Organization of IJA units

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Eugen Pinak
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Organization of IJA units

Post by Eugen Pinak » 15 Jul 2014 07:35

This topic is a continuation of the following topics on IJA organization:
http://forum.axishistory.com/viewtopic. ... 5&t=195850
http://forum.axishistory.com/viewtopic. ... 5&t=208926

After some research I've decided to start from the beginning, and here is the model organization of rifle company of type "C" infantry regiment in 1944. May not look like much, but believe me, there was some research and even guesswork involved, as IJA had no TO&Es of sub-units below company level.
type C rifle company-1944.png
Unfortunately, I still haven't figured out a job of one soldier (marked ?????). I suspect, he was a batman of company commander, but not sure, if IJA had permanent batmen?
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fontessa
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Re: Organization of IJA units

Post by fontessa » 15 Jul 2014 13:19

Good afternoon Eugen:

I would like to introduce a JACAR document. Pages 5 and 6 of JACAR C14010674000 show the table of soldier’s specialty for type “C” infantry regiment. According to it, the soldiers of a company were classified as follows. In the table, the number in the parenthesis shows persons from additional post.
162 soldiers
- 54 “riflemen”
- 36 “light machine gunner” (with escorts?)
- 33 “grenade discharger men” (for “grenade discharger” squad)
- 10 瓦斯手 (Chemical defense ?)
- 4 喇叭手 Buglers
- 18 狙撃手 Snipers
- 7 伝令 Runners
(- 3 鍛工手 Smiths)
(- 2 縫工手 Tailors)
(- 2 装工手 Shoemakers)
(- 4 担架兵 Stretcher carriers)

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hisashi
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Re: Organization of IJA units

Post by hisashi » 15 Jul 2014 18:35

a platoon: 1st-4th squad 13+13+13+12=51 (47 ranks + 4 seageants/corporals)
3 platoons: 141 ranks +12 seageants/corporals
a company: 186 (162 ranks + 18 seageants/corporals + 6 Officer/WO/CSM) +4 medics = 190

So I cannot read out how many of 21 ranks (162-141) were alloted among platoon HQs and company HQ in each duties.

I should stress that this company is type 'C'. type 'C' infantry regiment was for type 'C' divisions, which were prepared for security missions in China theater. Most of offensive missions in 1941-1942 were completed by type 'A' and type 'B' divisions. I am negative to assume that inteligence report from any hostile country about 'an infantry company' be linked to type 'C' formations. According to fontessa's page, a type 'C' regiment in 1943 had 3,409 personnels while a type 'A' regiment in 1940 had 4,487.

18 seageants/corporals in a company consisted of a weapon/gas NCO, a supply NCO, a lialison NCO and 15 others. 12 of 15 were used up in each platoons.

One master seageant and one warrant officer was in company HQ. 3 Platoon leaders and 1 company leader were all of officers in a company.

As fontessa explained, JACAR C14010674000 shows smiths, tailors, shoemakers and stretcher bearers 'shall be concurrently assigned', so they served as ranks in any position of the company. For example, those who finished stretcher bearer course in the company in reserve for battalion were sometimes gathered by the battalion leader at the disposal of battalion surgeon, to gather wounded soldiers to him and take heavily wounded ones rearward, where regimental/divisional medical staffs were working.

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Re: Organization of IJA units

Post by fontessa » 15 Jul 2014 21:17

Good morning hisashi:
hisashi wrote: type 'C' infantry regiment was for type 'C' divisions, which were prepared for security missions in China theater.
Although the Army reorganized some into security divisions later, type “C” divisions were not organized as security divisions at first. Because they had artillery regiments when organized. The type of security divisions was "D".

China Expeditionary Army classified their divisions into 3 categories by the mission when war with the Soviet Union broke out.
- 甲師団 category “A” division: thrown into the battle with Soviet Union as primary force
- 乙師団 category “B” division: thrown as secondary force or used as mobile force in China
- 丙師団 category “C” division: used as security force
Many type “C” divisions were assigned as categories “A” and “B” divisions.
http://www.fontessa.info/kaiyouhenseish ... d.html#CEA

In above web page, the meaning of abbreviations was as follows.
甲(野): type “A” division with field artillery regiment
乙(野): type “B” division with field artillery regiment
乙(山): type “B” division with mountain artillery regiment
丙(野): type “C” division with field artillery regiment
丙(山): type “C” division with mountain artillery regiment

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Re: Organization of IJA units

Post by fontessa » 16 Jul 2014 11:18

Good evening hisashi:
hisashi wrote:
So I cannot read out how many of 21 ranks (162-141) were alloted among platoon HQs and company HQ in each duties.
I can’t fix allotment, too. But I think 21 ranks were broken down as follows.
- 10 瓦斯手 (Gas men ?)
- 4 喇叭手 Buglers
- 7 伝令 Runners

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Re: Organization of IJA units

Post by Eugen Pinak » 16 Jul 2014 14:50

fontessa wrote:I would like to introduce a JACAR document. Pages 5 and 6 of JACAR C14010674000 show the table of soldier’s specialty for type “C” infantry regiment. 
Small correction - that table gives specialty types not for all soldiers, but for infantrymen (both line service and horse conductors). For example, for rifle company also had 4 medics.

As a whole, IJA TO&E consists of three different documents (unless I'm mistaken and there are more of them, of course). In case of type "C" infantry regiment they are:
C14010672300 (pp. 5-6) - gives overall number of men and horses in the unit, ranks and appointments of officers and NCO, number of specialists;
C14010674000 (pp. 5-6) - gives breakdown of specialities among "line" soldiers; < My theory is, that it was introduced later on, as those "line soldiers" become more and more specialized.
C14010674200 (can't find exact page) - gives breakdown of armament and equipment.
My reconstruction is based on all three, plus other sources.
hisashi wrote:As fontessa explained, JACAR C14010674000 shows smiths, tailors, shoemakers and stretcher bearers 'shall be concurrently assigned', so they served as ranks in any position of the company. For example, those who finished stretcher bearer course in the company in reserve for battalion were sometimes gathered by the battalion leader at the disposal of battalion surgeon, to gather wounded soldiers to him and take heavily wounded ones rearward, where regimental/divisional medical staffs were working.
Of course. I've tried to recreate only typical (from my point of view) organization. In real live losses and shortages of personnel will lead for some inevitable changes.
Some assumptions are pretty straightforward. For example, 33 grenade discharger-men include 6 chemical defence soldiers = 2 per GD squad.
Some are less so straightforward - but I doubt, for example, that tailors or shoemakers were assigned to rifle squads with their menial labour, while having a lot of clothes/shoes repairs to do.
And, of course, Soviet intel data on IJA infantry company (which, BTW, corresponds to a man with 1944 US estimates of standard infantry company) was a great help too. Details of organization are different, but general organizational guidelines can be established with the help of this document.
fontessa wrote:China Expeditionary Army classified their divisions into 3 categories by the mission when war with the Soviet Union broke out.
- 甲師団 category “A” division: thrown into the battle with Soviet Union as primary force
- 乙師団 category “B” division: thrown as secondary force or used as mobile force in China
- 丙師団 category “C” division: used as security force
Many type “C” divisions were assigned as categories “A” and “B” divisions.
I see. So being type “C” division doesn't automatically mean, that division will be used only on security duty?
fontessa wrote:But I think 21 ranks were broken down as follows.
- 10 瓦斯手 (Gas men ?)
- 4 喇叭手 Buglers
- 7 伝令 Runners
It's possible. But I have doubts about it, because:
1. Soviet 1938 intel document says, that each rifle squad had 1 chemical defence soldier, while each GD squad had 2. In 1944 TO&E there are 2 chemical defence soldiers for each GD squad - so each rifle squad had to have 1 chemical defence soldier too.
2. I doubt, that tailors or shoemakers were assigned to rifle squads with their menial labour, while having a lot of clothes/shoes repairs to do.

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Re: Organization of IJA units

Post by Wellgunde » 16 Jul 2014 22:32

Eugen, You raise an interesting question. I wonder to what extent the USA and USSR shared intelligence on Japanese forces?

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Re: Organization of IJA units

Post by Eugen Pinak » 17 Jul 2014 10:29

Wellgunde wrote:Eugen, You raise an interesting question. I wonder to what extent the USA and USSR shared intelligence on Japanese forces?
I have no idea. Some intelligence exchange simply had to happen, despite mutual distrust. But was is so detailed, so even was covering TO&Es - I don't know.

Meanwhile, here is my attempt on machine-gun company:
type C machine gun company-1944.png
Unfortunately, this time more guesswork was involved.
Note, that I have no idea about allocation of the pistols within the company. I think, that at least squad leader should have them - but who else???
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Re: Organization of IJA units

Post by fontessa » 17 Jul 2014 13:01

Good afternoon Eugen:
Eugen Pinak wrote: I see. So being type “C” division doesn't automatically mean, that division will be used only on security duty?
Yes they were organized not for security duty at first. Whether a certain division was a security division or not depended on the existence of an artillery regiment.

The 35th Division case is interesting. It was organized as a type ”C” division with a field artillery regiment by Army Regulation “A” No.6 dated 7 February 1939. And by Army Regulation “A” No.11 dated 5 February 1943, it was reorganized into a security division, in other word, into type “D” division with the elimination of the field artillery regiment. Thereafter the Army decided to dispatch this division to the East Indonesia. Because the division lacked an artillery regiment, the 4th Independent Mountain Artillery Regiment was added to its composition for the firepower reinforcement by IGHQ Army Order No.957 dated 2 March 1944. Thus the division was reorganized into a type “C” division again.

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Re: Organization of IJA units

Post by Eugen Pinak » 17 Jul 2014 15:53

This 35th division probably offended some god of military bureaucracy :)
But if seriously, you've pointed out one very important fact - that some divisions were changing its' organization types during their existence. I've thought, that this only 23rd division changed its' type after Halhin Gol.

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Re: Organization of IJA units

Post by Wellgunde » 17 Jul 2014 19:17

How were the several divisions of the final 1945 mobilization classed? Did they represent a new table of organization?

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Re: Organization of IJA units

Post by Eugen Pinak » 17 Jul 2014 19:39

Wellgunde wrote:How were the several divisions of the final 1945 mobilization classed? Did they represent a new table of organization?
See this post: http://forum.axishistory.com/viewtopic. ... 0#p1761223
Apparently Coast Deployment Divisions were rather unusual mix between ordinary infantry and fortress units, while Mobile Striking Divisions more or less resembled standard infantry divisions.

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Re: Organization of IJA units

Post by fontessa » 18 Jul 2014 12:12

Good morning Wellgunde:
Eugen Pinak wrote:
Wellgunde wrote:How were the several divisions of the final 1945 mobilization classed? Did they represent a new table of organization?
See this post: http://forum.axishistory.com/viewtopic. ... 0#p1761223
Apparently Coast Deployment Divisions were rather unusual mix between ordinary infantry and fortress units, while Mobile Striking Divisions more or less resembled standard infantry divisions.
The organization of Coast Deployment Divisions is here.
http://www.fontessa.info/hondokessenshi ... nsei1.html

That of Mobile Striking Divisions is here.
http://www.fontessa.info/hondokessenshi ... nsei2.html

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Re: Organization of IJA units

Post by Eugen Pinak » 23 Jul 2014 09:42

Here is some more results of my work with Japanese TO&Es - general organization of IJA type C infantry regiment 1944.
Hope it'll help to understand some general details of the organization.
IJA type C infantry regiment 1944.png
Some notes.
1. Regiment is extremely weak in heavy weapons. Of course, it's a 3rd-rate unit, intended mainly for garrison and anti-partisan work, but this was not a rule. And in 1944 even Chinese hand number of better-armed regiments.
2. Some units/sub-units are almost unarmed. For example, battalion MG company has only 16 pistols for 138 other ranks, battalion gun platoon has only 4 pistols for 68 other ranks while regimental gun company has 1 rifle and 8 pistols for 133 other ranks.On the other hand, infantry company has rifles even for tailors, shoemakers and stretcher-bearers - strange.
3. There are grenade dischargers at battalion and regimental HQ, but no dedicated crew to serve them - I think those are replacement weapons.
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Re: Organization of IJA units

Post by Wellgunde » 26 Jul 2014 06:16

Thank you, Eugen, I hope we will see more charts from you in the future. Good work.
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