Japanese Minesweepers

SOKAITEI!

IJN Minesweeper W-1: Tabular Record of Movement
© 2005-2018 Bob Hackett and Peter Cundall
Revision 12

10 May 1922:
Kobe. Laid down at the Harima Shipbuilding and Engineering Co. yard.
6 March 1923:
Launched and numbered W-1.
30 June 1923:
Completed and registered in the Yokosuka Naval District.
16 July 1923:
Attached to the First Minesweeper Force in the Yokosuka Naval district. In service as a training minesweeper.
27 July 1923:
Her call sign is GQOA.
1 May 1924:
Attached to the Combined Fleet First Fleet First Minesweeper Force.
1 December 1925:
Lt Akiyama Teruo (41) is appointed the Commanding Officer.
12 January 1926:
Attached to the First Fleet Unit.
20 January 1926:
1310 ~ 1405, in drydock.
21 January 1926:
Arrives at Yokosuka.
22 January 1926:
Departs Yokosuka and returns later that day.
27 January 1926:
Departs Yokosuka and returns later this day.
3 June 1926:
Departs Yokosuka.
19 October 1926:
Arrives at Yokosuka.
12 November 1926:
Departs Yokosuka and returns later that day.
25 November 1926:
At 1030, enters drydock.
1 December 1926:
W-1 is placed in reserve at Yokosuka attached to the Yokosuka Defense Force First Minesweeper Force. In service as a training and security minesweeper.
6 December 1926:
Departs Yokosuka.
20 January 1928:
LtCdr (Vice Admiral, posthumously) Akiyama Teruo (41)(former CO of YUGURE) is appointed the Commanding Officer.
10 October 1928:
In service as a First Class Minesweeper.
1 November 1928:
Lt (Rear Admiral, posthumously) Mutaguchi Kakuro (44)(former CO of USHIO) is appointed CO. Foreign officers visit the ship.
15 April 1929:
Lt (Rear Admiral, posthumously) Shoji Kiichiro (45)(former CO of W-12) is appointed CO.
1 May 1930:
Attached to the Combined Fleet First Minesweeper Force.
1 December 1930:
Lt (Rear Admiral, posthumously) Kubota Toshi (46) is appointed the CO. Attached to the Yokosuka Defense Force First Minesweeper Force. In service as a training minesweeper.
1 December 1931:
Lt (Rear Admiral, posthumously) Yamada Yusuke (48)(former torpedo officer of YUKAZE) is appointed CO.
23 April 1932:
An unknown officer is appointed CO.
8 October 1933:
Her call sign changes to JXAD.
3 August 1934:
Arrives at Kure.
2 August 1934:
Arrives at Yokosuka and departs later this day.
19 September 1935:
Arrives at Ominato.
29 September 1935:
Departs Ominato.
1 December 1936:
LtCdr Moriya Setsuji (51) (former Chief Torpedo Officer, JINTSU) is appointed CO.
28 July 1937:
Detached from the Yokosuka Defense Force.
1 December 1937:
An unknown officer is appointed CO.
5 August 1938:
Attached to the First Minesweeper Force.
15 November 1939:
LtCdr Ono Shiro (54) is appointed CO.
15 October 1940:
An unknown officer is appointed CO.
15 November 1940:
Attached to the Combined Fleet Second Fleet First Base Force First Minesweeper Force.
10 April 1941:
Attached to the Combined Fleet Third Fleet First Base Force First Minesweeper Force.
1 October 1941:
Attached to the Combined Fleet Southern Expeditionary Fleet Ninth Base Force First Minesweeper Force.
1 November 1941:
Assigned to Vice Admiral Ozawa Jisaburo's (37) South Expeditionary Fleet in Rear Admiral (later Vice Admiral) Hiraoka Kumeichi's (39) (former CO of HIEI) 9th Base Force.
8 November 1941:
Departs Kure.
17 November 1941:
Arrives at Sana (now Ya Xian), Hainan island and conducts patrols.

1 December 1941:
Her call sign changes to JXAP. At 1700 W-1, W-5 and W-6 depart Sana, Hainan Island to sweep ahead of the planned convoy route. Thereafter the ships are to refuel and replenish at Camranh Bay, French Indochina and join the 1st Escort Force at 1530 on 5 December 1941.

3 December 1941:
At 1430 all three ships arrives at Camranh Bay, Indochina.

5 December 1941:
At 0630 W-1, W-5 and W-6 depart Camranh Bay. At 1500, joins the main convoy with W-5 and W-6 after refueling and replenishing at Poulo Condore French Indochina (now Con Son, Vietnam).

11 December 1941:
At 1530, W-1 arrives off Singora, Siam (Thailand). Thereafter, supports the invasion.

13 December 1941:
At 1425 departs Singora.
16 December 1941:
At 0923 arrives at Camranh Bay.
19 December 1941:
At 0830 departs Camranh Bay.
23 December 1941:
W-1 and W-2 both arrive back at Singora.
30 December 1941:
W-1 and W-2 both depart Singora.
1 January 1942:
W-1 returns to Singora.
7 January 1942:
At 1850 departs Singora.
12 January 1942:
At 0755 arrives at Pulo Condore with W-2, W-3, W-4 and W-5.
20 January 1942:
W-1 departs Camranh with W-2, W-3, W-4 and W-5 and light cruiser SENDAI, DesDiv 11's FUBUKI, HATSUYUKI and SHIRAYUKI, DesDiv 20's ASAGIRI, AMAGIRI and YUGIRI escorting 11 troop transports consisting of NAKO, NAGARA, SASAGO, SADO, SAGAMI, SAKITO, HIROKAWA, KYUSHU, AOBASAN, CANBERRA and KANSAI MARUs.
22 January 1942:
The convoy arrives at Singora.
26 January 1942:
At 0700 the convoy arrives at Endau.
27 January 1942: The Battle off Endau:
Singapore. LtCdr B. S. Davies' old WW1 destroyer HMS THANET and LtCdr W. T. A. Moran's HMAS VAMPIRE are dispatched to make a night attack on the troop transports at Endau, about 80 miles N of Singapore. At 0237, approaching Endau, they engage a warship they take to be a destroyer, but actually is minesweeper W-1. HMAS VAMPIRE launches two torpedoes at W-1, but they miss. W-1 raises the alarm and the Allied destroyers continue towards Endau.
At 0318, HMAS VAMPIRE sights SHIRAYUKI to port and launches two torpedoes at her, but they miss. Then HMS THANET launches all four of her torpedoes, but also misses. Both Allied destroyers open fire with their 4-inch guns. SENDAI and SHIRAYUKI return fire. The Allied destroyers retire SE at maximum speed.
At about 0400, HMS THANET is hit in the engine and boiler rooms. Her speed falls off and an explosion wrecks the old destroyer. She goes dead in the water, lists heavily to starboard and begins to sink. HMAS VAMPIRE lays a smoke screen, but HMS THANET is attacked by FUBUKI, HATSUYUKI, ASAGIRI, AMAGIRI, YUGIRI and W-1. At 0415, HMS THANET sinks. HMAS VAMPIRE is undamaged and without casualties, but she has no chance to pick up survivors. She makes for Singapore arriving there at 1000.
Troop transports KANSAI MARU and CANBERRA MARU are damaged in the action. Later, SHIRAYUKI picks up 31 survivors from HMS THANET. They are never seen again.

28 January 1942:
At 0835 W-1 and W-5 depart from off Endau.
January 1942:
Kaibokan SHIMUSHU receives a signal from Vice Admiral Ozawa Jisaburo's (37) First Southern Expeditionary Fleet's flagship CHOKAI that orders the kaibokan to locate the wreck of British battleship HMS PRINCE OF WALES sunk off Kuantan, Malaya by IJN aircraft on 10 December.
29 January 1942:
South China Sea, E of Malaya. SHIMUSHU, escorted by minesweepers W-1, W-2, W-3, W-4 and W-5, locates the wreck of British battlecruiser HMS REPULSE and marks it with a buoy.
31 January 1942:
At 0055, W-1 arrives at the Anambas Islands.
1 February 1942:
SHIMUSHU reports locating the wreck of HMS PRINCE OF WALES at a depth of 60 meters. The site is marked with a buoy and the IJN ships are recalled.
2 February 1942:
Assigned to escort the Bangka-Palembang, Sumatra invasion force.
9 February 1942: Operation "L" - The Invasions of Palembang and Banka Island:
MineSweepDiv 1's minesweepers W-1, W-2, W-3, W-4 and W-5 and SubChasDiv 11's CH-7 and CH-8 depart Camranh Bay, Indochina for Palembang escorting eight transports. Rear Admiral (later Vice Admiral) Hashimoto Shintaro's (41) DesRon 3's light cruiser SENDAI with DesDiv 11's FUBUKI, HATSUYUKI and SHIRAYUKI, DesDiv 20's ASAGIRI provides close cover.
11 February 1942:
W-1, W-3 and W-4 escort eleven transports of the invasion force.
14 February 1942:
The ships arrive at Muntok.
15 February 1942:
The ships depart Muntok.
16 February 1942:
The transports land troops near Palembang.
18 February 1942: Operation "J" - The Invasion of Java, Netherlands East Indies:
W-1 is in Rear Admiral (later Vice Admiral) Hirose Sueto's (39) (former CO of AOBA) 2nd Base Force in Cdr (Rear Admiral, posthumously) Amano Shigetaka's (47)(former CO of KAGERO) MineSweepDiv 1 with W-2, W-3, W-4 and W-5 of Vice Admiral Takahashi Ibo's (39) Third Fleet, Southern Force, Netherlands East Indies Force.
21 February 1942:
Java Sea. Sweeps for mines in the Bantam Bay area in support of the invasion landings.

28 February 1942: The Battle of the Sunda Strait:
USS HOUSTON (CA-30) and Australian cruiser HMAS PERTH sortie for Tjilatjap via the Sunda Strait.
Bantam Bay. 27 transports land the main body of the IJA's 2nd Infantry Division. At 2215, USS HOUSTON and HMAS PERTH attack the Japanese troop transports that are screened only by destroyers HARUKAZE, HATAKAZE and FUBUKI and MineSweepDiv 1's W-1, W-2, W-3 and W-4. The escorts make smoke to mask the transports. FUBUKI charges and launches a salvo of torpedoes at USS HOUSTON and HMAS PERTH.

At 2300, the IJN’s Western Support Force's MIKUMA and MOGAMI, destroyer SHIKINAMI, Third Escort Force's light cruiser NATORI and destroyers SHIRAKUMO, MURAKUMO, SHIRAYUKI, HATSUYUKI and ASAKAZE arrive and engage USS HOUSTON and HMAS PERTH with gunfire and torpedoes.
1 March 1942:
At 0108, torpedoes strike both USS HOUSTON and HMAS ERTH. At 0142, HMAS PERTH sinks at 05-51-42S, 106-07-52E. At 0135, torpedoes fired by MOGAMI sink W-2 and sink or disable transports SAKURA, HORAI, TATSUNO and RYUJO (SHINSHU) MARUs, the latter carrying LtGen Imamura Hitoshi, Commander-in-Chief of the invading 16th Army. Imamura jumps into the sea, but survives. One crewman is lost from SAKURA MARU, and 38 passengers (mainly men unloading the ship) and 18 crewmen are killed on HORAI MARU with casualties for the other ships unknown. At 0142, HMAS PERTH sinks at 05-51-42S, 106-07-52E. At 0206, USS HOUSTON sinks at 05-48-45S, 106-07-55E.
8 March 1942:
MinesweepDiv 1 and DesRon 3's DesDiv 10 and DesDiv 20 depart Singapore escorting four invasion transport ships to Sabang and Koetaradja, Sumatra.
12 March 1942: Operation "T" - The Seizure of North Sumatra:
Sweeps for mines and covers troop landings at Kutaradja and Sabang.
13 March 1942:
W-1, W-3, W-4 and W-5 depart Sabang.
15 March 1942:
At 1200 the ships arrive at Penang.
19 March 1942:
MineSweepDiv 1's W-1, W-3 and W-4 and SubChasDiv 91's CHOKO MARU and SHONAN MARU Nos. 5 and 7 are assigned to the No. 2 Escort Unit comprised of light cruiser KASHII (F), escort SHIMUSHU, minelayer HATSUTAKA, destroyers of DesRon 3 and 5 being ASAKAZE, MATSUKAZE, SHIKINAMI and HATAKAZE, with HARUKAZE replacing HATAKAZE en route, Submarine chaser CH-7, and the 9th Base Force's gunboat EIKO MARU. The No. 2 Escort Unit departs Singapore escorting 32 transports carrying the IJA's 56th Infantry Division. The convoy consists of SHUNSEI, YAE, KOAN, TATEISHI, HAVRE (5467 grt), HIBURI, HOKUMEI, YAMAZUKI, GLASGOW, SYDNEY, SHINANOGAWA, AOBASAN, KAZUURA, KIZAN, KUSUYAMA, KOTOHIRA, SANKO, SAKITO, SHINAI, SHINRYU, SUMATRA, GENOA, TSUYAMA, TOKIWA, NAKO, NAGARA, NICHIRAN, NAPLES, HARUNA (10420 grt), HOFUKU, MYOKO (4103 grt), ATLAS, CALCUTTA, KUWAYAMA, MEIGEN, KYUSHU and MOMOYAMA MARUs and six unidentified merchant ships.
Because of size and differing ship speeds the convoy is broken into two sections. The first section consists of ATLAS, YAMAZUKI, NAGARA, KYUSHU, TOKIWA and AOBASAN MARUs and five other ships from the above list that sail on 20th March. The remaining section sails on the 19th March.
20 March 1942: Operation “D” – The Seizure of the Andaman Islands.
Indian Ocean. Sweeps for mines in the Andaman Islands area in support of the invasion landings. Appears to have only provided distant escort cover to U convoy.

23 March 1942:
At 0200 W-1, W-3, W-4 and W-5 arrive at Port Blair, Andamans.
25 March 1942:Operation “U” – The Seizure of Rangoon, Burma.
The transports begin landing troops at Rangoon.
27 March 1942:
At 1730 W-1 departs Port Blair.
28 March 1942:
Arrives at Penang.
30 March 1942:
Departs Penang.
1 April 1942:
Strait of Malacca. Off Pulau Perak, Malaya. Empty Army transports YAE MARU (four crewmen and two gunners KIA) and SHUNSEI MARU (two crewmen KIA) are torpedoed and sunk by Royal Navy Lt Cdr Balston's submarine HMS TRUANT. HMS TRUANT escapes a counterattack by the escort. Arrives at Singapore later that day.
3 April 1942:
Arrives at Singapore. Drydocked.
10 April 1942:
At 1400 undocked.
13 April 1942:
At 0830 departs Singapore and at 1228 arrives at Seletar.
20 May 1942:
Reassigned to the Sasebo Naval District First Minesweeper Force. In service as a security minesweeper.
3 June 1942:
At 0900 W-1 and W-4 arrive at Mako.
7 June 1942:
At 1400 W-1, W-3, W-4 and W-5 departs Mako escorting convoy No. 220 consisting of SHINYO MARU (4163 gt) DAISHO, RYUWA, DELAGOA and YAMAGATA MARUs and seven unidentified merchant ships.
11 June 1942:
Arrives at Mutsure. W-3 and W-5 detach en route and both arrive at Sasebo at 1700.
12 June 1942:
Patrols near the Okuma archipelago. At 1400 W-1 and W-4 arrives at Sasebo.
23 June 1942:
At 0800 W-1, W-3, W-4 and W-5 all depart Sasebo on ASW patrol. At 1700 all four minesweepers arrive at Tamanoura, near Nagasaki.
26 June 1942:
At 0800 W-1 and W-4 depart Tamanoura.
3 July 1942:
At 0745 W-1 and W-4 arrive back at Sasebo.
5 July 1942:
At 1700 W-1 and W-4 depart Sasebo.
10 July 1942:
At 0735 W-1 alone arrives at Sasebo.
11 July 1942:
At 1700 departs Sasebo.
15 July 1942:
Attached to the Osaka patrol unit. Patrols in the Kii Straits.
16 July 1942:
At 1555 W-1, W-3 and W-5 arrive at Yuranai.
8 August 1942:
At 0700 W-1, W-3, W-4 and W-5 all depart Yuranai.
10 August 1942:
At 1420 W-1 and W-3 arrive back at Yuranai. At 1450 W-4 and W-5 also arrive back at Yuranai.
27 August 1942:
At 0630 W-1, W-3, W-4 and W-5 depart Yuranai, all arriving at Osaka between 1145 and 1203.
31 August 1942:
Reassigned to the Sasebo Naval District. Conducts convoy escort duties and patrols the Sasebo and Kyushu's Nisikita Sea areas.

1 September 1942:
At 0800 W-1, W-3, W-4 and W-5 all depart Osaka together.
2 September 1942:
Between 1655 (W-5), 1713 (W-3), 1714 (W-4) and 1715 (W-1) all arrive back at Sasebo.
8 September 1942:
At 0800 W-1, W-3 and W-4 depart Sasebo. Patrols the Okuma strait area.

15 September 1942:
At 1815 W-1 arrives alone back at Sasebo.(W-3 had already arrived at 1628)
18 September 1942:
At 1800 W-3, W-4 and W-5 depart Sasebo. W-1 follows 5 minutes later.
20 September 1942:
Between 1236 and 1310 all four minesweepers arrive back at Sasebo.
22 September 1942:
At 1600 W-1 and W-3 both depart Sasebo.
23 September 1942:
At 1400 and 1403 W-1 and W-3 arrive at Saiki.
29 September 1942:
At 0550 and 0655 respectively W-1 and W-3 depart Saiki.
1 October 1942:
At 1745 W-1 alone arrives at Tokuyama presumably to bunker.
2 October 1942:
At 1500 departs Tokuyama. At 2020 arrives at Saiki.
3 October 1942:
At 0800 W-1 departs Saiki alone. W-3 follows later that day at 1225.
5 October 1942:
ARGUN MARU is attacked by unknown submarine (possibly USS GROUPER) in 32.09N 128.43E. Sasebo Naval Base despatches minelayers KAMOME, HIRASHIMA and minesweeper W-1 to the position to find and attack the submarine.
8 October 1942:
At 1315 W-1 arrives at Sasebo, followed at 1350 by W-3.
10 October 1942:
At 0800 W-1 and W-3 depart Sasebo.
13 October 1942:
Between 1515 and 1604 W-1, W-3, W-4 and W-5 all arrive back at Sasebo.
27 October 1942:
At 0800 W-1 and W-3 both depart Sasebo.
3 November 1942:
At 1000 W-1, and at 1025 W-3, arrive back at Sasebo.
4 November 1942:
At 0800 both W-1 and W-3 depart Sasebo.
6 November 1942:
Between 1420 and 1452 W-1, W-3, W-4 and W-5 all arrive at Sasebo.
7 November 1942:
Between 1608 and 1613 W-1, W-3, W-4 and W-5 all depart Sasebo.
11 November 1942:
At 1446 W-3 arrives back at Sasebo, followed at 1500 by W-1.
16 November 1942:
At 0830 W-1 and W-4 depart Sasebo, returning there at 1630.
17 November 1942:
At 0830 W-1 and W-4 depart Sasebo again.
18 November 1942:
At 1600 W-1 arrives back at Sasebo, followed at 1608 by W-4.
21 November 1942:
At 0800 W-1 and W-4 depart Sasebo.
23 November 1942:
At 1530 W-1 arrives back at Sasebo, followed at 1546 by W-4.
24 November 1942:
At 0730 W-1 and W-4 both depart Sasebo.
27 November 1942:
At 1700 and 1703 respectively, W-1 and W-4 arrive back at Sasebo.
30 November 1942:
At 0830 W-1 and W-4 depart Sasebo.
5 December 1942:
At 0917 W-4 arrives at Sasebo, followed at 0930 by W-1.
7 December 1942:
At 0800 W-4 departs Sasebo, followed at 0845 by W-1.
9 December 1942:
Between 1217 and 1335 W-1, W-3, W-4 and W-5 all arrive at Sasebo.
15 December 1942:
At 0800 W-1 and W-4 both depart Sasebo.
20 December 1942:
At 1445 W-1 arrives back at Sasebo, followed at 1514 by W-4.
22 December 1942:
At 0800 W-1 and W-4 depart Sasebo.
30 December 1942:
At 1445 W-4 arrives back at Sasebo, followed at 1500 by W-1.
3 January 1943:
At 0830 W-1 and W-4 depart Sasebo.
7 January 1943:
At 0900 W-1 and W-4 arrive back at Sasebo.
8 January 1943:
At 0800 W-1 departs Sasebo, followed at 0829 by W-4.
14 January 1943:
At 1341 W-3 arrives at Sasebo, followed at 1345 by W-1.
18 January 1943:
At 0830 W-1 and W-3 depart Sasebo but both return later that day, W-1 at 1530 and W-3 at 1534.
20 January 1943:
At 0830 W-1 and W-3 both depart Sasebo.
22 January 1943:
Between 1540 and 1645 W-1, W-3, W-4 and W-5 all arrive at Sasebo.
27 January 1943:
At 0800 (except W-5 at 0758) W-1, W-3, W-4 and W-5 all depart Sasebo.
2 February 1943:
At 0700 due to depart Moji escorting Army landing craft depot ship AKITSU MARU at 16 knots. AKITSU MARU is bound for Surabaya via Sakito Suido. At an unknown date and time W-1 breaks off escort and returns to Japan.
9 February 1943:
At 1500 arrives back at Sasebo.
14 February 1943:
At 0800 W-1 and W-5 depart Sasebo.
15 February 1943:
At 1330 W-1 arrives back at Sasebo.
27 February 1943:
At 1320 W-1 departs Sasebo, returning shortly after at 1515.
28 February 1943:
At 0830 W-1 departs Sasebo.
10 March 1943:
At 1630 W-1 and W-5 arrive at Sasebo.
15 March 1943:
At 0800 W-1 departs Sasebo, followed at 0829 by W-4 and at 0830 by W-5. Both W-1 and W-5 return to port at 1600.
17 March 1943:
At 0800 W-1 departs Sasebo.
18 March 1943:
At 1130 arrives at Seso, Amami-Oshima.
19 March 1943:
At 1700 departs Seso.
20 March 1943:
At 0900 arrives at Naha.
25 March 1943:
At 0800 departs Naha.
1 Apri1 1943:
Reassigned to the Yokosuka Guard Unit. Attached to the Yokosuka Naval District Force Yokosuka Defense Force First Minesweeper Force.
12 Apri1 1943:
Arrives at Yokosuka.
22 April 1943:
Attached to the Megawa area. Conducts convoy escort duties in the Aomori, Iwate and Miyagi areas.
8 July 1943:
Off Sanriku Bight, NE Honshu. At 0936 (K), LtCdr Harry B. Dodge's USS SEAL (SS-183) fires three torpedoes at a 5,000-ton freighter in a three-ship convoy and misses. An Aichi E13A1 "Jake" patrol floatplane from the Yamada Bay detachment, escorting the freighter, attacks the submarine at 0940 with two depth bombs. W-1, escorting the same convoy, joins the hunt at 0944, dropping two depth charges.
Another E13A1 patrolling in that area spots an oil slick, moving north. Its pilot alerts W-4 and the auxiliary minesweeper MISAGO MARU No. 1, who chase the submarine until 1213. As a result of damage received in the course of several successive attacks, USS SEAL is forced to terminate her seventh war patrol.
July 1943:
Lt Okuhara Koichi is appointed Commanding Officer.
1 June 1944:
At 0608 departs Yamada.
4 June 1944:
At 1529 arrives at Yamada after escorting convoy No. 2601A consisting of KOUSEI and SHINNAN MARUs and possibly others.
7 June 1944:
At 0152 departs Yamada and escorts TAIKO MARU (897 gt). Then escorts SHUYO MARU.
9 June 1944:
At 0438 arrives at Yamada.
13 June 1944:
At 1735 departs Yamada.
14 June 1944:
At 1621 arrives at Yamada.
16 June 1944:
At 1125 departs Yamada. Meets up with and escorts YUKIKAWA MARU, then HACHIJIN MARU and finally SAGAMIGAWA MARU.
18 June 1944:
W-29 takes over escort of firstly HACHIJIN and later SAGAMIGAWA MARUs. At 1713 W-1 arrives at Yamada.
22 June 1944:
At 0800 departs Yamada.
23 June 1944:
At 0620 arrives at Onagawa and departs there at 2200.
25 June 1944:
At 1037 arrives at Yamada.
28 June 1944:
At 1000 departs Yamada.
29 June 1944:
At 1915 arrives at Yamada.
4 July 1944:
At 1300 departs Yamada and escorts CHOZAN MARU headed south, and later joins convoy No. 1704 heading north consisting of one unidentified ship. Then escorts SAGAMIGAWA MARU being towed by salvage tug NASU MARU.
5 July 1944:
At 0800 arrives at Onagawa.
6 July 1944:
At 0400 departs Onagawa.
7 July 1944:
At 0850 arrives at Yamada.
8 July 1944:
At 0500 departs Yamada.
10 July 1944:
At 1308 arrives at Yamada.
12 July 1944:
At 1900 departs Yamada to escort convoy No. 1711. Later begins escorting convoy No. 2713B.
14 July 1944:
At 1914 arrives at Yamada.
16 July 1944:
At 0800 departs Yamada and joins and escorts ferry SEIKAN MARU No. 7 that is headed north.
18 July 1944:
At 1021 arrives at Yamada.
21 July 1944:
At 1000 departs Yamada.
22 July 1944:
At 1500 arrives at Onagawa.
23 July 1944:
At 0900 departs Onagawa and at 1920 arrives at Yamada.
25 July 1944:
At 0600 departs Yamada and joins SHINRYU MARU.
26 July 1944:
Escorts convoy No. 2726.
27 July 1944:
At 0930 arrives at Yokosuka. Drydocked.
18 August 1944:
Undocked.
20 August 1944:
Departs Yokosuka.
21 August 1944:
Arrives at Yamada.
23 August 1944:
Departs Yamada.
24 August 1944:
Arrives at Yamada.
28 August 1944:
Departs Yamada and joins tanker SEIKO MARU No. 2.
29 August 1944:
Arrives at Yamada.
31 August 1944:
Departs Yamada.
1 September 1944:
At 1631 arrives at Onagawa.
2 September 1944:
At 1000 departs Onagawa and later that day at 1630 arrives at Yamada.
7 September 1944:
At 0357 departs Yamada and later that day at 1201 arrives at Onagawa.
8 September 1944:
At 1114 departs Onagawa.
9 September 1944:
At 0800 arrives at Yamada with W-29 but both return to port later that day at 1245 .
13 September 1944:
Departs Yamada.
14 September 1944:
Arrives at Yamada.
15 September 1944:
Departs Yamada and later that day arrives at Hachinohe.
16 September 1944:
Departs Hachinohe escorting YUZUKI MARU.
17 September 1944:
At 1514 arrives at Yamada.
19 September 1944:
At 1345 departs Yamada and joins convoys No. 2919A and 2919B.
21 September 1944:
Ar 1547 arrives at Yamada.
23 September 1944:
At 0923 departs Yamada and later joins convoy No. 2924 consisting of SHINKYU and SHINMEI MARUs.
25 September 1944:
At 0814 arrives at Yamada.
28 September 1944:
At 1452 departs Yamada.
29 September 1944:
At 0951 arrives at Onagawa and departs there at 2357.
30 September 1944:
Arrives at Yamada.
2 October 1944:
Departs Yamada.
3 October 1944:
Arrives at Onagawa and departs later the same day. Joins and escorts UZUKI MARU.
4 October 1944:
Arrives at Yamada.
9 October 1944:
Departs Yamada and meets up and escorts SHINKO MARU.
10 October 1944:
Arrives at Onagawa.
11 October 1944:
Departs Onagawa and meets up with AWA MARU and then convoy No. 1010.
12 October 1944:
Arrives at Yamada.
17 October 1944:
Departs Yamada and meets up with convoy No. 2017.
18 October 1944:
Arrives at Onagawa and departs later the same day. Joins convoy No. 2018.
19 October 1944:
Arrives at Yamada.
22 October 1944:
Departs Yamada and meets up with an unknown convoy consisting of HOKURYU, KATSURAGAWA and SHINSEN MARUs. Later escorts HOKURYU MARU after this ship detaches from the convoy.
23 October 1944:
Arrives at Onagawa.
24 October 1944:
Departs Onagawa and later that day arrives at Yamada.
27 October 1944:
Departs Yamada and escorts tanker TOSEI MARU No. 3 then convoy No. 2027 probably consisting of RYUHO MARU No. 1 and INARI MARU.
28 October 1944:
Arrives at Onagawa.
29 October 1944:
Departs Onagawa.
30 October 1944:
Arrives at Yamada.
1 November 1944:
Departs Yamada and escorts TAISHUN MARU.
2 November 1944:
Arrives at Yamada.
4 November 1944:
Departs Yamada.
5 November 1944:
Arrives at Onagawa.
6 November 1944:
Departs Onagawa and later that day arrives at Yamada.
11 November 1944:
Departs Yamada.
12 November 1944:
Arrives at Yamada.
13 November 1944:
Departs Yamada and joins convoy No. 1111 and later that day arrives at Onagawa.
14 November 1944:
Departs Onagawa and later that day arrives at Shiogama where the ship is docked for repairs.
On that day, FRUMEL provides the following [incorrect] information: "Convoy of 3 ships escorted by KURETAKE and Minesweepers 1, 3, and 7, left Manila at 1800 on 12th for Takao.
Noon positions: 13th: 14___N. 118-58E. 14th: 16-49N. 117-36E. 15th: 19-15N. 118-13E.16th: 21-12N. 119-41E." [2]
23 November 1944:
Departs Shiogama and later that day arrives at Onagawa.
24 November 1944:
Departs Onagawa and later that day arrives at Yamada.
27 November 1944:
Departs Yamada.
28 November 1944:
Arrives at Onagawa.
29 November 1944:
Departs Onagawa and later that day arrives at Yamada.
December 1944:
An unknown officer is appointed Commanding Officer.
3 December 1944:
Departs Yamada and meets up with convoy No. 2101 and then convoy No. 1201.
4 December 1944:
Arrives at Hachinohe and departs later that day.
5 December 1944:
Arrives at Yamada.
6 December 1944:
Departs Yamada and meets up with SHINYO MARU No. 3.
7 December 1944:
Arrives at Yamada.
10 December 1944:
Departs Yamada and escorts an unidentified convoy (likely convoy No. 2210A) consisting of NANREI and DAIGEN MARUs.
11 December 1944:
Arrives at Yamada.
14 December 1944:
Departs Yamada and escorts convoy No. 2214A.
15 December 1944:
Arrives at Onagawa.
16 December 1944:
Departs Onagawa and later that day arrives at Yamada.
18 December 1944:
Departs Yamada.
19 December 1944:
Arrives at Yamada.
23 December 1944:
Departs Yamada.
24 December 1944:
Arrives at Onagawa.
25 December 1944:
Departs Onagawa and escorts the water tanker SHINSUI MARU and later that day arrives at Yamada.
3 January 1945:
Indian Ocean. Andaman Islands. Lt D. Swanston's submarine HMS SHAKESPEARE surfaces and engages an armed medium-size supply ship. The merchant replies unsuccessfully to HMS SHAKESPEARE's fire, but the submarine manages to score three hits.
A warship alleged to be W-1, summoned by the supply ship, approaches the scene at high speed. Lt Swanston attempts to dive, but a shell from the supply ship penetrates HMS SHAKESPEARE's pressure hull and renders her unable to submerge. Swanston’s gun crews man their 3-inch, 20-mm Oerlikon and Vickers machine gun to fight it out on the surface.
The British silence the supply ship’s gun. Then HMS SHAKESPEARE concentrates her fire on the warship. During the engagement, the submarine is hit four more times. Finally, HMS SHAKESPEARE's gunners hit the warship in the engine room and disable her. The warship goes dead in the water and the submarine pulls out of range.
The unidentified warship alerts seaplanes at Port Blair that arrive and attack the submarine. The air attacks continue for eight hours until the arrival of darkness. Later, submarine HMS STYGIAN arrives and tows HMS SHAKESPEARE to Trincomalee, Ceylon. [3]
January 1945:
The above unidentified ship undergoes repairs at an unknown location.
11 January 1945:
At 1055 departs Yamada. Escorts SHINNAN MARU.
12 January 1945:
At 1121 arrives at Kamaishi.
13 January 1945:
At 0801 departs Kamaishi. Escorts TAKUSAN MARU and then convoy 2111 and later that day at 1011 arrives at Yamada.
19 January 1945:
At 1155 departs Yamada and meets up with convoy No. 2118 consisting of MUSASHI MARU.
20 January 1945:
At 1252 arrives at Onagawa.
22 January 1945:
At 0855 departs Onagawa and later that day at 1541 arrives at Yamada.
23 January 1945:
Departs Yamada and later that day returns to port.
28 January 1945:
At 1008 departs Yamada and escorts MUSASHI MARU then convoy No. 2128. At 1555 arrives at Onagawa.
29 January 1945:
At 1045 departs Onagawa and at 1730 arrives at Yamada.
E 1 March 1945:
Departs Yamada and escorts convoy No. 2228A before returning to Yamada.
8 March 1945:
Departs Yamada and escorts convoy No. 2307 and then convoy No. 2308B.
9 March 1945:
Arrives at Yamada.
10 March 1945:
Departs Yamada and later that day returns to Yamada.
18 March 1945:
Departs Yamada.
19 March 1945:
Arrives at Yamada.
24 March 1945:
Departs Yamada and escorts convoy No. 2324.
25 March 1945:
Arrives at Yamada.
30 March 1945:
Departs Yamada.
31 March 1945:
Arrives at Hachinohe.
1 April 1945:
Departs Hachinohe escorting EISO MARU.
2 April 1945:
Arrives at Yamada.
5 April 1945:
Departs Yamada escorting the ammunition ship SOYA but returns to port later that day.
6 April 1945:
Departs Yamada but returns to port later that day.
7 April 1945:
Arrives at Yamada.
11 April 1945:
Departs Yamada.
12 April 1945:
Arrives at Yamada.
14 April 1945:
Departs Yamada.
15 April 1945:
At 2330, USN codebreakers intercept and decrypt a message from the CO of W-1 that reads: “Commander Minesweeper Division No. 28 was killed when W-3 sank on the 9th after being hit by a torpedo.”
16 April 1945:
Off Yamada W-1 meets up with convoy No. 1415 consisting of HOKOKU, KOAN and SHINKYO MARUs bound for Hokkaido.
17 April 1945:
Arrives at Yamada.
18 April 1945:
Departs Yamada to escort UKISHIMA MARU but returns to port later that day.
22 April 1945:
Departs Yamada escorting ammunition ship SOYA and later SHINKO MARU
24 April 1945:
Arrives at Yamada.
26 April 1945:
Departs Yamada.
27 April 1945:
Arrives at Yamada.
28 April 1945:
Departs Yamada.
30 April 1945:
Arrives at Yamada.
4 May 1945:
Departs Yamada.
8 May 1945:
Arrives at Yamada and departs later the same day.
9 May 1945:
Arrives at Yamada and departs later the same day.
10 May 1945:
The First Minesweeper Force is demobilized. Attached to the Yokosuka Naval District Force Yokosuka Defense Force.
15 May 1945:
Arrives at Yamada.
17 May 1945:
Departs Yamada.
27 May 1945:
Arrives at Yamada.
30 May 1945:
Departs Yamada.
15 July 1945:
Attached to the Yokosuka Naval District Force Seventh Suicide Attack Force.
22 July 1945:
At 1600, W-1 and subchaser CH-42 depart Yohohama for Hakodate, Hokkaido escorting ENBUN MARU and HAKUTETSU MARU No. 5. The convoy assembles at Tateyama and departs at 2100. At 2300, off Cape Nojima the convoy comes under fire from eight American destroyers at a range of 3.5 miles. Both ENBUN MARU and HAKUTETSU MARU No. 5 are hit. Fires are started on HAKUTETSU MARU No. 5.
23 July 1945:
In the early morning, carrier-based planes arrive and bomb and strafe the convoy. ENBUN MARU reverses course back to Tateyama. HAKUTETSU MARU No. 5 sinks while under tow to Yohohama. The convoy is dissolved.
10 August 1945:
Yamada Bay, Iwate, Japan. Carrier-based planes from Task Force 38 of Admiral (later Fleet Admiral) William F. Halsey's (USNA ’04) Third Fleet, probably Curtiss SB2C-3 “Helldiver” dive-bombers of USS RANDOLPH's (CV-15) VB-16; attack and sink W-1 and subchaser CH-42 at 38-26N, 141-30E.

15 August 1945:
The End of Hostilities.
15 September 1945:
Officially deactivated.
3 May 1947:
Removed from the Naval list under instruction No. 327.

Author's Notes:
[1] Little data were found by the authors detailing W-1's movements during July 1943-May 1944 and February-July 1945. 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

[2] This is convoy MATA-32 that was actually being escorted by KURETAKE, CD-1, CD-3 and CD-7. An example of how Allied codebreakers sometimes got it wrong. W-1 was operating off the coast of Japan at this time.
[3] This is almost certainly wrong and was likely either Wa-3 or Wa-7. Another source claims it was Wa-1 not W-1 that was escorting AGATA MARU. Wa-1 had already been sunk by this time however. Nevertheless very strong doubt exists that W-1 was involved in this action.
Special thanks go to Hans Mcilveen of the Netherlands for info on FRUMEL intercepts.Thanks go to Sander Kingsepp of Estonia, John Whitman of the USA for info on CNO intercepts of Japanese messages, Matthew Jones for information on Commanding Officers, and to Gilbert Casse of France and Berend van der Wal of Netherlands for ongoing general assistance. Thanks go to readers Berend van der Wal of the Netherlands and George Kernahan of UK, a USN carrier aircraft researcher for info in Rev 8
-Bob Hackett and Peter Cundall.

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