Chemical mortar battalion
Encyclopedia
The United States chemical mortar battalions were army units attached to U.S. Infantry
division
s, and it was their responsibility to service the 4.2 in (107 mm) chemical mortar
during World War II
. For this reason they were also called the "Four-deucers".
After the 1943 reorganization a typical chemical mortar battalion had an establishment of 37 officers, 138 NCOs, and 481 junior enlisted men.
It consisted of:
A chemical mortar company usually had an establishment of 9 officers, 40 NCOs, and 118 junior enlisted men.
It consisted of:
A mortar platoon consisted of:
Chemical mortar battalions were not assigned as integral parts of divisions or other units. As other units went into combat, chemical mortar battalions were attached to them as support. In 1943 General Mark Clark's Fifth Army established a policy that no infantry division would be committed to combat without a chemical mortar battalion attached. As a result when infantry units were rotated out of combat, the mortar battalions often stayed in the line and were attached to the fresh infantry unit. Chemical mortars were in such high demand that often the companies of a battalion would be split up and assigned to different divisions. Two antiaircraft battalions in Fifth Army were retrained as chemical mortar battalions (99th and 100th.) On the first day that General George Patton's Third Army became operational in the summer of 1944, he issued a standing order to his staff that no infantry division would be committed to combat without a chemical mortar battalion attached, and no infantry regiment would be committed without a mortar company attached.
The 443rd, 483rd, 534th, 537th, 560th, 781st, and 782nd Battalions, although formed during the war, were activated too late to serve overseas.
After World War II, the U. S. War Department
transferred the operations and development of chemical mortars to the Ordnance Department, in this way making the mortar an official infantry weapon.
The 2nd Chemical Mortar Battalion was the last of the chemical mortar battalions, and the only one to see combat after World War II. It was reactivated in 1949 and saw 1008 days of combat during the Korean War
. In January 1953 its combat personnel were transferred to the 461st Infantry Battalion (Heavy Mortar.)
, incendiary
, and smoke
marker shell
s. Chemical shells were on stand-by during World War II, to be used in retaliation should the enemy employ chemical weapons first.
These same mortar
s, using high-explosive shells, came to be acknowledged by the U.S. Army command and army personnel as being one of the most effective means of striking at stationary targets, such as machine gun
nests, prepared strong points, pillboxes, or even the powerful German 88 mm gun
s. Another advantage chemical mortars offered, was their maneuverability, easy assembly, disassembly and reassembly from one location to another. The mortars were able to fire high-explosive shells from concealed positions, such as natural escarpments on hillsides, or from woods. The rifled barrel gave the mortar remarkable accuracy, and fire was often called on targets within fifty yards of friendly positions. The low-velocity shell was totally silent in transit, and gave no warning of the huge thump of the explosion, which tended to create panic among enemy forces who were subjected to their firepower. The mortar was called the "grass-cutter" by German troops because its HE shell exploded and fragmented just a few inches above ground level. The mortars often fired white phosphorus shells to block enemy observation with smoke, and WP also caused casualties and fires, being especially effective against dug-in troops because the burning WP particles arced upward and fell directly down into foxholes.
was developed from the British
World War I
Stokes Mortar
that in its turn had evolved to prevail against the random effect of the gas clouds that in adverse weather would affect friend and foe alike with sometimes disastrous results in the trench-warfare conditions at the time.
A Stokes mortar could fire twenty shells a minute and had a range of 1,100 yards (1001 m) and in this way was capable of overwhelming enemy trenches. The 4.2 in (107 mm) mortar, that had by then a rifled barrel installed, and was firing shells with fins attached, had a range of 2300 yards by 1924. After modifying the bore, improving the two-legged support and the recoil mechanism, and producing barrels made of seamless nickel steel, the M1A1 model was capable of sending shells 2,400 yards (2,195 m) during the 1930s.
By 1942, after authorization had been sought and granted to use high explosive shells, again stronger barrels were being built into the new M2 model.
ordered the formation of five additional chemical mortar battalions equipped with the mortar. (These were the 3rd, and the 81st through 84th.) Later, the mortar was developed to be capable of instantly firing shells from a mere 565 yards (517 m) at minimum propellant charge, to a range of 4400 yards (4023 m) by having propellant-charge disks of powder added that by then were being manufactured as square disks with a hole in the middle, strung together, fitted into cartridges, and sewn together into bundles of various thickness. Its rate of fire was 40 rounds in the first two minutes, 100 rounds in the first 20 minutes, and at sustained fire 80 rounds per hour. These variations were caused by the stresses and strains on barrels and the rest of firing mechanisms, that were being imposed by different firing conditions.
The mortars were transported in mortar carts, jeep
s, in island engagements in the Pacific by boat, and in difficult terrain by mule
.
During the Allied invasion of Sicily in the summer of 1943 - the first time the mortar had been used in war-time - 35,000 rounds were fired in 38 days of which more than 90% were HE.
Infantry
Infantrymen are soldiers who are specifically trained for the role of fighting on foot to engage the enemy face to face and have historically borne the brunt of the casualties of combat in wars. As the oldest branch of combat arms, they are the backbone of armies...
division
Division (military)
A division is a large military unit or formation usually consisting of between 10,000 and 20,000 soldiers. In most armies, a division is composed of several regiments or brigades, and in turn several divisions typically make up a corps...
s, and it was their responsibility to service the 4.2 in (107 mm) chemical mortar
M2 4.2 inch mortar
-External links:* early detailed article on 4.2 mortar...
during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. For this reason they were also called the "Four-deucers".
Chemical mortar battalions
Originally chemical mortar battalions consisted of four mortar companies and a HQ company. In 1943 this "square" organization was modified to three mortar companies for a better fit with the three rifle regiments of the "triangular" infantry divisions.After the 1943 reorganization a typical chemical mortar battalion had an establishment of 37 officers, 138 NCOs, and 481 junior enlisted men.
It consisted of:
- 1 chemical mortar battalion HQ company
- 1 company HQ section
- 1 battalion HQ section
- 1 maintenance section
- 3 ammo sections
- 3 chemical mortar companies.
A chemical mortar company usually had an establishment of 9 officers, 40 NCOs, and 118 junior enlisted men.
It consisted of:
- 1 mortar company HQ section
- 3 mortar platoons
A mortar platoon consisted of:
- 1 platoon HQ
- 4 squads each of which had 1 Squad leader (Sgt), 1 Gunner (Cpl), 3 Ammo Bearers (Jr. EM), 2 Truck drivers (Jr. EM), 1 Asst. Gunner (Jr. EM)
Chemical mortar battalions were not assigned as integral parts of divisions or other units. As other units went into combat, chemical mortar battalions were attached to them as support. In 1943 General Mark Clark's Fifth Army established a policy that no infantry division would be committed to combat without a chemical mortar battalion attached. As a result when infantry units were rotated out of combat, the mortar battalions often stayed in the line and were attached to the fresh infantry unit. Chemical mortars were in such high demand that often the companies of a battalion would be split up and assigned to different divisions. Two antiaircraft battalions in Fifth Army were retrained as chemical mortar battalions (99th and 100th.) On the first day that General George Patton's Third Army became operational in the summer of 1944, he issued a standing order to his staff that no infantry division would be committed to combat without a chemical mortar battalion attached, and no infantry regiment would be committed without a mortar company attached.
The numbers of the battalions
During World War II, there were a total of 25 chemical mortar battalions:- the 2nd and 3rd Battalions
- the 71st and 72nd Battalions
- the 80th through the 100th Battalions.
The 443rd, 483rd, 534th, 537th, 560th, 781st, and 782nd Battalions, although formed during the war, were activated too late to serve overseas.
After World War II, the U. S. War Department
United States Department of War
The United States Department of War, also called the War Department , was the United States Cabinet department originally responsible for the operation and maintenance of the United States Army...
transferred the operations and development of chemical mortars to the Ordnance Department, in this way making the mortar an official infantry weapon.
The 2nd Chemical Mortar Battalion was the last of the chemical mortar battalions, and the only one to see combat after World War II. It was reactivated in 1949 and saw 1008 days of combat during the Korean War
Korean War
The Korean War was a conventional war between South Korea, supported by the United Nations, and North Korea, supported by the People's Republic of China , with military material aid from the Soviet Union...
. In January 1953 its combat personnel were transferred to the 461st Infantry Battalion (Heavy Mortar.)
Chemical mortars
Chemical mortars are so named because of their capability of firing not only high explosive, but also chemical, gasGas
Gas is one of the three classical states of matter . Near absolute zero, a substance exists as a solid. As heat is added to this substance it melts into a liquid at its melting point , boils into a gas at its boiling point, and if heated high enough would enter a plasma state in which the electrons...
, incendiary
Incendiary ammunition
-World War I:One of the first uses of incendiary ammunition occurred in World War I. At the time, phosphorus—the primary ingredient in the incendiary charge—ignited upon firing, leaving a trail of blue smoke. They were also known as 'smoke tracer' for this reason. The effective range of...
, and smoke
Smoke
Smoke is a collection of airborne solid and liquid particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwanted by-product of fires , but may also be used for pest...
marker shell
Shell (projectile)
A shell is a payload-carrying projectile, which, as opposed to shot, contains an explosive or other filling, though modern usage sometimes includes large solid projectiles properly termed shot . Solid shot may contain a pyrotechnic compound if a tracer or spotting charge is used...
s. Chemical shells were on stand-by during World War II, to be used in retaliation should the enemy employ chemical weapons first.
These same mortar
Mortar (weapon)
A mortar is an indirect fire weapon that fires explosive projectiles known as bombs at low velocities, short ranges, and high-arcing ballistic trajectories. It is typically muzzle-loading and has a barrel length less than 15 times its caliber....
s, using high-explosive shells, came to be acknowledged by the U.S. Army command and army personnel as being one of the most effective means of striking at stationary targets, such as machine gun
Machine gun
A machine gun is a fully automatic mounted or portable firearm, usually designed to fire rounds in quick succession from an ammunition belt or large-capacity magazine, typically at a rate of several hundred rounds per minute....
nests, prepared strong points, pillboxes, or even the powerful German 88 mm gun
88 mm gun
The 88 mm gun was a German anti-aircraft and anti-tank artillery gun from World War II. It was widely used by Germany throughout the war, and was one of the most recognizable German weapons of the war...
s. Another advantage chemical mortars offered, was their maneuverability, easy assembly, disassembly and reassembly from one location to another. The mortars were able to fire high-explosive shells from concealed positions, such as natural escarpments on hillsides, or from woods. The rifled barrel gave the mortar remarkable accuracy, and fire was often called on targets within fifty yards of friendly positions. The low-velocity shell was totally silent in transit, and gave no warning of the huge thump of the explosion, which tended to create panic among enemy forces who were subjected to their firepower. The mortar was called the "grass-cutter" by German troops because its HE shell exploded and fragmented just a few inches above ground level. The mortars often fired white phosphorus shells to block enemy observation with smoke, and WP also caused casualties and fires, being especially effective against dug-in troops because the burning WP particles arced upward and fell directly down into foxholes.
The development and capabilities of the chemical mortar
The 4.2 in (107 mm) chemical mortarM2 4.2 inch mortar
-External links:* early detailed article on 4.2 mortar...
was developed from the British
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
Stokes Mortar
Stokes Mortar
The Stokes mortar was a British trench mortar invented by Sir Wilfred Stokes KBE which was issued to the British Army and the Commonwealth armies during the latter half of the First World War.-History:...
that in its turn had evolved to prevail against the random effect of the gas clouds that in adverse weather would affect friend and foe alike with sometimes disastrous results in the trench-warfare conditions at the time.
A Stokes mortar could fire twenty shells a minute and had a range of 1,100 yards (1001 m) and in this way was capable of overwhelming enemy trenches. The 4.2 in (107 mm) mortar, that had by then a rifled barrel installed, and was firing shells with fins attached, had a range of 2300 yards by 1924. After modifying the bore, improving the two-legged support and the recoil mechanism, and producing barrels made of seamless nickel steel, the M1A1 model was capable of sending shells 2,400 yards (2,195 m) during the 1930s.
By 1942, after authorization had been sought and granted to use high explosive shells, again stronger barrels were being built into the new M2 model.
History
In 1935, the 2nd Chemical Mortar Battalion was established at Edgewood Arsenal Maryland with the chemical mortar as its primary weapon. At the beginning of World War II there were a few other mortar battalions and companies, including one that was lost on Bataan in the Philippines. In 1942 General George MarshallGeorge Marshall
George Catlett Marshall was an American military leader, Chief of Staff of the Army, Secretary of State, and the third Secretary of Defense...
ordered the formation of five additional chemical mortar battalions equipped with the mortar. (These were the 3rd, and the 81st through 84th.) Later, the mortar was developed to be capable of instantly firing shells from a mere 565 yards (517 m) at minimum propellant charge, to a range of 4400 yards (4023 m) by having propellant-charge disks of powder added that by then were being manufactured as square disks with a hole in the middle, strung together, fitted into cartridges, and sewn together into bundles of various thickness. Its rate of fire was 40 rounds in the first two minutes, 100 rounds in the first 20 minutes, and at sustained fire 80 rounds per hour. These variations were caused by the stresses and strains on barrels and the rest of firing mechanisms, that were being imposed by different firing conditions.
The mortars were transported in mortar carts, jeep
Jeep
Jeep is an automobile marque of Chrysler . The first Willys Jeeps were produced in 1941 with the first civilian models in 1945, making it the oldest off-road vehicle and sport utility vehicle brand. It inspired a number of other light utility vehicles, such as the Land Rover which is the second...
s, in island engagements in the Pacific by boat, and in difficult terrain by mule
Mule
A mule is the offspring of a male donkey and a female horse. Horses and donkeys are different species, with different numbers of chromosomes. Of the two F1 hybrids between these two species, a mule is easier to obtain than a hinny...
.
During the Allied invasion of Sicily in the summer of 1943 - the first time the mortar had been used in war-time - 35,000 rounds were fired in 38 days of which more than 90% were HE.