Questions concerning the IJA merchant fleet

[daveh]

On reading glenn239’s fascinating and detailed concept for an invasion of Oahu, December 1941 I was struck by the large quantity of shipping that the IJA used

“the Army mobilized 2.16 million tons to lift and supply it's forces in all theatres”

Apart from "The Japanese Merchant Fleet in World War II" (which I have as yet not been able to see) are there any other sources (in English please) detailing how such vessels were obtained, crewed and organised.

To what extent did the navy co operate in providing escorts for these army vessels? how were any such escorts arranged? did the IJA ever provide there own escorts...I remember reading about army "aircraft carriers" for escort use.

I know that some specialised vessels were built to transport landing craft...were these ordered by the IJA? and if so to what extent was the IJN involved in their design?

so many questions..sorry

Any help will be much appreciated

[Carl Schwamberger]

I dont have anything that can answer those questions directly. I can recomend Ellis 'Brute Force' in that large volume is a section identifying year by year Japans ships available, ships built, and ships sunk. He also makes some remarks about the ammount of cargo carried by the merchant fleet vs what was required.

[Jerry Asher]

Hi Dave;

I am unaware of any outstanding work that covers this topic in English. Nor as yet have I been successful in teasing anything out of the internet in any other language. My threads in this forum, focusing on the movement of Japanese divisions in part have been an indirect approach. That said I offer the following:

It would seem that within the Japanese system the role of the Navy in regard to amphibious operations is solely limited to escorting and protection of the ships while at anchor. Loading and off loading are army operations with subordinate Navy participation.(in one operation the Navy was to build a pier for the army).

Priority given to escorting can not be overstated. Tojo appalled at Navy failure to protect troops in Battle of Bismark Sea lead to revision of use of transports where they would be exposed to allied air power. Failure to protect convey Take 1 to New Guinea, lead to preference of more but smaller ships for transport of troops and personnel.

IJN gave the highest priority to protection of troop carrying ships; somewhat less so for
cargo carrying. Even so, as pointed out in answer to one of my questions on this thread such a thing as IJA directed cargo ships may have sailed independently of IJN and convoy system.

Something like a "All the ships of the IJA would be useful." I refer you to the site maintained by our member Taki.

Often the terms "mobilized" as compared to requisitioned, "commercial" in contrast to merchant are used in translating from Japanese.

At some point in the late 1930's and early 1940's, separately British and American naval officers were surprised by the relatively small number of ships within the Japanese system it took to move a division. Japanese divisions often seemed to require twenty plus ships, where the British assumed thirty and the big American divisions of the later years of the war, were almost fifty five ships. (There was also some big-- approxiamatly one hundred ships Japanese invasions, ie. Guangzhou (Canton 1938), Dutch East Indies 1942).

[Akira Takizawa]

> To what extent did the navy co operate in providing escorts for these army vessels? how were any such escorts arranged?

It was decided by the negotiation of the army and navy. The central negotiation was made by GF and General Army and the local negotiation was made by fleet and army.

In Nov. 1943, the Escort GHQ was established in the IJN and it managed the escort duty.

> did the IJA ever provide there own escorts...I remember reading about army "aircraft carriers" for escort use.

Basically, the escort was the duty of the IJN. But, in the late of WWII, the ability of the navy escort declined and the IJA built some escort vessels.

http://www3.plala.or.jp/takihome/karo.html

> I know that some specialised vessels were built to transport landing craft...were these ordered by the IJA?

Yes

> and if so to what extent was the IJN involved in their design?

IJN was not involved.

Taki

[hisashi]

戦没船を記録する会(Lost-at-War ships recording association) have gathered numerous official records, research books and memoirs to edit a list of civilian ships lost. According to a report by an economics branch of Japanese government, Japan lost 15,518 ships in total. They are trying to name these circa 15,000 ships individually with the cause and place of their loss. Even they have little sourse on the ships mobilized by the army and the listing of them are relatively stagnant to navy counterparts.
Their website is totally in Japanese.
http://www.ric.hi-ho.ne.jp/senbotusen/

[daveh]

Thanks for everyones efforts.

I have been lent a copy of
The World's Merchant Fleets, 1939: The Particulars and Wartime Fates of 6,000 Ships by Roger Jordan

and I will see if that helps...

[tom!]

Hi.

Long ago since this thread was active but my Question fits into this one:

I found the websites http://www.tokusetsukansen.jpn.org/E/index.html (1), http://www.combinedfleet.com/Rikugun-sen.htm (2) and the Amazon books "Imperial Japanese Army Vessels 1894 - 1945 part I" and ".... Part II" by A. N. Balatov (3). There are some differences between the sources. The one I´m after today are regarding Boku Kikansen = Anti-Aircraft Ships, especially Aobasan Maru/Awobasan Maru.

Two of these sources (2, 3) are rating this ship a Bokusen, the third rates it as transport ship only (1). But there are some infos inside the two positive sources that are speaking against a Bokusen Rating (2, 3). One only mentions a transport armament (3), the other mentions that there were eight Bokusen including Shinshu Maru but gives data for nine (2).
Following the sources´ additional infos I think that most (all?) Bokusen were disarmed to transports level in late 1942/early 1943 (?) due to upgunning/equipping all transports with more and more AA-weapons.

So the question is: was Aobasan Maru rated a Bokusen during its career or not?

Yours

tom!

[fontessa]

Hello tom,

I knew the word "Bokusen" for the first time. This is a category that IJA did not have. Eight transports classified as "Bokusen" in combinedfleet.com were commissioned by IJA as transports. I can't understand why combinedfleet.com dared to classify them as "Bokusen". The anti-aircraft weapons they carry were for self-defense, not for convoy.

fontessa

[Akira Takizawa]

Aobasan Maru was not Bokusen. Eight Bokusens are as follows.

https://ja.wikipedia.org/wiki/%E9%98%B2 ... 0%E8%A6%A7

Taki

[fontessa]

Hello Taki,

Thanks for the info.

fontessa

[tom!]

Hi.

Same ship, another question, this time regarding a photo caption:



On several websites this ship is identified as Aobasan Maru before being requisitioned. The international name on the bow has 8 letters before "Maru", "Aobasan" would be 7 letters.

Was the name written "Awobasan" on the bow or is it a different ship from the same class (Arimasan Maru or Asakasan Maru)?

Yours

tom!