Imperial Japanese Army
1941 Infantry Division (square)
8 December 1941
This depicts a typical organization. Actual organizations and equipment could vary from unit by unit.
The square (four infantry regiment) infantry division was being gradually phased out by late 1941.
On paper, this type of division had about 25,000 men.
But the divisions were seldom as neat and tidy as the diagram above.
Elements were consistently being attached or detached, so that some divisions had as few as 17,000 men
and some as others as many as 32,000.
Also the divisions' own units did not not always have the same size or configuration. A typical example would be the cavalry "regiment". In some divisions (such as in the diagram above) this was a battalion sized unit of horse cavalry, in others it was a motorized unit with its own light tanks, [see Infantry Division (triangular)], or various combinations thereof. For example, the 5th Reconnaissance Regiment had 2 motorized infantry companies, 1 motorized HMG company, 1 motorized antitank company, and 2 tankette companies.
The artillery also suffered variations - in one case (19th Infantry Division) even having two regiments - some being equipped with different types and numbers of guns. The size of the Transport Regiment also tended to vary, depending on the mission assigned to the division, and whether the regiment itself was horse-drawn, partially or wholly motorized. For example, the transport "regiment" of the 18th Division had one horse-drawn company and three truck companies.
In the process of converting these divisions to the triangular (three infantry regiment) Organization, one brigade headquarters and an infantry regiment, (with the appropriate support units), might be withdrawn from the division and operate indepndently.
|Infantry Divisions (Square)|
LTG Fusataro TOYOSHIMA
|–||3 Fld||36x 75||3 Cav||3||3|
LTG Masao WATANABE
|–||5 Fld||24x 75
LTG Eitaro UCHIYAMA
|–||19 Mtn||36x 75||13 Cav||13||13|
LTG Renya MATAGUCHI
|–||18 Mtn||36x 75||22 Recon||12||18||(2)(3)|
LTG Yoshio KOZUKI
| 8x 150
LTG Hisashige NAGATSU
|20||26 Fld||36x 75||20 Recon||20||20|
LTG Mamoru IINUMA
|–||110 Fld||36x 75||110 Cav||110||110|
LTG Toshijiro KEUCHI
|–||122 Fld||36x 75||120 Cav||116||116|
(1) But: 2nd Epidemic And Water Supply Department. Included the Tank Unit, 5th Division.
(2) 35th Infantry Brigade with 124th Infantry Regiment operated independently as "Kawaguch1 Detachment", and was still at Camranh Bay.
(3) Only the 5th and 18th divisions were "motorized" square divisions, being equipped with 500 trucks each. The trucks were for the heavy
equipment and the artillery, whereas every soldier not riding in a motor vehicle rode a bicycle.