US Army in World War II
Artillery and AA Artillery
by Rich Anderson
Chemical Weapons
The 4.2" mortar battalions provided chemical warfare (WP, smoke, and gas)
support to Army divisions. Originally without an HE capability, inasmuch as
there were no HE rounds for the 4.2" mortar, in late 1942 a bright CW officer
thought that it would be a good idea to provide an HE round for the piece. As a
result the chemical mortars were available to provide welcome heavy mortar
support for the infantry by 1943. By the fall of 1944 there were sufficient
battalions in the ETO to allow for a normal assignment of one company per
infantry division. In some circumstances this would be augmented to a full
battalion.
The 2nd, 3rd, 81st, 83rd, 86th, 87th, 89th, 90th, 91st, 92nd, 93rd, 94th, 95th,
96th, 97th, and 99th Battalions served in the ETO. The 84th and 100th
Battalions served in Italy. The 71st, 80th, 82nd, 85th, 88th, and 98th
Battalions served in the PTO.
Artillery
In World War I the artillery arm of the U.S. Army had fought in Europe equipped
entirely with French or British weapons. There were many reasons for this: the
need to standardize Allied arms, lack of shipping space, and lack of industrial
capacity. However, another factor was that many ordnance specialists in Britain
and France felt that the indigenous American gun designs were not up to
European standards. As a result, in 1921 the U.S. Army Chief of Staff, General
Charles P. Sommerall (one of the most brilliant artillerymen in U.S. Army
history) established the Westervelt Board to examine the army's ordnance
requirements for the future. The board's report was impartial and farsighted,
and it had dramatic consequences for the U.S. Army artillery in World War II.
The board recommended that the standard divisional artillery piece be increased
in caliber from 75mm to 105mm, while the general support weapon for the
division was to be standardized as the 155mm howitzer. The 4.7" corps general
support gun (a British design) was to be discarded in favor of the 155mm gun (a
French design). In addition, the board recommended that heavier pieces of the
most modern type be designed, and that all artillery pieces be suitable for
rapid motorized road movement. Finally, improvements in fire control
methodology and communications were recommended, based upon concepts that had
been pioneered by Summerall as an artillery brigade commander in France.
The financial climate of the 1920s and 1930s delayed the deployment of such an
improved artillery system. However, sufficient funding was available to allow
innovative Artillery and Ordnance officers to continue experimenting with new
gun designs and doctrine. As a result, when the Army began to expand, much of
the background work to modernize the artillery was already complete. Designs
had been completed and prototypes developed and tested for most of the guns and
howitzers that were to see service during the war (the opposite of the
situation in the new Armor Branch, where prohibitive cost had stymied design
work on armored vehicle prototypes and doctrinal experimentation during the
1920s and 1930s).
Divisional pieces included the M1 105mm howitzer and the M1 155mm howitzer.
Both were excellent weapons, with good range and, particularly in the case of
the 155mm, excellent accuracy. Other new weapons were the M1 75mm pack howitzer
and the M3 105mm howitzer. Both were lightweight and could be easily broken
down into manageable loads suitable for transportation by pack animal (horse,
mule, or man as available) or by air, and if relatively short-ranged, were
ideal for airborne forces. The M3 also saw service after 1943 in the Cannon
Company of the infantry regiment. A SP version of the M1 105mm, the M7 Priest,
also equipped the field artillery battalions of the armor division.
Non-divisional artillery pieces included battalions equipped with these same
weapons, as well as other, heavier pieces. A companion of the 155mm howitzer
was the 4.5" gun (an indigenous 120mm gun was one of the few failures of the
inter-war design projects). The tube of this gun was of British design, while
the carriage was that of the 155mm howitzer (carriage commonality between
companion guns and howitzers was one of the hallmarks of U.S. artillery
designs). Unfortunately, the 4.5" -- although well liked by American
artillerymen - was not a very efficient weapon for its size. The shell (also of
British design) was of low-grade steel, thick-walled and with a small bursting
charge compared to the shell weight. The 4.5" projectile weighed 54.90 pounds,
but had only a 4.49 pound bursting charge, while the 105mm howitzer projectile
weighed 33 pounds, but had a 4.8 pound bursting charge. Its range was
insufficient to compensate for the relative ineffectiveness of this round and
as a result it was withdrawn from service soon after the end of the war.
A much more effective weapon was the M1 155mm gun, known as a "Long Tom" (an
appellation with a long and glorious tradition in the U.S. artillery.) It
combined long range, accuracy, and hitting power with a well designed, mobile
carriage.
A different 155mm gun was the M12 SP. Developed in 1942, it was an interesting
amalgam of the old and the new, utilizing the tube of the pre-war French
designed GPF (Grand Puissance, Failloux), itself developed in World War II, and
the chassis of the obsolescent M3 Grant tank. It was an experiment by the
Ordnance Department that had been turned down by the AGF in October 1943 on the
grounds that there was no requirement for it. However, in early 1944 urgent
requests from U.S. Army forces in England for a heavy SP gun resulted in 74
being rebuilt. They eventually equipped seven field artillery battalions in the
ETO and proved invaluable. An improved model, the M40, based upon the M1 gun
and M4 tank, was produced in 1944 and deployed in limited numbers to the ETO in
March 1945.
Heavier supporting artillery pieces were the M1 8" howitzer, an excellent and
accurate weapon; the M1 8" gun, which was developed as an answer to the superb
German 17cm gun, had greater range and a more lethal shell than the German
weapon, but suffered from poor accuracy and excessive barrel wear; and the
240mm howitzer, a good, if very heavy, weapon.
Nearly all US artillery battalions were organized with three firing batteries
and a total of twelve tubes. The exception was the eighteen-tube armored field
artillery battalion and the six-tube 8" gun and 240mm howitzer battalions. A
major advantage for the American artillery was that it was fully motorized and
highly mobile. All 105mm and 155mm howitzer battalions in the ETO were
truck-drawn, although a Table of Equipment (TE) for a tractor-drawn 155mm
battalion existed. The 155mm gun battalions were almost all tractor-drawn,
although a few evidently were also truck-drawn. The 4.5" gun, 8" gun, 8"
howitzer, and 240mm howitzer battalions were all tractor-drawn, although,
again, a TE for truck drawn battalions existed. The standard prime mover was a
two-and-one-half ton truck for the 105mm and a 4-ton Diamond T truck for the 155mm
howitzers. Tractors included the M5 thirteen-ton prime movers, which were
utilized for the 105mm M2 howitzer, the 4.5" gun, and 155mm M1 howitzer, and the M4
eighteen-ton hi-speed, full-track, heavy prime mover, which was utilized for the 3" AA gun,
the 90mm AA gun, the 155mm Long Tom gun, 8" howitzer, 8" gun, and 240mm howitzer. Redundant M3 medium
tank chassis, without armament, and M31 and M32 armored recovery vehicles were
also utilized as prime movers for the heavier artillery pieces.
Non-divisional artillery battalions were normally subordinated to field
artillery groups. The groups were formed in 1943 from the headquarters battery
of the broken up field artillery regiments. The field artillery group consisted
of an H&H Battery, with a command element and a fire-direction center
element, and a Service Battery. A group was usually assigned from two to six
battalions, although one or more of the battalions might be attached for direct
support of an individual division. Usually, the groups were assigned howitzer
and gun battalions of companion caliber, that is, 155mm howitzers were grouped
with 4.5" guns, 8" howitzers with 155mm guns, and 8" guns with 240mm howitzers.
The normal ratio was one gun battalion for every two howitzer battalions,
although this was not always firmly adhered to. Separate 105mm howitzer
battalions were normally grouped together, but were almost always assigned to
direct support of divisions. The 155mm SP gun battalions were assigned to
groups as the tactical situation warranted, or were frequently attached, by
battery or battalion, to armored or infantry divisions.
Field artillery brigades were also created, originally to command the separate
field artillery regiments and later, to command the field artillery groups.
However, the brigade eventually was seen as a redundant and unnecessary
additional layer of command. Most of the brigades were inactivated or were
redesignated as H&H batteries and assigned to different corps and
divisions. A few artillery brigades were retained and served as such, the 13th
in the MTO and the 32nd, 33rd, 34th, and 61st in the ETO. In the First Army in
the ETO, two field artillery groups were attached to the 32nd Field Artillery
Brigade. The brigade controlled all 8" gun and 240mm howitzer battalions of the
army, making it, in effect, a heavy artillery brigade. A similar, but less
centralized system was followed by Third, Seventh, and Ninth armies for control
of their heavy battalions.
All in all, the U.S. artillery was equipped with armament that was at least as
well designed as, if not better than, any other in the world. The U.S.
artillery further benefited from communications equipment and a fire control
system that was equaled only by that of the Royal Artillery. Individual forward
observers operated close to the front lines and had access, via powerful radios
and extensive telephone landlines, to a formidable array of weapons. The highly
redundant signals system meant that, even when all other contact with
front-line units and their headquarters was lost, the artillery communications
net usually remained open.
Perhaps more important, and making the U.S. artillery the best in the world,
was a fire-direction system that had been develop at the U.S. Field Artillery
School at Fort Sill, Oklahoma, between the wars. This was a highly refined
development of the crude system Summerall had pioneered in World War I. This
system permitted rapid engagements of targets, and allowed the coordination of
fires of many units from many widely separated firing positions. One of the
most deadly tactics employed was the time-on-target (TOT) concentration. A TOT
massed fires from several battalions onto a selected target and calculated the
times of flight for the shells from each battery so that they all arrived on
target at nearly the same instant (a similar tactic, called a "Stonk", had been
developed independently by the Royal Artillery in North Africa).
Further enhancing the deadliness of the U.S. artillery was the development and
deployment in the ETO in December 1944 of the new proximity fuse. Also known by
its code designation of VT (for variable-time) or POZIT, the proximity fuse
contained a tiny radar that triggered detonation at a preset distance from a
solid object. The POZIT fuse had been intended for use against air targets
(taking a heavy toll of German "Buzzbombs" in the fall of 1944). The fuse
significantly simplified and enhanced the lethality of air bursts and
eliminated the need for complicated and unreliable time fuses.
Although US artillery was second to none in the war, problems with ammunition
supply did hamper efficiency at various periods. This problem reached its nadir
during the fall of 1944, when the US artillery in Europe was reduced to strict
rationing of ammunition. At one point, the artillery was limited to fewer than
twenty 105mm rounds-per-day-per-gun. From 11 October to 7 November 1944, Third
Army fired a total of 76,325 rounds of all types (an average of 2,726 per-day),
which was less than the number fired on a single day during the Battle of the
Bulge. Indeed, at the end of the Battle of the Bulge, ammunition reserves in
the ETO were 31 percent of the War Department's planning levels (which were
already conceded to be too low). Like the personnel replacement problem, the
ammunition shortage was only truly solved by the ending of the war.
Initially, the troop basis allotted by the AGF for non-divisional artillery was
somewhat low, and it emphasized lighter artillery over heavier. Only fifty-four
heavy and eighty-one medium battalions, compared to 105 light battalions, were
authorized on 24 November 1942. However, lobbying by Generals McNair and
Sommervell in 1943 resulted in an increase. On 15 January 1944 the War
Department authorization had expanded to include 111 heavy and 111 medium
battalions, while the number of light battalions authorized had decreased to
95. In April 1944 a review of combat experience by the Lucas Board resulted in
a further expansion, with 143 heavy and 114 medium battalions authorized on 1
July 1944. Converting light artillery battalions made up most of the increased
numbers, by 1 July the authorized number of light battalions was down to
eighty. On 31 December 1944 the artillery reached its maximum strength. On that
date there were a total of 346 battalions active, 137 heavy, 116 medium, and 93
light. On 31 March 1945 there were 137 heavy, 113 medium and 76 light
battalions active, of which 307 were deployed or were about to deploy to active
theaters of war.
As of 8 May 1945 there were a total of 238 separate field artillery battalions
in the ETO, including:
Four 75mm howitzer battalions:
The 463rd Parachute, 464th Parachute, 601st Pack, and 602nd Pack;
Thirty-six 105mm howitzer battalions:
The 18th, 25th, 70th, 74th, 76th, 115th, 130th, 162nd Puerto Rican, 170th,
193rd, 196th, 241st, 242nd, 250th, 252nd, 255th, 280th, 281st, 282nd, 283rd,
284th, 394th, 401st, 512th, 522nd Nisei, 569th, 580th, 583rd, 627th, 687th,
688th, 690th, 691st, 692nd, 693rd, and 802nd;
Sixteen 105mm Armored Field Artillery Battalions (105mm SP):
The 58th, 59th, 62nd, 65th, 69th, 83rd, 87th, 93rd, 253rd, 274th, 275th, 276th,
400th, 440th, 695th, and 696th;
Seventeen 4.5" gun battalions:
The 172nd, 176th, 198th, 211th, 215th, 259th, 770th, 771st, 772nd, 773rd, 774th,
775th, 777th Colored, 935th, 939th, 941st, and 959th;
Seventy-one 155mm howitzer battalions:
The 2nd, 17th, 36th, 81st, 141st, 177th, 179th, 182nd, 183rd, 186th, 187th,
188th, 191st, 202nd, 203rd, 204th, 208th, 209th, 228th, 254th, 257th, 333rd
Colored, 349th Colored, 350th Colored, 351st Colored, 521st, 550th, 665th,
666th, 667th, 670th, 671st, 672nd, 673rd, 686th Colored, 689th, 751st, 752nd,
753rd, 754th, 755th, 758th, 759th, 761st, 762nd, 763rd, 764th, 767th, 768th,
776th, 805th, 808th, 809th, 937th, 938th, 940th, 942nd, 943rd, 945th, 949th,
951st, 953rd, 955th, 957th, 961st, 963rd, 965th, 967th, 969th Colored, 974th,
and 975th;
Thirty 155mm gun battalions:
The 190th, 200th, 240th, 244th, 261st, 273rd, 514th, 515th, 516th, 528th, 540th,
541st, 546th, 547th, 548th, 549th, 559th, 561st, 634th, 635th, 731st, 733rd,
734th, 976th, 977th, 978th, 979th, 980th, 981st, and 989th;
Six 155mm SP gun battalions:
The 174th, 258th, 557th, 558th, 987th, and 991st;
Thirty-eight 8" howitzer battalions:
The 194th, 195th, 207th, 264th, 529th, 535th, 578th Colored, 630th, 656th,
657th, 658th, 659th, 660th, 661st, 662nd, 663rd, 736th, 738th, 739th, 740th,
741st, 742nd, 743rd, 744th, 745th, 746th, 747th, 748th, 787th, 788th, 790th,
791st, 793rd, 932nd, 933rd, 995th, 997th, and 999th Colored;
Five 8" gun battalions:
The 153rd, 243rd, 256th, 268th, and 575th;
And fifteen 240mm howitzer battalions:
The 265th, 266th, 267th, 269th, 270th, 272nd, 277th, 278th, 538th, 539th, 551st,
552nd, 553rd, 697th, and 698th.
As of 8 May 1945 there were a total of sixteen separate field artillery
battalions in the MTO, including:
One 105mm howitzer battalion:
The 175th;
Two Armored Field Artillery Battalions (105mm SP):
The 432nd and 1125th;
Seven 155mm howitzer battalions:
The 75th, 178th, 248th, 631st, 765th, 766th, and 936th;
Four 155mm gun battalions:
The 173rd, 530th, 633rd, and 985th;
Two 8" howitzer battalions:
The 527th and 536th.
As of 8 August 1945 there were a total of fifty-three separate field artillery
battalions in the PTO, including:
Three 75mm howitzer battalions:
The 462nd Parachute, 612th Pack, and 613th Pack;
Eight 105mm howitzer battalions:
The 97th, 134th, 147th, 148th, 249th, 251st, 260th, and 694th;
Three Armored Field Artillery Battalions (105mm SP):
The 426th, 427th, and 428th;
Sixteen 155mm howitzer battalions:
The 4th, 55th, 145th, 154th, 165th, 181st, 198th, 225th, 429th, 756th, 757th,
760th, 769th, 803rd, 804th, and 947th;
Eight 155mm gun battalions:
The 168th, 223rd, 226th, 433rd, 517th, 531st, 532nd, and 983rd;
Seven 8" howitzer battalions:
The 465th, 655th, 749th, 750th, 786th, 789th, and 797th;
One 8" gun battalion:
The 780th;
Five 240mm howitzer battalions:
The 543rd, 544th, 545th, 778th, and 779th;
Two 4.5" rocket battalions:
The 421st and 422nd.
Antiaircraft Artillery
At the beginning of World War II the US antiaircraft artillery force was very
much the poor stepchild of the Coast Artillery Corps. The units were mostly
three battalion (a gun battalion, an automatic weapons battalion, and a
searchlight battalion) regiments and separate battalions. They were equipped
with a motley mix of obsolescent 3" guns and single barrel water-cooled .50
caliber machine guns. The German Blitzkrieg in Europe forced a widespread
reevaluation of the Army's AAA capability and, beginning in 1940-1941 a vast
expansion of the arm (it finally achieved an identity separate from the Coast
Artillery in 1943). On 30 September 1942, it was proposed that 811 AAA
battalions be organized (with a total strength of 619,000 men).
However, this massive buildup of AAA units became largely redundant when
another formerly poor relation of the US Army, the Army Air Corps, wrested
command of the air from the Luftwaffe in 1943 and 1944. Many AAA battalions
were disbanded to provide replacements in 1944, some were converted to
artillery. A total of 258 battalions were inactivated or disbanded between 1
January 1944 and 8 May 1945. Nevertheless, AAA remained a strong component of
the army and achieved something of resurgence in late 1944 in Belgium,
defending Antwerp from the threat of the V-1 "Buzzbomb." On 31 December 1944,
there was still a total of 347 AAA battalions (with 257,000 men) active in the
Army.
In 1943 the AAA regiments were broken up into separate battalions, with the
regimental H&H companies becoming new AAA Group Headquarters. The AAA
battalions were organized as either gun (equipped with the M1 90mm AA gun) or
automatic weapons (equipped initially with a U.S.-designed M1 37mm gun, but
later almost wholly re-equipped with the famous M1 40mm Bofors-designed gun,
and with the M51 or M55 quad-mount .50 caliber machine gun). Battalions were
further classified as mobile (that is towed), SP (utilizing halftrack-mounted
guns, the M16, a quad .50 caliber mounting, and the M15, a combination mounting
twin water-cooled .50 caliber and a single 37mm), or semi-mobile (with a
reduced number of prime movers, designed for the defense of static
installations).
The automatic weapons battalions of all types were organized with four firing
batteries, lettered A to D, an H&H Battery, and a Service Battery. Each
battery nominally contained eight towed 40mm or 37mm SP guns and eight quad .50
caliber towed or SP machine guns. However, many slight variations existed, some
battalions had batteries composed of eight towed 40mm guns, four quad .50
caliber mounts, and eight single, water-cooled .50 caliber machine guns (there
was a shortfall in production of the M51 and M55 mounts). Gun battalions were
organized identically, except the batteries were equipped with four 90mm guns
each and, usually, three water-cooled .50 caliber machine guns.
Normally, an AAA automatic weapons battalion was attached to each division, SP
if attached to an armored division, and mobile if attached to an infantry
division. A corps normally had one or more AAA groups attached. Each AAA group
consisted of two or more automatic weapons battalions (usually mobile),
although a gun battalion was occasionally attached. In the European Theater,
gun battalions were more frequently found in AAA groups attached to the army or
army group. Antiaircraft brigades were also formed and were normally attached
to armies or to theater commands. In addition, the IX Air Defense Command (in
effect an AAA division, originally organized as a part of the US Ninth Tactical
Air Force), with an average of ten to fifteen gun and automatic weapons
battalions, formed a powerful AAA reserve for the US 12th Army Group in Europe.
Copyright © 2000 Rich Anderson.
Written by Rich Anderson. If you have questions or comments on this
article, please contact Rich Anderson at:
richto90@msn.com.
About the author:
Richard C. Anderson, Jr. works as the Chief Historian at the The
Dupuy Institute (a non-profit organization dedicated to scholarly
research and objective analysis of historical data related to armed conflict
and the resolution of armed conflict. The Dupuy Institute provides
independent, historically-based analyses of lessons learned from modern
military campaigns.
Published online: 2000.
Last Modified: 02/11/2007.
* Views expressed by contributors are their own and do not necessarily represent
those of MHO.
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