KUSENTEI!

© 2005-2009 Bob Hackett, Sander Kingsepp and Peter Cundall

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1941:
Osaka. Laid down at the Sakurajima Iron Works shipyard.

21 May 1941:
Launched and numbered CH-21.

20 August 1941:
Completed and registered in the Kure Naval District.

8 December 1941:
Assigned to the Kure Guard Unit. Conducts patrols in the Bungo Straits.

February 1942:
Reassigned to Rear Admiral (later Vice Admiral) Kubo Kuji's (former CO of KAGA) 1st Base Force of Vice Admiral Ibo Takahashi's Third Fleet. Escorts the Bali, Java Invasion Force.

10 March 1942:
Makassar, Celebes (now Sulawasei). Reassigned to the 2nd Southern Expeditionary Fleet in Captain (later Vice Admiral)(40) (former XO of ATAGO) Mori Kunizo's 23rd Special Base Force with CH-19 and CH-20. Escorts convoys.

29 July 1942: Operation "T" - The Banda Sea Operations:
At 1500, the 3rd Attack Force departs Ambon, Moluccas. The force includes the 23rd Special Base Force's CH-21, carrying one company of Special Base Force 24 and CH-5 of Special Base Force 22 carrying a platoon of the 3rd Yokosuka Special Naval Landing Force (SNLF). Cover is provided by DesDiv 5's ASAKAZE, HAURUKAZE and MATSUKAZE of the 1st Southern Expeditionary Fleet.

August 1942:
Reassigned to the 11th Base Force at Saigon, Indochina in Vice Admiral (37)(former CO of HIEI) Okawachi Denshichi 's 1st Southern Expeditionary Fleet.

18 January 1943:
CH-21 joins fleet supply ship NOJIMA at 01-50S, 148-10E and escorts her to Rabaul.

15 February 1943:
At 1600, departs Truk escorting an unknown ship.

April 1943:
Escorts convoys to Penang.

11 July 1943:
South China Sea. At 1800, CH-21 departs Billiton Island for Rangoon, Burma escorting a convoy consisting of TAMASHIMA MARU and three unidentified ships.

26 July 1943:
The three unidentified ships are detached.

28 July 1943:
Tavoy Sea. At 1425, the convoy is attacked by B-24 "Liberator" bombers at 13-53N, 97-40E. The bombers score several hits on TAMASHIMA MARU and at 1448 she sinks. It is unclear where CH-21 makes port.

20 November 1943:
At 1500, CH-21 departs Rabaul escorting convoy O-006 consisting of NAPLES MARU and two unidentified merchant ships. That evening, the convoy is bombed by a PBY "Catalina" that sinks NAPLES MARU.

28 November 1943:
At 0500, arrives at Truk.

18 January 1944:
CH-21 departs St Jacques escorting convoy No. 458 consisting of eight unidentified merchant ships.

19 January 1944:
Arrives at Camranh Bay and waits because of submarine threat.

25 January 1944:
Departs Camranh Bay.

31 January 1944:
Arrives at Takao.

28 January 1944:
CH-21 departs St Jacques escorting convoy No. 460 consisting of six unidentified merchant ships.

30 January 1944:
Convoy No. 460 merges with convoy TE-02 from Yulin consisting of four unidentified merchant ships escorted by destroyer SHIOKAZE.

E 4 February 1944:
Arrives at Takao.

9 February 1944:
Southern Indochina. At about noon, while TONAN MARU No. 2 is enroute to Nagasaki, LtCdr Thomas W. Hogan’s USS BONEFISH (SS-223) torpedoes and damages her at 11-30N, 109-08E. Hogan claims four hits out of five torpedoes he fires.

Later that day, USN codebreakers intercept and decrypt a message that reads: "Order to Subchasers No. 21, 41, and 43 to attack the submarine that attacked TONAN MARU No. 2.

6 March 1944:
CH-21 departs Takao for Cap St Jacques, Indochina via Yulin, China with subchasers CH-41 and CH-43 and auxilary gunboat PEKING MARU escorting convoy TASA-08 consisting of NICHIREI, LONDON, ISHIKARI and TOYOKUNI MARUs and four unidentified ships.

8 March 1944:
SE of Hong Kong. At 1455, LtCdr Lowell T. Stone’s USS LAPON (SS-260) torpedoes and damages TOYOKUNI MARU. She loses power and goes dead in the water. NICHIREI MARU takes her in tow.

9 March 1944:
At 0150, while NICHIREI MARU is still towing TOYOKUNI MARU, LAPON torpedoes NICHIREI MARU. LtCdr Stone also torpedoes and hits TOYOKUNI MARU again. She floods and sinks. At about 0500, NICHIREI MARU sinks. CH-21 and the other escorts, including an aircraft, counterattack, but fail to damage LAPON.

10 March 1944:
Arrives at Quinhon, Indochina.

14 March 1944:
Arrives at St Jacques (Saigon).

23 March 1944:
CH-21 and CH41 depart St Jacques escorting convoy SATA-12 consisting of six unidentified merchant ships.

27 March 1944:
Arrives at Manila. Both escorts are detached.

29 May 1944:
CH-21 departs St Jacques escorting convoy SASHI-23 consisting of five unidentified merchant ships.

2 June 1944:
Arrives at Singapore.

11 June 1944:
CH-21 departs Kau Bay, Halmahera with second class destroyer TSUGA, patrol boat PB-104, subchaser CH-38, auxiliary netlayer KOREI MARU and auxiliary gunboat KAZAN MARU escorting convoy H-27 (return) consisting of AKAGISAN, KOAN, SORACHI, SHIROGANESAN, YOZAN and TAIYU MARUs and YOSHIDA MARU No. 3.

12 June 1944:
TSUGA and CH-38 are detached for Davao.

14 June 1944:
At 1003, LtCdr Willard R. Laughon's USS RASHER (SS-269) torpedoes and sinks KOAN MARU at 04-33N, 122-23E.

20 June 1944:
At 0925, arrives Manila.

25 June 1944:
At 1915, CH-21 departs Miri for Singapore with kaibokan CD-18, torpedo boat SAGI, minesweeper W-17 and auxiliary minesweepers CHOUN MARU No. 6 and TOSHI MARU No. 2 escorting convoy MISHI-03 consisting of fleet oiler NOTORO and tankers SAN DIEGO, NICHIYO, HIDA, FUYUKAWA, AYANAMI, KYOEI No. 8, BAIEI, NIPPO (ex-Swedish NINGPO), DAIZEN, TEIFU (ex-BOUGAINVILLE), SEIWA, SURAKARTA, HINAGA, MANILA, ARIMASAN, ROKKO, TATSUTAMA (ex-American SS ADMIRAL Y. S. WILLIAMS), TOA, KENZUI and JINEI MARUs.

28 June 1944:
South China Sea. Off Singapore. At 2100, Cdr (later Rear Admiral) Rueben T. Whitaker’s USS FLASHER's (SS-249) radar picks up the convoy. Whitaker, operating in relatively shallow water (150 feet) decides to wait until after the moon sets to make a surface attack.

29 June 1944:
At 0117, two or three torpedoes hit NIPPO MARU and two or three torpedoes hit NOTORO. NIPPO MARU breaks in two and sinks by the bow. NOTORO remains afloat, but goes dead in the water. The escorts begin blindly dropping depth charges. Whitaker, still on the surface, leaves the area on four engines.

30 June 1944:
At 1437, convoy MISHI-03 arrives at Singapore.

2 July 1944:
CH-21 departs Singapore escorting convoy SHISA-23 consisting of four unidentified merchant ships.

6 July 1944:
Arrives at St Jacques.

11 July 1944:
CH-21 departs Saigon with auxiliary gunboat CHOJUSAN MARU escorting convoy SAMA-09 consisting of three unidentified merchant ships.

17 July 1944:
Arrives at Manila.

23 July 1944:
At 0700, CH-21 departs Manila with minesweeper W-34 escorting convoy MASA-09 consisting of RAKUYO, NICHINAN and CHINZEI MARUs.

28 July 1944:
At 1800, arrives at St Jacques.

21 August 1944:
CH-21 departs Manila with patrol boat PB-104 escorting convoy MAYU-07 consisting of three unidentified merchant ships.

25 August 1944:
Arrives at Yulin.

28 August 1944:
At 0400, CH-21 departs Yulin, Hainan Island with patrol boat PB-104 escorting convoy YUTA-11 consisting of MITSUKI, SAIHO, ATLAS, KOKKA and HOKOKU MARUs.

2 September 1944:
Arrives at Keelung (Kirun), Formosa.

5 September 1944:
CH-21 departs Keelung for Moji with patrol boats PB-102 and PB-104 escorting convoy TAMO-25 consisting of SAIHO, MITSUKI, ATLAS, KOKKA, HENGSHAN, MEIRYU, TATSUSHO and TATSUTAMA MARUs. KOKKA MARU runs aground shortly after leaving Keelung. Later, she is refloated and returns to Keelung.

10 September 1944:
CH-21 is reassigned to the Southwest Area Fleet’s Third Southern Expeditionary Fleet's 21st Subchaser Division with CH-19 and CH-20.

11 September 1944:
Arrives at Moji.

23 September 1944:
At 1600, CH-21 departs Moji for Takao with kaibokan DAITO, patrol boat PB-104, auxiliary gunboat KAZAN (HUASHAN) MARU and auxiliary subchasers CHa-87 and CHa-92 escorting convoy MI-21 consisting of TEIKA, TSUYAMA, EJIRI, FUSHIMI, KEISHIN, KEIZAN, CHOSAN, TATSUBATO, KENEI and YOSHU MARUs and tankers SAN LUIS, SHUNTEN and EIKYO MARUs and an unidentified ship.

29 September 1944:
At 1700, arrives at Takao where the convoy is dissolved.

1 October 1944:
At 1700, CH-21 departs Takao with patrol boat PB-104, kaibokan DAITO and YASHIRO, auxiliary gunboat KAZAN (HUASHAN) MARU and auxiliary submarine chasers CHa-87, CHa-92 escorting convoy TAMA-28 consisting of TSUYAMA, CHOSAN, MURORAN, MACASSAR, FUYUKAWA, SHINSEI and TAISEI MARUs.

2 October 1944:
Luzon Strait. At about 2200, during a storm, LtCdr Frank C. Acker's USS POMFRET (SS-391) torpedoes and sinks TSUYAMA MARU at 20-51N, 121-31. TSUYAMA MARU was carrying 1600 men of the Mobile 18th Infantry Regiment and a total of 1273 men on board are killed. POMFRET then torpedoes and damages MACASSAR MARU at 21-02N, 121-36.

7 October 1944:
At about 0500, LtCdr Henry C. Stevenson's USS ASPRO (SS-309) torpedoes and sinks MACASSAR MARU at 17-30N, 119-53E.

8 October 1944:
At 1745, arrives at North San Fernando.

11 October 1944:
At 0600, departs North San Fernando. At 1748, arrives at Masinloc anchorage.

12 October 1944:
At 1320, departs Masinloc.

13 October 1944:
At 0400, arrives at Manila.

17 October 1944:
Manila. Japanese naval authorities, fearing another air attack by Vice Admiral John S. McCain's Task Force 38, order a number of ships out of Manila to relieve congestion in the harbor.

At 1820, CH-21 departs Manila with destroyer SHIOKAZE, auxiliary gunboat KAZAN (HUASHAN) MARU and torpedo boat HIYODORI escorting the "Taihi" (Refugee) convoy consisting of MANILA, EIMAN, TEIFU, DAIIKU, KENEI, DAIMEI, SHIRANESAN, ARABIA, SHINSEI and TAIKAI MARUs and NICHIYU MARU No. 2 and tanker KYOEI MARU No. 6.

18 October 1944:
At 0716, LtCdr (later Captain) Eric L. Barr's USS BLUEGILL (SS-242) torpedoes and damages ARABIA MARU at 14-4N, 119-52E. CH-21 attends the casualty and is joined by patrol boat PB-104 and HAKKO MARU from a separate small convoy. At 1208, BLUEGILL torpedoes ARABIA MARU again. She was carrying 3,500 men of the IJA's 20th Infantry Division. She sinks taking down 1,658 troops and 89 crewmen and gunners. After rescuing survivors, patrol boat PB-104 and HAKKO MARU return to Manila with survivors. CH-21 remains with the convoy.

At 2210, LtCdr Maurice W. Shea's USS RATON (SS-270) attacks the convoy at 12-30N, 119-10E. RATON torpedoes and sinks SHIRANESAN and TAIKAI MARUs.

19 October 1944:
At 0600, CH-21 is detached and makes for Manila. Soon after arrival, TF 38 attacks Manila harbor. CH-21 and patrol boat PB-104 are ordered to rejoin the convoy and depart at 0905.

20 October 1944:
At 1220, arrives at Bacuit Bay, Palawan Island.

21 October 1944:
At 0855, departs Bacuit Bay.

22 October 1944:
Attacked by B-24 "Liberator" heavy bombers.

23 October 1944:
Attacked by B-24 bombers.

24 October 1944:
At 1958, arrives at Gaya Bay, north Borneo. Some ships separate at this point.

26 October 1944:
At 0635, departs Gaya Bay. At 1835, arrives at Labuan.

27 October 1944:
At 1045, departs Labuan.

28 October 1944:
At 1650, arrives at Miri. At some point before arrival, EIMAN, DAIIKU, DAIMEI and NICHIYU MARU No.2 are detached from the convoy.

1 November 1944:
At 1200, CH-21 departs Miri with destroyer SHIOKAZE and torpedo boat HIYODORI escorting convoy MI-20 consisting of tankers DAIMEI, SHUNTEN, DAISHU and SAN DIEGO MARUs.

3 November 1944:
At 0100, LtCdr Norman D. Gage's USS GURNARD (SS-254) torpedoes and sinks DAIMEI MARU at 05-53N, 111-12E.

5 November 1944:
At 1430, arrives at Cap St Jacques.

30 December 1944:
At 0800, CH-21 and CH-18 depart North San Fernando for Takao, Formosa with old destroyer KURETAKE and three other unidentified escorts escorting convoy MATA-38 consisting of MURORAN, TEIKAI, KAZUURA and NISSHO MARUs.

Off Santiago Island, Luzon. At 1310, the convoy undergoes a series of air attacks by 26 of Fifth Air Force's B-25 “Mitchell” medium bombers, A-20 “Havoc” light bombers and P-40 “Warhawk” fighters that skip bomb at low level. CH-18 is hit and sunk as are MURORAN and TEIKAI MARUs. The planes also damage KAZUURA and NISSHO MARUs near Lingayen Gulf at 17-11N 120-45E.

Bashi Channel, 60 miles SE of Formosa. During the bombing, LtCdr Charles D. Brown's USS RAZORBACK (SS-394) sneaks in on the surface. In two attacks, Brown fires six torpedoes at destroyer KURETAKE, of which two hit and blow her bow off. She sinks at 21N, 121-24E.

2 January 1945:
Arrives at Takao.

5 February 1945:
At 0700, CH-21 departs Moji with kaibokan CD-40 and CD-69 escorting convoy MOHO-02 consisting of MIHO, KINSEN, PEKING and BANSAI MARUs.

9 February 1945:
At 1915, anchors at Chusan (Shoushan or Choushan) Islands.

10 February 1945:
Departs the anchorage.

14 February 1945:
At 1100, arrives at Hong Kong.

18 February 1945:
departs Keelung escorting convoy TAHO-01 consisting of 2 unidentified merchant ships escorted by minelayer Niizaki, destroyer Kiri and submarine chaser CH21.

21 February 1945:
Arrives at Hong Kong.

5 March 1945:
CH-21 is reassigned to the General Escort Command’s First Escort Fleet’s 31st Subchaser Division with CH-19, CH-20, CH-26 and CH-60.

8 March 1945:
CH-21 departs Yulin for Moji with kaibokan MIKURA, CD-33, CD-36 and CD-69 escorting convoy YUMO-01 consisting TATSUMIYA MARU. At 1959, the convoy is attacked at sea by USAAF 14th Air Force B-24 “Liberator” heavy bombers that severely damage CD-69 at 19-02, 111-50E. CD-69 is taken in tow and drops behind the convoy. The convoy seeks shelter at an anchorage on the eastern side of Hainan Island.

9 March 1945:
At 0806, USN codebreakers intercept and decrypt a message from CD-36 that reads: “At 1959 [on the 8th], Coast Defense Vessel No. 69 was bombed by enemy aircraft in position 19-02N, 110-56E. -----. Killed on Coast Defense Vessel No. 69: 3 (warrant officers and above?) and 23 ratings. Severely wounded ------. No damage to this vessel.”

Formosa Straits. A USN PB4Y “Liberator” carries out an unsuccessful attack on CH-21 at 22-23N, 115-03E.

11 March 1945:
Departs the anchorage.

12 March 1945:
At 1820, codebreakers decrypt a message from MIKURA that reads: “Under bombing attack in position 20-40 N., 111-57E.”

13 March 1945:
Arrives at Hong Kong. CD-33 probably is detached.

14 March 1945:
Departs Hong Kong.

15 March 1945:
At 1030, USAAF B-24s attack convoy YUMO-01 consisting of unidentified ships that departed Hong Kong the day before escorted by CD-36 and CH-21. They are both damaged at 23-03N 115-52E. CH-21 runs aground near Namoa Island, but is later refloated.

16 March 1945:
Eight miles off Hong Kong. CD-69 sinks while in tow at 22-00N, 113-40E. MIKURA, undamaged, arrives at Hong Kong with CD-33.

At 1136, codebreakers decrypt a message from the CO of CD-69 that reads: Because of heavy seas the engine room was cut off and at 0714 we sank quickly in position bearing 1300 (sic), 8 miles distant from Mawei------.”

17 March 1945:
Arrives at Ssu Chiao Shan.

21 March 1945:
Departs Ssu Chiao Shan.

25 March 1945:
Arrives at Moji.

March 1945:
Arrives at Sasebo. Undergoes repairs.

April 1945:
Reassigned to the General Escort Command’s First Escort Fleet’s 103rd Escort Squadron.

10 April 1945:
Departs Sasebo for Chinhae (Jinhae), Korea.

11 April 1945:
Arrives at Chinhae. Later, engages in convoy escort and patrol duties.

September 1945:
Maizuru. Surrendered to Allied Forces.

5 October 1945:
Removed from the Navy List.

22 November 1945:
Departs Hakata.

23 November 1945:
Arrives at Moppo (Mokpo) and departs later that day.

24 November 1945:
Arrives at Hakata.

4 December 1945:
Departs Hakata and later that day arrives and departs Pusan.

5 December 1945:
Arrives at Hakata.

1 December 1945:
Forally assigned to the Allied Repatriation Service.

8 December 1945:
Departs Hakata and later that day arrives and departs Pusan.

9 December 1945:
Arrives at Hakata.

21 December 1945:
Departs Hakata.

23 December 1945:
Arrives at Moppo (Mokpo) and departs later that day.

26 December 1945:
Arrives at Hakata.

6 January 1946:
Departs Hakata.

7 January 1946:
Arrives at Pusan and departs later that day.

9 January 1946:
Arrives at Shanghai.

12 January 1946:
Departs Shanghai.

15 January 1946:
Arrives at Hakata.

26 January 1946:
Departs Hakata.

27 January 1946:
Arrives at Pusan and departs later that day.

29 January 1946:
Arrives at Shanghai and departs later that day.

1 February1946:
Arrives at Hakata.Under repair there until 1 April 1946.

1 April 1946:
Repairs are completed. Departs Hakata.

4 April 1946:
Arrives at Shanghai and departs later that day.

6 April 1946:
Arrives at Hakata

9 April 1946:
Undergoes repairs at Kagoshima.

17 April 1946:
Repairs are completed.

23 April 1946:
Departs Sasebo.

25 April 1946:
Arrives at Shanghai.

30 April 1946:
Departs Shanghai.

2 May 1946:
Arrives at Maizuru.

12 May 1946:
Undergoes repairs at Nagasaki.

22 May 1946:
Repairs are completed.

23 May 1946:
Departs Sasebo.

25 May 1946:
Arrives at Shanghai.

27 May 1946:
Departs Shanghai

30 May 1946:
Arrives at Sasebo.

5 June 1946:
Departs Sasebo.

7 June 1946:
Arrives at Shanghai.

8 June 1946:
Departs Shanghai.

12 June 1946:
Arrives at Sasebo.

17 July 1946:
Departs Sasebo.

19 July 1946:
Arrives at Korojima near Tsientsin

21 July 1946:
Departs Korojima.

27 July 1946:
Arrives at Hakata.

5 August 1946 :
Undergoes repairs at Kagoshima.

20 August 1946 :
Repairs are completed.

23 August 1946:
Departs Hakata.

27 August 1946:
Arrives at Korojima.

29 August 1946:
Departs Korojima.

1 September 1946:
Arrives at Hakata.

8 September 1946:
Departs Hakata.

12 September 1946:
Arrives at Korojima.

15 September 1946:
Departs Korojima.

19 September 1946:
Arrives at Hakata.

28 September 1946:
Departs Hakata.

2 October 1946:
Arrives at Korojima.

5 October 1946:
Departs Korojima.

8 October 1946:
Arrives at Hakata.

19 October 1946:
Departs Hakata.

23 October 1946:
Arrives at Korojima.

3 November 1946:
Departs Korojima.

5 November 1946:
Arives at Hakata.

19 November 1946:
Departs Hakata.

22 November 1946:
Arrives at Okinawa.

23 November 1946:
Departs Okinawa.

25 November 1946:
Arrives at Kure.

7 October 1947:
Singapore. Ceded to the United Kingdom as a war reparation.

1947:
Singapore. Scrapped.

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Authors' Note:
[1] Some sources list CH-21 as damaged by marine casualty on this date; other sources attribute the damage to USN carrier-based aircraft.

Thanks go to John Whitman of the USA for info on CNO intercepts of Japanese messages.

-Bob Hackett, Sander Kingsepp and Peter Cundall.

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