and fleet supply ship SHIRASAKI escorted by destroyers HATSUSHIMO and WAKABA.

23 June 1943:
Arrives at Paramushiro, Kuriles.

25 June 1943:
Captain Yokoyama is relieved by an unknown officer.

1 July 1943:
Paramushiro. Provides repairs for destroyers HIBIKI and HATSUSHIMO.

2 July 1943:
Paramushiro. Provides repairs for destroyers NAGANAMI and YUGUMO.

4 July 1943:
Repairs are completed. Provides repairs for destroyer SAMIDARE.

5 July 1943:
Repairs are completed.

30 July 1943:
Paramushiro. Provides repairs for destroyer WAKABA that collided with destroyer HATSUSHIMO on 26 July.

31 July 1943:
Repairs are completed.

3 August 1943:
Paramushiro. Provides repairs for destroyer HATSUSHIMO that collided with destroyer WAKABA on 26 July.

4 August 1943:
Repairs are completed.

5 August 1943:
Paramushiro. Provides repairs for damaged kaibokan KUNASHIRI that collided with light cruiser ABUKUMA on 26 July.

28 August 1943:
At 1500, HAKKAI MARU departs Paramushiro Island with AKASHISAN MARU escorted by destroyer WAKABA.

1 September 1943:
Arrives at Ominato.

8 September 1943:
Captain (Rear Admiral, posthumously) Morino Sorokuro (40)(former CO of ASAHI) assumes command.

21 September 1943:
At 1300, HAKKAI MARU departs Tokyo Bay for Truk in convoy No. 3921 consisting of KIKUKAWA, HIYOSHI, MUTSUYO (BOKUYO), HARUNA, KAIKO and TAIAN MARUs and NANKAI MARU No. 2 and MIKAGE MARU No. 18 escorted by kaibokan OKI and FUKUE.

28 September 1943:
SW of Anatahan Island, Marianas. At 0715, TAIAN MARU is detached for Saipan escorted by auxiliary minesweeper FUMI MARU No. 2 and auxiliary subchaser KYO MARU No. 10 that steamed out to meet her. At 1422, LtCdr (later Rear Admiral) William S. Post's USS GUDGEON (SS-211) torpedoes and sinks TAIAN MARU. The two escorts drop 17 depth charges unsuccessfully.

1 October 1943:
Convoy No. 3921 arrives at Truk.

1 October -9 November 1943:
Truk. Provides repairs for bomb-damaged ammunition supply ship KIKUKAWA MARU.

4 October 1943:
Truk. Provides repairs for transport OKITSU MARU.

6 October 1943:
Repairs are completed.

7 October 1943:
Truk. Provides salvage efforts on KIKUKAWA MARU after the ammunition ship caught fire.

19 October 1943:
Provides repairs for transport YAMASHIMO MARU.

8 November 1943:
Captain (Rear Admiral, posthumously) Inose Masamichi (40)(former CO of IWATE) assumes command.

9 November 1943:
Departs Truk with NICHII MARU.

12 November 1943:
Arrives at Rabaul.

21 November 1943:
Provides repairs on water carrier KOAN MARU.

28 November 1943:
Provides further repairs on KOAN MARU.

17 January 1944:
Rabaul. Twenty-nine USN "Dauntless" SBD dive-bombers and 18 TBF "Avenger" torpedo-bombers escorted by P-38 “Lightning” fighter-bombers of the 44th and 339th Fighter Squadrons and RNZAF Vought F4U "Corsair" fighter-bombers of No. 15 Fighter Squadron, all from Cape Torokina, Bougainville, bomb shipping in Simpson harbor.

At 1055, HAKKAI MARU is hit in the engine room by a torpedo. She floods and sinks by the stern at about noon at 04-13S, 152-15E. HAKKAI MARU comes to rest upright, with her stern in 80 feet of water and the bridge in 100 feet. 25 crewmen are KIA.

The planes also sink transport KENSHIN MARU and army cargo ship KOSEI MARU and damage aircraft transport LYONS MARU. Eight P-38’s are lost in the raid.

10 March 1944:
Removed from the Navy List.

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Authors' Notes:
[1] Also known as HACHIKAI MARU.

- Bob Hackett, Sander Kingsepp and Peter Cundall

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