I have a question regarding IJA unit nomenclature

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Imad
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I have a question regarding IJA unit nomenclature

#1

Post by Imad » 19 Mar 2007, 14:21

Hello
One often hears of "Independent Mixed Brigades" and other "Independent" units in the IJA.
I was wondering what type of units these were - were they ad hoc Kampfgruppe type of units or were they permanent sub-structures of other permanent IJA divisions or regiments?
Thx in advance.

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#2

Post by stulev » 19 Mar 2007, 15:26

The Independent Mixed Brigade is a unit somewhat smaller the a IJA division and normally consisted of 4 to 6 Independent Infantry Battalions, and artillery,signals and engineer unit - operational units had 4 to 6000+ men -- highest number IMB number 136 was activated in Manchuria in July 1945 probably from garrison troops.


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Akira Takizawa
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#3

Post by Akira Takizawa » 19 Mar 2007, 17:15

Independent Mixed Brigade was formed as garrison unit in occupied territories. Because its main duty was defence, its firepower and mobility are inferior to division. Instead of infantry regiment in division, It had Independent Infantry Battalions to disperse at important positions in the defending area.

Independent Artillery Regiment and Independent Engineer Regiment are independent units not to belong to division. They were attached to Army.

Other independent units like independent tank company or independent AA gun company were detached from regiment or battalion to send to far place. They had some support staffs to act independently.

Taki

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#4

Post by stulev » 20 Mar 2007, 15:32

Taki

Independent Mix Brigades had artillery and Engineer units attach as part of IMB - not the Independent Artillery and Engineer unit you note above these must have been small units probably Company size

example is the 117th IMB OOB

117 IMB HQ
707 Independent Infantry Battalion
708 IIB
709 IIB
710 IIB
711 IIB
712 IIB
117 IMB Artillery Unit
117 IMB Engineer Unit
117 IMB Signal Unit

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Akira Takizawa
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#5

Post by Akira Takizawa » 20 Mar 2007, 16:35

stulev wrote:Taki

Independent Mix Brigades had artillery and Engineer units attach as part of IMB - not the Independent Artillery and Engineer unit you note above these must have been small units probably Company size
No, I did not talk about IMB artillery unit or engineer unit. I talked about other independent units than IMB.

Taki

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ghost1275
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Re: I have a question regarding IJA unit nomenclature

#6

Post by ghost1275 » 26 Jan 2021, 20:23

Independent Mixed Brigades were combined arms maneuver units, analogous to modern day US Army's Brigade Combat Team concept. Basically they were scaled down Japanese infantry divisions.

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Re: I have a question regarding IJA unit nomenclature

#7

Post by wdgysin » 27 Jan 2021, 12:49

Gentlemen;
As Taki pointed out, the units were originally raised for occupation duties mostly in China and Manchuria from the late 30's. Many were used in part or in whole to supplement offensive operations in the late 30's and early 40's in China, but this was not their primary role. It wasn't until the 44-45 time frame that these units started to be converted for regular combat operations because of the US advances in the Pacific and SWPA areas. Also, the term "Independent" in the IJA equates to the term "Separate" in most western armies.

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Re: I have a question regarding IJA unit nomenclature

#8

Post by ghost1275 » 27 Jan 2021, 18:13

I have to disagree. Among the very first such formations, the now famous 1st Independent Mixed Brigade (獨立混成第1旅團) was clearly not raised for occupation duty. Instead it was an experimental combined arms unit to test out IJA armor/infantry tactics for maneuver warfare. This unit was involved in numerous combat operations from Marco Polo Incident of 1937 to Battle of Taiyuan two months later. Later in 1938, the unit was inactivated and its tank battalions formed the 1st Tank Group (第1戦車団) aka Yasuoka Detachment (安岡支隊) during the Battle of Khalkhin Gol in which it was pretty much annihilated by the Soviet forces.

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Re: I have a question regarding IJA unit nomenclature

#9

Post by Akira Takizawa » 28 Jan 2021, 02:46

1st Independent Mixed Brigade formed in 1934 is not Independent Mixed Brigade in the late 1930s. It is different type, though it is the same nomenclature. When it was re-raised in 1939, it was formed as Independent Mixed Brigade of the late 1930s.

Taki

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Re: I have a question regarding IJA unit nomenclature

#10

Post by ghost1275 » 30 Jan 2021, 16:57

Akira Takizawa wrote:
28 Jan 2021, 02:46
1st Independent Mixed Brigade formed in 1934 is not Independent Mixed Brigade in the late 1930s. It is different type, though it is the same nomenclature. When it was re-raised in 1939, it was formed as Independent Mixed Brigade of the late 1930s.

Taki
Thank you for the update. I do realize 1st IMB was raised twice during the war.
Do you have info on another type of separate brigade and want to share it? I am looking into IJA Amphibious Brigade
(海上機動旅団) and their larger cousins Ocean Division (海洋師団)。

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Re: I have a question regarding IJA unit nomenclature

#11

Post by wdgysin » 30 Jan 2021, 23:39

ghost1275;

Amphibious Brigades
These link will give you a good synopsis of the history of each brigade. The Japanese link is the most accurate and can be
easily translated with a translation app.

https://en.wikipedia.org/wiki/Amphibiou ... nese_Army)

https://ja.wikipedia.org/wiki/海上機動旅団

en.wikipedia corrected material on structure:
Amphibious Brigade
Brigade Headquarters
I, II III Infantry Battalions
each of: HQ, 3 Rifle Companies, Mortar Unit, Artillery Unit, and Pioneer Platoon
Tank Unit
Machine Cannon Unit
Engineer Unit
Signal Unit
Sea Transportation Unit
Medical Unit

Ocean Divisions
These Divisions were intended to hold islands with the Island Defense Regiments with the Amphibious Regiment to be used
as a counter landing force. This link provides the Divisions converted to Ocean Divisions and can be translated with any
translation app.

http://www1.odn.ne.jp/tobu7757/J_wsd/ar ... ion/AD.htm

Structure of Ocean Divisions:
Ocean Division
Division Headquarters
two Island Defense Infantry Regiments
each of: Regiment HQ, I, II, III Infantry Battalions, Artillery Unit, Engineer Unit, Signal Unit, Supply Unit, and Medical Unit
Amphibious Infantry Regiment
of: Regiment HQ, I, II, III Infantry Battalions, Tank Unit, Machine Cannon Unit, Engineer Unit, Signal Unit, and Medical Unit
Division Tank Unit
Transport Unit
Sea Transport Unit
Supply Unit
Ordnance Duty Unit
Division Field Hospital

If you would like a further breakdown of structures or list of armaments just ask.

other sources:
Rikugun Vol I, Leland Ness, Helion & Co, Ltd, Solihull, UK, 2014, pp 116-122
Japanese and English Wikipedia

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ghost1275
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Re: I have a question regarding IJA unit nomenclature

#12

Post by ghost1275 » 31 Jan 2021, 20:33

wdgysin wrote:
30 Jan 2021, 23:39
ghost1275;

Amphibious Brigades
These link will give you a good synopsis of the history of each brigade. The Japanese link is the most accurate and can be
easily translated with a translation app.

https://en.wikipedia.org/wiki/Amphibiou ... nese_Army)

https://ja.wikipedia.org/wiki/海上機動旅団

en.wikipedia corrected material on structure:
Amphibious Brigade
Brigade Headquarters
I, II III Infantry Battalions
each of: HQ, 3 Rifle Companies, Mortar Unit, Artillery Unit, and Pioneer Platoon
Tank Unit
Machine Cannon Unit
Engineer Unit
Signal Unit
Sea Transportation Unit
Medical Unit

Ocean Divisions
These Divisions were intended to hold islands with the Island Defense Regiments with the Amphibious Regiment to be used
as a counter landing force. This link provides the Divisions converted to Ocean Divisions and can be translated with any
translation app.

http://www1.odn.ne.jp/tobu7757/J_wsd/ar ... ion/AD.htm

Structure of Ocean Divisions:
Ocean Division
Division Headquarters
two Island Defense Infantry Regiments
each of: Regiment HQ, I, II, III Infantry Battalions, Artillery Unit, Engineer Unit, Signal Unit, Supply Unit, and Medical Unit
Amphibious Infantry Regiment
of: Regiment HQ, I, II, III Infantry Battalions, Tank Unit, Machine Cannon Unit, Engineer Unit, Signal Unit, and Medical Unit
Division Tank Unit
Transport Unit
Sea Transport Unit
Supply Unit
Ordnance Duty Unit
Division Field Hospital

If you would like a further breakdown of structures or list of armaments just ask.

other sources:
Rikugun Vol I, Leland Ness, Helion & Co, Ltd, Solihull, UK, 2014, pp 116-122
Japanese and English Wikipedia
Those "unit" designator denotes to company or platoon sized formation I assume? Based on your info, IJA Amphibious Brigades are not unlike contemporary JGSDF amphibious rapid deployment brigade with one possible exception: they had organic landing crafts.

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Re: I have a question regarding IJA unit nomenclature

#13

Post by wdgysin » 01 Feb 2021, 09:01

ghost1275;

Tai (隊) is a word that is translated as unit or corps (as in a unit of the branch). There is a tendency of western sources to translate
the word into whatever size the unit fits in western armies, but the actual translation when tai by itself is used is unit. A tai can be many
different sizes, but usually is battalion sized or below. It is very similar to the German abteiiung, which can be anywhere in size from an
army to a company but is usually battalion sized.

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ghost1275
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Re: I have a question regarding IJA unit nomenclature

#14

Post by ghost1275 » 02 Feb 2021, 05:17

wdgysin wrote:
01 Feb 2021, 09:01
ghost1275;

Tai (隊) is a word that is translated as unit or corps (as in a unit of the branch). There is a tendency of western sources to translate
the word into whatever size the unit fits in western armies, but the actual translation when tai by itself is used is unit. A tai can be many
different sizes, but usually is battalion sized or below. It is very similar to the German abteiiung, which can be anywhere in size from an
army to a company but is usually battalion sized.
The abteilung comparison is a good analogy I guess. But in the context of those units under IJA amphibious brigade, I believe many of them were company instead battalion sized. Also in Japanese military terminology tai (隊) and gun(軍) can be used interchangeably. Tai is the preferred term now days to avoid historical militarism.

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