SOKAITEI!

© 2009-2017 Bob Hackett and Peter Cundall

Revision 5

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1942:
Tokyo. Laid down at Ishikawajima Shipbuilding.

5 April 1943:
Launched and numbered W-29. Tentatively attached to Yokosuka Naval District.

22 October 1943:
Completed and registered in the IJN. Lt (later Lt Cdr) Naito Shigeru is the Commanding Officer.

Until September 1944 the vessel is engaged in convoy escort duties on the north-east Honshu coast covering north and southbound convoys transiting the Iwate and Miyagi Prefectures coastline.

1 June 1944:
At 0956 arrives at Yamada.

2 June 1944:
At 1818 departs Yamada.

3 June 1944:
At 1422 arrives at Yamada.

7 June 1944:
At 0850 departs Yamada and at 1830 arrives at Onagawa.

8 June 1944:
At 0849 departs Onagawa and at 1744 arrives at Yamada.

12 June 1944:
At 0602 departs Yamada and at 1215 arrives back at Yamada.

14 June 1944:
At 1042 departs Yamada and at 1853 arrives back at Yamada.

17 June 1944:
At 0901 departs Yamada and at 1737 arrives back at Yamada.

19 June 1944:
At 1000 departs Yamada. Later takes over escort from W-1 of firstly HACHIJIN and later SAGAMIGAWA MARUs

20 June 1944:
At 1316 arrives at Yamada.

25 June 1944:
At 1109 departs Yamada and escorts convoy No. 1623 and later after handing over the Submarine Chaser CH-42, convoy No. 1624.

27 June 1944:
At 0500 arrives at Yamada.

2 July 1944:
At 0805 departs Yamada. meets up and escorts MIYO MARU.

3 July 1944:
Arrives at Yamada.

6 July 1944:
At 1415 departs Yamada to escort ARAOSAN MARU.

7 July 1944:
At 1046 returns to Yamada.

8 July 1944:
At 1000 departs Yamada and escorts tanker KOSHIN MARU.

9 July 1944:
At 1316 arrives at Onagawa.

10 July 1944:
At 0852 departs Onagawa and later that day at 1540 arrives at Yamada.

17 July 1944:
At 0856 departs Yamada. At 1700 arrives at Onagawa and departs at 1800.

18 July 1944:
Escorts convoy No. 1717.

19 July 1944:
Collides with motor sailboat TORAI MARU at 0736 off Ofunato, with unknown consequences. At 1625 arrives at Yamada.

25 July 1944:
At 1500 departs Yamada and escorts convoy No. 2725, also escorted part way by submarine chaser CH-44.

26 July 1944:
At 1420 arrives at Onagawa.

27 July 1944:
At 0800 departs Onagawa. Later that day at 1500 arrives at Yamada.

30 July 1944:
At 0850 departs Yamada.

31 July 1944:
Arrives at Onagawa.

1 August 1944:
Arrives at Yamada.

4 August 1944:
Departs Yamada.

5 August 1944:
Arrives at Onagawa and departs later that day.

6 August 1944:
Arrives at Yamada.

7 August 1944:
Departs Yamada but returns later that day.

9 August 1944:
Departs Yamada and later takes over escort of KIFUNE MARU from submarine chaser CH-44.

11 August 1944:
Arrives at Yamada.

16 August 1944:
Departs Yamada.

17 August 1944:
Arrives at Yamada.

18 August 1944:
Departs Yamada.

19 August 1944:
Arrives at Yamada.

25 August 1944:
Departs Yamada and then escorts SHORI, YUZUKI and MINAZUKI MARUs consecutively.

26 August 1944:
Arrives at Onagawa.

27 August 1944:
Departs Onagawa and later that day arrives at Yamada.

1 September 1944:
At 0849 departs Yamada but returns to port later that day at 1613.

6 September 1944:
At 1950 departs Yamada and escorts convoy No.2906 southwards.

7 September 1944:
At 1459 arrives at Yamada.

8 September 1943:
At 0803 departs Yamada but returns to port later that day at 1113 with W-3 and W-29.

9 September 1943:
At 0803 departs Yamada with W-1 but both return to port later that day at 1245.

14 September 1944:
At 1446 departs Yamada.

15 September 1944:
At 0927 arrives at Yamada.

20 September 1944:
At 1230 departs Yamada.

21 September 1944:
At 0704 arrives back at Yamada.

24 September 1944:
At 1530 departs Yamada and escorts convoy No. 2920 southwards and then SHUNSEN MARU and tanker FUKUEI MARU No. 12.

25 September 1944:
At 1650 arrives at Yokosuka.

28 September 1944:
At 1200, W-29 departs Yokohama with torpedo boat CHIDORI and auxiliary subchaser SHONAN MARU No. 8 escorting convoy No. 3928 consisting of TAKUNAN MARU and HIYOSHI MARU No. 2. At 1630, anchors at Tateyama.

29 September 1944:
At 1000, departs Tateyama.

1 October 1944:
At 0328, Cdr (later Rear Admiral) Roy M. Davenport's (USNA ’33) USS TREPANG (SS-412), on her first war patrol, torpedoes and sinks supply ship TAKUNAN MARU, loaded with foodstuffs, at 30-30N, 138-27E. One crewman is KIA.

3 October 1944:
At 1400, arrives at Haha Jima, Bonin Islands.

4 October 1944:
Departs Haha Jima with torpedo boat CHIDORI escorting convoy No. 4004B consisting of HIYOSHI MARU No. 2 GO.

8 October 1944:
Arrives at Yokohama and then Yokosuka.

15 October 1944:
Lt Naito is promoted LtCdr.

18 October 1944:
Departs Yokosuka and arrives at Tateyama.

19 October 1944:
W-29, torpedo boat CHIDORI, kaibokan AMAKUSA and destroyer HATAKAZE depart Tateyama escorting convoy No. 3017 consisting of IKUTAGAWA MARU (bound for Hachijo Jima with AMAKUSA and HATAKAZE escorting) and KAIKO MARU and Oil Tanker No. 3998.

23 October 1944:
Arrives at Chichi-Jima. Departs later that day with torpedo boat CHIDORI escorting convoy No. 4023A consisting of KAIKO MARU and Oil Tanker No. 3998.

26 October 1943:
Arrives at Tateyama.

27 October 1943:
Arrives at Yokosuka.

8 November 1944:
Departs Yokosuka with kaibokan AMAKUSA and later that day arrives at Tateyama.

9 November 1944:
W-29, kaibokan AMAKUSA and torpedo boat CHIDORI depart Tateyama escorting convoy No. 3108 consisting of HIYOSHI MARU No. 2 GO (bound for Chichi-Jima and escorted by W-29 and CHIDORI) and JUZAN MARU I GO bound for Haha Jima and escorted by AMAKUSA.

14 November 1944:
Arrives at Chich-Jima.

15 November 1944:
W-29, and torpedo boat CHIDORI depart Chichi-Jima escorting convoy No. 4115 consisting of HIYOSHI MARU No. 2 GO (from Chichi-Jima and escorted by W-29 and CHIDORI) and JUZAN MARU I GO joining up from Haha Jima and escorted by kaibokan AMAKUSA.

19 November 1944:
Arrives at Yokosuka and undergoes repairs for the rest of the month.

3 December 1944:
At 0941 undocked.

6 December 1944:
Repairs are completed.

9 December 1944:
Departs Yokosuka and later that day at 0825 arrives at Tateyama.

12 December 1944:
At 1415, W-29 departs Tateyama with kaibokan CD-6, CD-12 and subchaser CH-42 escorting convoy No. 3209 consisting of JUZAN, YAEI, KAIKO and SHOTO MARUs.

13 December 1944:
At 1136, arrives Hachijo Jima. At 1653, departs port.

16 December 1944:
At 0229, LtCdr Robert R. Williams' (USNA ’34) USS FINBACK (SS-230) torpedoes and sinks JUZAN MARU at 27-24N, 141-44E. 33 crewmen are killed. Williams also fires torpedoes at minesweeper W-29 and subchaser CH-42 for no results, but the escorts do not counter-attack. At 1249, the convoy enters Futami Harbor, Chichi-Jima. Unloading is begun immediately

17 December 1944:
At 1350 W-29 departs Futami with kaibokan CD-6, CD-12 and subchaser CH-42 escorting convoy No. 4217 consisting of YAEI, KAIKO and SHOTO MARUs.

20 December 1944:
Arrives at Hachijo Jima.

21 December 1944:
At 0700, departs Hachijo Jima.

22 December 1944:
At 0314, arrives at Tateyama. Later that day transfers to Yokosuka, arriving at 1420.

26 December 1944:
Transfers from Yokohama to Tateyama, arriving at 0900.

27 December 1944:
At 2300 W-29, submarine chaser CH-42 and kaibokan CD-12 depart Tateyama escorting convoy No. 3226 consisting of YAEI, SHIBAZONO, YONEYAMA MARUs and NANYO MARU No. 1.

31 December 1944:
At 1511 arrives at Chichi-Jima.

1 January 1945:
At 1700, W-29 departs Chichijima with kaibokan CD-12 and subchaser CH-42 escorting convoy No. 4101 consisting of SHIBAZONO, YONEYAMA, YAEI MARUs and NANYO MARU No. 1.

3 January 1945:
At 2030, LtCdr Talbot E. Harper's (USNA ’37) USS KINGFISH (SS-234) torpedoes and sinks cargo ships SHIBAZONO and YAEI MARUs at 30-21N, 142-15E. 57 crewmen on SHIBAZONO MARU and two passengers, two gunners and 27 crewmen on YAEI MARU are killed. CH-42 and CD-12 launch unsuccessful depth charge attacks.

6 January 1945:
At 0151, arrives at Tateyama. At 0918 departs Tateyama and at 1600 arrives at Yokosuka.

13 January 1945:
At 1010 transfers from Yokosuka to Yokohama.

15 January 1945:
At 0200 departs Yokohama and later that day at 1840 arrives at Tateyama.

16 January 1945:
At 1200, W-29 departs Tateyama with kaibokan CD-13 and CD-56 and subchasers CH-42 and CH-47 escorting convoy No. 3115 consisting of Kuretake, YONEYAMA MARUs and NANYO MARU No. 1 and UNYO MARU No. 6.

19 January 1945:
After beating off an air attack at 1046, the convoy arrives at Futami, Chichijima at 1142.

20 January 1945:
At 0013, W-29 departs Futami with kaibokan CD-12 and CD-56 escorting a convoy consisting of KURETAKE MARU and NANYO MARU No. 1.

23 January 1945:
At 0100, arrives at Tateyama.

25 January 1945:
At 0807 departs from Tateyama and later that day at 1325 arrives at Yokosuka.

31 January 1945:
At 0807 departs from Yokosuka with kaibokan CD-12 escorting convoy 3131 consisting of RYUJIN MARU and an unidentified merchant ship (name ending San/Yama). Later that day arrives at Tateyama

February 1945:
Lt Udono Fumio assumes command.

1 February 1945:
At 0300 departs Tateyama with auxiliary submarine chaser TAKUNAN MARU No. 2 as an additional escort.

4 February 1945:
At 0740 arrives at Chichi Jima.

5 February 1945:
Off Chichi Jima. W-29 is damaged by mine.

2 April 1945:
At 1400 arrives at Sasebo.

17 April 1945:
Off Shanghai. Cargo ship SONJO MARU (ex-Chinese CHUEN TIAO) strikes a mine laid by USAAF 20th Air Force B-29's and sinks at 31-13N, 121-52 E. Five troops and 18 crewmen are killed.

At 1800, USN codebreakers intercept and decrypt a message from W-29 that reads: “At 1749, SONJO MARU sank at Middle Ground."

26 April 1945:
Coast of China. At 0755, W-29 departs Shishiyosan, E of Shanghai, for Moji with destroyer ASAGAO, patrol boat PB-102 (ex-USS STEWART, DD-224), kaibokan UKU and CD-26 and subchaser CH-20 escorting convoy SHIMO-03 consisting of KASHIMA, BANSHU, ABUKUMAGAWA, SHINTON and TAIKYU MARUs and tanker NANRYU MARU No. 9.

27 April 1945:
Convoy SHIMO-03 is attacked by aircraft and unidentified submarine(s). The planes make many attacks and bomb and strafe the convoy. UKU and patrol boat PB-102 are damaged at 34-52N, 124-23E.

S of Japan. Kaibokan YASHIRO, SAKITO and CD-41 join the escort of convoy SHIMO-03.

28 April 1945:
At 1200, arrives at Moji.

1 May 1945:
At 1905 anchors off Yuya Wan with patrol boat PB-102 and tanker NANRYU MARU No. 9.

2 May 1945:
At 0610 the ships depart Yuya Wan and at 1201 arrive at Moji.

7 May 1945:
Kanmon Strait. After beaching mined cargo vessel KASHIMA MARU at 33-54.4N, 135-52E, and while standing by, W-29 strikes a mine and sinks at 34-02N, 130-54E. [1]

8 May 1945 :
At 0025, USN codebreakers intercept and decrypt a message from CO W-29 that reads: “…this vessel struck a mine aft. The after part of the ship (aft of No. 3 hold) broke away and sank. No. 2 boiler room, the engine room and No. 2 hold are flooded. The ship is listing 20 [degrees] to port. Have dropped the main anchor and the ship is steady. Do not believe she will sink.”

W-29 also reports that she has 43 missing, 15 severely wounded.

10 August 1945:
Removed from the Navy List.

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Author's Notes:
No data were found by the authors on W-29's movements during Nov '43-Sep '44. W-29 may have been used for local escort and mineweeping duties in home waters during that time. Readers with access to such data are requested to post the information on the Discussion and Questions board or at j-aircraft.org's IJN Ship Message Board.

[1] The mines were laid in Shimonoseki Strait by USAAF B-29s.

Thanks go to Matthew Jones for help in identifying COs. Thanks also go to John Whitman for info on USN intercepts of Japanese messages and to Mr. Sander Kingsepp of Estonia and Mr. Gilbert Casse of France for general assistance.

Photo credit goes to Gakken via J. Ed Low.

-Bob Hackett and Peter Cundall.

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