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The division was the largest
permanent formation in the land
forces of most participants in the Second World War. It
varied in size
from 6,000 to 25,000 men and was usually led by a major general
or lieutenant general.
The army division should not be
confused with the naval
command echelon called a division, which consists of just ten to
under a junior officer. Divisions in Western armies were organized
United States. U.S.
normally consisted of three infantry
regiments, an artillery regiment,
engineer battalion, with other
elements. The authorized strength in 1943 was 14,253 officers and men.
three infantry regiments each had a strength of 3118 men; the
regiment comprised 2160 men, 36 105mm howitzers, and 12 155mm
howitzers; and the engineering battalion numbered 647 men. In
there was a reconnaissance
of 155 men, a medical
battalion of 465 men, a quartermaster
company of 193 men, an ordnance
company of 147 men, a signals
company of 226 men, a military
police platoon of 73
men, a headquarters
company of 110 men, and a marching band of 58 men. The total
weapons count was 6518
243 automatic rifles, 157 0.30 machine
guns, 236 0.50 machine guns, 90 60mm
54 81 mm mortars, 557 bazookas,
57 57mm antitank guns,
howitzers, and 2012 vehicles.
U.S. soldiers tended to
their division, particularly in former National
Guard divisions, which were regional in character.
Prior to the war, the U.S. Army still had a number of square divisions containing four regiments organized into two brigades. This organization was less flexible than the three-regiment triangular division, and the square divisions were in the process of being triangularized when war broke out. The extra regiments were organized into new divisions or broken up for cadre.
The U.S. Army made the decision to retain much of the supporting
units for divisions at the army
level, in order to keep divisions as flexible and mobile as
possible. For example, supplies were expected to be delivered to
individual battalions directly from army-level depots, and certain
supporting arms were raised as independent battalions controlled
at the army level and assigned to divisions as needed. These
included independent tank
destroyer battalions, antiaircraft
battalions, and chemical
mortar battalions. This did
not work out especially well. Most divisions began using their
organic transport to distribute supplies received from army-level
depots, and it was found that tank battalions needed to train with
the infantry they would support to achieve adequate tank-infantry
coordination. As a result, there was a
tendency to attach a tank battalion to each infantry division on a
semi-permanent basis, though
this did not become a formal part of the division table
of organization and
equipment until after the war had ended.
Army infantry divisions, but were slightly larger (17,465 officers
men in 1944) and formalized the attachment of a tank battalion
early in the war. This
battalion consisted of 36 Stuart light tanks in 1942. The 1942
included a special weapons battalion equipped with two 37mm
gun batteries, a 40mm antiaircraft
battery, and a 75mm self-propelled gun battery. The
engineer battalion was joined by a pioneer battalion (for
unloading supplies on the
beach) and, early
in the war, a Naval Construction
Battalion. For a
short time these were organized into a single engineer regiment in
division, before the Navy pulled the Seabees out of the Marine
divisions. As LVTs became
available, an amphibious tractor battalion was assigned to each
No armored divisions saw combat in the Pacific, but one airborne and one cavalry division were assigned to the Southwest Pacific Area. 1 Cavalry Division retained the square structure (two brigades of two regiments) and fought as elite infantry. 11 Airborne Division also fought largely as elite infantry, with its elements making only two combat drops during the war. It had a triangular structure, with two glider infantry and one parachute infantry regiment when first deployed. Later the ratio was reversed, so that the division had one glider infantry and two parachute infantry regiments.
Britain. British divisions had brigades in the place of regiments, but otherwise resembled American divisions. Each brigade consisted of three or four battalions. The battalions could be drawn from various regiments, which in the British system were regional recruiting and training formations that were the repositories of military tradition. For this reason, British troops identified with their regiment rather than their division.
China. The typical Chinese division was triangular, with a manpower of 10,923 on paper. The actual strength was typically 6000 to 7000 men. There was no real replacement system. Authorized equipment was 3,821 rifles, 274 light machine guns, 54 heavy machine guns, 243 grenade launchers, 16 mountain guns, and 30 battalion guns, but, again, only on paper. In practice, a Chinese division had barely enough rifles for its men, a third the number of machine guns of a Japanese division, and no other support elements to speak of. It was reckoned that a Japanese division had the combat strength of three Chinese divisions under even the best of conditions (for the Chinese).
A few Chinese divisions were organized, trained, and equipped to
higher standard. The Germans
trained about 30 divisions for Chiang
in the late 1930s, but most of these were destroyed at Shanghai in 1937. Later the
Americans organized a training camp at Ramgarh
in India that trained and
handful of divisions to a standard previously unknown in the
Army. These divisions fought mainly in Burma.
divisions were highly
variable in composition, with some garrison divisions consisting
men, while a few divisions retained the square organization and
25,000 men. However, the organization of most divisions
resembled that of
a U.S. infantry division, with three infantry regiments organized
infantry group. There was no officer rank between colonel and
general in the Japanese Army, and divisions were commanded by
lieutenant generals. The infantry group was commanded by a major
general who also acted as deputy division commander.
The Japanese divisions that fought in the early battles in China
were regular or Type A divisions and "special" or wartime
divisions composed mostly of reservists. As the war dragged on, a
number of additional regular divisions were activated; some as
Type A divisions, using regiments released by triangularization of
existing Type A divisions, and others as Type B divisions, built
around cadre from disbanding a number of wartime divisions that
had seen service in China.
The standard or Type B triangular division had, in addition to its three infantry regiments, a reconnaissance regiment with 16 light tanks or armored cars; an artillery regiment with 36 guns; and an engineer regiment. The artillery regiment was highly variable in composition, from 24 75mm guns and 12 105mm howitzers to 12 each of 75mm guns, 105mm howitzers, and 150mmhowitzers. The combat units were supported by a signals unit, a transportation regiment, an ordnance unit, a medical unit, three field hospitals, a water supply unit, and a veterinary hospital. The latter supported the division's 3466 horses, for there was typically only 310 trucks. Total weapons counts were 6867 rifles, 264 light mortars, 273 light machine guns, 78 heavy machine guns, 14 37mm antitank guns, 18 70mm howitzers, 12 75mm infantry guns, 36 artillery pieces of 75mm to 150mm, and 16 light tanks or armored cars. Total manpower was 15,220 officers and men.
The Type A were reinforced to about 20,000
officers and men with improved equipment while retaining
the same organization as the "Type B" divisions.
Type C divisions were wartime divisions organized as two brigades of four battalions each, without a regimental echelon. These had a smaller manpower than a triangular division, about 12,000 officers and men, and they had almost no artillery and no reconnaissance regiment. They were intended primarily for garrison and antiguerrilla duty. They were distinct from "Special" wartime divisions having a triangular structure.
In October 1943 the Army published a new TO&E for an ocean division. This consisted of two static defense regiments and an amphibious regiment. Two divisions were immediately converted to the new organization, and another three a few months later. The divisions proved well suited for deployment by sea but had poor mobility once landed. Allied intelligence got wind of the reorganization, and concluded these divisions had an experimental "regimental combat team" organization, with artillery and other heavy weapons permanently distributed to the individual regiments.
Almost all the divisions raised in 1944 and 1945 lacked
reconnaissance regiments, and many were badly understrength in
artillery. Few of those raised in 1945 had more than a battalion
In 1945, the Japanese began raising coastal and mobile divisions for the final defense of the home islands. Mobile divisions had three infantry regiments and an artillery regiment, but no reconnaissance regiment. They were given relatively young, fit officers and men and as many active duty soldiers as could be scraped together. Coastal divisions had a single battalion of artillery, three static regiments with virtually no mobility (so that they were expected to fight to the death where they were positioned), poor weaponry (with some men equipped with no more than bamboo spears), and a single mobile regiment for local counterattack. By May 1945, mobile divisions no longer were assigned any artillery and coastal divisions were reduced to three regiments.
The Japanese Army also raised a large number of independent mixed
brigades, which typically had about five infantry battalions and a
battalion of artillery along with supporting units. In some
the independent mixed brigades resembled small divisions with a
narrow division slice, and some
eventually redesignated as divisions.
infantry divisions were
typically raised on a regional basis, like British battalions or
Guard divisions, but at all echelons. For example, the men in a
company might all be from the same small town. This
to unit cohesion, but it also meant that the destruction of a unit
devastating to the folks back home in the town from which the unit
Japanese citizens from Gifu
Prefecture still make visits
to Mount Austen on Guadalcanal,
regiments recruited from their fishing villages were annihilated
search for remains.
The Japanese assigned one or more depot divisions to each divisional district. These were training formations whose function resembled that of British regiments in a number of respects. In peacetime, the depot divisions trained each years' class of conscripts. If war suddenly broke out, the bulk of the depot division was used as cadre and filled out with reservists to create a field division, usually bearing the same number as the depot division, which could quickly be committed to combat. The remainder of the depot division was then rebuilt with other reservists or conscripts. During a more prolonged war, when a new division needed to be raised, a small nucleus of cadre was drawn from a depot division and filled out with reservists and conscripts to create a new field division with its own number. This new division was billeted in its own wartime barracks while undergoing as much training as the situation permitted before being committed to combat. Depot divisions were also responsible for providing replacements to field divisions, usually those that were earlier raised from the same divisional district.
Late in the Pacific War, the Japanese Army began creating Field
Replacement Units for its divisions. Each unit had two infantry
battalions plus supporting elements, not necessarily drawn from
the same divisional district, and after training together the unit
was sent to a theater, where it might be broken up to provide
replacements for several divisions. The Army also began using
experienced troops drawn from divisions in quiet sectors to
provide replacements for other divisions that had suffered heavy
losses. Both methods of replacement were disliked by the Army
because of their tendency to reduce unit cohesion, and so were
regarded as measures of desperation.
The Japanese activated four armored divisions during the war.
were originally square divisions, with two brigades of two tank
regiments and a single mobile infantry regiment, but by the end of
war the Japanese had settled on a triangular organization of three
regiments and a mobile infantry regiment. The infantry were
by 300 trucks and the tank regiments each were allocated 31 light
50 medium tanks plus 76 trucks. There was also an artillery
12 75mm guns and 24 205mm howitzers, an antiaircraft unit, a
reconnaissance unit with 32 light and 10 medium tanks, and other
Divisions in all armies had a considerable number
support duties, with only a fraction normally on the firing
line. In addition, there were considerable numbers of
troops. The total manpower under arms per division is known as the
division slice. This includes non-divisional support troops,
in some calculations the associated air forces.
The U.S. Army had the broadest
division slice, with large numbers of supporting troops. This
superb logistics and engineering support, but it
led to a
severe shortage of replacements for rifle companies by late
Japanese divisions had a very thin division slice, which reduced
staying power considerably, because the support services just
when they were needed. British divisions were somewhere in
The U.S. division slice varied by theater during the Second World
War. It was calculated (Leighton and
Coakley 1955) at 35,480 men in Europe; 32,481 in the
34,340 in the Southwest Pacific; and 53,020 in the Central Pacific
the end of the war. The latter calculation is distorted by
presence of Marine divisions that received some Army support but
not included in the calculation. If we take 34,000 as a typical
and take the division strength as about 13,500 men, then support
constituted 60% of total strength. In other words, in the U.S.
took about three men to support every two combat soldiers.
Japanese Military Forces" (1944-9-15)
Leighton and Coakley (1955)
Peattie et al. (2011)
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