(KENYO MARU prewar)
IJN KENYO MARU:
Tabular Record of Movement
© 2011-2018 Gilbert Casse, Bob Hackett and Peter Cundall
24 November 1937:
Aioi. Laid down by Harima K.K. Zosensho shipyard as a 6,486-tons cargo ship for Inui Kisen K.K., Kobe.
8 August 1938:
Launched and named KENYO MARU.
15 October 1938:
Completed and registered at Kobe. Chartered to Mitsui Bussan K.K. and placed on their Sakhalin (Karafuto) ~ Dairen (now Dalian)
line for coal transportation. Later to Malaya ~ Japan service carrying ore.
19 June 1940:
Stranded on Iki Hirashima, Tairajima Island, S Nagasaki
E June 1941:
Kanji suffix changed and renamed KENYO MARU. 
2 September 1941:
Requisitioned by the IJN.
4 September 1941:
Conversion to her military role begins at Uraga shipyard, Uraga Dock K.K.
5 September 1941:
Registered in the IJN as an auxiliary transport under internal order No. 1025 and attached to the Yokosuka Naval District. Her home port is Yokosuka Naval Base.
30 September 1941: E October 1941:
Conversion is completed.
Assigned to Yokosuka Naval District as an auxiliary transport, (Ko) category. 
21 November 1941: E November-December 1941:
Operates in the South Seas area (Japanese mandated islands).
27 December 1941:
Arrives at Yokosuka. Then departs and arrives at Kobe at unknown dates.
8 January 1942:
16 February 1942:
Arrives at Yokosuka. Then departs and arrives at Yokohama at unknown dates.
1 March 1942:
21 April 1942:
Arrives at Yokohama.
23 April 1942:
Departs Yokohama for Aioi, Hyogo Prefecture.
25 April 1942:
Arrives at Aioi. Probably undergoes maintenance and repairs at Harima shipyard.
23 May 1942:
Assigned to Combined Fleet's Second Fleet under secret Navy instruction No. 554 to transport troops for the campaign third phase. (Effective date of assignment: 05 June).
24 May 1942:
Departs Aioi for Yokosuka.
25 May 1942:
Arrives at Yokosuka.
28 May 1942:
Departs Yokosuka for Sasebo.
31 May 1942:
Arrives at Sasebo.
7 June 1942:
Departs Sasebo. Following IJN’s defeat at Midway, the campaign's third phase’s strategy is revised. KENYO MARU is assigned to transport the 14th and 15th Naval Construction Units to the Solomon Islands area.
26 June 1942:
Departs Truk in convoy with KINAI MARU carrying elements of Sasebo 5th Special Landing Force.
1 July 1942:
Arrives at Rabaul.
6 August 1942: 7 August 1942:
Departs Rabaul, New Britain for Buna, New Guinea in a convoy also consisting of KINAI and NANKAI MARUs escorted by light cruiser TATSUTA, destroyers YUZUKI and UZUKI and subchasers CH-30 and CH-23 carrying 3,000 men of the 14th and 15th Naval Construction Units, their construction equipment, vehicle, and some army supplies.
Following American landings at Guadalcanal and Tulagi, the convoy is recalled by Vice Admiral Gunichi Mikawa (38), commander of the newly established 8th Fleet, when it is only part way to its destination. Arrives back at Rabaul later the same day.
8 August 1942:
Departs Rabaul still in same convoy.
9 August 1942:
Arrives back at Rabaul again. Following American landings at Guadalcanal, the campaign's fourth phase’s strategy is revised. KENYO MARU is assigned to steam in ballast to Tainan, Formosa and pick-up remaining elements of the 15th Naval Construction Unit.
12 August 1942:
Departs Rabaul still in same convoy.
13 August 1942:
Arrives at Basabua and departs late that day.
15 August 1942:
Arrives back at Rabaul.
17 August 1942: Basabua Landings:
Departs Rabaul for the Buna-Gona area in a convoy also consisting of transports RYOYO and KAZUURA MARUs with an unidentified escort. Aboard is the main body of the IJA South Seas Detachment, (Nankai Shitai) (less a rear echelon which is to come later): Detachment Headquarters under MajGen Horii Tomitaro, 2nd and 3rd Battalions, 144th Infantry Regiment with attached gun company, signal unit, and ammunition sections; two companies of the 55th Mountain Artillery, 47th Field AAA Battalion, a company of 55th Cavalry with attached antitank gun section; part of the divisional medical unit, base hospital, collecting station and divisional decontamination and water-purification unit. The convoy also includes a naval liaison detachment, a couple of hundred men of the No. 5 Sasebo Special Naval Landing Force (SNLF), 700 natives of Rabaul, 170 horses and a large tonnage of supplies.
18 August 1942:
Late afternoon. Without being detected by Allied air units, the transports reach Basabua beach and are unloaded.
19 August 1942:
The convoy departs Basabua for Rabaul with KAZUURA MARU.
21 August 1942:
Without having been attacked by Allied Air Units on its way back to Rabaul, the convoy arrives safely at its destination. KENYO MARU then departs Rabaul at an unknown date.
13 October 1942:
Arrives at Yokosuka.
25 October 1942:
6 November 1942:
Departs Truk in convoy with transport CHIHAYA MARU (ex Dutch TJISAROEA). En route to Rabaul the convoy is met by minesweeper W-20.
10 November 1942:
At 0720 arrives at Rabaul.
26 November 1942:
At 1600 departs Rabaul in a convoy also consisting of HOKKAI MARU escorted by minesweeper W-22.
28 November 1942:
Arrives at Shortland.
13 December 1942:
Due to dpart Shortland.
7 January 1943:
Departs Yokosuka for Tokuyama, Yamaguchi Prefecture.
10 January 1943:
Arrives at Tokuyama.
15 January 1943:
Departs Tokuyama and arrives the same day at Wakamatsu, Fukuoka Prefecture.
18 January 1943:
Departs Wakamatsu and arrives the same day at Kure.
20 January 1943:
E January-February 1943:
KENYO MARU auxiliary transport shifts to (Otsu) category .
21 January 1943:
Departs Saeki for Palau in V Convoy (No.8 Military Movement Operation) consisting of DAKAR and KENYO MARUs escorted by minelayer NATSUSHIMA and cable-minelayer TSURUSHIMA.
E 22 January 1943:
At 29N the escorts are detached.
E 28 January 1943:
Arrives at Palau.
11 March 1943:
At 1100 arrives at Truk. Protected by air patrols as ship nears Truk waters.
15 March 1943:
At 1030 departs Truk via north entrance.
21 March 1943:
Arrives at Saipan from Truk in convoy with SEIKAI and MANKO MARUs.
22 March 1943:
Departs Tanapag Harbor, Saipan for Japan in convoy with presumed SEIKAI and MANKO MARUs. KENYO MARU’s ultimate destination is Osaka. MANKO MARU is headed to Yokosuka.
23 March 1943:
About 120 nms NNW of Saipan Island, Marianas. LtCdr (later Captain) Albert C. Burrows' (USNA ‘28) USS WHALE (SS-239) intercepts the convoy. At 0300, Burrows torpedoes and obtains two hits on KENYO MARU, the first one under her bridge, the second at her stern, at 17-16N, 144-56E. Twenty minutes after being torpedoed, KENYO MARU sinks by the bow at 17-20N, 145-00E. 130 engineer passengers, 30 comfort women (IJA prostitutes) and four crewmen are KIA.
1 May 1943:
Removed from the Navy List under internal order No. 1162.
 Not to be confused with auxiliary fleet oiler KENYO MARU (10024 GRT, 1939) or Wartime Standard 2D Type cargo KENYO MARU (2235 GRT, 1944).
 There were two categories of Zatsuyosen. (Ko) category with an IJN Captain as supervisor aboard and (Otsu) category without.
Thanks go to Gengoro S. Toda of Japan.
-Gilbert Casse, Bob Hackett and Peter Cundall
IJN Transports Page