KUSENTEI!

© 2005-2011 Bob Hackett, Sander Kingsepp and Peter Cundall

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E 1942:
Koyagi. Laid down at Kawaminami’s shipyard.

1943:
Launched and numbered CH-51.

8 November 1943:
Completed and registered in the Yokosuka Naval District. Attached to the Yokosuka Guard Force.

December 1943:
Escorts an unidentified convoy to Chichi-Jima, Bonin Islands.

15 January 1944:
CH-51 departs Chichi-Jima for Minami Torishima (Marcus Island) accompanied by auxiliary netlayer KOGI MARU escorting YOSHIDA MARU.

18 January 1944:
LtCdr (later Rear Admiral) Reuben T. Whitaker's (USNA '34) USS FLASHER (SS-249) torpedoes and sinks YOSHIDA MARU at 23-46N, 151-30E.

YOSHIDA MARU was carrying 129 naval personnel, 116 civilian employees and 1,394-tons of military supplies. 76 passengers, eight crewmen and 15 gunners are KIA.

24 January 1944:
At 1200, arrives at Minami Torishima.

22 March 1944:
Tokyo Bay. CH-51 departs Kisarazu for Saipan with DesDiv 5's HATAKAZE, DesDiv 6's IKAZUCHI and DesDiv 32's TAMANAMI, torpedo boat OTORI, kaibokan HIRADO and NOMI and subchasers CH-48 and CH-54 escorting Marianas troop reinforcement convoy Higashi Matsu "East Pine" No. 3" consisting of 11 transports, and supply ship HAYASAKI.

25 March 1944:
The convoy is attacked by LtCdr B. E. Lewellen's (USNA '31) old USS POLLACK (SS-180). Lewellen sinks subchaser CH-54 and claims damage to several transports.

30 March 1944:
Arrives at Saipan.

3 June 1944:
At 1600, CH-51 departs Truk Atoll with kaibokan CD-6, subchasers CH-31, CH-32 and CH-20 escorting a convoy consisting of MOJI, IMIZU, TATSUGAWA, KOJUN, NITCHO, KYOEI MARUs and NANKO MARU No. 1 and 13 unidentified ships.

7 June 1944:
At 1140 arrives at Saipan.

11 June 1944:
At 0400, CH-51 departs Saipan for Tokyo Bay with kaibokan CD-4, torpedo boat OTORI, subchasers CH-33, CH-50 auxiliary subchasers CHa-20 and CHa-50, auxiliary minesweeper Wa-6 and auxiliary netlayer KOKKO MARU escorting convoy No. 4611 consisting of BATAVIA, HINKO, SHINTO (KAMISHIMA), IMIZU, NITCHO, REIKAI, TENRYUGAWA, KEIYO, BOKUYO (MUTSUYO), FUKOKU, MOJI, MAMIYA, IMARI and TATSUTAKAWA MARUs and 15 other unidentified ships.

12 June 1944: American Operation “Forager” – The Invasion of Saipan::
Vice Admiral (later Admiral) Richmond K. Turner’s (USNA '11) Task Force 52 lands Marine LtGen Holland M. Smith’s V Amphibious Corps and the invasion of Saipan begins. Vice Admiral (later Admiral) Marc A. Mitscher’s (USNA '10) Task Force 58 launches aircraft from 15 carriers to attack airfields, defenses and shipping in the Marianas.

At 0935, that same day, at 17-32N, 144-10E, TG 58.4’s carriers ESSEX (CV-9), LANGLEY (CVL-27) and COWPENSs (CVL- 25) find and decimate convoy No. 4611. They sink OTORI, KOKKU, BATAVIA, HINKO, SHINTO (KAMISHIMA), IMIZU, NITCHO, REIKAI, TENRYUGAWA, BOKUYO, FUKOKU, MOJI and TSUSHIMA MARUs and damage TATSUTAKAWA MARU, CD-4, CH-33, CH-50 and CH-51, CHa-20 and Wa-6. [1]

19 June 1944:
CH-51 arrives at Yokosuka and puts 3 wounded men ashore.

14 July 1944:
At 1440, CH-51 departs Tateyama for Iwo Jima with kaibokan CD-4, subchaser CH-50 and APD No. 2 escorting convoy No. 3714 consisting of NISSHU, HASSHO, KATASURAGAWA MARUs and UNKAI MARU No. 10

17 July 1944:
UNKAI MARU No. 10 straggles behind the convoy.

18 July 1944:
At about 0200, LtCdr 's Albert L. Becker's (USNA '34) USS COBIA (SS-245) torpedoes and sinks UNKAI MARU No. 10 at 28-58N, 139-04E. 19 crewmen are KIA.

At 0650, COBIA attacks the main convoy. Becker torpedoes and sinks NISSHU MARU at 28-40N, 139-25E. 48 IJA soldiers, three crewmen and 45 gunners are KIA.

29 July 1944:
CH-51 and CH-52 departs Tateyama for Chichi-jima with destroyer escort MATSU, flagship of the 2nd Convoy Escort Group's Commander Rear Admiral Takahashi Ichimatsu (40)(former CO of TSUGARU), destroyers HATAKAZE escorting convoy No. 3729 consisting of SHOGEN, TONEGAWA, ENJU, KYUSHU and HOKKAI MARUs and UNKAI MARU No.7.

That same day, light carrier ZUIHO, escorted by destroyer FUYUTSUKI, sorties from Yokosuka to provide air and anti-submarine cover for the convoy.

1 August 1944:
Arrives at Futami Harbor, Chichi-jima. Upon arrival, some of the cargo ships depart for Iwo Jima. Bad weather causes delays in unloading. ZUIHO and FUYUTSUKI, after maintaining position near the lzu Shichi Islands, make for the West Inland Sea..

4 August 1944:
About 0930, an air raid warning is received from Tokyo. All ships proceed to sea in convoy No. 4804. From 1030 on, the convoy is attacked by three waves of aircraft of Rear Admiral (Admiral-Ret) Joseph J. Clark's (USNA '37)(former CO of YORKTOWN, CV-10) Task Group 58.1. The first wave attacks the convoy 20 miles NW of Chichi-Jima. Destroyer HATAKAZE suffers rudder damage. At about 1100, CD-4 is near-missed by bombs fore and aft to starboard. She suffers slight damage with two men KIA. The Japanese claim shooting-down several aircraft.

In the second raid, ENJU MARU is sunk. The third strike occurs between 1600 and 1630, during which the majority of the ships succumb to torpedo attacks from both sides of the convoy. CD-12 incurs some damage. After organizing the rescue of the convoy’s survivors, flagship MATSU leads the still intact escort group and TONEGAWA MARU, the lone surviving cargo ship, northwards.

At 1254, Rear Admiral (Admiral-Ret) Laurance T. DuBose's (USNA '13) Task Unit 58.1.6 consisting of CruDiv 13’s USS SANTA FE (F) (CL-60), MOBILE (CL-63), BILOXI (CL-80) and OAKLAND (CL-95), DesDiv 100’s COGSWELL (DD-651), INGERSOLL (DD-652) and KNAPP (DD-653) and DesDiv 91’s IZARD (DD-589), CHARRETTE (DD-581), BURNS (DD-588) and BROWN (DD-546) is detached to sink the cripples.

At 1800, CD-4 sights DuBose's warships closing from the south. Rear Admiral Takahashi orders CD-4 to protect TONEGAWA MARU and continue fleeing while his flagship MATSU attempts to draw off the Americans. At 1930, MATSU is taken under fire and sunk by shell fire of COGSWELL, INGERSOLL and KNAPP at 27-40N, 141-48E. Rear Admiral Takahashi is KIA, as are all but six of MATSU's crew. He is promoted Vice Admiral, posthumously.

Later, the Americans overtake and sink TONEGAWA MARU. CH-51, HATAKAZE and CD-4 and CD-12 escape.

E 9 August 1944:
Arrives at Tateyama.

23 August 1944:
At 1400, CH-51 departs Yokosuka with auxilary minesweepers Wa-11 and Wa-14 escorting convoy No. 3823B consisting of midget submarine HA-66 towed by 479 grt NAGATA MARU, midget submarine HA-71 by 315 grt HAKUGIN MARU and midget submarine HA-75 by 376 grt FUYO MARU escorted by subchaser CH-51, auxilary minesweepers Wa-11 and Wa-14. The convoy's planned arrival at Chichi-jima is 1930, 27 Aug '44, but soon after departure encounters a typhoon. FUYO MARU later turns back to Tateyama with HA-75.

30 August 1944:
At 0530, HAKUGIN MARU and HA-71 arrive at Hachijo-Jima. At 2200, NAGATA MARU and HA-66 arrive at Chichi-jima.

1 September 1944:
CH-51 departs Yokohama with torpedo boat CHIDORI and kaibokan OKI escorting convoy No. 3901 consisting of KYUSHU MARU and TOKAI MARU No. 4. Arrives at Tateyama later that day.

5 September 1944 :
At 0700, departs Tateyama.

10 September 1944:
Arrives at Chichi Jima. At 1600, CH-51 departs for Yokosuka with kaibokan (ex-Chinese light cruiser) YASOJIMA and auxiliary subchaser TAKUNAN MARU No. 10 escorting convoy No. 4901A consisting of NAGATA and TAKUNAN MARUs and HAKUUN MARU No. 2.

11 September 1944:
At 0400, LtCdr Robert R. William's (USNA '34) USS FINBACK (SS-230) torpedoes and sinks HAKUUN MARU No. 2 at 27-45N, 140-00E. Four men are KIA. The remainder of convoy No. 4901A arrives at Yokosuka.

11 October 1944:
At 0800, CH-51 departs Yokosuka with kaibokan OKI escorting convoy No. 3009 consisting of MUTSUKI MARU.

16 October 1944 :
Arrives at Chichi Jima.

18 October 1944 :
At 1400, CH-51 departs Chichi-Jima. At 0955 arrives Hahajima. At 1055, 15 B-24 "Liberator" heavy bombers attack the convoy. After several near misses, MUTSUKI MARU has to be beached, a total loss. The convoy is dissolved.

5 December 1944:
CH-51 departs Yokosuka for Hachijo-Jima, Bonin Islands with subchaser CH-52 escorting an unidentified convoy. Enroute, CH-51 and CH-52 collide and suffer damage.

December 1944:
CH-51 returns to Yokosuka. Thereafter, undergoes repairs.

26 January 1945:
At 0900, CH-51 departs Yokosuka for Chichi-Jima with kaibokan CD-47, subchaser CH-52 and auxiliary subchaser TAKUNAN MARU No. 10 escorting convoy No. 3126 consisting of AITOKU, TAISHO, KYUSHU and RYUJIN MARUs. Anchors overnight at Tateyama.

29 January 1945:
At 0600, departs Tateyama.

29 January 1945:
At 2108, three North American B-25 “Mitchell” medium bombers attack the convoy. They hit auxiliary subchaser TAKUNAN MARU No. 10 with five rockets that leave her flooding and unnavigable. At about 0200, CH-52 takes her under tow, but the tow line parts and TAKUNAN MARU No. 10 sinks. CD-47 is also damaged by the planes, probably by strafing, at 27-45N, 142-00E.

30 January 1945:
The convoy arrives at Chichi-Jima and unloads. At 2230, all ships depart except RYUJIN MARU.

3 February 1945:
Arrives at Tateyama.

February 1945:
Escorts convoys to Hachijo-Jima.

7 March 1945:
Off Hachijo-Jima. CH-51 is damaged by aircraft.

24 June 1945:
CH-51 departs Yokosuka with kaibokan SHISAKA escorting convoy No. 1624 consisting of EIKAN, KAMITSU MARUs and fleet supply ship SOYA.

26 June 1945:
At 1030, LtCdr Woodrow W. McCrory's (USNA '38) USS PARCHE (SS-384) torpedoes and sinks KAMITSU MARU at 39-25N, 142-04E. 192 men are KIA.

PARCHE also damages EIKAN MARU that is beached on shore at Iwate Ken. After some cargo is salvaged, EIKAN MARU later breaks in two. After further attacks by carrier aircraft, she is abandoned.

During a counterattack by CH-51, PARCHE fires a Mark 27 "Cutie" acoustic homing torpedo at CH 51, but it misses. The convoy proceeds to Hakodate.

15 August 1945: End of Hostilities:
Yokosuka. CH-51’s crew is notified of Japan’s surrender.

15 September 1945:
Removed from the Navy List.

29 November 1945:
Undergoes repairs at Tsurumi Zosen.

1 December 1945:
Assigned to the Allied Repatriation Service and designated a special transport ship.

28 February 1946:
Repairs are completed, but CH-51 never makes any repatriation voyages.

1 August 1948:
Completes scrapping.

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Authors' Note:
[1] MAMIYA MARU is detached from the convoy and sunk three days later near Iwo Jima. TATSUTAGAWA MARU is left drifting and is finished off by gunfire three days later.

-Bob Hackett, Sander Kingsepp and Peter Cundall.

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