Thus far tanks usually have been employed by the Japanese in independent units which are attached to infantry commands as operational expediency dictates. This practice can be expected to continue, in view of the preponderant emphasis of Japanese tactical doctrine upon the decisive role of infantry both in offense and defense. Yet large tank units exist in the Japanese Army, and there is evidence of an increasing disposition to allocate them to higher echelon control.

Evidence indicates that the Japanese may have both the "square" and the "triangular" types of armored divisions. The square-type division has a total estimated strength of 12,550 officers and enlisted men and is equipped with a total of about 2,000 vehicles, including 230 medium tanks and 170 light tanks.

Division headquarters has a total personnel of 500. The division is organized in two brigades, each having two tank regiments. The strength of a tank regiment is about 920. The division also includes a mechanized infantry regiment with a strength of 2,900. Also included is a motorized artillery regiment of 1,200 officers and enlisted men. The regiment is armed with 75-mm field guns and with 105-mm howitzers; 150-mm howitzers may also be included.

The square division also has a number of units under direct division control. There is a reconnaissance unit and an engineer unit, as well as an antitank unit armed with 47-mm antitank guns and an antiaircraft unit equipped with 75-mm antiaircraft guns. A machine cannon unit, armed with 20-mm machine cannons, also is included in the division organization. Transport of supplies, ammunition, fuel, and other necessities is integrated under a transportation unit. The division also has a maintenance unit.

There is evidence that a heavier type of square division may also be in existence. Strength of such a division would be in the vicinity of 14,000 officers and enlisted men. It would probably have a total of 450 tanks, including heavy tanks.

The chief difference between the square and the triangular types of armored divisions is the fact that the latter is not organized into brigades but has a tank group comprising three tank regiments. The strength of the triangular division would be from 10,500 to 11,250. A triangular armored division recently identified was organized as follows:

The three tank regiments—the chief components of the triangular armored division—are organized into a tank group which has a total personnel of about 2,950 officers and men and is assigned 500 vehicles, including about 250 tanks. In addition to the tank group, there is a mechanized infantry unit with 2,800 officers and enlisted men. The mechanized artillery unit of the triangular armored division has a strength of 1,200 with about 220 vehicles. There also are included in the division organization a reconnaissance unit with a strength of 530; an antitank unit armed with 47-mm antitank guns; an antiaircraft unit equipped with 75-mm guns; a machine-cannon unit armed with 20-mm machine cannon; an engineer regiment with a strength of 1,030; a transport unit with 1,500; a medical unit with 285; a field hospital with 220; and a maintenance unit with a strength of 600.

Organization and strength of tank regiments in the square and triangular armored divisions are virtually the same. There also are a number of independent tank regiments in the Japanese Army. Before the war tank regiments had three companies; at Guadalcanal, however, a four-company regiment was identified and since that time a number of similar identifications have been reported. There are five-company regiments too: it seems that the trend is to have five-company regiments as components of armored divisions, while the independent tank regiments have three- or four-company structure.

In a five-company regiment, about which full information has been secured, headquarters personnel aggregated 89. The light tank company of the regiment had a total strength of 104, while each of the four medium tank companies had 143. There was a maintenance unit, or company, of 175. The light tank company had 12 such vehicles, while each medium company had 11 medium tanks and four light tanks.

JAPANESE FIVE-COMPANY TANK REGIMENT

	O	WO	NCO	EM	Total	Tanks		Troop  Carriers		Trucks	Light  Repair Cars	AT Guns		Hv MG  Mtzd  on  Veh	#92   Hv   MG
						M	L	L	S			57-mm	37-mm
Regt Hq	11	2	31	45	89	4	3	1	2	4	-	4	3	14	-
No. 1 Co	4	2	35	63	104	-	12	-	1	4	-	-	12	24	-
No. 2 Co	4	2	43	94	143	11	4	-	1	5	-	11	4	30	-
No. 3 Co	4	2	39	98	143	11	4	-	1	5	-	11	4	30	-
No. 4 Co	4	2	43	94	143	11	4	-	1	5	-	11	4	30	-
No. 5 Co	4	2	32	105	143	11	4	-	1	5	-	11	4	30	-
Maint Unit (co?)	5	3	20	147	175	2	-	-	3	34	6	2	-	4	3
Total	36	15	243	646	940	50	31	1	10	62	6	50	31	162	3

In some of the stronger types of triangular infantry divisions, in addition to a reconnaissance unit, a tank unit of about 700 men is included. In other types of triangular divisions, namely those composed of combat teams, a smaller division tank unit has replaced the reconnaissance unit. A number of the latter type of tank units have been identified; however, few details are available.

Several cavalry brigade tank units are known to exist. The total strength of a unit of this type is approximately 350, and estimated armament includes 33 (or 27) light tanks, 250 rifles and carbines, and 15 pistols. Each unit has a headquarters with a total personnel of 30; two light tank companies each with a personnel of 130; and a train with an aggregate personnel of 60 officers and enlisted men, apportioned to ammunition and chemical warfare matériel sections with a reserve of six light tanks. Each constituent company of the cavalry brigade tank unit has three light tank platoons and a train.

Independent Tank Units

The Japanese also have independent tank groups. A tank group has a total strength of approximately 2,500 officers and enlisted men and is commanded by a major general. Each tank group consists of a headquarters, three regiments, and a train. Headquarters has a total personnel of 61, while each of the three constituent regiments has 600. In addition to these units there are a tank signal unit, a tank group engineer unit, and a maintenance matériel depot. The tank group is equipped with 70 light tanks and 135 of the medium type. Although no conclusive information is available, artillery units presumably would be included or attached to the group. It is possible that some of these tank groups were used as a nucleus around which triangular divisions were organized.

Strength of independent tank regiments has been reported from 500 to 800. One recently studied was divided into three companies and a combat train. Each company had three medium tank platoons, equipped with five tanks each, and a light tank platoon which had four light tanks. Total company tank strength aggregated six light and 16 medium tanks. The whole regiment had 21 light tanks, 49 medium tanks, and a reserve of 6 light and 15 medium tanks.

Sometimes the light tanks are assembled into one company, making a fourth or light tank company.

A variant has been reported with 700 officers and enlisted men, and a total of 60 tanks. The light tank company had ten tanks, while each medium tank company was equipped with ten medium and two light tanks. The remaining tanks were assigned to headquarters units and the reserve.

A four-company independent regiment, about which information is available, had a total strength of 601, with 75 authorized for headquarters, 90 to the light tank company, and 112 to each of the three medium tank companies. The regimental train had a total personnel of 100. The primary armament of the regiment comprised 23 light and 45 medium tanks.

Company Organization

Each company, in addition to headquarters, had three platoons and a company train. The platoon, in addition to the lieutenant in command, had three sections; the train had two repair sections, an ammunition section, and a fuel section.

The company was commanded by a captain and each of the three platoons was under a lieutenant. There were also a warrant officer and 29 noncommissioned officers. The strength of the medium tank company was 112; in the light tank company it was only 90. The medium tank company was equipped with two light tanks and ten medium tanks. There were four radio sets, one for the company commander and one for each platoon leader’s tank. It also had 15 trucks, two passenger cars, and one motorcycle.

Armament totals were:

Model 97 (1937) 57-mm tank guns   _ _ _ _ _ _ _ _ _ _ _		10
Model 94 (1934) 37-mm tank guns   _ _ _ _ _ _ _ _ _ _ _		2
Model 97 (1937) 7.7-mm tank machine guns   _ _ _ _ _ _ _		28
Model 38 (1905) 6.5-mm carbines   _ _ _ _ _ _ _ _ _ _ _		84
Pistols   _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _		4
Bayonets   _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _		107

A company in the four-company regiment carries in its train enough tank fuel for seven days. A 15-day lubricating oil supply is carried, while a four-day supply of gasoline and lubricating oil for transport vehicles likewise normally is included. Ordinary rations sufficient for five days are carried, as well as a five-day supply of emergency rations.

Tankette Companies

Tankettes are widely used by the Japanese Army for reconnaissance as well as for other purposes. There are two types of independent tankette companies, according to Japanese designation, termed "armored vehicle companies" and "light armored vehicle companies". So far as known, the only distinction between the two types is in the model of tankette with which they are equipped.

The organization of the two types is the same. Each company has a headquarters with a total personnel of 30, and is organized into four platoons each with a strength of nine. Each platoon comprises four sections, each of which is equipped with one tankette and a light armored trailer. Total strength of the company is 121, of which 55 are allotted to the company train. If the company is equipped with a Type 98 (1938) tankette, or a later model, the strength of the company apparently is increased to 138. A total of 17 tankettes is allotted to the company.

It is interesting to note the inclusion of the tracked trailers which may indicate that the units are used for tactical supply purposes as well as for combat and reconnaissance. Each platoon has an enlisted man specially trained in chemical warfare, while the personnel of the company train includes a noncommissioned officer and two enlisted men with such training.

In addition to independent tankette companies there are infantry group tankette companies, of which at least nine are known to be operative. Companies of this type have a headquarters with a total personnel of 20. There are three platoons, each with a total strength of 10, and a train with an authorized personnel of 30. Each platoon is organized into three sections.

The total strength of the company is estimated at 80. Ten tankettes are allotted, and supplementary armament includes 50 rifles and carbines and 20 pistols.