(TOSAN MARU, prewar)
Tabular Record of Movement
© 2012-2016 Bob Hackett
23 July 1937:
Nagasaki. Laid down at Mitsubishi Heavy Industries, Ltd.’s
Shipyard & Machinery Works as Yard No. 710, an 8,684-ton passenger-cargo
ship for Settsu Shosen KK, Osaka.
4 February 1938:
Launched and named TOSAN MARU. 
During her sea trails, she reaches a speed of 19.9 knots.
30 April 1938:
Completed. She can accomodate four 1st class pasengers and carries a crew of 68.
Chartered to affiliate Osaka Shosen Kaisha (OSK), K. K. Departs Nagasaki for the Philippines on her maiden voyage.
Arrives in the Philippines, loads a cargo of sugar and departs calling at Kirun, Formosa (Keelung, Taiwan), Dairen, Manchuria and returns to unload at various Japanese ports.
E June 1941:
Departs Kobe for Los Angeles, California and New York via the Panama Canal.
12 July 1941:
Arrives at New York.
In retaliation to Japan’s occupation of French Indochina, the United States delays Japanese shipping through the Panama Canal. 
TOSAN MARU departs New York on her long return voyage to Japan via the Staits of Magellan, Chile and Cape Horn, South America.
E September 1941:
Arrives at Kobe.
4 November 1941:
Requisitioned by the Imperial Army (IJA) and converted to a troop transport. Allotted IJA No.918.
4 December 1941:
At 0600, TOSAN MARU departs Samah, Hainan Island in Vice Admiral Ozawa Jisaburo’s (37)(former CO of HARUNA) Malaya Invasion Group consisting of 18 transports carrying LtGen Yamashita Tomoyuki's (the "Tiger of Malaya") 25th Army to the Gulf of Thailand escorted by light cruiser SENDAI, DesDivs 12’s MURAKUMO, DesDiv 19's AYANAMI, ISONAMI, SHIKINAMI and URANAMI,
DesDiv 20’s AMAGIRI, ASAGIRI, YUGIRI and SHIRAKUMO, minelayer HATSUTAKA, MinSweepDiv 1’s W-1, W-2, W-3, W-4, W-5, W-6 and W-8 and subchaser CH-9.
Distant cover is provided by Rear Admiral (later Vice Admiral) Kurita Takeo's (former CO of KONGO) CruDiv 7’s MOGAMI, MIKUMA, SUZUYA and KUMANO and destroyers FUBUKI, SHIRAYUKI and HATSUYUKI. Air cover is provided from seaplane
tenders SANYO, SAGARA and KAMIKAWA MARUs and by IJAAF fighters from Phu Quok Island’s airfield.
The convoy carries the Pattani, Kra Isthmus, Singora and Kota Bharu, Siam (Thailand)Invasion Units consisting of MajGen Takumi Hiroshi's 5th Division’s 23rd Infantry Brigade and other units. En route, the convoy and its escorts split into the respective Invasion Units and head for their assigned landing and covering points.
7 December 1941:
Pattani, Siam. At 2340, TOSAN MARU arrives with the
Patani Siam (Thailand) Invasion Unit consisting of transports HIROKAWA KINKA and
SAGAMI MARUs escorted by DesDivs 12’s SHINONOME and DesDiv 20’s SHIRAKUMO.
8 December 1941:
At 0400, disembarks troops of the IJA’s 5th
Infantry’s 42nd Regiment and 22nd airfield unit.
13 December 1941:
Thepha, west of Patani. At about 0005, Dutch Ltz. 1
(KIA) Anton J. Bussemaker’s submarine Hr.Ms. O-16 (later lost) fires eight
torpedoes and badly damages anchored TOSAN, ASOSAN and KINKA MARUs. All three
transports settle to the bottom in shallow water, but are later salved.
TOSAN MARU is towed to Hong Kong.
April to E December 1942:
Hong Kong. Undergoes repairs.
26 February 1943:
TOSAN MARU departs Sasebo and joins convoy No. 131
that departed that day from Moji consisting of SHOZUI MARU and four unidentified merchants escorted
by patrol boat PB-2.
3 March 1943:
Arrives at Takao.
7 March 1943:
TOSAN MARU departs Takao for Moji in convoy No. 238
also consisting of KENRYU MARU and three unidentified merchant ships, escorted
by destroyer FUYO.
13 March 1943:
The convoy arrives at Moji.
19 July 1943:
TOSAN MARU departs Shanghai in a convoy also consisting of MIIKE, SETSUZAN and TSUKUBA MARUs. TOSAN MARU carries the 54th Division’s 121st Infantry Regiment 2nd Battalion (less 5th Company)
30 July 1943:
Arrives at Saigon. Disembarks troops.
Settsu Shosen K.K merges with Osaka Shosen Kaisha (OSK), K. K. Thereafter, TOSAN MARU is registered to OSK.
7 December 1943:
TOSAN MARU departs Takao for Singapore in a convoy
also consisting of transports ARIMASAN, KINUGASA and SHINSHU MARUs.
12 December 1943:
Arrives at Singapore
3 January 1944:
TOSAN MARU departs Takao for Moji in convoy HI-26
also consisting of AMATSU, ARIMASAN, MIIKE NOTO, OMINESAN, OTOWASAN and TAKASAKI
MARUs and several unidentified merchants and MAYASAN and SHINSHUMARUs escorted
by light cruiser KASHII as.
7 January 1944:
At 1830 arrives at Moji.
27 February 1944:
At 2100, TOSAN MARU departs Ujina for Saipan,
Marianas in convoy Higashi Matsu No. 1 also consisting of army transports AKI
and SAKITO MARUs and escorted by destroyers ASASHIMO, KISHINAMI and OKINAMI.
TOZAN MARU carries about 4,000 men including elements of the IJA's 50th Infantry
Regiment, elements of the 29th Division’s tanks, transportation, maintenance and
hospital units and the 44th Field Machine Cannon Company assigned to the 31st
29 February 1944:
At 0246, destroyer ASASHIMO’s Type 22 radar detects
a submarine. At 0255, ASAHIMO snaps on her searchlight and illuminates LtCdr
John J. Flachenhar‘s USS ROCK (SS-274) and fires 15 rounds from her main
armament at the submarine. One shell hits and wrecks ROCK’s periscope shears.
ROCK crash dives. ASAHIMO drops just two DCs. Flachenhar is forced to terminate his patrol.
At 1753, LtCdr (KIA) Albert H. Clark’s (USNA ’33) USS TROUT
(SS-202)(lost) attacks the convoy. Clark fires three torpedoes at SAKITO MARU
and gets two hits portside in her engine room at 22-40N, 131-50E. She floods and
a cargo of gasoline ignites. AKI MARU is hit in the bow, probably by a dud torpedo and suffers flooding,
but is able to continue. TOSAN is also hit, probably by a dud, but she too is able to continue.
From 1755 to about 1815, ASASHIMO counter attacks and drops a series of DCs.
At 1816, a heavy underwater explosion is heard and oil seen gushing to the surface.
This probably marks the end of USS TROUT and her brave crew.
1 March 1944:
SAKITO MARU sinks at 22-40N, 131-50E. 2,000 IJA
soldiers, 65 gunners and 52 crewmen are KIA. ASAHIMO and OKINAMI rescue 1,720
4 March 1944:
TOSAN and AKI MARUs escorted by destroyer KISHINAMI
arrive at Guam, Marianas.
6 March 1944:
SAKITO MARU’s survivors are landed on Saipan.
7 April 1944:
At 0330, TOSAN MARU departs Tateyama, Tokyo Bay in
convoy Higashi Matsu No. 5 (outbound) also consisting of ASOSAN, MIIKE, NOTORO
and SEIYO MARUs escorted by destroyer SATSUKI and kaibokan KASADO and MANJU and
CD-4. En route, CD-4 is detached for Chichi-jima.
24 April 1944:
Arrives at Saipan.
26 April 1944:
At 1640, TOSAN MARU departs Palau for Tokyo in convoy
Higashi Matsu No. 5 also consisting of ASOSAN, MIIKE and NOTO MARUs escorted by
destroyer SATSUKI and kaibokan KASADO and MANJU and CD-4.
27 April 1944:
At about 0100, LtCdr (later Vice Admiral) Frederick J.
Harlfinger's (USNA ’37) USS TRIGGER (SS-237) torpedoes and hits and damages
ASOSAN and MIIKE MARUs. At 0430, as ASOSAN MARU is being abandoned, Harlfinger
torpedoes and blows the bow off kaibokan KASADO. Fuel flowing from MIIKE MARU
catches fire and sets the ship abaze. MANJU is able to rescue some survivors,
but MIIKE MARU drifts away and sinks the next day. MIIKE MARU was carrying 752
IJA troops and other passengers and 26 funerary urns. Two crewmen, seven gunners
and nine passengers are KIA. TOSAN, ASOSAN and NOTO MARUs and KASADO reverse
course back to Palau.
29 April 1944:
TOSAN MARU departs Palau for Tokyo with destroyer
SATSUKI in a repeat of Higashi Matsu No 5's journey. The convoy also consists of
NOTO MARU escorted by destroyer SATSUKI and kaibokan CD-4
2 May 1944:
At 1500, TOSAN MARU departs Keelung, Formosa for Moji
with in convoy TAMO-18 also consisting of ANNETTE FRITZEN GO, BISAN, CHEFOO,
KONEI, NEIHA (NINGPO), RYUKO (5626 GRT), TEIKA (ex-Vichy French CAP VARELLA),
TAINAN, TOYOURA, SAINAN, MARUs, SHINSEI MARU No. 5, Stores Ship MAMIYA and two
unidentified merchants escorted by kaibokan FUKUE and CD-2
E 3 May 1944:
TOSAN, ANNETTE FRITZEN GO, BISAN, CHEFOO, KONEI, NEIHA
(NINGPO) and SAINAN MARUs are detached for Shanghai.
3 May 1944:
W of Ogasawara Gunto. LtCdr William P. Gruner's (USNA
’35) USS SKATE (SS-305) fires four torpedoes at the convoy, but they all miss.
CD-4 and SATSUKI counter-attack, but SKATE escapes damage.
4 May 1944:
Arrives at Tokyo.
14 May 1944:
At 0430, TOSAN MARU departs Tateyama Fuel Depot, Tokyo
Bay in convoy Higashi Matsu No. 8 also consisting of army transport NOTO MARUs
and navy transport MANJU (ex-SANTOS) MARU escorted by destroyer SATSUKI and
kaibokan AMAKUSA, CD-4 and CD-6. The convoy carries elements of the IJA's 43rd
Infantry Division including the 135th and 136th Infantry Regiments and steams in
a wide arc in bad weather.
19 May 1944:
Arives at Saipan at 1030. Disembarks troops.
27 June 1944:
Arrives at Ujina. Loads troops.
28 June 1944:
Departs Ujina. Arrives at Moji.
3 July 1944:
At 2000, TOSAN MARU departs Moji for Manila in convoy
MOMA-01 also consisting of KASHII, NISSHO, TAMATSU, MIZUHO, RAKUYO and NICHIRAN MARUs and IJN landing craft depot ship MAYASAN MARU escorted by destroyer
HARUKAZE and kaibokan CD-11, CD-20, CD-26, CD-28 and subchaser CH-28. The convoy is transporting the IJA's 5th Field Heavy Artillery and 58th Independent Mixed
7 July 1944:
Formosa Straits. Convoy MOMA-01 is ordered to turn
back to Keelung, Formosa. Arrives that day. ARABIA MARU may have joined the
9 July 1944:
12 July 1944:
Arrives at Takao and departs.
Bashi Strait. At 0330, LtCdr (later Cdr) Walter P. Schoeni's (USNA ’31)
USS APOGON (SS-308) fires a full bow spread of torpedoes at MAYASAN MARU.
Schoeni fails to damage her, but USS APOGON is rammed during the attack and
forced to abort her patrol..
At 0720, LtCdr Harold E. Rubles' (USNA ’33) USS PIRANHA (SS- 389)
torpedoes and sinks NICHIRAN MARU carrying elements of the IJA's 5th Field Heavy
Artillery and 58th Independent Mixed Brigade at 18-50N, 122-40E. KASHII MARU
rescues survivors, but 1,245 troops, one gunner and 15 crewmen are KIA. The
convoy seeks shelter in Aparri Harbor, Philippines.
13 July 1944:
At 0800, departs Aparri.
15 July 1944:
At 1400, arrives at Manila.
24 July 1944:
At 0600, convoy HI-68 departs Manila for Moji. The
convoy sails in three columns consisting of landing ship MAYASAN MARU, oilers
OTORISAN MARU and NICHINAN MARU No. 2 and escort carrier TAIYO in column No. 1;
transports TOSAN, AKI, KASHII and NISSHO MARUs and TAKATSU MARU (a.k.a. KOZU
MARU) in column No. 2, and ex-seaplane tender KIYOKAWA MARU and oilers
ITSUKUSHIMA, TOA, TOHO and SHIMPO MARUs in column No. 3. The convoy is escorted
by kaibokan HIRADO (F), KUSAGAKI, KURAHASHI, ISHIGAKI, MIKURA, CD-11, CD-20 and
torpedo boat HIYODORI. Air cover is provided by escort carrier KAIYO.
A three-submarine wolf pack of Cdr (later Rear Admiral) Rueben T.
Whitaker’s (USNA ’34) USS FLASHER (SS-249), LtCdr Franklin Hess’s (USNA ’35)
ANGLER (SS-240) and LtCdr Francis D. Walker’s (USNA ’35) CREVALLE (SS-291)
tracks the convoy.
25 July 1944:
Off NW Luzon. At 1540, transports TOSAN and AKI MARUs
successfully evade an attack by Walker’s CREVALLE.
26 July 1944:
South China Sea. Luzon Strait. At 0211, in a night
surface radar attack, FLASHER fires three torpedoes at the AKI MARU and his last
three torpedoes at OTORISAN MARU. One torpedo hits AKI MARU amidships, another
strays and hits TOSAN MARU. OTORISAN MARU blows up and illuminates the
night.torpedoes and damages TOSAN MARU. AKI and OTORISAN MARUs sink.
ANGLER torpedoes and blows the bow off KIYOKAWA MARU. At 0655, the ship
leaves the convoy and heads for Takao, Formosa. At 1137, CREVALLE torpedoes and
further damages TOSAN MARU in her No. 3 and No. 4 holds. Later, she catches
27 July 1944:
At 0430, the fires ignite 1,000 stored shells and 18
depth charges. At 1045, TOSAN MARU sinks. Nine crewmen, 8 gunners and 18
passengers are KIA. The remainder of the convoy arrives at Takao.
 Also known as TOZAN MARU.
 On 20 Sep ’41, the United States formally closes the Panama Canal to Japanese shipping.
Thanks go to the late John Whitman and Fontessa-san of Japan for troop info. Thanks also go to Erich Muethlthaler of Germany.
to IJA Transports