ZATSUYOSEN!

(OKITSU MARU prewar)

IJN OKITSU MARU:
Tabular Record of Movement


© 2011-14 Gilbert Casse, Bob Hackett and Peter Cundall

Revision 2


25 August 1938:
Aioi. Laid down by Harima Zosensho K.K. shipyard as a 6,666-ton passenger/cargo ship for Nippon Yusen K.K., Tokyo.

9 August 1939:
Launched and named OKITSU MARU.

15 October 1939:
Completed. Her registered port is Tokyo.

22 October 1939:
Departs Yokohama on her first voyage for Calcutta, India.

E November 1939:
Arrives at Calcutta.

2 May 1941:
Departs Kobe on her fifth voyage for Bombay (now Mumbai), India.

E May 1941:
Arrives at Bombay.

16 August 1941:
NYK is notified that OKITSU MARU soon will be requisitioned under secret war preparation instruction No. 74.

31 August 1941:
Departs Pusan (Busan), Chosen (now S Korea).

2 September 1941:
Arrives at Rashin (Najin), Chosen.

3 September 1941:
Departs Rashin and later that day arrives at Seishin (Chongjin), Chosen.

5 September 1941:
Requisitioned by the IJN as a transport (Ippan Choyosen). [1]

7 September 1941:
Departs Seishin.

11 September 1941:
Arrives at Moji and departs later that day for Kure.

12 September 1941:
Arrives at Kure then transfers to nearby Hiroshima. Begins conversion to an auxiliary transport at Mukaijima Dock K.K. shipyard.

20 September 1941:
Registered in the IJN under internal order No. 1093 and attached to the Kure Naval District. Her home port is Kure.

22 October 1941:
The conversion is completed.

1 December 1941:
Attached to Combined Fleet as an auxiliary transport, (Ko) category. [2]

20 December 1941:
Departs Takao for Davao, Mindanao, Philippines.

E December 1941:
Arrives at Davao.

29 December 1941:
Departs Davao in a convoy also consisting of auxiliary transports TOEI and TAITO MARUs, auxiliary aircraft transport LYONS MARU and IJA transport YAMAZUKI MARU escorted by destroyer AMATSUKAZE bound for Takao.

4 January 1942:
Arrives at Takao.

10 January 1942:
Departs Takao.

28 January 1942:
Assigned to refuel IJN Air Force units for the forthcoming operations S of Java, N.E.I.

1 February 1942:
Balikpapan, Borneo. OKITSU MARU is lightly damaged during an airstrike and undergoes emergency repairs.

20 February 1942:
Departs Balikpapan for Makassar, Celebes.

22 February 1942:
Arrives at Makassar. Later, departs for Bali, N.EI.

24 February 1942:
About 120 nms NE Bali. LtCdr Kenneth C. Hurd’s (USNA ’25) USS SEAL (SS-183) sights the transport. At 0500, Hurd torpedoes and scores one hit on OKITSU MARU at 06-45S, 117-24E. However, the unreliable Mark 14 torpedo is a dud and OKITSU MARU resumes her course, arriving at Bali later that same day.

1 March 1942:
Currently assigned to supply IJN Air Force units in the southern area.

5 March 1942:
Assigned to transport IJN Air Force Base personnel in the southern area.

8 March 1942:
Departs Bali for Kupang, Timor, N.E.I.

11 March 1942:
Arrives at Kupang.

20 March 1942:
Departs Kupang for Makassar.

23 March 1942:
Arrives at Makassar.

30 March 1942:
Departs Makassar for Takao.

9 April 1942:
Arrives at Takao.

10 April 1942:
Assigned to transport IJN Air Force base personnel under a secret military order.

16 April 1942:
Departs Takao for Kendari, Celebes.

21 April 1942:
Arrives at Kendari.

9 May 1942:
Departs Kendari for Davao.

14 May 1942:
Arrives at Davao.

27 May 1942:
Departs Davao for Cebu, Philippines.

30 May 1942:
Arrives at Cebu.

7 June 1942:
Departs Cebu for Takao.

11 June 1942:
Arrives at Takao.

18 June 1942:
Departs Takao arriving later that day at Mako, Pescadores.

19 June 1942:
Departs Mako for Osaka in convoy No. 224 also consisting of SHIROGANE, KIRIHA, REKIZAN, TOYOOKA MARUs and nine unidentified merchant ships escorted by auxiliary gunboat PEKING MARU.

24 June 1942:
SHIROGANE MARU is detached for Sasebo. Later that day the rest of the convoy arrives at Moji.

25 June 1942:
Arrives outside Osaka Port. IJN Captain (Rear Admiral posthumously) Shimizu Ryutaro (36) is assigned CO (til 28 Nov ‘43).

26 June 1942:
Departs Osaka area for Kure.

27 June 1942:
Arrives at Kure.

28 June 1942:
IJN Captain Yoshida disembarks.

2 July 1942:
Captain Shimizu embarks. Departs Kure for Osaka.

3 July 1942:
Arrives at Osaka.

4 July 1942:
Innoshima. Enters dock at Osaka Iron Works for maintenance and repairs.

11 July 1942:
Undocked.

13 July 1942:
Departs Osaka for Kure.

14 July 1942:
Arrives at Kure. Later, enters dock at the Navy arsenal for new equipment and armament fittings.

3 August 1942:
Undocked.

5 August 1942:
Departs Kure for Miike.

6 August 1942:
Arrives at Miike.

8 August 1942:
Departs Miike and arrives later that day at Sasebo to complete her refit.

E August 1942:
The refit is completed.

20 August 1942:
Departs Sasebo for Shanghai, China.

22 August 1942:
Arrives at Shanghai.

25 August 1942:
Departs Shanghai for Sasebo.

29 August 1942:
Arrives at Sasebo. Docks later for hull repairs.

12 September 1942:
Undocked. Departs Sasebo for the Solomons area, transporting the 16th quartering party escorted by auxiliary minelayer MA-4 and auxiliary gunboat TOMITSU MARU.

E 14 September 1942:
At 27N, escorts are detached and OKITSU MARU proceeds alone.

20 September 1942:
About 65 nms S New Britain. LtCdr Marvin G.Kennedy’s (USNA ’29) USS WAHOO (SS-238) sights the transport. At 0000, Kennedy torpedoes and scores one hit on OKITSU MARU at 07-45N, 150-34E. The torpedo, another Mark 14, is probably a dud and OKITSU MARU resumes her course to Truk, Carolines.

21 September 1942:
Arrives at Truk.

22 September 1942:
Departs Truk for Buin, Bougainville, Solomons.

26 September 1942:
Arrives at Buin anchorage.

6 October 1942:
Departs Buin for Truk.

10 October 1942:
Arrives at Truk.

15 October 1942:
Departs Truk for Yokosuka possibly with SHOJU MARU (the latter as far as Saipan only).

24 October 1942:
Arrives at Yokosuka.

15 November 1942:
Departs Truk in a convoy also consisting of SHOJU and KITAKAMI MARUs escorted by auxiliary gunboat CHOUN MARU.

16 November 1942:
At 9-15N 152-07 CHOUN MARU is detached from the convoy.

11 December 1942:
Departs Tokyo.

13 February 1942:
Departs Shimoda, Shizuoka Prefecture.

24 February 1943:
Arrives at Chichi Jima, Ogasawara Gunto (Bonins).

1 March 1943:
Departs Chichi Jima for Yokosuka.

4 March 1943:
Arrives at Yokosuka.

14 March 1943:
Assigned to the Inner South Seas Forces.

E March 1943:
Departs Tarawa for Makin, Gilberts.

23 March 1943:
Arrives at Makin. Departs later for Tokyo.

3 April 1943:
Arrives at Tokyo. Transfers later to Yokosuka.

14 April 1943:
Departs Yokosuka and waits at anchor in Tokyo Bay.

15 April 1943:
Departs Tokyo in a convoy also consisting of SHINSEI MARU No.18 escorted by minesweeper W-3.

11 May 1943:
Departs Truk for Kwajalein, Marshalls in a convoy also consisting of ASAYAMA (CHOZAN) MARU and possibly others.

16 May 1943:
Arrives at Kwajalein.

20 May 1943:
Departs Kwajalein for Roi-Namur, Marshalls.

21 May 1943:
At 0630 departs towing IRO to Jaluit, Marshalls. The ships are escorted by destroyer OITE, submarine chaser CH-31 and auxiliary sub-chaser TAMA MARU No. 5.

23 May 1943:
Departs Jaluit towing Fleet oiler IRO, in damaged condition after having been torpedoed in Feb ’43, with destroyer OITE and subchaser CH-31 as escorts.

E 30 May 1943:
The convoy arrives at Saipan, Marianas.

1 June 1943:
The convoy departs Saipan for Kure with an auxiliary netlayer as an additional escort that returns to Saipan the following day.

10 June 1943:
SE of Fuka Island, Oita Prefecture. At about 0500, IRO, still under tow, is hit by two of four torpedoes fired by LtCdr (later Rear Admiral) Lawrence R. Daspit's' (USNA ’27) USS TINOSA (SS-283) at 31-14N, 132-44E. IRO sustains some flooding, but continues under tow. OKITSU MARU is undamaged.

Auxiliary minesweepers TAKUNAN MARU No. 3 and TAKUNAN MARU No. 8 join as additional escorts at 31-52N, 132-25E.

12 June 1943:
The convoy finally arrives at Kure. The tow of some 4,600 miles has been completed at an average speed of 5-6 knots through treacherous waters. The crew of OKITSU MARU receives deservedly profuse congratulations.

18 June 1943:
OKITSU MARU departs Kure for Tokyo.

21 June 1943:
Arrives at Tokyo. Transfers later to Yokosuka.

2 July 1943:
Departs Yokosuka for the Solomons area.

E July 1943:
Arrives at Truk.

24 July 1943:
Departs Truk for Tokyo in a convoy also consisting of CHIHAYA MARU (ex-Dutch TJISAROEA) escorted by destroyer YUGIRI.

1 August 1943:
Arrives at Tokyo. Transfers later that same day to Yokosuka.

21 August 1943:
Departs Yokosuka for Truk in convoy No. 3821A also consisting of auxiliary transport YAMAFUKU MARU, escorted by kaibokan MUTSURE.

30 August 1943:
At 0700, arrives at Truk.

14 September 1943:
Departs Truk for Rabaul, New Britain in convoy No. 1143 also consisting of MANKO MARU escorted by auxiliary gunboat CHOKO MARU No.2 GO and possibly others.

19 September 1943:
Arrives at Rabaul.

25 September 1943:
Auxiliary stores ship TAKUNAN MARU comes alongside OKITSU MARU and replenishes her with 35-tons of fresh water.

27 September 1943:
At 0600, departs Rabaul for Truk in convoy No.2272 also consisting of fleet supply ship SOYA, IJN requisitioned transport TATSUURA MARU and auxiliary stores ship TAKUNAN MARU, escorted by subchaser CH-30 and auxiliary subchaser CHa-12.

28 September 1943:
TAKUNAN MARU has engine trouble and straggles from the convoy.

29 September 1943:
TAKUNAN MARU rejoins the convoy.

30 September 1943:
At 0530, TATSUURA MARU loses power and is left behind with CHa-12 in attendance.

1 October 1943:
At 1200, both TATSUURA MARU and CHa-12 rejoin the convoy. That same day, OKITSU MARU is shifted from (Ko) to (Otsu) category. [2]

2 October 1943:
At 1000, arrives at Truk.

4 October 1943:
Auxiliary repair ship HAKKAI MARU comes alongside OKITSU MARU to provide her repairs. (til Oct 6).

9 October 1943:
At 1800, departs Truk for Rabaul in convoy No. 1092 also consisting of tanker TENNAN MARU escorted by subchaser CH-30.

13 October 1943:
Arrives at Rabaul.

23 October 1943:
During an air raid on Rabaul OKITSU MARU is hit by a bomb that penetrated No.6 hold and exploded in the tween deck area. One workman is killed and damage to the upper deck and bulwarks is recorded.

25 October 1943:
Departs Rabaul for Truk in convoy No. 2252 also consisting of auxiliary transport (ex-seaplane tender) KINUGASA MARU, escorted by torpedo boat HIYODORI.

29 October 1943:
At 0700, arrives at South Channel, Truk. Departs later for Saipan.

5 November 1943:
Arrives at Saipan.

10 November 1943:
Departs Saipan for Truk in a convoy also consisting of auxiliary transport AKIBASAN MARU escorted by destroyers ASANAGI and later INAZUMA.

14 November 1943:
About 135 nms ENE Truk. LtCdr (later Cdr) Walter P. Schoeni’s (USNA ‘31) USS APOGON (SS-308) intercepts the convoy. At 0930, Schoeni attacks and torpedoes OKITSU MARU at 08-20N, 154-15E but scores no hits. The convoy resumes its course to Truk.

15 November 1943:
At 1000, arrives at Truk via the south channel.

28 November 1943:
An unknown officer assumes command. Captain Shimizu is later posted CO of auxiliary ammunition ship NICHIRO MARU.

3 January 1944:
Departs Truk for Mortlock Islands, Carolines.

4 January 1944:
Arrives at Mortlock.

14 January 1944:
Departs Mortlock.

E January 1944:
Arrives at Truk.

24 January 1944:
Departs Truk for Eniwetok Atoll, Marshalls, carrying 518 personnel of a Navy Construction Unit and 86 civilian workers, in a convoy also consisting of auxiliary water carrier NIPPO MARU (3763 GRT), escorted by destroyer SUZUKAZE and subchaser CH-33. [3]

26 January 1944:
NW of Ponape, Carolines. LtCdr (later Cdr) George G. Molumphy’s (USNA’31) USS SKIPJACK (SS-184) intercepts the convoy. At 0003, Molumphy fires four torpedoes and scores two hits on SUZUKAZE at 08-51N, 157-10E. The destroyer sinks rapidly with a heavy loss of life. CH-33 commences an unsuccessful search for the submarine, then rescues 22 survivors while OKITSU and NIPPO MARUs clear the area.

About 146 nms N Ponape. USS SKIPJACK continues to track the convoy. At 0400, Molumphy torpedoes and hits OKITSU MARU in her starboard hold No. 4. The transport floods and begins sinking by the stern. Abandon Ship is ordered. At 0425, OKITSU MARU sinks at 09-24N, 157-45E, taking down 169 Navy passengers and seven crewmen.

A torpedo room accident during this attack damages USS SKIPJACK, requiring her to return to Pearl Harbor for repairs where she arrives on 7 Mar.

10 March 1944:
Removed from the Navy List under internal order No. 427.


Authors Notes:
[1] See Zatsuyosen home page for full explanation.
[2] There were two categories of Zatsuyosen. (Ko) category with an IJN Captain as supervisor aboard and (Otsu) category without.
[3] This unit is described in Allied decrypts as No. 221 Pioneer Unit.

Thanks go to Gengoro S. Toda of Japan.

-Gilbert Casse, Bob Hackett and Peter Cundall


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