RIKUGUN BOKU KIKANSEN!

(ZENYO MARU, prewar)

AA Transport ZENYO MARU:
Tabular Record of Movement

© 201-2013 Bob Hackett and Gilbert Casse
Revision 3


5 November 1936:
Yokohama. Laid down at Mitsubishi Zosenshoís Yokohama Dock Co. as a 6,442-ton cargo ship for Toyo Kisen, K.K.

10 April 1937:
Launched and named ZENYO MARU.

7 July 1937: The "First China Incident" and the Beginning of the Second Sino-Japanese War:
Hun River, Lukuokiao, China. Imperial Japanese Army (IJA) troops on night maneuvers at the Marco Polo Bridge fire blank cartridges. Chinese troops across the river think they are under attack. They fire live round back, but do not cause injuries. At morning roll call, the Japanese discover a soldier missing and assume the Chinese have captured him. The Japanese demand entry to the Peiping (Beijing) suburb of Wanping to look for the soldier, but the Chinese refuse. The Japanese then shell the city. An undeclared war on China begins.

16 August 1937:
Completed and chartered by the Imperial Japanese Army (IJA) as a troop transport.

28 August 1937:
ZENYO MARU departs Ujina and arrives at Moji.

29 August 1937:
Departs Moji in a convoy also consisting of BAIKAL, MIZUHO, NOSHIRO, PINTUNG, SHINKO, YOSHINO and MARUs. ZENYO MARU carries 610 men and 313 horses horses of the 3rd Divisionís 18th Infantry Regiment including the Machine-gun Unit, 2nd Battalion, 2nd Company and Machine-gun Platoon, 3rd Calvary Regiment, HQ and 1st Company, 3rd Engineer Regiment, 2nd Company and horses for Equipment Platoon, 3rd Engineer Regiment and part of 2nd Company, 5th Tank Battalion.

2 September 1937:
Arrives at Wusung, China.

E 1938:
Released by the IJA. Enters Toyo Kisenís service as a cargo ship carrying timber.

4 November 1941:
Requisitioned by the Imperial Army and alloted Army No. 266. Converted to a Boku Kikansen (anti-aircraft) vessel. Fitted with six Type-88 75-mm AA guns and six Type-98 20-mm AA machine-cannons. Departs Ujina, Hiroshima Prefecture, for Nanking (Nanjing), China.

7 November 1941:
Arrives at Nanking.

11 November 1941:
Departs Nanking for Humen, South China.

13 November 1941:
Arrives at Humen.

23 November 1941:
Departs Humen for Saint Jacques, Indochina.

25 November 1941:
Arrives at Saint Jacques.

7 December 1941:
Gulf of Siam (Thailand). At 0300, ZENYO MARU departs Phu Quoc Island, French Indochina (Vietnam), with transports MIIKE and TOHO MARUs escorted by kaibokan SHIMUSHU. Later that morning, the group makes a rendezvous at sea with seven other unidentified transports carrying three battalions of the IJA 55th Infantry Division escorted by No. 2 Escort Unit's light cruiser KASHII. At 1035, all units depart for landing sites in Siam.

8 December 1941: Operation "E" - The Invasion of Malaya:
Beginning at 1000, troops are landed at four points on the Kra Isthmus, Siam (Thailand). ZENYO, MIIKE and TOHO MARUs land troops at Nakorn Sri Thammarat, S Siam, covered by SHIMUSHU. The transports carry 1,510 men including the IJA 143rd Regimentís 3rd Battalion and 50 trucks.

13 December 1941:
Arrives at Singora.

14 December 1941:
Departs Singora for Shanghai.

18 December 1941:
Arrives at Shanghai.

30 December 1941:
Departs Shanghai for Ujina.

31 December 1941:
Arrives at Ujina. Departs later and arrives at Moji at an unknown date.

3 January 1942:
Departs Moji for Hong Kong.

5 January 1942:
Arrives at Hong Kong.

6 January 1942:
Departs Hong Kong for Davao, Mindanao, Philippines.

16 January 1942:
Arrives at Davao.

27 January 1942:
Departs Davao for Ambon.

31 January 1942: The Invasion of Ambon Island, Ceram Island. Moluccas, Netherlands East Indies:
ZENYO MARU departs Bangka anchorage, near Menado, with the Ambon invasion convoy also consisting of transports AFRICA, YAMAURA, RYOYO, MIIKE, YAMAGIRI, KIRISHIMA, HINO, KATSURAGI and YAMAFUKU MARUs carrying Rear Admiral (later Vice Admiral) Hatakeyama Koichiro's (39) (former CO of KINUGASA) Kure No. 1 Special Naval Landing Force (SNLF), elements of the Sasebo SNLF and the 228th Infantry Regiment.

Escort is provided by Rear Admiral (later Vice Admiral) Tanaka (41)'s DesRon 2ís light cruiser JINTSU, DesDiv 8ís ASASHIO, MICHISHIO, ARASHIO and OSHIO, DesDiv 15ís HAYASHIO, KUROSHIO, OYASHIO and NATSUSHIO, DesDiv 16ís TOKITSUKAZE, HATSUKAZE, AMATSUKAZE and YUKIKAZE, MineSweepDiv 11ís W-7, W-8, W-9, W-11 and W-12, SubChasDiv 1ís CH-1 and CH-2, and Patrol Boat Squadron 1ís PB-34. Seaplane tenders CHITOSE and MIZUHO arrive at Ceram and provide air cover for the invasion convoy.

3 February 1942:
Ambon is secured.

February 1942: The Invasion Timor Island:
Timor is divided into two separate colonies governed by Holland and Portugal. Portugese East Timor is neutral, still Japan decides to invade. The IJA is responsible for the landings at Kupang, Dutch West Timor. The IJN is responsible for the landings at Dili on the Portuguese NE coast of the island.

17 February 1942:
At 0500, ZENYO MARU departs Ambon in the 1st echelon of the Kupang, Dutch West Timor Invasion Force with patrol boats PB-1 and PB-2 and IJA troop transports AFRICA, MIIKE and RYOYO MARUs escorted by DesDiv 15ís HAYASHIO, KUROSHIO, DesDiv 16ís TOKITSUKAZE and AMATSUKAZE and MineSweepDiv 21's W-7 and W-8. Enroute, they are joined by IJN transport KUNIKAWA MARU from Kendari, Celebes (now Sulawesi).

The Timor invasion convoy carries the IJAís 38th Divís 228th Infantry Regiment and an IJN Special Naval Landing Force (SNLF). Distant cover is provided by Rear Admiral (later Admiral, posthumously) Takeo Takagi's (former CO of MUTSU) CruDiv 5ís NACHI and HAGURO and destroyers KAWAKAZE, YAMAKAZE, INAZUMA and AKEBONO.

18 February 1942:
At 0230, the 2nd Echelon departs Ambon for Portuguese East Timor escorted by escorted by Rear Admiral (later Vice Admiral) Tanaka Raizoís DesRon 2 JINTSU (F) and DesDiv 7ís USHIO and SAZANAMI. IJA transport YAMAURA MARU is temporarily under the control of the IJN. En route, they are joined by IJN transport NISSHUN MARU from Kendari.

20 February 1942:
Dutch West Timor. At 0235, landings begin on the east and west sides of Cape Mali coast. By 0315, the landings are completed without resistance. The Kupang force then heads over the mountains towards Kupang. At 1030, An unknown number of transport planes drop LtCdr Fukumi Koichiís No. 3 Yokosuka SNLF paratroops 4 km NW of Babau.

Portuguese East Timor. At 0030, the 2nd Echelon arrives 1 km NW of Dili. Landings begin, but fierce resistance is encountered. Destroyers USHIO and SAZANAMI take the enemy positions under fire. Because of the resistance, the landing craft head westward. At 0218, landings begin at the mouth of the Carmona River. By 1100, Buton airfield is captured and by 1230 Dili Town is also captured.

21 February 1942:
Dutch West Timor. By 1200, Kupang Town is captured and by 1400 the local airfield is also captured. SNLF paratroops then make a second drop. During the two operations, no transports incur damage.

3 March 1942:
At 0800, after unloading, the invasion convoy departs for Kendari.

5 March 1942:
Arrives at Kendari. ZENYO MARU departs later that day.

19 March 1942:
Arrives at Takao, Formosa (now Kaohsiung, Taiwan).

21 March 1942:
Departs Takao.

10 April 1942:
Arrives at Saigon, Indochina (now Ho Chi Minh City, Vietnam).

14 April 1942:
Departs Saigon.

26 April 1942:
Arrives at Kobe. Departs later and arrives at Moji at an unknown date.

16 May 1942:
Assigned to the MI Sakusen (Midway Operation). Departs Moji for Saipan, Marianas.

18 May 1942:
ZENYO and and NANKAI MARUs depart Ujina carrying LtCol Ichiki Kiyonao's IJA detachment. ZENYO MARU carries the Ichiki Detachmentís headquarters and main body. NANKAI MARU carries the remaining elements of the task force built around Colonel Ichikiís 28th Infantry: four infantry companies, one machine gun company, one infantry gun platoon, one engineer company, and one antitank company.

19 May 1942:
Moji. The 8th Independent rapid fire company joins the Ichiki Detachment for a total 2,507 men.

25 May 1942:
Arrives at Saipan.

26 May 1942:
CruDiv 7 arrives at Guam (after its capture renamed Omiyajima by the Japanese) to provide close support for Rear Admiral (later Vice Admiral) Tanaka (41) Raizo's (former CO of KONGO) Midway Invasion Transport Group's oiler AKEBONO MARU and transports ZENYO, KIYOZUMI, ARGENTINA, BRAZIL, AZUMA, KEIYO, GOSHU, KANO, HOKUROKU, KIRISHIMA and NANKAI MARUs and TOA MARU No. 2.

28 May 1942: Operation "MI" - The Battle of Midway:
ZENYO MARU is in Vice Admiral (later Admiral) Kondo (35) Nobutake's (former CO of KONGO) Midway Invasion Force's Transport Group with oiler AKEBONO MARU, transports ARGENTINA, BRAZIL, AZUMA, KEIYO KIYOSUMI, GOSHU, KANO, HOKURIKU, KIRISHIMA and NANKAI MARUs and TOA MARU No. 2 and Rear Admiral (later Vice Admiral) Fujita Ruitaro's (former CO of FUSO) CHITOSE and KAMIKAWA MARU. The transports carry 5,000 troops including an airfield construction unit, LtCol Ichiki's detachment and two battalions of Special Naval Landing Forces (SNLF). Departs Saipan for Guam.

Rear Admiral Tanaka's DesRon 2's light cruiser JINTSU and DesDiv 15's KUROSHIO and OYASHIO, DesDiv 16's AMATSUKAZE, HATSUKAZE, TOKITSUKAZE and YUKIKAZE and DesDiv 18's KAGERO provide the escort with destroyer-transports SHIRANUHI, KASUMI and ARARE.

30 May 1942:
CruDiv 7's MOGAMI, MIKUMA, KUMANO and SUZUYA and DesDiv 8's ASASHI and ARASHIO rendezvous with the Transport Group and NICHIEI MARU.

31 May 1942:
Calls at Guam and departs later towards Midway Islands.

3 June 1942:
At about 1700, the convoy is attacked by LtCol (later General) Walter C. Sweeney's nine Boeing B-17 "Flying Fortress" heavy bombers from Midway. They score no hits, but ARGENTINA MARU and KIYOSUMI MARU are near missed.

4 June 1942:
About 2354 (JST), the convoy is attacked by four torpedo-carrying Consolidated PBY-5A "Catalina" amphibious patrol planes of Patrol Squadron 24 from Midway. Lt William L. Richards, the flight leader of the mission, scores a hit on AKEBONO MARU's bow with an obsolete Mark-XIII Mod 1 torpedo at 26-34N, 174-14W. The torpedo hit detonates AKEBONO MARU's AA shell magazine and tears a 10-meter long gash in her side. KIYOSUMI MARU is strafed and eight men of the embarked Kure SNLF are wounded.

5 June 1942:
At 0255, the Combined Fleet's Commander-in-Chief, Admiral (Fleet Admiral, posthumously) Yamamoto (32) Isoroku (former CO of AKAGI), aboard flagship YAMATO, orders Operation MI cancelled. In the early morning, the officers and men of the Ichiki Detachment of the 28th Infantry Regiment perform morning colors, a ceremonial hoisting of the national ensign.

6 June 1942:
Due to MI Sakusen cancellation, the Transport Group steams to Guam.

13 June 1942:
The Transport Group arrives at Guam, Marianas, and disembarks LtCol Ikki's detachment.

24 June 1942:
Departs Guam for Ujina.

1 July 1942:
Arrives at Ujina. Departs later and arrives at Moji at an unknown date.

10 July 1942:
Departs Moji for Canton, China.

17 July 1942:
Arrives at Canton.

18 July 1942:
Departs Canton for Singapore.

24 July 1942:
Arrives at Singapore.

2 August 1942:
Departs Singapore. Malacca Strait. N of Penang, Malaya. At 0842, Dutch Ltz. I (LtCdr) Albertus M. Valkenburgís submarine HrMs O-23 spots a convoy consisting of four merchant ships of 3000-5000 tons that are preceded by an armed merchant of about 4,000 tons about five miles ahead.

Valkenburg torpedoes ZENYO MARU and gets a hit port side in the engine room that sets the ship afire. She burns out and is abandoned at 05-36N, 99-53E. 19 AA gunners and eight crewmen are KIA. At an unknown date the wreck is towed to Singapore, but deemed a comprehensive total loss and scrapped.


Authors' Note:
Thanks go to Bill Somerville for additional details on the invasion of Timor in Rev 1. Thanks also to John Whitman of Virginia and Fontessa-san of Japan for info about troops carried in 1937.

Bob Hackett and Gilbert Casse


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