SOKAITEI!

(W-7 class minesweeper scanned from SOTW, V. 507)

IJN Minesweeper W-11:
Tabular Record of Movement

© 2005-2013 Bob Hackett and Peter Cundall

Revision 6


30 May 1937:
Tokyo. Laid down at Uraga Dockyard.

28 December 1938:
Launched and numbered W-11.

15 July 1939:
Completed and commissioned in the IJN at the Sasebo Naval District.

1 June 1941:
W-11 is assigned to Third Fleet's 1st Base Force in MineSweepDiv 21 with W-7, W-8, W-9, W-10 and W-12.

21 September 1941:
Lt Imamura Kiyoshi (61) assumes command.

21 September 1941:
Cdr (Rear Admiral, posthumously) Kitamura Masayuki (45) assumes command of MineSweepDiv 21.

28 November 1941:
Departs Yokosuka.

3 December 1941:
Arrives at Mako, Pescadores.

7 December 1941:
Departs Mako. Escorts an invasion convoy.

17 December 1941:
Departs Amami O-Shima. Escorts a convoy to Lamon Bay and Davao, Philippines.

9 January 1942: Operation "H" - The Invasion of Celebes, Netherlands East Indies:
MineSweepDiv 21's W-11, W-7, W-8, W-9 and W-12 depart Davao in Rear Admiral Kubo Kyuji's (38) 1st Base Force with light cruiser NAGARA, SubChasDiv 1's CH-1, CH-2, CH-3 and patrol boats PB-1, PB-2 and PB-34 escorting eight transports carrying Captain (later Vice Admiral) Mori Kunizo's (40)(former CO of SATA) Sasebo No. 1 Combined Special Naval Landing Force (SNLF).

21 January 1942:
Escorts the Kendari invasion convoy and conducts minesweeping.

23-24 January 1942: The Invasion of Kendari, Celebes:
MineSweepDiv 21’s W-11, W-7, W-8, W-9 and W-12, DesRon 10’s light cruiser NAGARA, DesDiv 15’s HAYASHIO, KUROSHIO, OYASHIO and NATSUSHIO, DesDiv 16’s TOKITSUKAZE, HATSUKAZE, AMATSUKAZE and YUKIKAZE, and Subchaser Div 1’s CH-1 and CH-2 escort Rear Admiral Kubo’s Kendari Invasion Force under consisting of six troop transports carrying Captain (later Vice Admiral) Mori Kunizo’s Sasebo Combined Special Naval Landing Force (SNLF). The 11th Seaplane Tender Division’s CHITOSE and MIZUHO provide distant support.

29 January 1942:
Departs Kendari. Escorts the Ambon, invasion convoy.

31 January 1942: The Invasion of Ambon Island, Netherlands East Indies:
MineSweepDiv 21, including W-11, SubChasDiv 1 and patrol boats PB-34 and PB-39 escort the invasion convoy that includes ten transports carrying 820 men of Rear Admiral (later Vice Admiral) Hatakeyama Kouichiro's (39) (former CO of KINUGASA) Kure No. 1 SNLF, elements of the Sasebo SNLF and the 228th Infantry Regiment.

Additional escort is provided by Rear Admiral (later Vice Admiral) Tanaka Raizo's (41) light cruiser JINTSU, DesDiv 8, DesDiv 15 and DesDiv 16. Cover is provided by CruDiv 5's NACHI and HAGURO, DesDiv 6's IKAZUCHI and DesDiv 7's USHIO and SAZANAMI. Air cover is provided by CarDiv 11's MIZUHO and CHITOSE.

2 February 1942:
Ambon Bay. While minesweeping, Lt Imamura's W-11 sets off a mine that damages her stern. That same day, Rear Admiral Hatakeyama's troops capture Laha airfield. A few days later, Hatakeyama orders the execution of Dutch and Australian POWs. [1]

10 March 1942:
Surabaya, Java. W-11 is assigned to the 2nd Southern Expeditionary Fleet's Special Base Force 21 with W-8 and W-12. That same day, she completes repairs.

20 April 1942:
At 0700 departs Ambon with W-12. Escorts convoys.

21 April 1942:
At 1240 W-11 and W-12 arrive at Kendari and depart at 1440.

24 April 1942:
At 1600 W-11 and W-12 arrive at Surabaya, Java and from there escorts convoys .

30 June 1942:
Lt Hirano Yorozu assumes command.

17 July 1942:
Departs Surabaya.

5 August 1942:
Arrives at Sasebo. Drydocked. Undergoes battle-damage repairs.

24 October 1942:
Undocked.

28 November 1942:
Departs Sasebo for Surabaya.

8 December 1942:
CH-2 departs Surabaya with minesweeper W-11 and auxiliary gunboat OKUYO MARU escorting the Oki convoy consisting of an unidentified number of merchant ships.

13 December 1942:
Minesweeper W-11 is detached.

14 December 1942:
Subchaser CH-2 is detached.

15 December 1942:
Subchaser CH-20 joins convoy.

18 December 1942:
Subchaser CH-18 joins convoy and CH-20 is detached.

22 December 1942:
An unknown submarine attacks the convoy. OKUYO MARU drops three depth charges. Later that day, the convoy arrives at Rabaul.

27 December 1942:
Arrives at Surabaya.

7 January 1943:
Early am departs Surabaya escorting TAMISHIMA MARU to Kupang, Timor.

12 January 1943:
Late evening arrives at Kupang.

16 January 1943:
Departs Kupang on an escort mission.

23 January 1943:
Arrives at Surabaya.

8 March 1943:
Departs Waingapu.

11 March 1943:
Arrives at Surabaya.

16 March 1943:
Departs Surabaya on an escort mission.

20 March 1943:
Arrives at Kupang.

22 March 1943:
Departs Kupang on an escort mission.

23 March 1943:
Arrives at Dili.

24 March 1943:
Departs Dili and later that day arrives at Lautem.

28 March 1943:
Departs Lautem and arrives later at Kupang.

29 March 1943:
Departs Kupang and arrives later that day at Ende.

30 March 1943:
Departs Ende on escort mission and anti submarine patrol.

3 April 1943:
Arrives at Surabaya.

6 April 1943:
Departs Surabaya on an escort mission.

11 April 1943:
Arrives at Macassar.

12 April 1943:
Departs Macassar.

13 April 1943:
Arrives at Surabaya.

18 April 1943:
Departs Surabaya on an anti submarine sweep.

21 April 1943:
Arrives back at Surabaya.

22 April 1943:
Departs Surabaya on an escort mission.

25 April 1943:
Arrives at Waingapu.

28 April 1943:
Departs Waingapu on an escort mission.

29 April 1943:
Arrives at Kupang.

7 July 1943:
Arrives with a convoy at Lautem.

9 July 1943:
Departs Lautem on an escort mission.

14 July 1943:
Arrives at Surabaya.

17 July 1943:
Departs Surabaya and undertakes minesweeping in the western channel.

22 July 1943:
Returns to Surabaya.

7 August 1943:
At 1200 departs Surabaya to escort a convoy.

9 August 1943:
At 1600 arrives at Balikpapan.

10 August 1943:
Departs Balikpapan.

12 August 1943:
At 1250 arrives at Surabaya.

13 August 1943:
At 0700 departs Surabaya on an anti submarine sweep.

18 August 1943:
At 1135 arrives back at Surabaya.

20 August 1943:
At 1050 departs Surabaya on an escort mission.

24 August 1943:
At 0902 arrives at Surabaya.

27 August 1943:
At 1225 departs Surabaya on an escort mission.

30 August 1943:
At 1400 arrives at Balikpapan. Departs soon after.

1 September 1943:
At 1245 arrives at Surabaya.

17 September 1943:
At 0800 departs Surabaya on an escort mission.

21 September 1943:
At 1100 arrives back at Surabaya.

24 September 1943:
At 1537 departs Surabaya on an escort mission.

28 September 1943:
At 2000 arrives at Jakarta.

October 1943:
An unknown officer assumes command.

1 October 1943:
At 0900 departs Jakarta.

3 October 1943:
At 1000 arrives at Surabaya.

4 October 1943:
At 1000 departs Surabaya on anti submarine patrol.

6 October 1943:
At 0915 transfers to Lesser Sundas area and undertakes anti submarine sweep.

12 October 1943:
Undertakes convoy escort duties.

24 October 1943:
At 1230 arrives at Surabaya.

26 October 1943:
At 1230 departs Surabaya on an escort mission.

31 October 1943:
At 1400 arrives at Surabaya.

9 November 1943:
At 1200 departs Surabaya on an escort mission.

15 November 1943:
At 1830 arrives at Ambon.

19 November 1943:
At 1130 departs Ambon on an escort mission.

26 November 1943:
W-11 and W-12 depart Ambon for Surabaya escorting SUEZ MARU carrying 1,102 mostly sick British and Dutch POW's as well as sick and wounded Japanese soldiers. SUEZ MARU also carries a damaged E13A1 "Jake" float plane on her fore deck that is scheduled for repairs by the No. 102 Repair Depot at Surabaya. Enroute, reports are received of American air dropped magnetic mines in Surabaya's harbor.

27 November 1943:
W-11 is detached and heads due west. Two days later, SUEZ MARU is torpedoed by LtCdr (later Cdr) Thomas W. Hogan's (USNA ’31) USS BONEFISH (SS-223) and sinks with great loss of life (69 passengers and about 850 POWs). W-12's rescues about 200-250 Japanese and Koreans, but is unable to accommodate any POW's. After much arguing, and on the insistence of Lt Kawano Atsumu, CO of W-12, IJA Lt Koshio Masaji, in charge of the POW's, agrees to massacre the survivors in the water. Between 1415 and 1630, a rifle party of a dozen men is based on the warship's foredeck and together with a machine gun mounted on the bow opens fire on the POW's. Either in the ensuing massacre, or in the water over the next few days, all but possibly one of the POW's are killed. A solitary survivor, British Soldier Kenneth Thomas, was allegedly rescued 24 hours later by the Australian minesweeper HMAS BALLARAT, although this is unconfirmed.

28 November 1943:
Arrives at Kendari, Celebes.

12 December 1943:
Arrives at Christmas Island on an escort mission.

E 14 December 1943:
Departs Christmas Island.

21 December 1943:
At 1020 arrives back at Surabaya.

16 January 1944:
Departs Surabaya on an escort mission.

3 February 1944:
Departs Surabaya.

5 February 1944:
At 1600 arrives at Macassar.

6 February 1944:
At 0600 departs Macassar on an escort mission. At 1800 arrives at Surabaya.

8 February 1944:
Departs Surabaya on a patrol.

9 February 1944:
At 1325 arrives back at Surabaya.

12 February 1944:
At 1200, W-11 departs Surabaya escorting fleet oiler TSURUMI.

14 February 1944:
At 0800, W-11 is detached and TSURUMI proceeds unescorted.

16 February 1944:
At 1100 arrives back at Surabaya.

17 February 1944:
At 1400 departs Surabaya escorting tanker JAMBI MARU for Balikpapan, Borneo.

20 February 1944:
At 1240 arrives back at Surabaya.

24 February 1944:
At 1522, W-11, W-8 and auxiliary subchaser TAKUNAN MARU No. 5 depart Surabaya escorting RYUSEI and TANGO MARUs (ex-Dutch TOENDJOEK) to Ambon. [2]

25 February 1944:
25 miles N of Bali Island. At 2045, LtCdr Willard R. Laughon's (USNA ’33) USS RASHER (SS-269) torpedoes and sinks TANGO MARU at 07-41N, 115-10E. W-11 promptly reports the ship has been hit by three torpedoes in this location and on fire and sinking. The ship sinks with over 3,000 men most of them romusha, Indonesian indentured laborers. [2]

At 2225, that same day, LtCdr Laughon sets up and fires four torpedoes at RYUSEI MARU. Laughon gets three hits and she goes down at 07-55N, 115-15E. The casualties are 31 crewmen and 4,968 passengers killed, a mixture of soldiers and romusha [3].

6 March 1944:
At 1500 arrives back at Surabaya.

12 March 1944:
At 1050 departs Surabaya on an anti submarine sweep.

18 March 1944:
At 1940 arrives at Surabaya.

19 March 1944:
At 1230 departs Surabaya on an escort mission.

26 March 1944:
At 1510 arrives back at Surabaya.

27 March 1944:
At 1715 departs Surabaya on an escort mission.

17 April 1944:
At 1300 arrives back at Surabaya.

19 April 1944:
At 0900 departs Surabaya on an escort mission.

24 April 1944:
At 1115 arrives back at Surabaya.

26 April 1944:
At 1500 departs Surabaya on an escort mission.

1 May 1944:
At 1720 arrives back at Surabaya.

3 May 1944:
At 1200 departs Surabaya on an escort mission.

9 May 1944:
At 0900 arrives back at Surabaya.

15 May 1944:
Departs Surabaya on an escort mission.

1 June 1944:
W-8 and W-11 depart Kau probably escorting a convoy to Ambon.

8 June 1944:
Pulau Boelenroe. Receives 65 tons of No. 1 Grade fuel oil from KIYOKAWA MARU.

12 June 1944:
Arrives at Surabaya.

26 June 1944:
At 1300, W-11 departs Surabaya for Kotabaru, Borneo escorting TAI MARU, TORA MARU No. 1 and oilers ENOSHIMA and YOSEI MARUs and HISHI MARU No. 2. At 2039, anchors at Menpa before proceeding.

28 June 1944:
At 0915, YOSEI MARU incurs engine trouble and straggles.

29 June 1944:
At 2003, reaches mouth of Laut River.

30 June 1944:
Arrives at Kotabaru, N Laut Island.

4 July 1944:
At 0800 W-11 and minelayer WAKATAKA departs Kota Baru, Laut Island escorting TAIKO, TAKASAN MARUs and UNKAI MARU No. 12.

5 July 1944:
At 1858 arrives at Doangdoangan Island.

6 July 1944:
At 0558 departs Doangdoangan Island.

7 July 1944:
At 0735 arrives at Macassar.

11 July 1944:
At 1000 W-5, minelayer WAKATAKA, cable layer escort TATEISHI depart Macassat with TAIKO MARU. W-11 apparently detaches at an unknown point.

14 July 1944:
At 1600 arrives at Surabaya.

19 July 1944:
At 1805 departs Surabaya on patrol.

21 July 1944:
At 0920 arrives back at Surabaya.

24 July 1944:
At 1155 departs Surabaya on an escort mission.

11 August 1944:
At 1530 departs Surabaya on an escort mission and returns some time later.

14 August 1944:
At 1000, W-11 departs Surabaya escorting IKUTAGAWA MARU (ex Italian CALITEA II), KIMIKAWA MARU and German supply ship BOGOTA to Macassar, Celebes. At 2030, KIMIKAWA MARU and BOGOTA detach and steam independently.

15 August 1944:
At 1220, anchors N of Petan Lighthouse leaving at 2110.

16 August 1944:
At 1800, arrives at Macassar.

22 August 1944:
At 1015 arrives at Surabaya.

25 August 1944:
At 1400 W-11 departs Surabaya escorting a convoy consisting of TENCHO MARU and oiler KORYU MARU. At 1800 anchors at Probolinggo.

26 August 1944:
At 0100, departs Probolinggo.

29 August 1944:
At 1835, arrives at Bima, NE Sumbawa.

1 September 1944:
At 1930 arrives at Surabaya.

4 September 1944:
At 1740 departs Surabaya on an escort mission and then an anti submarine sweep.

8 September 1944:
At 1500 arrives at Surabaya.

9 September 1944:
At 0300 departs Surabaya on an escort mission.

14 September 1944:
At 1800 arrives at Surabaya.

17 September 1944:
At 0833, W-11 departs Surabaya escorting ex-seaplane tender SANUKI MARU and IKUTAGAWA MARU to Macassar.

18 September 1944:
At 1600, the convoy arrives safely at Macassar.

29 September 1944:
Bacuit Bay. W-8 and W-11 joins remnants of convoy MIMA-11 then consisting of cargo ships SHIKISAN, TENSHIN, TATSUHARU MARUs, SHINSEI MARU No.1 and tankers KYOEI MARU and KYOEI MARU No.6. [4]

1 October 1944:
Bacuit Bay. CH-31 joins as an additional escort.

2 October 1944:
The convoy departs Bacuit Bay. Later that day, arrives at Busuanga Island.

3 October 1944:
Departs Busuanga Island. Later that day, arrives at Lubang Island.

4 October 1944:
Departs Lubang Island. Later that day arrives at Manila.

10 October 1944:
At 1920 arrives at Surabaya.

11 October 1944:
At 1400 departs Surabaya on an anti submarine sweep.

15 October 1944:
At 1500 arrives at Surabaya.

4 November 1944:
At 0920 departs Surabaya on an anti submarine sweep.

5 November 1944:
At 1300 departs Surabaya on an anti-submarine sweep in Madura Strait and along the north coast of Bali.

11 November 1944:
At 1008 arrives at Surabaya.

12 November 1944:
At 1500 departs Surabaya escorting survey ship HEIYO (the former British survey ship HERALD).

14 November 1944:
Off entrance to Adang Bay (SE coast of Borneo), HEIYO runs onto a mine and sinks at 01-45S 116-35E.

15 November 1944:
After the sinking of HEIYO, a mine warning is broadcast saying that enemy aircraft had laid mines in Adang Bay.

16 November 1944:
At 0010, W-11 is officially released from duty of escorting HEIYO.

17 November 1944:
At 1725 arrives at Surabaya.

21 November 1944:
At 1000 departs Surabaya on an escort mission.

28 November 1944:
At 1700 arrives at Surabaya.

30 November 1944:
At 0930 departs Surabaya on an escort mission.

10 December 1944:
At 1000 arrives at Surabaya.

15 December 1944:
At 0852, W-11 departs Surabaya with W-103, subchaser CH-2 and auxiliary subchaser CHa-36 escorting convoy SUBA-02 consisting of KITA, KENZAN, TOKUYAMA MARUs and NANSHIN MARUs No. 12 and No. 16.

19 December 1944:
At 0947, W-11 and subchaser CH-2 are ordered to join another convoy and are detached.

23 December 1944:
At 1150 arrives at Surabaya.

26 December 1944:
At 1300 departs Surabaya on an escort mission.

30 December 1944:
Arrives back at Surabaya.

February 1945:
Lt Kikuchi Takeshi assumes command.

6 February 1945:
At 0700, W-11, patrol boat PB-2 and auxiliary subchaser CHa-104 depart Surabaya escorting the Suiten Maru convoy consisting of SUITEN, SUGI and KENZAN MARUs and NANSHIN MARU No. 12.

9 February 1945:
At 1600, the convoy arrives safely at Balikpapan. SUGI and KENZAN MARUs had detached for Macassar prior to this time.

19 February 1945:
At 2000 W-11 arrives at Surabaya.

26 February 1945:
At 1500 departs Surabaya on an escort mission escorting KAKO GO, NANPO MARU and the tug MATSUNOURA MARU. The latter is towing an unidentified Communication boat.

3 March 1945:
At 1500 arrives back at Surabaya.

4 March 1945:
At 1500 departs Surabaya.

5 March 1945:
At 1030 arrives back at Surabaya.

8 March 1945:
At 1025 departs Surabaya on a transport mission. Minesweepers W-12 and W-34 depart on the same mission soon after.

12 March 1945:
According to a message from KARI, W-11 participated in an attack against a submarine sighted by KARI off the north coast of Sumbawa, in 08-00S, 117-37E, dropping five depth charges after 2239. The results could not be observed owing to darkness.

13 March 1945:
At 1730 W-11 arrives back at Surabaya with KARI, W-12 and W-34

17 March 1945:
At 1800 departs Surabaya on an escort mission.

21 March 1945:
At 1030 arrives back at Surabaya.

24 March 1945:
At 1100 departs Surabaya on an anti submarine sweep. At 1200 W-12 and W-34 depart and join W-11.

28 March 1945:
W-11 and W-34 arrive at Macassar escorting convoy SUMA-4 consisting of unidentified ships.

Off Macassar. W-11 is attacked by 13th Air Force B-24 "Liberator" heavy bombers and sunk at 05-06S, 119-14E.

At 2113, USN codebreakers intercept and decrypt a message from that reads: “1. Minesweeper No. 34 proceed as scheduled at top speed to Surabaya. 2. Rescue Guard Force No. 3 engage in rescue of survivors of minesweeper No. 11.”

30 March 1945:
At 0143, codebreakers decrypt a message from the CO of W-11 that reads: “1. On March 28th at 1900 inside Macassar Harbor, I engaged a B-24. I drove it off, but received a large number of hits at point blank range, near the -----, and sank at 1930. Position 1 mile at 29 degrees from ----.”

10 May 1945:
Removed from the Navy List.


Authors' Notes:
[1] Vice Admiral Hatakeyama is KIA in China in Jan '45.

[2] By an incredible coincidence, a second TANGO MARU, also a captured Dutch ship ( former tanker TALANG AKAR) had been sunk by USS RASHER on 8 November 1943. Thus, the same submarine sank the only two vessels of the same name, both of which had been captured from the Dutch.

[3] The combined total of these two sinkings by USS RASHER exceeds German WILHELM GUSTLOFF's 7,700 deaths, the worst seagoing disaster in history.

[4] One of these ships, perhaps TENSHIN MARU, left with the fast contingent on 25 September.

Thanks go to Mr. Aki of Japan and Matthew Jones of Ohio for help in identifying COs. Thanks also go to John Whitman of the USA for info on CNO intercepts of Japanese messages, and to Mr. Gilbert Casse of France and Mr Erich Muhlthaler of Germany for general assistance.

Photo credit goes to Ships of the World (SOTW) via J. Ed Low.

-Bob Hackett and Peter Cundall.


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