(TENRYU MARU prewar)
IJN TENRYU MARU:
Tabular Record of Movement
© 2012-2015 Gilbert Casse, Bob Hackett and Peter Cundall
Innoshima. Laid down by Osaka Ironworks K.K. shipyard for Naigai Kisen K.K., as a 4,864-tons cargo ship.
15 November 1936:
Launched and named TENRYU MARU. 
28 December 1936:
Completed and registered in Kobe. Her Gross Registered Tonnage (GRT) is 4,864-tons and her Net Registered Tonnage (NRT) 2,914-tons. 
Her GRT and NRT are respectively changed to 4,861-tons and 2,885-tons. 
7 November 1941:
Requisitioned by the IJN.
10 November 1941:
Arrives at Osaka. Starts conversion to military duty.
15 November 1941:
Registered in the IJN as an auxiliary transport, (Otsu) category and attached to the Kure Naval District with Kure as homeport under internal order No. 1418. 
23 November 1941:
24 November 1941:
Arrives at Kure.
29 November 1941:
The conversion is completed. Departs Kure.
6 December 1941:
Arrives at Palau, Western Carolines. Preparation is made for the invasion of Davao, Mindanao.
16 December 1941: The Occupation of Davao, Mindanao, Philippines:
TENRYU MARU is assigned to the Philippines Invasion Group under command of Vice Admiral Takahashi Ibo’s (36) Third Fleet as part of the Davao Invasion Unit under command of Rear Admiral (later Vice Admiral) Irifune Naosaburo (39).
The occupation of Davao is a combined IJN/IJA operation which involves General (later Field Marshal) Count Terauchi Hisachi’s command’s Southern Expeditionary Army. The 16th Army, under LtGen (later General) Imamura Hitoshi
fields MajGen (later LtGen) Sakaguchi Shizuo's “Sakaguchi” Detachment of about 6,000 troops consisting of the 56th Division’s 56th HQ Company (Coy), 146th Infantry Regiment, 2nd Btn of 56 Art Rgt with 12 75mm field guns, one Tank Coy, one Eng Coy, one Transport Coy, one Signal unit platoon, 56th medical Unit Field Hospital Unit and the “Miura” Detachment of about 1,200 troops of the 16th Div’s Heavy weapons Coy of 33th Inf Rgt, 3rd Inf. Bn. and two Eng. platoons of the 56th Div. Two AA and one Signals Regiment are stationed on IJA transports.
The invasion units are embarked on eight IJA transports: HANKOW, HAVANA, HITERU, KANKO, KURETAKE, LIVERPOL, TEIRYU (ex-German AUGSBURG) and YAMAZUKI MARUs.
The Navy force consists of Vice Admiral (later Admiral) Kondo Nobutake's (35) (former CO of KONGO) Southern Force, Philippines Invasion Group that includes Vice Admiral Takahashi Ibo’s (36) (former CO of YAMASHIRO) Third Fleet. Rear Admiral (later Vice Admiral) Irifune Naosaburo (39) Invasion Unit consists of his 32nd Special Base Force aboard TONAN MARU No 2, elements of 103rd Aerial Field Repair Shop and a detachment of 3rd Munitions Unit aboard KINUGASA MARU, a company of the No.1 Kure Special Naval Force (SNLF) aboard AMAGISAN MARU, 2nd Construction Unit Rgt, aboard TAITO MARU and 3rd Construction Unit Rgt aboard KOSHIN MARU.
Other transports are EIKO MARU No.2 GO, TENRYU, KIRISHIMA and TATSUKAMI MARUs transporting equipment and material for the future Davao and Jolo airbases.
The convoy’s close escort consists of minelayer SHIRITAKA and patrol boats PB-36 and PB-37. Cover is provided by Rear Admiral (later Vice Admiral) Tanaka Raizo’s (41) light cruiser JINTSU, DesDiv 15’s HAYASHIO, NATSUSHIO,
OYASHIO and KUROSHIO and DesDiv 16's YUKIKAZE, HATSUKAZE and AMATSUKAZE. Rear Admiral (Admiral posthumously) Takagi Takeo’s (39) (former CO of MUTSU) CruDiv 5's NACHI, MYOKO and HAGURO provide distant cover. Air cover is provided by
light carrier RYUJO and seaplane carrier CHITOSE.
The convoy is subdivided in three divisions:
KIRISHIMA (IJN), YAMATSUKI (IJA), TAITO (IJN), KINUGASA (IJN) and AMAGISAN (IJN) MARUs.
2nd subdivision: TONAN MARU No. 2 (IJN), TENRYU (IJN), TEIRYU (ex-German AUGSBURG) (IJA) (carrying elements of the 3rd Munitions Unit & the 103rd Aerial Field Repair Shop) and KURETAKE (IJA) MARUs, escorted by minelayer
SHIRATAKA and destroyers AMATSUKAZE and OYASHIO.
3rd subdivision: HANKOW (IJA), HAVANA (IJA), TATSUKAMI (IJN), and KOSHIN (IJN) MARUs and EIKO MARU No. 2 GO (IJN).
16 December 1941:
At 1600, the 3rd subdivision departs Palau.
17 December 1941:
At 0700, the 2nd subdivision departs Palau.
17 December 1941:
At 1300, the 1st subdivision departs Palau.
19 December 1941:
200 miles E of Davao. In the afternoon, RYUJO launches six planes to attack the radio station at Cape San Augustin, at the eastern tip of Davao Gulf, while seaplane carrier CHITOSE launches planes to
20 December 1941:
The transports arrive off Davao after midnight. At 0145, the 1st subdivision arrives at Tibungko Anchorage (15 km NNE of Davao). At 0320, the 3rd subdivision arrives at Talomo Anchorage (6 km SW of Davao). At 0440, the 2nd subdivision arrives at Tibungko Anchorage At 0500, troops of LtCol Miura Toshio's 33rd Infantry Regiment's detachment, covered by RYUJO's aircraft, begin landing in the northern section of Davao while elements of the Sakaguchi Detachment come ashore along the coast SW of the city. Resistance by the garrison of some 3,500 Filipino-American troops is quickly overcome and, by 1500, that same day, Davao and its airfield are occupied. That evening a seaplane base is established S of the city.
29 December 1941:
Departs Davao in a convoy also consisting of auxiliary transports OKITSU and TAITO MARUs, auxiliary aircraft transport LYONS MARU and IJA transport YAMAZUKI MARUs escorted by destroyer AMATSUKAZE bound for Takao.
10 January 1942:
Arrives at Kure.
12 January 1942:
14 January 1942:
Arrives at Tokyo.
17 January 1942:
3 February 1942:
5 February 1942:
Arrives at Banga Island, near Mindanao.
12 February 1942:
Departs Banga island.
14 February 1942:
Arrives at Ambon, Moluccas.
17 February 1942: The Invasion of 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.
At 0800, TENRYU MARU and eight transports including IJA AA/transport ZENYO MARU, IJA troop transports AFRICA, MIIKE and RYOYO MARUs and three unidentified transports depart Ambon in the 1st echelon of the Kupang, Dutch
West Timor Invasion Force with patrol boats PB-1 and PB-2 escorted by DesDiv 15’s HAYASHIO, KUROSHIO, DesDiv 16’s 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 IJA’s 38th Div’s 228th Infantry Regiment and men of the Yokosuka No. 3 Special Naval Landing Force (SNLF). Distant cover is provided by Rear Admiral (later Admiral, posthumously) Takeo
Takagi's (former CO of MUTSU) CruDiv 5’s NACHI and HAGURO, DesDiv 24’s KAWAKAZE and YAMAKAZE, DesDiv 6’s INAZUMA and IKAZUCHI and DesDiv 7’s AKEBONO.
18 February 1942:
At 0230, the 2nd Echelon consisting of IJA transport YAMAURA MARU temporarily under the control of the IJN, fast transport (converted destroyer) PB-34 and four unidentified transports departs Ambon for Portuguese East Timor escorted by Rear Admiral (later Vice Admiral) Tanaka Raizo’s DesRon 2 JINTSU (F) and DesDiv 7’s USHIO and SAZANAMI. Air cover is provided by Mitsubishi F1M2 “Pete” floatplanes from the seaplane carrier MIZUHO. Enroute, they are joined by IJN transport NISSHUN MARU from Kendari.
19 February 1942:
That night, both convoys arrive off Timor. Operating as part of the American-British-Dutch-Australian ABDA FLOAT, the U. S. Asiatic Fleet's USS PIKE (SS-173) under under LtCdr William A. New (USNA ’25), LtCdr Lewis Wallace's (USNA ’25) USS TARPON (SS-175) and LtCdr B. E. Bacon's (USNA ’25) USS PICKEREL (SS-177) make contact with the invasion force.
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 Koichi’s No. 3 Yokosuka SNLF paratroops 4 km NW of Babau.
Alor island. At 0243, USS PIKE attacks what LtCdr New misidentifies as two "light cruisers". The ships, in fact, are W-7 and W-8. New fires two torpedoes from 4,000 yards, but they miss ahead. The minesweepers move out of
range before New can set up for another attack.
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.
1 March 1942:
After unloading, departs Kupang, Timor with patrol boat PB-1 escorting LYONS, TENRYU and NANIWA MARUs. At some point the ships are joined by PB-2 and LYONS MARU is detached and KATSURAGI MARU joins.
3 March 1942:
Arrives at Kendari, Celebes.
8 March 1942:
13 March 1942:
Arrives at Angaur, Palaus.
17 March 1942:
Departs Angaur and arrives at Palau later in the day.
18 March 1942:
27 March 1942:
Arrives at Yokohama.
30 March 1942:
Calls at Tokyo ~ Otaru, Hokkaido ~ Yokosuka ~ Kobe ~ Nagasaki ~ Kure ~ Moji ~ Yawata, Fukuoka Prefecture ~ Chinnampo, Chosen and Kure.
30 May 1942:
Arrives at Innoshima, Hiroshima Prefecture and docks at Osaka Ironworks K.K. shipyard for maintenance and repairs.
17 June 1942:
Repairs are completed. Departs Innoshima.
19 June 1942:
Arrives at Miike, Fukuoka Prefecture.
21 June 1942:
23 June 1942:
Arrives at Osaka.
25 June 1942:
Departs Osaka towing motor-schooner SHONAN MARU No. 100.
7 July 1942:
Arrives at Taroa, Marshalls.
18 July 1942:
19 July 1942:
Arrives at Roi-Namur, Marshalls.
21 July 1942:
Departs Roi-Namur and arrives at Kwajalein, Marshalls later that day.
2 August 1942:
4 August 1942:
Arrives at Ponape, Eastern Carolines.
16 August 1942:
25 August 1942:
Arrives at Yokohama.
28 August 1942:
Departs Yokohama and arrives at Yokosuka later that day.
4 September 1942:
Departs Yokosuka and arrives at Yokohama later in the day.
8 September 1942:
10 September 1942:
Arrives at Kure.
13 September 1942:
24 September 1942:
Arrives at Kavieng, New Ireland.
10 October 1942:
At 0600, TENRYU MARU moors alongside auxiliary tanker TONAN MARU No. 2 and loads cargo bound for IJNAF Kanoya Ku (Kokutai). At about 1105 (JST), from 3,500 yards outside the harbor, LtCdr John A. Bole’s (USNA ’28) USS AMBERJACK (SS-219) fires four torpedoes at two large ships inside. Bole hits and sinks TONAN MARU No. 2 in shallow water and gets one torpedo hit port side on TENRYU MARU rear hold. Hold No. 2 is flooded as coal bunker and boiler room. At 1500, damage control parties stop most of the flooding but the ship still leaks from the bottom.
13 October 1942:
Fleet auxiliary salvage and repair tug NAGAURA arrives to inspect the damage. Over the next few weeks, No. 1 and No. 2 holds are patched and pumped out and work on boiler room commenced.
28 October 1942:
Tied up alongside NAGAURA. Repair operations center on boiler room, starboard coal bunker and bilges.
29 October 1942:
Bottom hull is patched and water is pumped out.
31 October 1942:
Drainage work is completed on bottom hull. Emergency repairs are made to watertight compartments and bulkheads.
2 November 1942:
Emergency repairs are completed on Hold No. 2 watertight compartments and bulkheads.
4 November 1942:
Drainage work starts on the boiler room.
5 November 1942:
Separated from NAGAURA.
16 January 1943:
A reduced crew consisting of 15 NCOs and 10 sailors remain aboard. 32 sailors and four NCO disembark.
The coal bunker is pumped out and coal unloaded.
6 October 1943:
Auxiliary minesweeper TOSHI MARU No. 3 is instructed to take on fuel from the wrecks of IJN requisitioned cargo ship (B-AK) FLORIDA MARU (bombed 3 Apr ’43) and TENRYU MARU before taking over minesweeping duties from W-26.
18 October 1943:
Repairs of watertight compartments and bulkheads are completed on the coal bunker.
Additional drainage work is performed.
29 November 1943:
Work starts on engine overhaul, auxiliary machinery maintenance, cleaning of coal gas chamber and pipes leading to the engine room.
25 December 1943:
Rear Admiral (later Admiral) Frederick C. Sherman’s (USNA ’10) (former CO of USS LEXINGTON, CV-2) TG 50.2 aircraft from USS BUNKER HILL (CV-17) and USS MONTEREY (CVL-26) attack Japanese ships at Kavieng. At 0540, TENRYU MARU is hit amidships by a large bomb. At 1805, she sinks at 02-36S, 150-49E, taking down five crewmen. Auxiliary transport (ex-AMC) KIYOSUMI MARU and minesweepers W-21 (nine sailors KIA) and W-22 are also damaged during the same attack.
5 February 1944:
Removed from the Navy’s list under internal order No. 305.
 Not to be confused with the IJA transport (555 GRT ’39)
 NRT is a ship's cargo volume capacity expressed in "register tons", one of which equals to a volume of 100 cubic feet (2.83 m3). It is calculated by subtracting non-revenue-earning spaces i.e. spaces not available for carrying cargo, for example engine rooms, fuel tanks and crew quarters, from the ship's gross register tonnage (GRT). Net register tonnage (NRT) is not a measure of the weight of the ship or its cargo, and should not be confused with terms such as deadweight tonnage or displacement.
 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.
Photo credit goes to Erich Muehlthaler of Germany.
Gilbert Casse, Bob Hackett and Peter Cundall
IJN Transports Page