Japanese Army Auxiliary Anti-Aircraft Transports

RIKUGUN BOKU KIKANSEN

(Wartime Boku Kikansen by Ueda Kihachiro)

IJA AA Transport SADO MARU:
Tabular Record of Movement
© 2011-2014 Bob Hackett and Gilbert Casse
Revision 1

15 October 1938:
Nagasaki. Laid down at Mitsubishi as a 7,180-ton passenger-cargo ship for the Nippon Yusen Kaiha (NYK) Line.
8 April 1939:
Launched and named SADO MARU. [1]
30 June 1939:
Completed and placed in NYK’s service.
1940-1941:
SADO MARU is used mainly on NYK’s eastbound "Europe-Line" and “New York-Line”.
For the “Europe-Line, her usual ports of call are from Kobe to Nagoya, Osaka, Moji, Shanghai, Kirun, Hong-Kong, Singapore, Penang, Colombo, Aden, Port Said, Naples, Marseilles, Gibraltar and London. From London, she steams to Antwerp and Middlesbrough, and then returns to Japan by the same route, omitting Port Said. Her cargo consists of raw silk from Japan and general cargo. On her return trip, she carries steel products and general cargo.
For the “New York-Line, she calls from Kobe to the Philippines, Hong Kong, Kirun, Shanghai and Tientsin (Taku) then returns to Japan with calls at Osaka, Kobe, Yokohama and other domestic ports. Then after crossing the Pacific to Los Angeles she steams to New York via Balboa, the Panama Canal and Cristobal. After calls at the east coasts port of Boston, Baltimore, Philadelphia and Norfolk, Virginia, she returns back to Japan following roughly the same route. Her cargo consists of raw silk from Japan and general cargo, sugar, manganese and palm oil from the Philippines. On her return trip, her cargo usually consists of steel products, cotton and general cargo.
27 July 1939:
Departs Kobe for her first trip on the Europe Line.
11 January 1940:
Departs Kobe for her second trip on the New York Line.
10 July 1940:
Departs Kobe for her third trip on the New York Line.
8 February 1941:
Requisitioned by the Imperial Army with Army number No. 810 and converted to a Boku Kikansen (anti-aircraft -AA) vessel. Fitted with eight Type 88 75-mm AA and eight Type 98 20-mm AA Machine Cannons.
26 October 1941:
Departs Ujina, Hiroshima Prefecture, for Shanghai.
27 October 1941:
Arrives at Shanghai.
31 October 1941:
Departs Shanghai for Haikou, Hainan Island.
2 November 1941:
Arrives at Haikou.
16 November 1941:
Departs Haikou for Samah, Hainan Island.
17 November 1941:
Arrives at Samah.
18 November 1941:
Departs Samah for Haikou.
19 November 1941:
Arrives at Haikou.
20 November 1941:
Departs Haikou for Samah.
22 November 1941:
Arrives at Samah.
30 November 1941:
Joins other Army transports carrying elements of 5th Division.
4 December 1941:
At 0600, departs Samah in convoy (see composition below) heading south.
6 December 1941: Operation “E” – The Invasion of Malaya:
SADO MARU is part of the Singora Invasion Unit. This combined IJN/IJA operation is under operational control of the IJA.
The IJA Singora Invasion Unit is under command of LtGen Yamashita Tomoyuki’s 25th Army. Troops involved are elements of 5th Division (5th Hy Company, Kawamura Detachment Brigade, 5th Engineer Battalion (Bn), 5th Rec Bn, 1st Tank Bn with 37 Med Type 97 and 20 Lt Type 95 tanks, 9th Railroad Eng Bn, 11th Eng Bn and various Air units. Troops are carried by Army landing craft depot ship SHINSHU (RYUJO) MARU and Army transports AOBASAN, ASAKA, ATSUTASAN, KANSAI, KYUSHU, NAMINOUE, NAKO, SADO and SASAGO MARUs. One Ship AA Rgt and one Ship Signal Rgt are also carried on the transports. Further Invasion Units are destined for Kota Bharu, Malaya.
The IJN Singora Invasion Unit consists of minelayer HATSUTAKA (F) with the 9th Base Force Unit aboard, auxiliary seaplane tender KAMIKAWA MARU with six Mitsubishi Type 0 F1M2 (plus two in reserve) and three Aichi Type 0 E13A1 (plus one in reserve) floatplanes, auxiliary seaplane tenders SANYO and SAGARA MARUs each with six Mitsubishi Type 0 F1M2 and two Kawanishi Type 95 E8N2 (in reserve) floatplanes; destroyers AMAGIRI, ASAGIRI, YUGIRI and MURAKUMO; minesweepers W-1, W-4, W-5 and W-6; subchaser CH-8; auxiliary minesweeper tender EIKO MARU with 91st Naval Guard Unit aboard and auxiliary transport NOJIMA MARU with 91st Ports & Docks Unit and 91st Naval Signal Unit aboard.
7 December 1941:
At 2340, the Invasion Convoy arrives at Singora, Siam (now Songhkla, Thailand). Landings proceed without strong opposition.
E December 1941:
SADO MARU departs Singora and calls at Samah at unknown dates. Later departs for Humen, southern China.
19 December 1941:
Arrives at Humen.
20 December 1941:
Departs Humen for Camranh Bay, Indochina.
E December 1941:
Arrives at Camranh Bay.
E January 1942:
Departs Camranh Bay for Singora.
7 January 1942:
Arrives at Singora.
8 January 1942:
Departs Singora.
E January 1942:
Arrives at Camranh Bay at an unknown date.
9 February 1942: Operation "L" – The Invasions of Muntok, Banka Island and Palembang, Sumatra:
SADO MARU departs Camranh Bay, Indochina in an invasion convoy consisting of transports ALASKA, MANSEI, TAJIMA, ANYO, OYO, KINUGAWA and TACOMA MARUs escorted by Rear Admiral Hashimoto Shintaro’s [41] DesRon 3 light cruiser SENDAI, DesDiv 11's FUBUKI, HATSUYUKI and SHIRAYUKI, DesDiv 20’s AMAGIRI, YUGIRI and ASAGIRI, MinSwpDiv 1’s W-1, W-2,W-3,W-4 and W-5 and SubChasDiv 11’s CH-7 and CH-8. Air cover is provided by floatplane fighters from seaplane tenders SAGARA and KAMIKAWA MARUs.
The convoy carries seven companies of the 229th Regiment, a mountain gun battery of the 10th Independent Mountain Artillery Battalion, an engineer company of the 38th Engineer Regiment and men of the 38th Medical Unit.
14 February 1942:
OYO MARU suffers slight damage in an air attack, probably by RAAF Lockheed “Hudson” light bombers.
16 February 1942:
SAGARA and KAMIKAWA MARUs leave a detachment of F1M2 scouts at Bangka Island to operate from Muntok. Sumatra. Moesi River. In the late afternoon, two of SAGARA MARU's detachment of F1M2 Petes intercept Hudson bombers of the RAAF's 8 Squadron from Palembang over the IJN invasion ships. During their attack, one of the two “Petes” is shot down. Arrives at Palembang.
E 17 February 1942:
Departs Palembang for Muntok.
18 February 1942:
Arrives at Muntok.
26 February 1942:
SADO MARU departs Muntok for Singapore.
2 March 1942:
Arrives at Singapore.
3 March 1942:
Departs Singapore for Singora.
5 March 1942:
Arrives at Singora.
E March 1942:
Departs Singora.
E March 1942:
Arrives at Saint Jacques, Indochina.
E March 1942:
Departs Saint Jacques for Lingayen Gulf, Luzon, Philippines.
19 March 1942:
Arrives at Lingayen Gulf.
20 March 1942:
Departs Lingayen Gulf for Takao, Formosa (now Kaohsiung, Taiwan).
22 March 1942:
Arrives at Takao.
26 March 1942:
Departs Takao.
30 April 1942:
Arrives at Ujina.
E May 1942:
Departs Ujina and arrives at Moji at an unknown date.
7 May 1942:
Departs Moji for Palau, Carolines.
15 May 1942:
Arrives at Palau.
16 May 1942:
Departs Palau.
1 June 1942:
Arrives at Davao, Mindanao, Philippines.
E June 1942:
Departs Davao and arrives at Manila at an unknown date.
2 July 1942:
Departs Manila for Mako, Pescadores.
6 July 1942:
Arrives at Mako. Departs later that day for Ujina.
9 July 1942:
Arrives at Ujina. Probably undergoes some maintenance and repairs.
E July 1942:
Departs Ujina and arrives at Kobe at an unknown date.
31 July 1942:
Departs Kobe for Pusan, Chosen (Korea).
1 August 1942:
Arrives at Pusan.
3 August 1942:
Departs Pusan and arrives that same day at Ujina.
E August 1942:
Departs Ujina and arrives at Moji at an unknown date..
8 August 1942:
At 2200, SADO MARU and transport ASAKASAN MARU depart Moji for Rabaul with an unknown escort.
13 August 1942:
The convoy arrives at Palau. Embarks troops.
16 August 1942:
At 1600, departs Palau.
20 August 1942:
At 0900, the convoy arrives at Truk.
24 August 1942:
SADO and ASAKASAN MARUs depart Truk escorted by Rear Admiral Hashimoto Shintaro’s (41) DesRon 3 light cruiser SENDAI, DesDiv 20’s AMAGIRI, ASAGIRI, YUGIRI and SHIRAKUMO.
26 August 1942:
At 0900, the convoy receives orders from the IJA 17th Army to rush 600 soldiers of MajGen Kawaguchi Kiyotaki’s Brigade directly for Guadalcanal, Solomons. At noon, in mid-ocean, 600 men of the 2nd Battalion, 124th Infantry Regiment are transferred to DesDiv 20’s four destroyers and head for Guadalcanal as ordered.
27 August 1942:
The convoy arrives at Rabaul, New Britain. The remainder of Kawaguchi’s brigade are disembarked.
28 August 1942:
The majority of the 1st Battalion, 124th Infantry Regiment embark on SADO MARU and depart Rabaul for Shortlands escorted by DesDiv 11’s FUBUKI, SHIRAYUKI and HATSUYUKI.
29 August 1942:
Arrives at Shortlands.
31 August 1942:
Kawaguchi Brigade’s 600 soldiers advance party is disembarked at Guadalcanal.
7 September 1942:
Departs Shortlands and arrives later that same at Rabaul. Departs later for Palau.
9 September 1942:
Arrives at Palau. Departs later that same day for Rabaul.
E 11 September 1942:
Arrives at Rabaul.
13 September 1942:
SADO MARU departs Rabaul for Shortlands escorted by destroyer ARASHI.
14 September 1942:
Arrives at Shortlands.
E 17 September 1942:
Departs Shortlands for Rabaul.
18 September 1942:
Arrives at Rabaul.
20 September 1942:
Departs Rabaul for Palau.
E 22 September 1942:
Arrives at Palau.
E 24 September 1942:
Departs Palau.
28 September 1942:
Arrives at Manila.
29 September 1942:
Departs Manila for Palau.
1 October 1942:
Arrives at Palau. Departs later that day for Rabaul
9 October 1942:
Arrives at Rabaul.
13 October 1942: - First Assault Convoy for Tassafaronga, Guadalcanal:
SADO MARU departs Shortlands for in a high-speed convoy also consisting of AZUMASAN, KYUSHU, NANKAI, SAKITO and SASAKO MARUs escorted by Rear Admiral Takama Tamotsu’s [41] DesRon 4’s AKIZUKI (F) and Desdivs 2’s YUDACHI, HARUSAME, SAMIDARE, MURASAME and DesDiv 27’s SHIGURE, SHIRATSUYU and ARIAKE. [1]
Arrives at Buin, Bougainville and embarks troops. 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, a battalion of AA guns, the 1st Independent Tank Company, ammunition and provisions. Air cover is provided by the 11th Air Fleet and the R-Area Air Force's floatplane fighters.
SADO MARU carries about two rifle companies of the 230th Infantry, the 38th Division’s medical unit, the 19th Independent Engineer Regiment (less 1st Company), and about 1,000 men of the 2nd Battalion (less 4th Company) and and the 10th Independent Mountain Artillery Regiment with six 75mm mountain guns.
At midnight, the convoy arrives at Tassafaronga, Guadalcanal, Solomons and proceeds with unloading.
14 October 1942:
At dawn, Mitsubishi A6M "Zeke" 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 is damaged as is a floatplane fighter.
At about 1030, the transports are attacked by the “Cactus Air Force” (later AirSols) 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 1150, after most of the transports have 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. The transports' 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. At 1742, SADO and SAKITO MARUs and their escorts depart Tassafaronga for Rabaul.
18 October 1942:
Arrives at Rabaul.
25 October 1942:
Departs Rabaul for Shortlands.
26 October 1942:
Arrives at Shortlands.
12 October 1942:
Departs Shortlands for Tassafaronga but the convoy is recalled part way and steams back arriving at Shortlands later that same day.
13 November 1942: - Second Assault Convoy for Tassafaronga, Guadalcanal:
At 1730, SADO MARU departs Shortlands for Tassafaronga, Guadalcanal, Solomons with ComDesRon 2’s Rear Admiral (later Vice Admiral) Tanaka Raizo's Reinforcement Group’s troop transports carrying 38th Army Division and Special Naval Landing Force (SNLF) troops, equipment and provisions in BRISBANE, SHINANOGAWA, CANBERRA, NAGARA, ARIZONA, NAKO, HIROKAWA, KINUGAWA, YAMAURA and YAMATSUKI MARUs escorted by Tanaka Raizo’s (41) DesRon 2’s HAYASHIO, AMAGIRI, KAGERO, KAWAKAZE, MAKINAMI, MOCHIZUKI, NAGANAMI, OYASHIO, SUZUKAZE, TAKANAMI and UMIKAZE. Air cover is provided by the 11th Air Fleet and the R-Area Air Force's floatplane fighters.
14 November 1942:
At 0849, as Tanaka's Reinforcement Group proceeds down the "Slot" between the New Georgia and Santa Isabel Islands, the 23-ship convoy is sighted by two reconnaissance SBD dive-bombers from USS ENTERPRISE (CV-6). SADO MARU is carrying the 19th Independent Engineer Regiment, two rifle companies of the 230th Infantry and the 38th Division’s medical unit.
At 0908, the SDBs each attack a transport, but miss and one SBD is shot down by Japanese fighters.
Off Guadalcanal. At 1250, 18 Marine Corps SBD dive-bombers and seven USN Grumman "Avenger" TBF torpedo-bombers of VT-10 attack the convoy. Mitsubishi A6Ms shoot down some aircraft, but are engaged by Grumman F4F fighters and cannot stop the attack.
NAGARA MARU is torpedoed and CANBERRA MARUs is bombed and sunk. Destroyers AMAGIRI and MOCHIZUKI rescue 1,500 survivors of transports CANBERRA MARU and NAGARA MARU. The Americans also damage SADO MARU that is detached with AMAGIRI and MOCHIZUKI to the Shortlands carrying MajGen Tanabe Suketomo, CO of the IJA’s 38th Division and other survivors. [1]
At about 1430, 13 SBD’s make another attack and set BRISBANE MARU ablaze until she later sinks. At about 1500, a flight of seven B-17 “Flying Fortress” heavy bombers from the 11th Bomb Group (H) at Espiritu Santo attack two transports, but score no hits. About 15115, a second flight of eight B-17s attacks but also score no hits, although their gunners claim 6 of 15 attacking A6Ms.
At about 1530, SHINANOGAWA and ARIZONA MARUs are attacked by eight SBDs from ENTERPRISE covered by 12 F4F fighters. Both transports are hit by 1,000-lb bombs and abandoned. SHINANOGAWA MARU sinks at 08-30S, 158-45E. Destroyer NAGANAMI rescues 570 survivors from SHINANOGAWA MARU and MAKINAMI rescues 1,020 survivors from ARIZONA MARU. [2]
In the last attack of the day, beginning about 1610, 14 Marine and Navy SBDs and three TBFs, covered by seven F4Fs, sink transport NAKA MARU. Destroyer SUZUKAKE rescues 1,100 survivors. The surviving ships and their escort depart Tassafaronga for Shortlands. [3]
15 November 1942:
Arrives at Shortlands.
18 November 1942:
Shortland Islands. While anchored at Elebenta, SADO MARU is sunk in an air raid by USAAF B-17s and P-38s aircraft.

Authors’ Notes:
[1] SADO MARU was also known as SATO MARU, SAKITO MARU was also known as SAKIDO MARU and SASAKO MARU was also known as SASAGO MARU.
[2] Reports of the number of survivors rescued by NAGANAMI and MAKINAMI vary from 1,562 to 1,590.
[3] The Japanese lose about 450 men KIA in the 13 Nov '42 action. Although troop losses and other casualties for individual ships are unknown, the destroyers rescue more than 4,800 men.
Thanks go to Erich Muehlthaler of Germany and to John Whitman of Virginia and Fontessa-san of Japan.

-Bob Hackett and Gilbert Casse

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