IJA fleet organization, OOB etc.

[tom!]

Hi.

There are so many sources about IJN naval organisation, OOBs, command structures etc. but I never found anything similar for the IJA naval branch. Are there any data or sources available (english if possible)?

I´m specially interested in any informations for January 1937, December 1941 and January 1944.

Yours

tom!

[fontessa]

There are so many sources about IJN naval organisation, OOBs, command structures etc. but I never found anything similar for the IJA naval branch. Are there any data or sources available (english if possible)?

I´m specially interested in any informations for January 1937, December 1941 and January 1944.

tom!

I can't imagine which unit or organization "the IJA naval branch" refers to. Locations, Commanding Officers, Equipment etc. If you have any additional information, it may be a clue.

fontessa

[Akira Takizawa]

IJA naval branch will mean 陸軍船舶司令部. Below is Japanese Wiki page. I don't know any English source.
https://ja.wikipedia.org/wiki/%E8%88%B9 ... 4%E9%83%A8

Taki

[tom!]

Hi.

IJA naval branch will mean 陸軍船舶司令部. Below is Japanese Wiki page. I don't know any English source.
https://ja.wikipedia.org/wiki/%E8%88%B9 ... 4%E9%83%A8

Taki

That´s one of the bigger things I was searching for, many thanks.

I can't imagine which unit or organization "the IJA naval branch" refers to. Locations, Commanding Officers, Equipment etc. If you have any additional information, it may be a clue.

I´m interested in almost anything regarding the IJA Naval organisation as infos are very scarce (if not to say non-existent) here in the west. All I know is that IJA naval branch fielded up to 300.000 soldiers. There must have been an organisation and Taki gave me a clue where to start on this part of the topic.

But my request also includes answers to questions like:
-was there a permanent assignment of transports to a certain operating unit?
-which ship was operated by which unit at the given dates,
-which unit operated the shipborne guns (if possible on which ship),
-which unit operated wireless and other equipment (if possible on which ship) including the Ki-76 and autogyros on the small carriers
-how was the cooperation with IJN organised during the various landing operations
-How was air support provided (IJA and IJN).
-who was in charge of equipment development like gunboat prototypes, transport subs or the modification of land-based guns for ship service and other special equipment,
etc.

This includes requisitioned transports and military ships like the landing support ships, escort carriers, transport speedboats and submarines but also tugs and gunboats etc.

Commanding officers of the units involved would be nice, too.

By the way: Is there a list of all army commanded convoys since summer 1937?



So everything available would be cool. I know this is an enormous subject and so I don´t expect detailed answers instantly. As mentioned give me sources and I try to learn. I´m not very familiar with the japanese language but everything on the net can be translated. And I will ask if something isn´t clear to me.

Yours

tom!

[Akira Takizawa]

-was there a permanent assignment of transports to a certain operating unit?
All transport ships belonged to 陸軍船舶司令部(IJA shipping HQ) directly.

-which ship was operated by which unit at the given dates,
All transport ships were operated by employed merchant sailors.

-which unit operated the shipborne guns (if possible on which ship),
They were operated by 船舶砲兵(Shipping artillery force). They were not fixed on ship, but moved from ship to ship according to operation.

-which unit operated wireless and other equipment (if possible on which ship) including the Ki-76 and autogyros on the small carriers

Wireless was operated by 船舶通信隊(Shipping communcation unit). Ki-76 was operated by IJAAF 1st Independent Flying Company. Autogyro was only tested and not used on carrier.

-how was the cooperation with IJN organised during the various landing operations
It was case by case. Cannot explain generally.

-How was air support provided (IJA and IJN).
It was case by case. Cannot explain generally.

-who was in charge of equipment development like gunboat prototypes, transport subs or the modification of land-based guns for ship service and other special equipment

Shipping equipments were developed by 陸軍運輸部(IJA Transport Department). Most special shipping equipments like Daihatsu, AB-Tei, Shinshu Maru etc. were developed by it. From 1944, IJA 10th Technical Laboratory developed shipping equipments. Maru-Re was developed by it.

Taki

[fontessa]

Hello tom,

By the way: Is there a list of all army commanded convoys since summer 1937?

I´m specially interested in any informations for January 1937, December 1941 and January 1944.

No convoy was formed in January 1937 and December 1941.
Many convoys were formed in January 1944.
Large convoys were abbreviated as:
HI-xx: Japan homeland ⇔ Singapore
MOTA-xx: Moji→Takao
TAMO-xx: Takao→Moji
MOMA-xx: Moji - Manila
MAMOxx: Manila→Moji
TAMA-xx: Takao1→Manila
MATA-xx: Manila→Takao
PATA-xx: Palau→Takao
TAPA-xx: Takao→Palau
MI-xx: Japan homeland ⇔ Miri
Large Convoys in January 1944
HI -31: 4 transports with 4 escorts / Departed Moji on 11 January and arrived Singapore on 20 January
HI -30: 4 transports with 1 escort / Departed Singapore on 19 January and arrived Keelung on unclear day (cancelled here)
HI -32: 6 transports with 2 escorts / Departed Singapore on 25 January and arrived Moji on 4 February

Convoys were formed at 船舶司令部 Army Shipping Command in 宇品 Ujina. It’s staff officers gathered transport ships and escort ships to form a convoy. After August 1944, 船団護衛司令部 Convoy Escort Headquarters controlled large scale convoys. A large number of documents were made in Army Shipping Command, most of them were lost in the turmoil at the end of the war. Therefore, the details of convoys are not very clear.
As for H-71, see the below;
viewtopic.php?f=65&t=255390&start=30#p2327336

Japanese Wiki says about some of Hi-convoy.
https://ja.wikipedia.org/wiki/%E3%83%92 ... 9%E5%9B%A3


The below is the list of Convoy Escort Headquarters;

1st Convoy Escort Headquarter 第1船団護衛司令部
Commanding Officers
RADM / ??? Baron IJUIN Matsuji 伊集院松治 (43): 8 April 1944 - 24 May 1944 (KIA) (5 C13072097200)
Staff Officers (TEMPORAL)
LCDR / LCDR HANDA Nikichi 半田仁貴知 (58): 8 April 1944 - 12 April 1944 (26 C13072097200 / 31 C13072097200)
CDR / CDR / CAPT* HIGASHI Tetsuo 東徹雄 (56): 1 May 1944 - 24 May 1944 (KIA) (38 C13072098000)
During the escort of Hi-63, flagship IKI on her 1st Convoy Escort HQ member boarded was sunk by torpedo attack of USS RATON on 24 May 1944.

2nd Convoy Escort Headquarter 第2船団護衛司令部
Commanding Officers
RADM / RADM KIYOTA Takahiko 清田孝彦 (42): 8 April 1944 - 8 July 1944 (5 C13072097200 / 16 C13072100000)
RADM / RADM / VADM* TAKAHASHI Ichimatsu 高橋一松 (40): 8 July 1944 - 4 August 1944 (KIA) (16 C13072100000)
Staff Officers (TEMPORAL)
CDR / CDR INOUE Masao 井上正夫 (55): 8 April 1944 - 26 May 1944 (20 C13072097200 / 13 C13072100400)
CAPT / CAPT TANAKA Masao 田中正雄 (50): 28 April 1944 - 1 May 1944 (13 C13072097500 / 38 C13072098000)
CDR / CDR INOUE Masao 井上正夫 (55): 1 May 1944 - 8 May 1944 (38 C13072098000 / 30 C13072098100)
CAPT / CAPT / RADM* OKA Iwao 岡巌 (50): 24 July 1944 - 4 August 1944 (KIA) (20 C13072100200)

3rd Convoy Escort Headquarter 第3船団護衛司令部
Commanding Officers
RADM / RADM TSURUOKA Nobumichi 鶴岡信道 (43): 8 April 1944 - 1 June 1944 (5 C13072097200 / 1 C13072099300)
RADM / RADM / VADM* MONZEN Kanae 門前鼎 (42): 1 June 1944 - 9 June 1944 (KIA) (1 C13072099300)
Staff Officers (TEMPORAL)
CDR / CDR MIYAZAKI Isao 宮崎勲 (52): 8 April 1944 - 8 May 1944 (20 C13072097200 / 30 C13072098100)
CAPT / CAPT KOYAMA Tadashi 小山貞 (50): 8 May 1944 - 9 June 1944 (Survived) (30 C13072098100)
CDR / CDR / CAPT* HINO Takeyoshi 桧野武良 (55): 1 June 1944 - 9 June 1944 (KIA) (45 C13072099400)
During the escort of Convoy No.3606, flagship MATSUKAZE on her 3rd Convoy Escort HQ member boarded was sunk by the torpedo attack of USS Swordfish on 9 June 1944.

4th Convoy Escort Headquarter 第4船団護衛司令部
Commanding Officers
RADM / RADM NAKAMURA Motoji 中邑元司 (39): 8 April 1944 - 20 May 1944 (5 C13072097200 / 30 C13072098200)
Staff Officers (TEMPORAL)
LCDR / CDR 古浜智 (55): 8 April 1944 - 10 May 1944 (26 C13072097200 / 39 C13072098100)

5th Convoy Escort Headquarter 第5船団護衛司令部
Activated on 8 April 1944.
Deactivated on 20 January 1945.
Commanding Officers
RADM / RADM SATO Namizo 佐藤波蔵 (39): 8 April 1944 - 15 April 1944 (5 C13072097200 / 19 C13072097300)
RADM / RADM YOSHITOMI Setsuzo 吉冨説三 (D.C.): 15 April 1944 - 25 December 1944 (3 C13072102800) (19 C13072097300)
RADM / RADM HISAMUNE Yonejiro 久宗米次郎 (41): 25 December 1944 - 20 January 1945 (3 C13072102800 / 8 C13072103100)
Staff Officers (TEMPORAL)
CDR / CDR OKADO Yasuhiko 岡戸靖彦 (51): 8 April 1944 - 10 June 1944 (19 C13072097200 / 26 C13072099500)
CDR / CDR KUROKI Teruo 黒木照男: 2 July 1944 - 15 August 1944 (48 C13072099900 / 34 C13072100600)
CDR / CAPT YAKAHASHI Masaru 高橋優 (50): 12 August 1944 - 20 January 1945 (12 C13072100600 / 8 C13072103100)

6th Convoy Escort Headquarter 第6船団護衛司令部
Commanding Officers
RADM / RADM / VADM* KAJIOKA Sadamichi 梶岡定道 (Mobilized): 8 April 1944 - 12 September 1944 (KIA) (5 C13072097200)
Staff Officers (TEMPORAL)
CAPT / CAPT IMAZATO Yoshimitsu 今里義光 (50): 8 April 1944 - 22 May 1944 (19 C13072097200 / 49 C13072098200)
LCDR / LCDR ITO Mitsuji 伊藤光治 (61): 14 July 1944 - 25 September 1944 (7 C13072100100 / 1 C13072101400)
During the escort of Hi-72, flagship HIRATO on her 6th Convoy Escort HQ member boarded was sunk by the torpedo attack of USS Growler on 12 September 1944.

7th Convoy Escort Headquarter 第7船団護衛司令部
Commanding Officers
RADM / RADM MATSUYAMA Mitsuharu 松山光治 (Mobilized): 8 April 1944 - 23 December 1944 - ??? (5 C13072097200 / 50 C13072102400)
RADM / RADM KOMAZAWA Katsuki 駒沢克己 (43): 23 December 1944 - 25 February 1945 (50 C13072102400 / 8 C13072103600)
Staff Officers (TEMPORAL)
CDR / CDR SUGITA Binzo 杉田敏三 (54): 8 April 1944 - 11 May 1944 (20 C13072097200 / 47 C13072098100)
CAPT / CAPT UGAKI Tamaki 宇垣環 (50): 18 May 1944 - 15 July 1944 (29 C13072098200 / 35 C13072100100)
CDR / CDR TAGAHARA Yoshitaro 田ケ原義太郎 (50): 25 July 1944 - 7 October 1944 (43 C13072100300 / 48 C13072101500)
Staff Officers
LCDR / LCDR TANII Tokumitsu 谷井徳光 (63): 20 September 1944 - 23 January 1945 (23 C13072101000 / 33 C13072103100)
LCDR / LCDR YOSHII Toshio 吉井俊雄 (61): 23 January 1945 - 20 February 1945 (33 C13072103100 / 20 C13072103700)

8th Convoy Escort Headquarter 第8船団護衛司令部
Commanding Officers
RADM / RADM SATO Tsutomu 佐藤勉 (Mobilized): 15 April 1944 - 9 January 1945 (19 C13072097300 / 11 C13072102900)
Staff Officers (TEMPORAL)
CDR / CDR SHIBATA Otokichi 柴田音吉 (54): 20 April 1944 - 12 August 1944 (27 C13072097400 / 3 C13072100600)
CDR / CDR SHIBATA Otokichi 柴田音吉 (54): 25 August 1944 - 25 September 1944 (6 C13072100700 / 38 C13072101000)
Staff Officers
LCDR / LCDR ISHIGE Chifuyu 石毛千冬 (61): 25 September 1944 - 20 January 1945 (38 C13072101000 / 13 C13072103100)

fontessa

[Eugen Pinak]

Akira, Fontessa - thank you for the insights on this little-known topic.

[fontessa]

including the Ki-76 and autogyros on the small carriers

Ki-76 was operated by IJAAF 1st Independent Flying Company. Autogyro was only tested and not used on carrier.

2nd Shipping Flight Company (Anti-submarine) belonged to 船舶司令部 Army Shipping Command was a flight unit that uses autogyros, which was rare in the world. At the end of World War II, it served as a convoy escort and anti-submarine patrol for a very short period of time. The history of Japanese autogyro began with the purchase of Avro's Sherpa C19 by the Navy and Asahi Shimbun.
In the Army, the artillery unit, which had used balloons for artillery observer, focused on the autogyro and aimed to put it into practical use. Since the request was from the artillery unit instead of the normal aviation unit, the development of the weapons administration was led by 陸軍技術本部 Army Technology Headquarters instead of 陸軍航空本部 Army Aviation Headquarters. The Army Technology Headquarters took over the damaged KD-1A that was purchased from Kellett in the United States for prewar research by the Army Aviation Headquarters, and made prototypes based on it by 萱場製作所 Kayaba Seisakusho (Airframe) and 神戸製鋼 Kobe Steel (Motor and drive mechanism). Since it was not in charge of the Army Aviation Headquarters, it was not given a Ki number, and the developed aircraft was called the "Kayaba Ka-1" (later “Kayaba O-1”). The domestic autogyro was completed in early 1944 and the test flight was successful, but the severe battlefield did not allow the autogyro to artillery observer. Under these circumstances, the idea of "Kayaba Ka-1" using the Army Special Ship "Akitsu Maru" as a mother ship and "Kayaba Ka-1" for anti-submarine patrol emerged. In June 1944, using Kellett KD-1A instead of Kayaba K-1, a takeoff and landing test was conducted on Akitsu Maru. The second photo shows Akitsu Maru rear view. The takeoff and landing test at the "Akitsu Maru" of the autogyro was conducted in this state. The test pilot said "Because there was a mast at the rear of the ship, it was not possible to enter straight from the stern, and it was difficult to land." This mast was removed during the conversion to an "aircraft carrier".
https://www.youtube.com/watch?v=8PUv8HThZxs&t=5s
https://www.youtube.com/watch?v=pAa0dagcXkQ
(The reason why the rotor blades are rotated in the autogyro in the stationary posture is to give power by the intermittent operation of the clutch and to create a "trigger" for the rotor blades to rotate. When the rotation of the rotor is stable, disengage the clutch and start sliding.)

“Akitsu Maru" was refurbished from April to July 1944, adding equipment needed for “aircraft carrier”, and in August, the takeoff and landing test for Ki-76 was also successful. The 3rd photo shows Ki-76s on AKitsu Maru. Because "Kayaba Ka-1" production delayed due to several causes, Akitsu Maru, equipped with 1st Independent Flight Company, took anti-submarine patrol service in the Korea Strait from August to November. However, the shortage of transport vessels by US submarines became extremely serious, and Akitsu Maru was also used as a transport vessel after her anti-submarine patrol mission was released, and she returned to Monji on November 9. She was in a hurry to leave Imari on November 14th to transport 64th Infantry Regiment of 23 Division and 20th Sea Raiding Squadron etc. as one transport vessel of convoy Hi-81. Hi-81 controlled by 8th Convoy Escort Headquarter (Commanded by RADM SATO Tsutomu 佐藤勉) was tracked by a US submarine immediately after sailing, and the Akitsu Maru sank off the Goto Islands on November 15 due to 2 torpedoes launched by USS Queenfish, SS/AGSS-393.

The 2nd Shipping Flight Company was formed as an anti-submarine patrol unit to operate autogyros. (The organization was ordered on December 31, 1945, and the organization was completed on January 4, 1945.) It seems the Unit Code was "暁 Akatsuki 2490" from the Ship Command. The 2nd Shipping Flight Company, which lost its mother ship, served as a fleet escort and anti-submarine patrol at Tsutsuki Beach Airfield in Iki, and later as a base for Shimotsushima Airfield in Shimotsushima and Matsunami Airfield in Noto.

カ号2型観測機.jpg

あきつ丸.jpg

あきつ丸_Ki-76.jpg

fontessa

[Akira Takizawa]

2nd Shipping Flight Company (Anti-submarine) belonged to 船舶司令部 Army Shipping Command was a flight unit that uses autogyros, which was rare in the world. At the end of World War II, it served as a convoy escort and anti-submarine patrol for a very short period of time.

I did not know it. Thank you.

Taki

[Berend]

I would like to add some of this information about the aircraft carried by Akitsu Maru in the Akitsu Maru trom.
Below shows wat information her trom currently contains about its aircraft usage.

13 April 1944:
Aioi. Undergoes remodelling construction at Harima shipyard. The bridge and funnel are moved to starboard to allow installation of a flight deck for flying off the ship’s her seven Army Ki-76 aircraft. A single lift is at the aft end of this deck.

30 July 1944:
Remodelling is completed.

6 August 1944:
Departs Ujina. Her aircraft probably conduct airborne anti-submarine patrols.

8 August 1944:
Arrives at Fusan (Pusan), Korea.

9 August 1944:
Departs Fusan. Her aircraft probably conduct airborne anti-submarine patrols.

11 August 1944:
Arrives at Moji.

12 August 1944:
Departs Moji.

14 August 1944:
Arrives at Otaru.

19 August 1944:
Departs Otaru.

21 August 1944:
Arrives at Mutsure.

30 September 1944:
Departs Moji. Her aircraft probably conduct airborne anti-submarine patrols.

6 November 1944:
Arrives at Fusan.

9 November 1944:Departs Fusan. AKITSU MARU's aircraft probably conduct airborne anti-submarine patrols. Later that day arrives at Moji
13 November 1944:
Departs Moji and arrives at nearby Imari Bay.

14 November 1944:
Departs Imari Bay for Singapore in convoy HI-81 also consisting of SHINSHU, KIBITSU, ARITA, OTOWASAN, HASHIDATE, KIYOKAWA, MAYASAN, MIRII and TOA MARUs escorted by destroyer KASHI and kaibokan ETOROFU (F), TSUSHIMA, DAITO, KUME, SHONAN, CD-9 and CD-61. The convoy carries about 4,500 men of the IJA’s 23rd Infantry Division being deployed to the Philippines.

AKITSU MARU is loaded with the 23rd Division’s artillery and men of Hq, 64th Infantry Regiment, 1st and 2nd Battalions, 64th Inf, 1st Company, 2nd Battalion 72nd Infantry Regiment, 1st Company, 23rd Engineers and about 500 horses.

AKITSU MARU carries also non-divisional units and the IJA’s 20th Sea Raiding Battalion with 104 “Maru-ni” explosive motor boats (EMB). Her flight and hangar decks are fully loaded with aircraft also intended for the Philippines.

AKITSU MARU also carries two Kayaba Ka-1 autogyros for anti-submarine use. The Ka-1’s each carry one small 60 kg (132 lb) depth charge.

Stops overnight at Goto Island.

If known what is/are:
The exact date of the Kellett KD-1A takeoff and landing test in June 1944?
The exact date of the Ki-76 takeoff and landing test in August 1944?
The dates, numbers and results of her aircraft anti-submarine patrols during the period August – November 1944?
Were there 2 Kayaba Ka-1 on board when she left Imari Bay on 14 November 1944?

Regards,

Berend.

[fontessa]

Hello Berend,

Thanks for the info.

The exact date of the Kellett KD-1A takeoff and landing test in June 1944?

On 4 June 1943.

The exact date of the Ki-76 takeoff and landing test in August 1944?

Yes. But exact date is not clear.

The dates, numbers and results of her aircraft anti-submarine patrols during the period August - November 1944?

The US Navy was refraining from dispatching submarines to the Sea of Japan from October 1943 to June 1945, so no anti-submarine combat occurred.

Were there 2 Kayaba Ka-1 on board when she left Imari Bay on 14 November 1944?

The transport of Ka-1 and Ki-64 was the reinforcement for Army troops in the Philippines, not for anti-submarine use. The anti-submarine patrol was performed by 14 Kate belonged to 931st Naval Air Group boarded Shinyo, one of the escort ships of convoy Hi-81. I am not certain about the correct number of these Ka-1 and Ki-64.

Additional Information
The number of Ki-76 aboard was 8.
Ki-76 was equipped with one 60 kg anti-submarine depth charge or two 30 kg depth charges.
Ki-76 had a landing hook.
Akitsu Maru was equipped with 着船指導灯 Landing Leading System and 陸上移動横索制動装置KX Arresting Wires.

There was another Army aircraft carrier 熊野丸 Kumano Maru.
As shown in the figure, her bridge was embedded below the front edge of the flight deck and the funnel was installed on the starboard side. These gave her an aircraft carrier-like appearance. She laid down on 15 August 1944 and launched on 31 March 1945. But the war situation had became so bad that aircraft carriers couldn't move, so she ended the war while evacuating to Ujina Port.

viewtopic.php?f=65&t=231904#p2108814

あきつ丸(改装後).jpg

熊野丸.jpg

fontessa
Ps. Wasn't there any comment to my previous post from Peter Cundal?
viewtopic.php?f=65&t=255390&start=90#p2344263

[Berend]

Hello Fontessa,

thank you for answering my questions. Very useful information.

Regarding the sinking of Kuretake:

According to Peter you answered the questions or taken the answers as far as possible based on the known facts. The detailed breakdown of the 10th Division carried in TAMA-36 is most useful.
On the POW Research Net answer their use of POW accounts rather casts the accuracy of their account into doubt in his mind. Unless trained observers, POWs often got ship names and convoy numbers wrong. The 2 tankers could for example easily be type 2As given these were engine aft vessels. Daii Maru could be one.

Regards,

Berend

[FORBIN Yves]

Here also and excellent blog !
http://niehorster.org/014_japan/__ighq.htm