SOKAITEI!

© 2009-2010 Bob Hackett and Peter Cundall

---

1942:
Tokyo. Laid down at Ishikawajima Shipbuilding.

1943:
Launched and numbered W-29.

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

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 USS TREPANG (SS-412), on her first war patrol, torpedoes and sinks supply ship TAKUNAN MARU at 30-30N, 138-27E.

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

15 October 1944:
Lt Naito is promoted LtCdr.

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 JUSAN, 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' USS FINBACK (SS-230) torpedoes and sinks JUSAN MARU at 27-24N, 141-44E. At 1249, the convoy arrives at Futami, Chichijima.

17 December 1944:
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.

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 and NANYO MARUs.

3 January 1945:
At 2030, LtCdr Talbot E. Harper's USS KINGFISH (SS-234) torpedoes and sinks cargo ships SHIBAZONO and YAEI MARUs at 30-21N, 142-15E.

6 January 1945:
At 0918, 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 and NANYO MARUs and UNYO MARU No. 6.

19 January 1945:
After beating off an air attack at 1046, the convoy arrives 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 and NANYO MARUs.

23 January 1945:
At 0100, arrives at Tateyama.

February 1945:
Lt Udono Fumio assumes command.

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

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.

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 P-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.

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.

---

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.

Photo credit goes to Gakken via J. Ed Low.

-Bob Hackett and Peter Cundall.

---

Back to the Minesweeper Page