M45 Quadmount

The M45 Quadmount (nicknamed the "meat chopper" and "Krautmower"[2] for its high rate of fire) was a weapon mounting consisting of four of the "HB", or "heavy barrel" .50 caliber M2 Browning machine guns (of the M2 Turret Type (TT) variant[2]) mounted in pairs on each side of an open, electrically powered turret. It was developed by the W. L. Maxson Corporation to replace the earlier M33 twin mount (also from Maxson).[2] Although designed as an anti-aircraft weapon, it was also used against ground targets. Introduced in 1943 during World War II, it remained in US service as late as the Vietnam War.

M45 Quadmount
Montaje Maxon
M45 on an M20 trailer in the Musée des Blindés
TypeAnti-aircraft gun
Heavy machine gun
Place of originUnited States
Service history
WarsWorld War II
Korean War
Vietnam War
Mass2,396 lb (1,087 kg)
Barrel length5 ft 3 in (1.6 m) L/50[1]

Shell.50 BMG (12.7×99mm NATO)
Shell weight21 oz (.6 kg)
Caliber0.50 in (12.7 mm)
ActionShort recoil-operated
Elevation-5° to +90°
Rate of fire575 x 4 = 2,300 rpm
Muzzle velocity2,900 ft/s (890 m/s)
Effective firing range4,900 ft (1.5 km) (effective AA)
15,000 ft (4.5 km) (maximum AA)
Maximum firing range1.1 mi (1.8 km) (horizontal)
1.6 mi (2.5 km) (maximum)
Feed systemBelt-fed (M2 or M9 links)[1]
G-102 White M16A1 Half-Track MGMC pic3
M16 MGMC in Overloon


G-508 GMC CCKW-353-B2 with m55 Machine-gun mount pic3
CCKW-353-B2 gun truck with M45 on M20 trailer in bed, loading ramps attached to side. This configuration did not see combat in World War II as it was still in testing by the cessation of hostilities.

In order to develop a mobile anti-aircraft weapon, several 0.5 inch (12.7 mm) twin machine gun mounts were tested on the chassis of the M2 half-track including Bendix, Martin Aircraft Company, and Maxson. The Maxson M33 turret mount was preferred and—on the larger M3 half-track (T1E2)—was accepted for service in 1942 as the M13 Multiple Gun Motor Carriage. The mount was also used on the similar M5 half track as the M14 Multiple Gun Motor Carriage.[3][4][5]

Experimentally, the Quadmount was also tested in 1942 on a M3 Light Tank in place of the tank's turret but the project was not proceeded with.[6]

Even as production of the two MGMC vehicles was underway, there was work to increase the firepower. Re-working the M33 to take four machine guns resulted in the M45 mounting.

The M45 Quadmount was the principal weapon (along with the 37mm gun) of highly mobile anti-aircraft artillery battalions deployed in the European Theater during World War II. These battalions provided invaluable air defense to much larger units, particularly field artillery. The M45 Quadmount units served as a very strong deterrent to strafing runs by enemy warplanes as, in addition to their gross firepower, its quartet of Browning M2HB "heavy barrel" .50 caliber guns were capable of being "tuned" to converge upon a single point at distances which could be reset while in use. Multiple-gun mounts were developed for the M2 Browning because the M2's rate of fire (450–550 rounds per minute) for a single gun was too low for anti-aircraft use.[2]

The M45 found use throughout the war as a land-based weapon, particularly during the Battle of the Bulge. Although the Allies achieved air supremacy by the invasion of Normandy in June 1944, German attack runs were still a threat. German Jabo fighter-bombers could approach and attack at low altitude and then quickly retreat to avoid Allied fighters. The Luftwaffe also mustered a large number of planes for Operation Bodenplatte that took place on New Year's Day 1945. On March 7, 1945 when the U.S. Army discovered the Ludendorff Bridge intact across the Rhine, M45-armed U.S. half-tracks defended the American troops crossing the bridge on March 9, 1945 to great effect. At Oppenheim, when the Allies were gathering to make a massive push after crossing the River Rhine (March 1945), 248 German warplanes were used in an effort to destroy the bridge first. U.S. Army anti-aircraft artillery battalions massed, shot down 30% of the attacking force mainly with M45 Quadmounts and prevented the bridge from being touched before the U.S. Third Army went into Germany.

It was also tested by the US Navy as a solution for the Kamikaze attacks that started in late 1944. Two Essex class aircraft carriers received six mounts each for operational testing starting with CV-16 Lexington in May 1945. Her gunnery department in general was positive towards the powered mounts but felt that the guns were too light and ineffective against the high speeds that the diving Kamikaze aircraft possessed.[7]

The M45 Quadmount was ineffective against the new, fast-flying planes of the Jet Age. However, it was used against infantry targets in US post-war service. In Vietnam they were pressed into service to defend bases and to ride escort convoys along Viet Cong roads.[8]

The French Army also used M45s in combat. M45 Quad Mounts were placed in trucks to deal with ambushes and four M45s were used during the Battle of Dien Bien Phu.[9]


Israeli TCM-20, Israeli Air Force Museum

The TCM-20 was a postwar Israeli development of the M45 mount, equipped with two 20mm Hispano-Suiza HS.404 cannons in lieu of machine guns. In frontline Israeli service, it was replaced by the M163 Vulcan Air Defense System in the 1970s, but some reserve units still used TCM-20s into the 1980s. The weapon was also exported to several third-world countries.


M20 trailer mount
M20 trailer mount, 1947
M17 trailer mount
M17 trailer mount, 1947

During World War II, the M45 turret was mounted on two specific systems; the M16 Multiple Gun Motor Carriage and the M51 Multiple Machine Gun Carriage. When mounted on the M20 trailer, it was known as the M55 Machine Gun Trailer Mount, but this system had not finished testing before the cessation of hostilities. M51s were withdrawn from service by the end of World War II in favor of the M55.

During the Korean War, the M55 and M16 saw extensive combat, and lessons learned in Korea led to the conversion of an additional 1200 M3 halftracks into the M16A1 variant by adding an M45 turret. These can be identified by the lack of fold-down armor and rear troop door on the crew compartment and were often fitted with the roller front bumper instead of the winch bumper fitted to all M16s. In 1954 an additional modification was made to roughly 700 M16 MGMCs, adding the rear troop door and bolting the fold-down armor in the up position. This modification became known as the M16A2 MGMC.

The M55 received a new, more powerful generator in the 1960s and served through the Vietnam War, usually mounted in the back of an M35 2.5 ton or M54 5-ton truck.

G-102 White M16A1 Half-Track MGMC pic2
Quad 0.50 used for convoy security along Route 9
Quadmount used for convoy security along Route 9, Vietnam 1968


The M45 is operated by two loaders and one gunner. The mount is capable of traversing a full 360 degrees around, with an angle elevation between -10 and +90 degrees. Traverse and elevation are electrically driven, powered by two rechargeable 6-volt batteries. All four guns could be fired at once, but standard practice was to alternate between firing the upper and lower pair of guns, allowing one pair to cool while the other was in use. This allowed for longer periods of action as overheating of the gun barrels was lessened.[2]

The "tombstone" model M2 ammunition chests held 200 rounds apiece — with one ammunition chest on an M45 system holding ten times as many rounds as each of the four twenty-round 20mm magazines of the German Flakvierling system held (and which, on the German ordnance system, had to be changed every six seconds on each gun of the quartet to ensure its own top 800 rpm "combined" firing rate), with each M2 ammo chest weighing 89 pounds apiece when full.

See also


  1. ^ a b c Chamberlain, Peter (1975). Anti-aircraft guns. Gander, Terry,. New York: Arco Pub. Co. p. 54. ISBN 0668038187. OCLC 2000222.
  2. ^ a b c d e Rottman, Gordon L., Browning .50-Caliber Machine Guns, Osprey Publishing (2010), ISBN 9781849083317, p. 19-20
  3. ^ Zaloga, M3 Infantry Half Track, Osprey Publishing (2004) p. 38.
  4. ^ Green (2000), p. 150.
  5. ^ Chamberlain & Ellis (1969) British and American Tanks of World War II Arco Publishing. p191
  6. ^ Chamberlain & Ellis (1969) p89-90
  7. ^ http://www.researcheratlarge.com/Ships/CV16/AAReport/index.html
  8. ^ Rottman, Gordon L. (20 Sep 2011). Vietnam Gun Trucks. New Vanguard 184. Osprey Publishing. p. 36. ISBN 9781849083553.
  9. ^ http://www.wehrmacht-awards.com/forums/showthread.php?t=764040


Training Manuals

  • TM 9-2800 Military vehicles dated 1947
  • TM 9-2010
  • TM 9-1223
  • FM 44-57

M20 trailer

  • SNL G220
  • TM 9-789

M17 trailer

External links

22nd Crash Rescue Boat Squadron

The 22nd Crash Rescue Boat Squadron (22nd CRBS) was a U.S. Air Force combat search and rescue unit formed during the Korean War. While its original task was ocean rescue of downed pilots, its speedy and well-armed boats soon became prime vehicles for inserting spies, espionage agents, and sabotage parties into enemy territory for the 6004th Air Intelligence Service Squadron. Despite the hazards of both their overt and covert missions, the airmen of the 22nd CRBS never lost a boat during their clandestine operations in the war.

2 cm Flak 30/38/Flakvierling

The Flak 30 (Flugabwehrkanone 30) and improved Flak 38 were 20 mm anti-aircraft guns used by various German forces throughout World War II. It was not only the primary German light anti-aircraft gun, but by far the most numerously produced German artillery piece throughout the war. It was produced in a variety of models, notably the Flakvierling 38 which combined four Flak 38 autocannons onto a single carriage.

71st Air Defense Artillery Regiment

The 71st Air Defense Artillery was a regiment in the United States Army.

Battle of Suoi Tre

The Battle of Suoi Tre (Vietnamese: suối Tre) occurred during the early morning of 21 March 1967 during Operation Junction City, a search and destroy mission by American military forces in Tay Ninh Province of South Vietnam, to the west of the capital Saigon. After being challenged heavily to begin with, the Americans gained the upper hand and completed a convincing victory over the Viet Cong (VC). They claimed to have found 647 bodies and captured seven prisoners, while recovering 65 crew-served and 94 individual weapons. The Americans losses were 36 dead and 190 wounded, a fatality ratio of more than twenty to one in their favour.

On 19 March, American helicopters dropped two infantry battalions off in a clearing near Suoi Tre to build a fire support base to be used in search and destroy missions against the VC. During the airlift, seven helicopters were damaged. On March 21, a VC attack started before dawn at 6:30 a.m., headlined by mortars, and followed by a large-scale infantry charge. They overwhelmed parts of the American perimeter at first, and forced them to withdraw inwards. After a period, American reinforcements broke through the VC envelope to assist their besieged colleagues, and firepower and artillery helped them gain the upper hand. The VC stubbornly fought on, with some carrying wounded compatriots forward in follow-up infantry charges, but they were eventually forced to withdraw with heavy casualties.

GMC CCKW 2½-ton 6x6 truck

The GMC CCKW, also known as "Jimmy", or the G-508 by its Ordnance Supply Catalog nr, was a highly successful series of off-road capable, 2​1⁄2-ton, 6x6 trucks, built in large numbers to a standardized design (from 1941 to 1945) for the U.S. Army, that saw heavy service, predominantly as cargo trucks, in both World War II and the Korean War. The original "Deuce and a Half", it formed the backbone of the famed Red Ball Express that kept Allied armies supplied as they pushed eastward after the Normandy invasion.The CCKW came in many variants, including open or closed cab, long wheelbase (LWB) CCKW-353 and short (SWB) CCKW-352, and over a score of specialized models, but the bulk were standard, general purpose, cargo models. A large minority were built with a front mounted winch, and one in four of the cabs had a machine-gun mounting ring above the co-driver's position.

Of the almost 2.4 million trucks that the U.S. Army bought between 1939 and December 1945, across all payload weight classes, some 812,000, or just over one third, were ​2 1⁄2-ton trucks. GMC's total production of the CCKW and its variants, including the 2​1⁄2-ton, 6x6, amphibian DUKW, and the 6x4, 5-ton (on-road) CCW-353, amounted to some 572,500 units – almost a quarter of the total WW II U.S. truck production, and 70 percent of the total ​2 1⁄2-ton trucks. GMC's total of ~550,000 purely 6x6 models, including the DUKW, formed the overwhelming majority of the ~675,000 six by six ​2 1⁄2-ton trucks, and came in less than 100,000 shy of the almost 650,000 World War II jeeps. Additionally, GM built over 150,000 units of the CCKW's smaller brother, the ​1 1⁄2-ton, 4x4 Chevrolet G506, at the same factory.

The GMC CCKW began to be phased out, once the M35 series trucks were first deployed in the 1950s, but remained in active U.S. service until the mid-1960s. Eventually, the M35 series, originally developed by REO Motors, succeeded the CCKW as the U.S. Army's standard ​2 1⁄2-ton, 6x6 cargo truck.

List of anti-aircraft guns

Anti-aircraft guns are weapons designed to attack aircraft. Such weapons commonly have a high rate of fire and are able to fire shells designed to damage aircraft. They also are capable of firing at high angles, but are also usually able to hit ground targets as well in a direct fire role.

List of anti-aircraft weapons

List of antiaircraft weapons. See also antiaircraft warfare.

List of military equipment of Cyprus

The Cyprus National Guard is a combined arms force and represents the organised air, land and sea capabilities of the Republic of Cyprus. Equipment has in the past, and usually still is, imported from other countries, since the country has only very limited heavy industrial and commercial industrial capacity due to its small population and land mass (excluding Northern Cyprus). The role of maintaining, upgrading and modifying military equipment is primarily the task of the National Guard Technical Corps, though more complex activities rely upon the availability of civil contracts.

M13 Multiple Gun Motor Carriage

The M13 Multiple Gun Motor Carriage (MGMC), otherwise known as the M13 Half-track, was a self-propelled anti-aircraft gun used by the U.S. Army during World War II that was armed with two .50 caliber M2HB heavy-barrel Browning machine guns. Developed in response to a requirement for a mobile anti-aircraft (AA) vehicle, the vehicle was produced by the White Motor Company between July 1942 and May 1943. The only time it was ever used in combat was when the Americans landed at Anzio in January 1944. It was replaced by the more heavily armed M16 Multiple Gun Motor Carriage in April 1944.

The M13 evolved from a series of several unsuccessful prototypes that were trialed from 1940 to 1942. Of these, the T1E4 was selected and given the official name of the M13 MGMC, before being placed into production. Half of the M13s produced were converted into M16s on the production lines.

M15 Halftrack

The M15 Halftrack, officially designated M15 Combination Gun Motor Carriage, was a self-propelled anti-aircraft gun on a halftrack chassis used by the United States Army during World War II. It was equipped with one M1 automatic 37 millimeter (1.5 in) gun and two water-cooled .50 caliber (12.7 mm) M2 Browning heavy machine guns. Based on the M3 Halftrack chassis, it was produced by the White Motor Company and Autocar between July 1942 and February 1944, and served alongside the M16 Multiple Gun Motor Carriage.

The M15 evolved from the T28 project, an outgrowth of a 37 millimeter (1.5 in) gun mounted on a M2 Halftrack. Initially designated as the T28E1 Combination Gun Motor Carriage (CGMC), it was accepted into service in 1943 as the M15. While conceived as an anti-aircraft weapon, its 37 mm gun was often used as an infantry support weapon during the later stages of World War II. The M15A1 was an improved variant with air-cooled machine guns mounted below the 37 mm gun. The M15 "Special" was an M15 armed with a single Bofors 40 mm gun.

During World War II, the vehicle served the U.S. Army throughout the Mediterranean, European, and Pacific Theaters of Operations. In the Korean War, the M15 served alongside the M16 providing infantry support.

M16 Multiple Gun Motor Carriage

The M16 Multiple Gun Motor Carriage, also known as the M16 Half-track, was an American self-propelled anti-aircraft weapon built during World War II. It was equipped with four 0.5 inch (12.7 mm) M2 Browning machine guns in a M45 Quadmount. 2700 were produced by White Motor Company from May 1943 to March 1944, with 568 M13 MGMCs and 109 T10 Half-tracks being converted into M16s as well.

The chassis was derived from the T1E2 chassis, an earlier version of the M13. Based on an M3 Half-track chassis, it replaced the M13 MGMC half-track after early 1944. As aircraft became more advanced, the usefulness of the M16 was reduced. In the Korean War, it was relegated primarily to the ground-support role, being put out of service in the U.S. Army in 1954.

Nicknamed the "Meat Chopper", the M16 was famous for its effectiveness against low-flying aircraft and infantry, making it extremely popular with soldiers. It was used by the United States Army, the British Commonwealth, and South Korea. A similar version of the M16, the M17, was based on the M5 Half-track and exported via Lend-Lease to the Soviet Union.

M2 Browning

The M2 Machine Gun or Browning .50 Caliber Machine Gun is a heavy machine gun designed toward the end of World War I by John Browning. Its design is similar to Browning's earlier M1919 Browning machine gun, which was chambered for the .30-06 cartridge. The M2 uses the much larger and much more powerful .50 BMG cartridge, which was developed alongside and takes its name from the gun itself (BMG standing for Browning Machine Gun). It has been referred to as "Ma Deuce", in reference to its M2 nomenclature. The design has had many specific designations; the official US military designation for the current infantry type is Browning Machine Gun, Cal. .50, M2, HB, Flexible. It is effective against infantry, unarmored or lightly armored vehicles and boats, light fortifications and low-flying aircraft.

The Browning .50 caliber machine gun has been used extensively as a vehicle weapon and for aircraft armament by the United States from the 1930s to the present. It was heavily used during World War II, the Korean War, the Vietnam War, the Falklands War, the Soviet–Afghan War, the Gulf War, the Iraq War and the War in Afghanistan in the 2000s and 2010s. It is the primary heavy machine gun of NATO countries, and has been used by many other countries as well. The M2 has been in use longer than any other firearm in U.S. inventory except the .45 ACP M1911 pistol, also designed by John Browning.

The current M2HB is manufactured in the U.S. by General Dynamics and U.S. Ordnance for use by the U.S. government, and for allies via Foreign Military Sales, as well as foreign manufacturers such as FN Herstal.

M3 Half-track

The M3 Half-track is an American armored personnel carrier half-track widely used by the Allies during World War II and in the Cold War. Derived from the M2 half-track Car, the M3 was extensively produced, with about 15,000 standard M3s and more than 38,000 variant units manufactured.

The M3 was extensively modified with several dozen variant designs produced for different purposes. The M3 and its variants were supplied to the U.S. Army and Marines, as well as British Commonwealth and Soviet Red Army forces, serving on all major fronts throughout the war. It and its variants were produced by many manufacturers including International Harvester and Autocar, and were designed for a wide variety of uses, such as a self-propelled anti-aircraft weapon or self-propelled artillery. Although initially unpopular due to its lack of significant armor or roof to protect from shrapnel, it was used by most of the Allies during the war.

M54 5-ton 6x6 truck

The M54 5-ton 6×6 truck (G744) was the basic cargo model of the M39 Series truck. It was designed to transport a 10,000 lb (4,500 kg), 14-foot-long (4.3 m) cargo load off-road in all weather. In on-road service the load weight was doubled.

The M54 was the primary heavy cargo truck of the U.S. Army and U.S. Marine forces during the Vietnam War, and was also used by the U.S. Navy, U.S. Air Force, and ARVN forces.The M39 Series began to be replaced by the M809 series in 1970, followed by the M939 series in 1982, but continues to serve in other nations' armed forces around the world.

Meat chopper

Meat chopper may refer to:

Cleaver, a large meat knife

M45 Quadmount, a World War II machine gun mounting

Norwegian coupling, a means of coupling railway cars

Rock Island Arsenal

The Rock Island Arsenal comprises 946 acres (383 ha), located on Arsenal Island, originally known as Rock Island, on the Mississippi River between the cities of Davenport, Iowa, and Rock Island, Illinois. It lies within the state of Illinois. It is home of First Army headquarters. The island was originally established as a government site in 1816, with the building of Fort Armstrong. It is now the largest government-owned weapons manufacturing arsenal in the United States. It has manufactured military equipment and ordnance since the 1880s. In 1919–1920 one hundred of the Anglo-American or Liberty Mark VIII tanks were manufactured, although too late for World War I. It is designated as a National Historic Landmark.

Established as both an arsenal and a center for the manufacture of leather accoutrements and field gear, today it provides manufacturing, logistics, and base support services for the Armed Forces. The Arsenal is the only active U.S. Army foundry, and manufactures ordnance and equipment, including artillery, gun mounts, recoil mechanisms, small arms, aircraft weapons sub-systems, grenade launchers, weapons simulators, and a host of associated components. Some of the Arsenal's most successful products include the M198 and M119 towed howitzers, and the M1A1 gun mount. About 250 military personnel and 6,000 civilians work there. The 2000 census population was 145.

Tet Offensive attack on Tan Son Nhut Air Base

The attack on Tan Son Nhut Air Base, headquarters of the Republic of Vietnam Air Force as well as Military Assistance Command, Vietnam, occurred during the early hours of 31 January 1968. Tan Son Nhut Air Base was one of the major air bases used for offensive air operations within South Vietnam and for the support of United States Army and Army of the Republic of Vietnam (ARVN) ground operations. The attack by Vietcong (VC) and People's Army of Vietnam (PAVN) forces was one of several major attacks on Saigon in the first days of the Tet Offensive. The attack was repulsed with the VC/PAVN suffering heavy losses; no material damage was done to the base.

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