Japanese Minesweepers

SOKAITEI!
( colorized photo of W-33 [(W-19 class] by irootoko jr)

IJN Minesweeper W-33: Tabular Record of Movement
© 2008-2017 Bob Hackett and Peter Cundall
Revision 8

E 1942:
Yokohama. Laid down at Yokohama Dock, K. K.
1943:
Launched and numbered W-33.
31 July 1943:
Completed and registered in the IJN. Lt (reserve) Fukuda Moichiro (former CO of CHOUN MARU No. 6) is the Commanding Officer.
2 August 1943:
At 0610 departs Yokohama escorting convoy No. 7801 consisting of unidentified merchant ships.
3 August 1943:
At 1530 arrives at Kure where the vessel is fitted out.
14 August 1943:
At 1116 departs Kure and later that day at 1530 arrives at Saiki.
16 August 1943:
Departs Saiki on patrol. 5 Miles northeast off Okishima is joined by YURIJIMA.
18 August 1943:
At 0510 arrives back at Saiki.
21 August 1943:
At 0715 departs Saiki with W-18 escorting convoy O-104 consisting of TAITO, KUMAGAWA, ALASKA and YAMAGATA MARUs to Palau. Auxiliary minesweepers TAMA MARU No. 6 and TAMA MARU No. 7 also escort the convoy initially.
E 22 August 1943:
At 30-30N 134-05 TAMA MARU No. 6 and TAMA MARU No. 7 are detached.
E 23 August 1943:
At 29-N W-33 is detached and later that day at 1540 arrives back at Saiki.
26 August 1943:
At 0820 departs Saiki and joins up with kaibokan IKI escorting convoy O-603 consisting of KANSAI, KINUGASA and MAYASAN MARUs.
E 27 August 1943:
At 29N W-33 is detached.
28 August 1943:
At 0810 arrives back at Saiki and then departs later that day at 1730 on an anti submarine sweep.
E 31 August 1943:
Meets up at 30-50N 135-20E with inbound convoy consisting of AIKOKU and GOKOKU MARUs escorted by destroyer USHIO and auxiliary minesweepers YACHIYO and AOI MARUs, TAKUNAN MARU No. 8 and TAKUNAN MARU No. 3.
1 September 1943:
The convoy arrives at Sukumo where all escorts except USHIO are detached. At 1440 W-33 arrives at Saiki.
3 September 1943:
At 0630 W-33, patrol boat PB-31 and auxiliary minesweeper YACHIYO MARU depart Saiki escorting convoy O-302 consisting of CHINZEI and TOYOKAWA MARUs.
E 4 September 1943:
At 30N YACHIYO MARU is detached and later that day at 29N W-33 is detached.
6 September 1943:
At 1015 W-33 arrives back at Saiki.
8 September 1943:
At 1700 departs Saiki.
9 September 1943:
At 1328 arrives at Kobe.
11 September 1943:
At 1000 departs Kobe escorting convoy No. 8911 consisting of unidentified merchant ships.
13 September 1943:
At 0805 arrives at Yokosuka.
17 September 1943:
At 0800 departs Yokosuka but returns at 1300.
18 September 1943:
At 0730 departs Yokosuka but at 1657 arrives back at Yokosuka.
19 September 1943:
At 1630 departs Yokosuka and at 1830 anchors off Tateyama.
20 September 1943:
At 0430 departs Tateyama and auxiliary submarine chaser SEKI MARU No. 2 escorting convoy No. 3919 consisting of auxiliary gunboat MAGANE MARU.
23 September 1943:
At 0530 arrives at Chichi Jima.
24 September 1943:
At 1130 departs Chichi Jima.
26 September 1943:
At 1630 arrives at Uraga with W-27 and destroyers SHIMAKAZE, HATAKAZE, SAZANAMI, SHIRATSUYU and minelayer UKISHIMA escorting damaged escort carrier TAIYO being towed by escort carrier CHUYO arriving at Yokosuka from Truk.
27 September 1943:
At 0630 departs Uraga and at 0830 arrives at Yokosuka. At 1000 departs Yokosuka escorting convoy No. 7927 consisting of tanker TONAN MARU No. 2 and two unidentified ships.
29 September 1943:
At 0330 arrives at Yura and departs there at 1100. At 1540 arrives at Kobe.
2 October 1943:
At 1200 departs Kobe escorting convoy No. 8002 consisting of unidentified merchant ships.
4 October 1943:
At 1430 arrives at Uraga and departs there at 1630. At 1730 arrives at Yokosuka.
6 October 1943:
At 1230 departs Yokosuka escorting convoy No. 7006 consisting of unidentified merchant ships.
8 October 1943:
At 0730 arrives at Kobe.
11 October 1943:
At 1205 departs Kobe escorting convoy No. 8011 consisting of unidentified merchant ships.
13 October 1943:
At 0850 arrives at Uraga and departs at 1100. At 1230 arrives at Yokosuka. At 1307 departs Yokosuka but returns at 1625.
16 October 1943:
At 1258 departs Yokosuka escorting convoy No. 7016 consisting of four unidentified merchant ships. The convoy sails at 7.5 knots.
18 October 1943:
At 0740 arrives at Kobe.
20 October 1943:
Departs Kobe escorting convoy No. 8020 consisting of two unidentified merchant ships. The convoy sails at 8.5 knots.
22 October 1943:
At 0640 arrives at Uraga and departs at 0930. At 1100 arrives at Yokosuka.
25 October 1943:
At 1500 departs Yokosuka and at 1700 arrives at Tateyama.
26 October 1943:
At 0400 departs Tateyama with auxiliary minesweeper MISAGO MARU No. 11 escorting ex auxiliary gunboat MAGANE MARU. The ships engage on an anti submarine sweep on the way south.
28 October 1943:
At 1730 arrives at Futami, Chichi Jima.
30 October 1943:
At 1200 departs Futami with auxiliary submarine chaser TAKUNAN MARU No. 8 on an anti submarine sweep.
2 November 1943:
At 1600 arrives at Uraga.
3 November 1943:
At 0825 departs Uraga and at 0950 arrives at Yokosuka.
6 November 1943:
At 1030 departs Yokosuka escorting convoy No. 1106 consisting of unidentified merchant ships.
9 November 1943:
At 0630 arrives at Muroran.
11 November 1943:
At 0950 departs Muroran escorting convoy No. 2111 consisting of unidentified merchant ships.
14 November 1943:
At 0730 arrives at Uraga but departs at 0930. At 1055 arrives at Yokosuka.
16 November 1943:
At 0625 departs Yokosuka escorting convoy No. 7116 consisting of unidentified merchant ships.
18 November 1943:
At 0945 arrives at Kobe.
20 November 1943:
At 1620 departs Kobe escorting convoy No. 8120 consisting of two unidentified merchant ships. The convoy sails at 13 knots.
22 November 1943:
At 0730 arrives at Uraga and departs at 0840. At 1045 arrives at Yokosuka.
25 November 1943:
At 1455 departs Yokosuka on a submarine sweep.
28 November 1943:
At 1500 arrives at Sasebo.
29 November 1943:
At 0630 departs Sasebo.
30 November 1943:
At 1342 arrives at Sasebo.
1 December 1943:
W-33 is assigned to the 1st Minesweeper Division.
13 December 1943:
W-33 departs Moji with destroyer SHIOKAZE escorting convoy No. 121 consisting of oilers SARAWAK and TENEI MARUs, OGURA MARU No. 2, FUSHIMI MARU No. 3, and cargo ships BATAVIA, NICHIREI and HIROTA MARUs and eight other unidentified merchant ships.
17 December 1943:
S of the Ryukyus. At 2226, LtCdr Henry C. Stevenson’s USS ASPRO (SS-309) torpedoes and damages SARAWAK MARU at 24-10, 124-40E. About the same time, USS ASPRO torpedoes and damages TENEI MARU at the same place. SHIOKAZE counterattacks, but USS ASPRO evades and escapes.
18 December 1943:
At 0325 a further submarine attacks takes place at 23-47N 124-20E but the convoy is able to avoid. NICHIREI MARU is detached and arrives at Kirun later this day.
20 December 1943:
At 1300 arrives at Takao.
16 June 1944:
Undocked after lengthy repairs. Later that day arrives at Shioya.
17 June 1944:
At 0800 departs Shioya and later that day at 1830 arrives at Onagawa.
21 June 1944:
At 0800 departs Onagawa.
24 June 1944:
At 1100 arrives at Onagawa.
27 June 1944:
At 0800 departs Onagawa.
28 June 1944:
Begins escorting a convoy.
30 June 1944:
At 0900 arrives at Onagawa.
3 July 1944:
At 0800 departs Onagawa with auxiliary minesweeper MISAGO MARU No. 1.
8 July 1944:
At 1500 arrives at Onagawa.
13 July 1944:
At 0800 departs Onagawa with auxiliary picket boat KOSHO MARU No. 2.
18 July 1944:
At 0900 arrives at Onagawa.
23 July 1944:
At 0800 departs Onagawa with auxiliary minesweeper MISAGO MARU No. 3. Later meets up and escorts convoy No. 1728.
26 July 1944:
At 0900 arrives at Onagawa.
29 July 1944:
At 0800 departs Onagawa.
August 1944:
Lt Kojima Takeo assumes command.
1 August 1944:
At 0900 arrives at Onagawa.
4 August 1944:
At 0800 departs Onagawa.
7 August 1944:
At 0900 arrives at Onagawa.
10 August 1944:
At 0800 departs Onagawa. Later escorts a convoy.
13 August 1944:
At 0930 arrives at Onagawa.
16 August 1944:
At 0800 departs Onagawa with auxiliary minesweeper MISAGO MARU No. 1.
19 August 1944:
Arrives at Onagawa.
22 August 1944:
At 0800 departs Onagawa with auxiliary minesweeper MISAGO MARU No. 1.
25 August 1944:
At 0900 arrives at Onagawa.
28 August 1944:
At 0800 departs Onagawa with auxiliary minesweeper MISAGO MARU No. 1.
1 September 1944:
Arrives at Onagawa.
3 September 1944:
At 0800 departs Onagawa. Later escorts a convoy.
6 September 1944:
At 0930 arrives at Onagawa.
9 September 1944:
At 0830 departs Onagawa with auxiliary patrolboat KOSHO MARU No. 2.
12 September 1944:
At 0900 arrives at Onagawa.
15 September 1944:
At 0830 departs Onagawa with auxiliary minesweeper MISAGO MARU No. 1.
18 September 1944:
At 0940 arrives at Onagawa.
24 September 1944:
At 0830 departs Onagawa.
27 September 1944:
At 0930 arrives at Onagawa.
30 September 1944:
At 0830 departs Onagawa with auxiliary minesweeper MISAGO MARU No. 1. Later escorts a convoy.
3 October 1944:
At 1030 arrives at Onagawa.
6 October 1944:
At 0830 departs Onagawa with submarine chaser CH-48.
7 October 1944:
At 1145 arrives at Ohara Wan.
9 October 1944:
At 0500 departs Ohara Wan. At 1000 arrives at Onagawa.
15 October 1944:
At 0830 departs Onagawa with auxiliary minesweeper WA-17. Later escorts a convoy.
18 October 1944:
At 0930 arrives at Onagawa.
24 October 1944:
At 0830 departs Onagawa with auxiliary submarine chaser CHa-141.
27 October 1944:
At 0930 arrives at Onagawa.
7 November 1944:
At 0830 departs Onagawa.
9 November 1944:
At 0930 arrives at Onagawa.
11 November 1944:
At 0832 departs Onagawa.
13 November 1944:
At 0200 arrives at Ohara Wan and departs at 0918 and meets up and escorts convoy No. 1111.
14 November 1944:
At 0940 arrives at Onagawa.
17 November 1944:
At 0830 departs Onagawa.
18 November 1944:
Meets up and escorts convoy No. 1117.
20 November 1944:
At 0940 arrives at Onagawa.
26 November 1944:
At 0830 departs Onagawa.
28 November 1944:
At 2250 arrives at Onagawa.
29 November 1944:
At 0630 departs Onagawa but returns at 1051.
4 December 1944:
At 0840 departs Onagawa.
8 December 1944:
At 1100 arrives at Onagawa.
11 December 1944:
At 1400 departs Onagawa.
13 December 1944:
Escorts SHIMOSA MARU and an unidentified ship.
15 December 1944:
At 1010 arrives at Onagawa.
19 December 1944:
At 1710 departs Onagawa.
22 December 1944:
At 1615 arrives at Onagawa.
25 December 1944:
At 0830 departs Onagawa and later meets up and escorts an unidentified convoy consisting of RYUHO MARU No. 1 and the tanker YOKO MARU.
29 December 1944:
At 0930 arrives at Onagawa.
4 January 1945:
Departs Onagawa.
7 January 1945:
Arrives at Onagawa.
13 January 1945:
Departs Onagawa.
16 January 1945:
Arrives at Onagawa.
22 January 1945:
At 0830 departs Onagawa with auxiliary submarine chaser CHa-178.
25 January 1945:
Arrives at Onagawa.
28 January 1945:
At 0830 departs Onagawa with auxiliary patrol boat KONGO MARU No. 2.
31 January 1945:
Arrives at Onagawa.
2 February 1945:
At 1120 departs Onagawa. At 1500 arrives at Shiogama. Drydocked. Remains there for the rest of February.
1 March 1945:
At Shiogama.
15 March 1945:
At 0530 departs Shiogama and later that day arrives at Onagawa.
18 March 1945:
Departs Onagawa but later that day returns to port.
19 March 1945:
At 0845 departs Onagawa.
21 March 1945:
At 0950 arrives at Onagawa.
23 March 1945:
Undertakes training exercises for rest of the month. Then undergoes repairs.
24 March 1945:
At 0520 departs Onagawa.
25 March 1945:
At 1105 arrives at Yokosuka.
18 April 1945:
Repairs at Onagawa are completed. Departs Onagawa and escorts SOYA travelling north. Both ships later arrive at Onagawa.
24 April 1945:
Departs Onagawa.
27 April 1945:
Arrives at Onagawa.
29 April 1945:
Arrives at Onagawa.
1 May 1945:
Arrives at Onagawa.
2 May 1945:
Departs Onagawa.
3 May 1945:
Arrives at Onagawa.
4 May 1945:
Departs Onagawa.
10 May 1945:
Arrives at Onagawa. W-33 is reassigned to an unknown unit.
12 May 1945:
Departs Onagawa.
13 May 1945:
Arrives at Onagawa.
15 May 1945:
Departs Onagawa.
17 May 1945:
Arrives at Onagawa.
22 May 1945:
Departs Onagawa.
23 May 1945:
Arrives at Onagawa.
25 May 1945:
Departs Onagawa and later escorts KAIO MARU No. 2 and then separately supply ship SOYA.
10 July 1945:
Off Yamada Bay, northern Honshu. At about 1100, LtCdr Raymond H. Bass’ (USNA ’31) USS RUNNER II (SS-476) torpedoes and sinks minesweeper W-27 at 39-20N, 142-07E. W-27 is escorting SHINYO MARU with W-33 and submarine chaser CH-47 when attacked. (UNYO MARU No. 10 was also in the same area). She receives two hits to starboard and sinks in 90 seconds.
9 August 1945:
Onagawa Bay, NE Honshu. W-33, supply ship SOYA, target ship OHAMA. kaibokan AMAKUSA and INAGI and subchaser CH-42 are at anchor when they are attacked by F-4U Mark IV "Corsair" fighter-bombers of Vice Admiral (later Admiral) Sir Bernard J. Rawlings, RN, Task Force 37’s (British Pacific Fleet) carrier HMS FORMIDABLE. W-33 is sunk in the attack. AMAKUSA, INAGI and OHAMA are also sunk.
The fate of Lt Kojima and the crew of W-33 is unknown.
During the attack, Lt Robert H. Gray, RCNVR, lead pilot of HMS FORMIDABLE’s 1841st Squadron flight of Corsairs, sinks his target, a "destroyer" (kaibokan), but is brought down by heavy AA fire and crashes flames. Gray is posthumously awarded the Victoria Cross, the fourth and last Commonwealth naval airman to be so honored.
Nagasaki. That same day, the CO of the 393rd Bomb Squadron of the 509th Composite Group, Major (later Brig Gen, ANG) Charles W. Sweeney, piloting a B-29 nicknamed "BOCKSCAR", drops "Fat Man", the second atomic bomb. Within a week, otherwise irresolute Japan agrees to an end of hostilities.
15 September 1945:
Removed from the Navy List.

Author’s Note:
Little data were found detailing W-33's movements, probably because she was used for minesweeping rather than escort duties. Nevertheless, readers with access to any movement data are requested to post the information on the Discussion & Questions board or the IJN Ship Message Board.

Thanks go to Matthew Jones of Tennessee for information on COs and to 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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