(AZUMASAN MARU. prewar)
IJN AZUMASAN MARU:
Tabular Record of Movement
© 2012-2016 Gilbert Casse, Bob Hackett and Peter Cundall
18 November 1932:
Tama. Laid down by Mitsui Bussan K.K. Zosensho shipyard as a 7,613-ton refrigerated cargo ship for Mitsui Bussan K.K., Kobe.
28 May 1933:
Launched and named AZUMASAN MARU.
31 July 1933:
Completed and registered in Kobe. Her Gross Registered Tonnage (GRT) is 7,613-tons and her Net Registered Tonnage (NRT) is 4,713-tons. 
E August 1933:
Placed on Mitsui Bussan’s New York commercial route (Yokohama ~ New York).
E September 1933:
Departs Yokohama. Calls at New York ~ Penang, Malaya ~ Singapore.
E September 1933:
Her GRT and NRT are changed respectively to 7,621-tons and to 4,708-tons.
E October 1933:
Her GRT and NRT are changed respectively to 7,622-tons and to 4,655-tons.
6 October 1937:
Arrives at Yokosuka.
5 December 1938:
Arrives at Manila from Kobe.
13 June 1939:
Arrives at San Francisco, California.
15 October 1941:
Sakurajima. Starts her conversion to an auxiliary transport at Osaka Iron Works Shipyard.
20 November 1941:
Registered in the IJN as an auxiliary transport (Ko) category under internal order No. 1495 and attached to the Maizuru Naval District. Her home port is Maizuru. 
10 December 1941:
Departs Osaka with GOYO MARU.
11 December 1941:
Arrives at Yokosuka.
12 December 1941:
The conversion is completed.
14 December 1941:
Transfers from Yokosuka to Shibaura.
16 December 1941:
Departs Shibaura, Tokyo with GOYO MARU transporting troops of the No. 2 Maizuru Special Naval Landing Force for the forthcoming “O” Operation.
E December 1941:
Arrives at Truk, central Carolines.
20 January 1942: Operation "R"- The Invasions of Rabaul, New Britain and Kavieng, New Ireland:
Auxiliary transports AZUMASAN and GOYO MARUs and auxiliary merchant cruiser KINRYU MARU depart Truk escorted by CruDiv 18's TENRYU and TATSUTA and DesDiv 23's KIKUZUKI, UZUKI and YUZUKI. They are screened by CruDiv 6's AOBA, KINUGASA, KAKO and FURUTAKA and CarDiv 11's seaplane carrier CHITOSE. Distant cover is provided by CarDiv 1's AKAGI and KAGA, CarDiv 5's SHOKAKU and ZUIKAKU, BatDiv 3/2's HIEI and KIRISHIMA and CruDiv 8's TONE and CHIKUMA.
23 January 1942:
About midnight, the transports land three companies of the No. 2 Maizuru Special Naval Landing Force. By 0335, they capture Kavieng's airfield. Later that same day, the invasion forces swiftly overcome light Australian opposition and occupy Rabaul.
E January 1942:
24 January 1942:
Assigned to transport three Daihatsu barges by secret order No. 49.
8 February 1942:
Arrives at Kure.
18 February 1942:
Departs Kure joining a convoy that had departed Yokosuka for Truk, also consisting of auxiliary transports SHOKA, CHOWA and AKIBASAN MARUs.
25 February 1942:
Arrives at Truk.
21 March 1942:
Departs Truk for Rabaul, New Britain in a convoy also consisting of SHOKA, CHOWA and AKIBASAN MARUs.
26 March 1942:
Arrives at Rabaul.
E March-April 1942:
Departs Rabaul and arrives at Truk at unknown dates.
22 April 1942:
Assigned to R District Command, Transport Force under Navy’s secret order No. 10 for the forthcoming “MO” operation.
28 April 1942: Operation “MO” – The Invasion of Tulagi and Port Moresby:
Rear Admiral (later Vice Admiral) Shima Kiyohide's (39) Tulagi Invasion Force departs Truk. The Invasion Force consists of minelayer OKINOSHIMA (F), auxiliary transport AZUMASAN MARU and auxiliary minelayer KOEI MARU, carrying elements of the No. 3 Kure Special Naval Landing Force (SNLF) and 7th Naval
Construction Unit. Troops are assigned to set-up a seaplane base at Tulagi, Solomons.
Escort is provided by DesDiv 23's KIKUZUKI and YUZUKI, SubChasDiv 56’s TOSHI MARU No. 3 and TAMA MARU No. 8, MineSweepDiv 14’s auxiliary minesweepers Wa-1 and Wa-2, HAGOROMO MARU, NOSHIRO MARU No. 2 and TAMA MARU.
2 May 1942:
Arrives in Tulagi’s vicinity. That same day, AZUMASAN MARU is scheduled to be fitted with optical devices such as telescope and stadimeter and their related spare parts, under Navy’s secret instruction No. 5289.
3 May 1942:
Tulagi. Disembarks troops.
4 May 1942:
100 miles S of Guadalcanal. Task Force 17's Rear Admiral (later Admiral) Frank J. Fletcher (USNA ’06) receives a signal that IJN transports are disembarking troops and equipment at Tulagi. At 0701, CV-5 USS YORKTOWN launches her first surprise strike on Shima's Invasion Force. The strike consists of 18 Grumman F4F-3 "Wildcats" fighters of VF-42, 12 Grumman TBD-1 “Devastator” torpedo-bombers of VT-5 and 28 Douglas SBD-3 “Dauntless” dive-bombers from VS-5 and BY-5.
Purvis Bay, Florida Island, Solomons. TBDs torpedo and sink KIKUZUKI. The auxiliary minesweepers Wa-1 and Wa-2 and four barges are also sunk. USS YORKTOWN's planes also damage destroyer YUZUKI by strafing, auxiliary transport AZUMASAN MARU, auxiliary minelayer KOEI MARU and five floatplanes. TAMA MARU is damaged and sinks two days later.
E May 1942:
Departs Tulagi and arrives at Rabaul at unknowns dates. Probably undergoes battle damage repairs.
23 May 1942:
Assigned to Second Fleet, Supply Force for the forthcoming “MI” operation. (Effective 5 Jun)
E May 1942:
Departs Rabaul and arrives at Saipan, Marianas at unknown dates.
28 May 1942:
Departs Saipan for Sasebo.
E June 1942:
Arrives at Sasebo.
6 June 1942:
Due to IJN’s defeat at Midway, Operation “MI” is cancelled.
10 June 1942:
Departs Sasebo for Truk carrying troops assigned to the forthcoming “SN” operation.
E June 1942:
Arrives at Truk. Attached to the 4th Fleet, Transport Force.
29 June 1942: Combined Fleet’s “SN” Operation: Establishment of airbases in the South Pacific:
AZUMASAN MARU departs Truk via Bougainville to Guadalcanal carrying airfield construction workers in a convoy also consisting of auxiliary transports AZUMA, HOKUROKU, MEIYO, KANTO and MATSUMOTO MARUs,
auxiliary ammunition ship KOTOKU MARU escorted by light cruiser YUBARI (F) DesDiv 29’s YUZUKI and OITE, DesDiv 30's UZUKI and DesDiv 34's AKIKAZE. The convoy carries a Special Naval Landing Force (SNLF) and 11th and 13th construction units.
4 July 1942:
Arrives at Savo Island anchorage.
5 July 1942:
Departs Savo Island anchorage for Lunga Point, Guadalcanal. Construction Unit troops disembark. Begins to unload building materials and supplies.
11 July 1942:
Departs Lunga Point.
E July 1942:
Arrives at Truk. Departs at an unknown date for Yokosuka.
30 July 1942:
Arrives at Yokosuka.
1 August 1942:
Detached from the 4th Fleet under Navy’s secret order No. 227. Probably undergoes maintenance, repairs and scheduled fittings.
5 September 1942:
Directly attached to the Combined Fleet. Arrives in the morning at Maizuru and tethers to pier. Begins to load equipment.
6 September 1942:
At 2000, loading operations are completed.
7 September 1942:
Embarks the No. 4 Maizuru Special Naval Landing Force (SNLF) troops and at 1500, departs Maizuru for Yokosuka.
10 September 1942:
Arrives at Yokosuka. Begins to transfer troops and equipment to CruDiv 9’s light cruisers OI and KITAKAMI.
12 September 1942:
At 1700, transfer operations are completed. CruDiv 9 departs Yokosuka.
16 September 1942:
E October 1942:
Arrives at Rabaul.
10 October 1942:
Attached to Combined Fleet, under Navy’s secret order No. 145. AZUMASAN MARU’s primary mission is to transport LtGen Harukichi Hyakutake’s 17th Army’s troops and IJN SNLF troops to Guadalcanal in a “High Speed Convoy”.
12 October 1942: - First Assault Convoy for Tassafaronga, Guadalcanal:
Departs Rabaul for Guadalcanal via Shortlands in a “High Speed Convoy” also consisting of IJA transports SADO, SAKITO and SASAKO MARU and IJN auxiliary transports KYUSHU and NANKAI MARUs escorted by Rear Admiral (later Vice Admiral) Takama Tamotsu’s (41) DesRon 4’s AKIZUKI (F), Desdivs 2’s YUDACHI, HARUSAME, SAMIDARE, MURASAME and DesDiv 27’s SHIGURE, SHIRATSUYU and ARIAKE.
The convoy carries about 4,500 troops including the IJA’s 16th Regiment, two battalions of the 230th Infantry Regiment and 824 men of the No. 4 Maizuru Special Naval Landing Force ( SNLF) from Rabaul and Shortlands. The ships also carry a battery of 100-mm guns and a battery of 150-mm howitzers, the 38th Field AA battalion, the 45th Field AA Battalion, one company of the 47th Field AA battalion, the 1st Company of the 38th Engineer Regiment, the 1st Independent Tank Company, one section of the 38th Division Signal Company, ammunition and provisions. Air cover is provided by the 11th Air Fleet and the R-Area Air Force's floatplane fighters.
At 1400, about 100 miles from Shortlands’ anchorage, the convoy is attacked by 30 aircraft of the ‘Cactus Air Force’. At 1530, a second attack occurs. Both are ineffective however and the ships sustain no damage, the convoy arriving at Shortlands later that same day.
13 October 1942:
The convoy departs Shortlands and arrives at midnight at Tassafaronga. Unloading operations are undergone.
14 October 1942:
At dawn, Mitsubishi A6M "Zekes" fighters from carriers HIYO and JUNYO and floatplane fighters of the R-Area Air Force provide cover over the unloading operation. At 0600, a flight of six Grumman F4F
"Wildcat' fighters strafe the transports. One F4F is lost and another damaged as is a floatplane fighter.
At about 1030, the transports are attacked by the “Cactus Air Force” (later Air Sols) from Henderson Field, Guadalcanal with a force of 25 aircraft including 12 Douglas "Dauntless" SBD dive-bombers, three USAAF P-39s and one P-400 “Airacobra” fighters, eight F4F fighter and one PBY-5 “Catalina” armed with two torpedoes. An SDB or the PBY hits SASAKO MARU and starts a fatal fire.
She is beached and becomes a total loss, but her troops, tanks, and guns are landed successfully.
At 1145, NANKAI MARU, having completed her unloading, departs the area escorted by destroyer ARIAKE. At 1150, after most of the remaining transports had landed almost all of their troops and heavy equipment, a flight of 11 B-17 “Flying Fortress” heavy bombers from Espiritu Santo attack the transports.
AZUMASAN MARU is hit and beached. At about 1330, in another American air attack KYUSHU MARU is hit by a bomb, set afire and beached. Their troops, tanks, and guns are landed successfully, but the tank fuel and ammunition they carried are lost. Both ships burn out and become total losses.
Rear Admiral Takama gets his ships underway to avoid further air attacks and the remains of the convoy heads N to Savo Island. At 1700, the convoy returns to Tassafaronga. At 1740, the convoy is attacked again, this time by a flight of four SBD dive-bombers of carrier USS ENTERPRISE’s VB-6 with no further damage.
15-16 October 1942:
Off Tassafaronga. Another raid by B-17s further damages AZUMASAN MARU’s wreck. During the night, she slips off the reef and sinks to a depth of 100-200 feet about 2nms SE of Bunina Point, at 09-21S,
1 February 1943:
Removed from the Navy’s list under internal order No. 108.
 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 reducing 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 also to John Whitman of Virginia for info provided on Sept ’42 movements.
Thanks go to Gengoro S. Toda of Japan.
-Gilbert Casse, Bob Hackett and Peter Cundall
IJN Transports Page