KOKAI HOKAN!

(KOSHO MARU, prewar – Berend Van der Wal collection)

IJN KOSHO MARU:
Tabular Record of Movement


© 2020 Gilbert Casse, Berend van der Wal and Peter Cundall


15 October 1939:
Osaka. Laid down by Namura Zosensho K.K. shipyard as a 1,365-tons cargo ship, part of the Peacetime Standard Ship Program but to a builders design, for Eguchi Kisen K.K.

9 March 1940:
Launched and named KOSHO MARU. [1]

25 October 1940:
Completed and registered in Tokyo. Her call sign is JNAO.

3 December 1941:
Performs trials.

5 December 1941:
Departs Kure and arrives at Ujina later that day.

10 December 1941:
Registered in the IJN as an auxiliary gunboat attached to the Kure Naval District under instruction No. 1624. Tactically assigned to Vice Admiral Niimi Masachi’s (36) Second China Expeditionary Fleet, 15th Squadron. That same day, Navy (Resv) Lt Oda Kasuo is appointed CO.

13 December 1941:
Begins conversion to military duty at Ujina shipyard.

15 December 1941:
Rated as a South Unit, Patrol Unit.

29 December 1941:
Conversion is completed.

January 1942:
Rated as an Amoy (now Xiamen), China Unit.

6 January 1942:
Departs Kure.

13 January 1942:
Arrives at Amoy.

15 January 1942:
Rated as a Patrol Unit under Amoy Area Command instruction No. 18.

16 January 1942:
Departs Amoy.

17 January 1942:
Arrives at Hunghai Bay, China.

18 ~ 23 January 1942:
Assists salvage of stranded Fleet supply ship NOJIMA. [2]

24 January 1942:
Arrives at Hong Kong and returns to Hunghai Bay later this day.

1 February 1942:
Departs Hong Kong.

5 February 1942:
Arrives at Amoy.

6 February 1942:
Departs Amoy.

11 February 1942:
Arrives at Sasebo.

15 February 1942:
Released from South Unit. Attached to Vice Admiral Ozawa Jisaburo’s (37) First Southern Expeditionary Fleet, 12th Special Base Force based at Port Blair, Andamans.

2 March 1942:
Departs Takao, Formosa (now Kaoshiung, Taiwan).

19 March 1942: Operation U. The transport operation to Burma (now Myanmar):
Departs Singapore with light cruiser KASHII, destroyers SHIKINAMI, ASAKAZE, HARUKAZE, HATAKAZE and MATSUKAZE, kaibokan SHIMUSHU, torpedo boat KARI, minelayer HATSUTAKA, minesweepers W-1, W-3 and W-4, subchasers CH-7 and CH-8, gunboat EIKO MARU, auxiliary subchasers CHOKO MARU, SHONAN MARU No. 5 and SHONAN MARU No. 7 escorting the first Burma transport convoy consisting of AOBASAN, CELEBES, GENOA, GLASGOW, HARUNA, HAVRE, HIBURI, HOFUKU, HOKUMEI, KAZUURA, KIZAN, KOTOHIRA, KUSUYAMA, MOMOYAMA, MYOKO, NAGARA, NAKO, NAPLES, NICHIRAN, SAKITO, SANKO, SHINAI, SHINANOGAWA, SHINRYU, SHUNSEI, SUMATRA, SYDNEY, TATEISHI, TOKIWA, TSUYAMA and YAE MARUs.

20 March 1942:
At Penang (renamed Tojo To by the Japanese), British Malaya (now Malaysia) auxiliary transport NOJIMA MARU joins the convoy.

23 March 1942:
At 1800, arrives with the convoy at Rangoon (now Yangon), Burma.

10 April 1942:
Attached to Vice Admiral Takahashi Ibo’s (36) Southwestern Area Fleet in Vice Admiral Ozawa Jisaburo’s (37) First Southern Expeditionary Fleet, 12th Special Base Force.

April ~ May 1942:
Attached to Southwestern Area Fleet, Malay Force, Rangoon Base Force under Malay Force Order No. 21.

20 May 1942:
Attached to Southwestern Area Fleet, Malay Force, Burma Base Force under Malay Force Order No. 22.

1 June 1942:
At Rangoon.

18 July 1942:
Departs Rangoon with subchaser SHONAN MARU No. 12 escorting IJA transport RASHIN MARU. At an unknown point, escorts are detached.

22 July 1942:
Arrives at Rangoon.

2 August 1942:
Departs Rangoon.

10 August 1942:
Arrives at Rangoon.

15 August 1942:
Departs Rangoon.

19 August 1942:
Arrives at Rangoon.

24 August 1942:
Departs Rangoon.

26 August 1942:
Arrives at Port Blair, Andamans.

27 August 1942:
Departs Port Blair.

29 August 1942:
Arrives at Rangoon.

14 September 1942:
Departs Rangoon.

28 September 1942:
Arrives at Port Blair.

5 October 1942:
Departs Port Blair.

9 October 1942:
Arrives at Port Blair.

15 October 1942:
Departs Port Blair.

17 October 1942:
Arrives at Port Blair.

20 October 1942:
Departs Port Blair.

23 October 1942:
Arrives at Penang.

25 October 1942:
Departs Penang.

29 October 1942:
Arrives at Padang, Sumatra, Netherlands East Indies (now Indonesia).

1 November 1942:
Departs Padang.

4 November 1942:
Arrives at Sabang, Sumatra.

6 November 1942:
Departs Sabang.

8 November 1942:
Arrives at Port Blair.

16 November 1942:
Departs Port Blair.

17 November 1942:
Arrives at Port Blair.

23 November 1942:
Departs Port Blair.

25 November 1942:
Arrives at Sabang.

26 November 1942:
Departs Sabang.

30 November 1942:
Arrives at Singapore.

1 December 1942:
Enters drydock.

10 December 1942:
Navy (Resv) LtCdr Nihei Kou is appointed CO.

24 December 1942:
Departs Singapore.

30 December 1942:
Arrives at Padang. Departs later.

2 January 1943:
Arrives at Rangoon.

6 January 1943:
Departs Rangoon.

9 January 1943:
Arrives at Sabang.

10 January 1943:
Departs Sabang.

12 January 1943:
Arrives at Port Blair.

13 January 1943:
Departs Port Blair.

17 January 1943:
Arrives at Port Blair.

21 January 1943:
Depart Port Blair.

22 January 1943:
Arrives at Rangoon.

26 January 1943:
Departs Rangoon.

28 January 1943:
Arrives at Penang.

30 January 1943:
Departs Penang.

1 February 1943:
Arrives at Port Blair.

2 February 1943:
Departs Port Blair.

4 February 1943:
Arrives at Port Blair.

6 February 1943:
Departs Port Blair.

8 February 1943:
Arrives at Sabang.

11 February 1943:
Departs Sabang.

12 February 1943:
Arrives at Port Blair.

14 February 1943:
Departs Port Blair.

17 February 1943:
Arrives at Penang.

19 February 1943:
Departs Penang and arrives at Malacca, British Malaya later that day.

20 February 1943:
Off Malacca meets up with unidentified ships.

21 ~ 22 February 1943:
Performs a joint exercise.

26 February 1943:
Departs Malacca.

28 February 1943:
Arrives at the Ceder (Cedar) Passage (now Aroih Raya), Atjeh (Aceh), Sumatra and departs there later this day.

29 ~ 31 March 1943:
Assigned to escort duty by 9th Base Force’s Commander.

21 April 1943:
At 07-32N, 97-44E carries out an anti-submarine sweep.

1 July 1943:
Navy (Resv) LtCdr Nihei Kou is confirmed as CO.

3 July 1943:
Arrives at Sabang.

4 July 1943:
Departs Sabang.

6 July 1943:
Arrives at Port Blair.

13 July 1943:
Departs Port Blair escorting auxiliary tranport KUNITSU MARU.

14 July 1943:
Arrives at Car Nicobar, Andamans. Departs there, escorting auxiliary transport KUNITSU MARU later this day.

17 July 1943:
Arrives at Rangoon.

21 July 1943:
At Rangoon. Salvage vessel KAMISHIMA MARU comes alongside KOSHO MARU for unknown reasons.

26 July 1943:
Departs Rangoon escorting auxiliary transport KUNITSU MARU.

28 July 1943:
Arrives at Port Blair.

29 July 1943:
Departs Port Blair escorting auxiliary transport KUNITSU MARU.

30 July 1943:
Arrives at Port Blair with auxiliary transport KUNITSU MARU.

31 July 1943:
Departs Port Blair escorting auxiliary transport KUNITSU MARU. Both return later that day.

28 October 1943:
Rated as a Western Command Supply Unit under Western Command Order No. 5.

1 December 1943:
Her owners are changed to Namura Kisen K.K.

22 May 1944:
At 1043 local time, Lt. John P. Angell’s HMS SEA ROVER (P-218) torpedoes KOSHO MARU at 04-52N, 100-16E off Penang Harbor S entrance. Two of the crew are killed.

Auxiliary subchaser CHa-50 takes KOSHO MARU in tow but the operation ends when the ship sinks.

CHa-50 carries out an anti-submarine sweep.

10 July 1944:
Removed from the Navy’s list under instruction No. 855.


Authors' Notes:
[1] Not to be confused with Std. 2TM Type (2,854 GRT, ’44).

[2] NOJIMA was torpedoed and heavily damaged 27 Dec ’41 by LtCdr David A. Hurt’s (USNA ’25) USS PERCH (SS-176).

Thanks go to Gengoro S. Toda of Japan.

- Gilbert Casse, Berend van der Wal and Peter Cundall.


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