KOSAKUKAN!

© 2008-2018 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 general transport.

8 December 1941:
Departs Moji and later that day arrives at Tokuyama.

12 December 1941:
Departs Tokuyama.

13 December 1941:
Arrives at Sasebo.

17 December 1941:
Departs Sasebo.

20 December 1941:
Arrives at Takao.

24 December 1941:
Departs Takao and later that day arrives at Mako.

31 December 1941:
Departs Mako.

2 January 1942:
At 1120 arrives at Sana (Samah).

6 January 1942:
At 1015 departs Sana.

7 January 1942:
At 1555 arrives at Camranh Bay.

8 January 1942:
At 1555 departs Camranh Bay.

9 January 1942:
At 1700 arrives at Saigon.

12 January 1942:
At 1015 departs Saigon.

16 January 1942:
At 1145 arrives at Sana.

18 January 1942:
At 0820 departs Sana and later that day at 0950 arrives at Yulin.

22 January 1942:
At 1950 departs Yulin.

25 January 1942:
At 0735 arrives at Takao.

26 January 1942:
At 1800 departs Takao.

30 January 1942:
At 1140 arrives at Yawata.

31 January 1942:
At 1655 departs Yawata.

1 February 1942:
At 1420 arrives at Sasebo.

2 – 7 February 1942:
Supplied with 500t of heavy oil. Embarks 229 staff for Takao, 24 passengers for Camranh and a further 86 passengers. Loads 4 reconnaissance seaplanes, 1200t aviation weapons, 400t volatile oil in drums, 230t aviation oil, 600t weapons and munitions, 96t oil in drums, 110t munitions, 950 bombs, 4 fighter aircraft, 100t oil, empty drums and 700t militairy supplies and sundries.

8 February 1942:
At 1350 departs Sasebo.

11 February 1942:
At 1250 arrives at Takao.

17 February 1942:
At 0820 departs Takao.

20 February 1942:
At 0935 arrives at Camranh Bay.

21 February 1942:
At 2010 departs Camranh Bay.

23 February 1942:
At 1235 arrives at Saigon.

4 March 1942:
At 1630 departs Saigon.

9 March 1942:
At 0125 arrives at Takao and departs later the same day at 1625, apparently with MANSHU MARU.

10 March 1942:
Missed by three torpedoes in position 28-11N, 122-10E.

13 March 1942:
At 1120 arrives at Shimonoseki.

17 March 1942:
At 1600 transfers from Shimonoseki to nearby Yawata, arriving at 1810.

20 March 1942:
At 0750 departs Yawata.

21 March 1942:
At 1030 arrives at Sasebo.

26 March 1942:
At 1400 departs Sasebo.

30 March 1942:
At 0800 arrives At Takao.

6 April 1942:
At 1205 departs Takao.

9 April 1942:
At 1705 arrives at Sasebo.

10 April 1942:
At 1400 departs Sasebo.

11 April 1942:
At 0905 arrives at Moji.

13 April 1942:
At 1615 departs Moji.

14 April 1942:
At 1800 arrives at Miike.

15 April 1942:
At 1020 departs Miike.

16 April 1942:
At 1135 arrives at Tokuyama.

17 April 1942:
At 1610 departs Tokuyama.

18 April 1942:
At 0635 arrives at Kure.

23 April 1942:
At 1815 departs Kure.

2 May 1942:
At 1220 arrives at Ambon.

6 May 1942:
DAt 1620 departs Ambon and later that day at 1745 arrives at Laha.

9 May 1942:
At 1725 departs Laha.

13 May 1942:
At 1310 arrives at Surabaya.

22 May 1942:
At 1525 departs Surabaya.

27 May 1942:
At 1325 arrives at St Jacques.

28 May 1942:
At 0720 departs St Jacques.

31 May 1942:
Arrives at Hongay.

3 June 1942:
At 1505 departs Hongay and later that day at 1715 arrives at Port Campha.

5 June 1942:
At 1855 departs Campha.

8 June 1942:
At 1150 arrives at Mako.

10 June 1942:
At 1235 departs Mako in convoy No. 221 consisting of HAKKAI MARU and four unidentified merchant ships escorted by minelayers HOKO and SOKUTEN.

15 June 1942:
Arrives at Moji and then departs port and later that day at 2205 arrives at Fushiki.

18 June 1942:
At 1010 departs Fushiki.

20 June 1942:
At 0840 arrives at Moji.

21 June 1942:
At 1630 departs Moji and later that day at 1950 arrives at Sasebo.

24 June 1942:
Off-hire as general transport and soon after begins conversion to a repair ship.

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.

2 October 1942:
In Rabaul anchorage. At 1348 commences repairs on damaged light cruiser TENRYU.

Mid October 1942:
At Rabaul. Undertakes repairs of auxiliary seaplane tender KIYOKAWA MARU damaged on 11 October by a direct hit on the engine room on the north side of Buka Island (arrived Rabaul 14 October).

20 October 1942:
Completed repairs on damaged light cruiser TENRYU.

22 October 1942:
Rabaul. Provides emergency repairs for ammunition ship ONOE MARU, torpedoed and damaged by LtCdr Edward C. Stephan’s (USNA ’29) USS GRAYBACK (SS-208) that same day.

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.

26-30 December 1942:
At Rabaul repaired damaged transport KAGU MARU.

29-30 December 1942:
At Rabaul repaired damaged transport NANKAI MARU.

6 January 1943:
At Rabaul repairs of damaged NANKAI MARU were resumed.

12 January 1943:
Repairs on NANKAI MARU completed and vessel underwent trials.

24 February 1943:
At Rabaul repaired damaged aircraft transport KEIYO MARU.

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

21 May 1943:
Departs Rabaul in convoy No. 2152 also consisting of NARUTO MARU escorted by submarine chaser CH-32.

25 May 1943:
Arrives at Truk.

26 May 1943:
At 1700, HAKKAI MARU departs Truk by the north channel for Yokosuka in convoy No. 4526 consisting of transport NOTO MARU 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 at 1654, LtCdr Nicholas J. Nicholas' (USNA ’32) 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:
At 0700 arrives at Yokosuka. Fitted with defensive armament and engine maintenance works undertaken. Electrically powered sounding sonar and searchlights and six 13mm AA guns are installed.

11 June 1943:
Enters dock No.2.

14 June 1943:
Undocked.

15 June 1943:
At 1300 departs Yokosuka escorted by destroyer NAMIKAZE.

19 June 1943:
At 1330, arrives at Ominato. At 1730 departs Ominato in an unnumbered convoy consisting of HAKKAI, TERUKAWA and AKASHISAN MARUs and fleet supply ship SHIRASAKI escorted by destroyers HATSUSHIMO and WAKABA. The ships sail at 11 knots.

23 June 1943:
At 1200 arrives at Paramushiro, Kuriles. Undertakes repairs of equipment on submarine tender HEIAN MARU.

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. Completes repairs on destroyers HIBIKI and HATSUSHIMO. Provides repairs for destroyers NAGANAMI and YUGUMO.

3 July 1943:
Continues repairs of destroyer NAGANAMI.

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.

2-3 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.

7 August 1943:
Repairs are completed.

20 August 1943:
Comes nearby AKASHISAN MARU, which at 0630 ran aground in the vicinity of Shiomizaki, Shimushiro Jima, Kuriles. Proceeds to a full inspection of the damage. Hull is patched and unloading is carried out. Auxiliary minesweeper AOI MARU comes alongside and pumps out oil to ease AKASHISAN MARU.

At 1900, both fishing-boat YONEYAMA MARU at the bow, and small tanker HINODE MARU (321 GRT) at the stern, drag the stranded transport. At 2010, AKASHISAN MARU is finally refloated. Arrives later this day at Paramushiro.

22 August 1943:
Paramushiro. Provides urgent repairs for AKASHISAN MARU that ran aground off Shiomisaki, Shimushiro Jima on 20 August.

22 – 27 August 1943:
Kataoka Wan (Bay). Auxiliary repair ship HAKKAI MARU proceeds to emergency repairs to AKASHISAN MARU’s hull.

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

1 September 1943:
Arrives at Ominato.

2 September 1943:
Departs Ominato escorted by destroyer WAKABA.

5 September 1943:
Arrives at Yokosuka.

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, HAKKAI, YAMAKUNI and TAIAN MARUs and NANKAI MARU No. 2 and MIKAGE MARU No. 18 escorted by kaibokan OKI and FUKUE. Later this day the convoy arrives at Tateyama.

22 September 1943:
At 0430, convoy No. 3921 departs Tateyama with minesweeper W-27 as additional escort.

23 September 1943:
At 2130, W-27 detaches and returns to Tateyama.

E September 1943:
At some point, NANKAI MARU No. 2 probably encounters some mechanical trouble and returns back to Japan.

27 September 1943:
Requisitioned (B-AK) YAMAKUNI MARU departs Saipan to join the convoy escorted by auxiliary subchaser KYO MARU No. 10 and auxiliary minesweeper SEKI MARU No. 3.

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 (USNA ’30) USS GUDGEON (SS-211) torpedoes and sinks TAIAN MARU transporting 106 passengers, 2,867-tons of cargo and 1,400kg of mail parcels. 46 passengers and 14 crewmen are KIA. The two escorts drop 17 depth charges unsuccessfully.

1 October 1943:
At 1400 Convoy No. 3921 arrives at Truk.

4 October 1943:
Truk. At 1217 provides repairs for transport OKITSU MARU.

6 October 1943:
Repairs are completed.

7 October 1943:
Truk. Provides salvage efforts on KIKUKAWA MARU at Dublon Is anchorage after the ammunition ship caught fire. This continues over several days.

19 October 1943:
At 0740 provides repairs for transport YAMASHIMO MARU.

8 November 1943:
Captain (Rear Admiral, posthumously) Inose Masamichi (40)(former CO of IWATE) assumes command. Attached to the Southeastern Fleet. Transfers from Harushima (Spring Island) anchorage to Natsushima (Dublon Island) anchorage.

9 November 1943:
At 0430 departs Truk for Rabaul in convoy No. 2102 also consisting of transport HIE MARU and Ammunition ship NICHII MARU and allegedly cargo ship KANAYAMASAN MARU escorted by destroyers NOWAKE, MAIKAZE and YAMAGUMO.

11 November 1943:
At 0512 190 miles NNW of Kavieng, New Ireland. LtCdr (later Captain) Delbert F. Williamson's (USNA ’27) USS DRUM (SS-228) is on patrol between the Carolines and New Ireland to intercept expected Japanese reinforcements during the forthcoming invasion of Tarawa. Alerted by an Ultra message, Williamson sights a convoy, sets up and fires six Mark-14 steam torpedoes at HIE MARU at 01-00N, 149-20E. The first torpedo explodes prematurely. Transport KANAYAMASAN MARU reports three torpedo explosions astern. NOWAKE counterattacks unsuccessfully. The convoy suffers no damage in the attack.

At 1029 that day, a USAAF Fifth Air Force B-24 "Liberator" bombs the convoy and damages HIE MARU. 31 crew and passengers are KIA, 28 badly wounded, 110 lightly wounded.

12 November 1943:
At 1645 the convoy and damaged HIE MARU make port at Rabaul.

16 November 1943:
At Rabaul provides urgent repairs to transport HAKUSAN MARU, which had been damaged in low-level air attack on 2 November.

20 November 1943:
Personnel from HAKKAI MARU undertakes survey of wreck of RYUOSAN MARU at Kavieng. HAKKAI MARU remains at Rabaul.

21 November 1943:
From 0735-0940 takes on fresh water from water carrier KOAN MARU.

23 November 1943:
Personnel undertake further surveys of RYUOSAN MARU and survey ship TSUKUSHI wrecks at Kavieng.

28 November 1943:
From 0840-1150 takes on fresh water from KOAN MARU.

1 December 1943:
Rabaul. Provides repairs for minesweeper W-26. Hull repair preparatory work starts.

During the month at unknown dates undertakes repairs on TAISHO MARU (which continue into early January) and EIFUKU MARU.

6 December 1943:
Hull repair preparatory work ends.

7 December 1943:
Undertakes survey of damaged places on W-26.

10 December 1943:
Survey of damaged places is finished.

11 December 1943:
Work starts to drain flooded sections and to reinforce cracked upper deck of W-26.

22 December 1943:
Work starts to get access to the blocked and drained No.2 boiler room of W-26.

24 December 1943:
Repair of W-26’s 25mm MG starts.

27 December 1943:
No.1 cutter is repaired.

28 December 1943:
Repair of W-26’s 25mm MG is finished.

30 December 1943:
Access to No.2 boiler room is achieved.

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. 23 gunners and two crewmen are KIA.

The planes also sink transport KENSHIN MARU (22 crewmen KIA) and army cargo ship KOSEI MARU carrying barges, steel water tanks and general cargo - 14 landing barges were still on board when sunk (two crewmen KIA) 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. Not to be confused with auxiliary gunboat (2921 GRT, ’40).

Thanks go to Toda Gengoro of Japan for information in Revision 1 and to Erich Muehlthaler of Germany for new info on convoy No. 3921 and to Mr. Gilbert Casse of France for general assistance.

Photo credit goes to Gilbert Casse of France.

- Bob Hackett, Sander Kingsepp and Peter Cundall.

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