M42 Duster - the fire dragon

The US military relied on air superiority during World War II. Anti-aircraft defense of the troops provided towed cannons, or. self-propelled anti-aircraft devices M16 MGMC on halftrack landing gear. It was only at the end of the war that M19 anti-aircraft tanks with a 40 mm Bofors double cannon on the chassis of the M24 Chaffee tank entered production. However, the end of the war caused less than 300 pieces to be built.

At the end of World War II, it was clear that 12.7 mm machine guns are insufficient to destroy air targets. Therefore, the development of the T17 machine gun caliber 15.2 mm was started. On the chassis of the new light tank was to be placed a turret with a shooting radar and four of these machine guns. The vehicle marked "Gun Motor Carriage T100 Stinger" was completed in September 1951; but the difficulty of constant detentions with machine guns and low fire efficiency led to the termination of the project.

Taiwanese M42A1 Duster

Proven bofors

As early as August 30, 1951, the protocol of the Armament Committee OCM 33869 ( Ordnance Committee Minutes ) approved the development of a new self-propelled anti-aircraft vehicle with a separate radar on the second vehicle. Three prototypes were ordered: a transitional T141 armed with two M2A1 cannons (licensed bofors) caliber 40 mm with an optical sight, the final T141E1 with the same armament but the possibility of fire control using a radar and a vehicle for fire control and target search T53.

Work on the T141 progressed very quickly. The tower could be taken over from the older M19 after minor modifications. It was only necessary to adjust the diameter of the tower rim and equip the tower with a more modern collimator sight. Thanks to the larger combat space, it was possible to increase the firing range from 352 to 480 rounds. The first vehicle, the T141, was completed in April 1952.

It was worse with the main projected variant, equipped with a radar. With the component base based on vacuum tubes at the time, it was not possible to build a sufficiently compact superstructure. The second major problem was the reliability of the electronics when driving off-road, where the glass flasks of the tubes suffered from shocks and impacts. Already on March 9, 1952, the T141E1 / T53 project was abandoned and remained with the T141.

The first serial T141s were manufactured by Cadillac in Cleveland in August 1952, and intensive military tests began immediately, running until 9 September. The results were satisfactory. The examination commission proposed a total of 37 changes, such as the replacement of the original funnel flame silencers with split, three-arm, addition of an exhaust silencer to an auxiliary generator, modification of the driver's and commander's hatches and other similar modifications.

M42A1 Duster with suspended shock absorbers

By the protocol of the armament committee OCM 35012 of October 22, 1953, the vehicle was included in the armament as a self-propelled 40mm double cannon M42. The same document reclassified the older M19 on the chassis of the M24 tank for limited use.

Due to the war in Korea , production began immediately at another plant, ACF Industries, Pennsylvania, in April 1953. However, it did not last long: it ended in December of the same year, because a ceasefire was signed in Korea, eliminating urgent demands for the supply of new anti-aircraft equipment.Production at the Cadillac plant continued until December 1959. The total number of pieces produced reached 3700.

Vehicle construction

Technically, the M42 was nothing revolutionary. The chassis was taken from the M41 Walker Bulldog tank with minor modifications. The drive was powered by an in-line air-cooled six-cylinder Continental AOS-895-3 with a displacement of 14,680 cm ³ and an output of 370 kW. From February 2, 1956, the M42A1 version with an AOSI-895 ("I" - Injection) engine with direct fuel injection was included in the armament. As a result, consumption decreased and range increased by 20%. Gradually, most older vehicles were modified to the M42A1 version.

In front of the body sat the driver on the right and the commander of the vehicle on the left, also acting as a radio operator. The front plate was less inclined against the M41 tank, so both men could be equipped with separate hatches on the ceiling. In addition, there was a large rectangular hatch in front, used primarily for loading ammunition.

Type 64 light tank: a combination of the M42 Duster chassis and the M18 Hellcat tower

The main armament consisted of the two above-mentioned 40mm cannons with a barrel length of 60 calibers, mounted in an open turret with a circular measurement and elevation of -5 to + 85 °. The tower had an electro-hydraulic drive, a 360 ° turn lasted nine or 10.5 seconds with an emergency manual drive. The cannons had a theoretical cadence of 120 shots per minute; but after 10 shots it was recommended to stop the shooting and let the barrel cool down, or. to replace them. This operation took twice three minutes. The life of the main was 4,000-16,000 shots, depending on the intensity of fire.

The cannons had a range at a distance of 9500 m and a height of 5000 m. They were equipped with an optical collimator sight M24C with automatic correction of target speed and dive angle. These two parameters were entered by the commander into the analog computer M38. The cannons were loaded with tapes of four rounds. The entire firing range consisted of 480 pieces of ammunition.

The tower was manned by a commander sitting in front to the left of the cannons. There was a shooter on the other side. Behind the cannons, two chargers had their positions with folding seats. Auxiliary armament, designed primarily to defend the crew against infantry, consisted of a machine gun Browning M1919 , later replaced by a more modern M60 .

M42 Rear duster

For combat units

Despite the accelerated start of production, the M42 Duster did not fight in the Korean War. Instead, they quickly replaced the air defense division funds formed by the older M19 , or towed cannons or World War II halftracks M16 .

Each tank or mechanized division was included in the anti-aircraft division, the American terminology ADA AWSP ( Air Defense Artillery Automatic Weapon Self-Propelled ). The division consisted of one command and four firing batteries. Each battery had two firing squads with eight M42 Duster . The anti-aircraft division thus had 64 firing vehicles at its disposal.

The main task of the anti-aircraft division was, of course, defense against aircraft, but secondarily, the M42 were able to destroy ground targets.Due to the weak armor and small range, it was not possible to replace them with tanks, but when firing from a suitable hiding place, the cannonade of 40mm twins was murderous for both manpower and lightly armored targets.

In the late 1950s, it became clear that the M42 was no major advance compared to World War II anti-aircraft tanks. It was to be replaced by the T249 Vigilante system from Sperry, armed with a turret with a six-barrel rotary cannon caliber 37 mm, located on a modified chassis of the M113 transporter. Another replacement in the form of the MIM-46 Mauler missile system did not get into production due to the overall complexity, high costs and technical problems during development.

A real replacement for the duster thus became a pair of M163 , which was a six-barrel rotary cannon M61 Vulcan caliber 20 mm, mounted on the chassis of the M113 transporter, and a rocket MIM-72 Chaparral . Its armament was four modified guided missiles AIM-9D Sidewinder , mounted on a simple retractable tower. Although this was to be a temporary solution in both cases, the result was surprisingly viable assets, extensively exported to many countries.

Although both did not get into service until 1968, M42 Duster have been removed from the status of regular units of the US Army since 1963 and transferred to the National Guard, or. offered for sale. The only exception was the machines of the 3rd and 4th batteries of the 4th Anti-Aircraft Division, defending the Panama Canal, because the Panamanian government did not agree to the deployment of missile batteries MIM-23 HAWK . The M42 served in Panama until the 1970s.

However, the elimination of the M42 from service did not take long. In 1966, they were reclassified because their services were needed in Vietnam. The command considered them more reliable and useful than missiles. The threat of Vietnamese air raids was minimal and the M42 showed very good results when firing on ground targets. Here, the vehicle got its nickname " Duster ", because when shooting with a small elevation rose clouds of dust.

Three divisions of the M42 Duster were transferred to Vietnam, ie more than 190 pieces. Each section was reinforced with a battery of anti-aircraft four-machine guns M55 (combination of M45 with an M20 trailer) and a battery of anti-aircraft headlights. Operator formed by reservists undergoing pre-deployment preparation for the 1st Brigade for individual advanced training PVO (1 ^st Advancenced Individual Training Brigade AD) at Fort Bliss in Texas .

Due to the limited range of the North Vietnamese MiGs, the duster was unlucky to fire at air targets. On their shoulders lay mainly the defense of fire bases against attacks by ground troops, or. escort of supply convoys. They were less suitable for reconnaissance by fighting, because when they broke through the roads in the dense jungle, their engine overheated and it wore out quickly.On the other hand, thanks to the high-quality suspension and the high floor of the battle area, the dusters were able to withstand the explosion of bottom anti-tank mines without serious losses in the crew.

When defending the bases, the M42A1 Duster were mostly placed in stationary positions. Previously, the number of crew members was reduced to five, by merging the functions of commander and commander of the tower. In stationary positions, the driver alternately performed the function of a charger, so it was possible to reduce the crew to four men.

Fire Dragon

The North Vietnamese had a very bad experience with dusters. A few doses of fragmentation-explosive rounds HE-T Mk.II ( High Explosive Tracer ) managed to disperse the attack of the entire platoon of soldiers. The penetrating M81 AP-T ( Armor Piercing Tracer ) pierced the armor of Soviet PT-76 light tanks and their Chinese Type 63 clones, not to mention trucks or armored personnel carriers, without any problems. Until the arrival of medium T-54 tanks in Vietnamese armaments, the M42 Duster was sufficient to perform most of the firing tasks.

An comparison with the M55 quadruplets (M45) is interesting. The soldiers appreciated the murderous effectiveness of the duster's explosive charges in the open. It was worse in the vegetation. Sensitive lighters caused the grenades to explode on contact with weaker branches, and the effectiveness of the fire decreased significantly. In similar conditions, they preferred M55 fire, placed on the bodies of gun trucks . Heavy projectiles of "half-thumbs" (12.7 mm) had no problem penetrating dense vegetation. The Forties had greater range against machine guns and, using data from artillery computers, could lead to indirect fire.

Dusters were usually distributed in pairs so that their firing sectors overlapped. Most crews in Vietnam dismantled the flame arresters from the main: this reduced the amount of dust swirling when firing at small angles, and also increased the psychological effect. At a cadence of 2 × 120 rounds / min. a wall of fire literally opened up in front of the attackers. Not for nothing did the Vietnamese call the M42 a "fire dragon."

Due to the fact that the guerrilla units operated mainly at night, the dusters were assigned headlight batteries. They were armed with 56cm headlights AN / MSS-3 and more modern 76cm AN / TVS-3. Both types were able to work in the visible or infrared spectrum.

In practice, the infrared mode was used during patrols so that the position of the headlights was not revealed. Repelling the operator's attack, they removed the filters, illuminated the targets with white light, and the M42 Duster opened fire. Thanks to the power of the spotlights, the attackers were effectively blinded. However, the headlight operators also handled such pieces as the indirect illumination of the battlefield with light reflected from low clouds.

Dusters were not only deployed in ground operations in Vietnam. Several M42s were placed on landing craft, and in the Mekong Delta they acted as improvised gunboats within the 9th Infantry Division's Mobile Riverine Forces. The massive M42 firepower impressed mainly the Marines, so it initiated the construction of the LVTAA-X1 SPAAG prototype, which was nothing more than a duster tower located on the ceiling of the hull of the LVTP-5 amphibious transporter.However, it did not see mass production.

Prototype LVTAA-X1 SPAAG

During the entire war in Vietnam, there was not a single combat loss of the M42 Duster . On the other hand, their crews could not boast of a chest hung with metal. However, in the ranks of anti-aircraft units is one holder of the Medal of Honor of Congress . It's a chat. Mitchel William Stout from Battery C of the 1st Battalion of the 44th Anti-Aircraft Regiment. In defense of the Khe Gio Bridge, the Vietnamese threw a grenade into the bunker, where the anti-aircraft headlight was operated. Chet. Stout picked him up and tried to take him out. The grenade exploded just at the exit of the bunker as it was carried against its body, effectively shielding the explosion at the cost of its own life and preventing injury to other members of the unit.

Dusters were detached from Vietnam in 1971 and regular army units handed over their machines to the National Guard after the dissolution. It used them until 1988. Part of the M42 Duster was handed over to South Vietnamese troops.

Foreign users

The M42 Duster has been widely exported. Already in 1956, the Federal Republic of Germany received 496 machines for the newly built Bundeswehr. The official German designation was "Flak 40 mm L60 ZwSF" ( Zwillig Selbstfahrlafette ), but "Flakpanzer M42", "Panzerflak M42" or "(Panzer) Flakzwilling M42" can be found in various documents. Dusters were delivered including the original American machine guns Browning M1919A4 ; but the Germans soon replaced them with their own MG1 / MG3.

The organizational structure of the German anti-aircraft divisions differed from the American ones. Each division had one staff and two firing batteries. The firing batteries consisted of three platoons of three vehicles. Dusters lasted in service for a relatively long time, until 1976, when they began to be replaced by significantly more modern anti-aircraft tanks Cheetah . Dusters decommissioned from the Bundeswehr were sold to Greece. The traditional rival of Turkey bought 262 M42A1 Duster discarded from the US Army.

The largest user of the M42 Duster in the Middle East was Jordan , which purchased 222 units, of which 216 were combat-ready; others were used for training, or. as a source of spare parts. They were discarded at the beginning of the 21st century. Another 15 M42 served in the Lebanese army. Some of these machines were captured by the Israelis. In addition, 18 M42 Duster served in Tunis . They were delivered in two groups: the first numbered 12 machines and the second six. Users in this area appreciated the simplicity of the device.

Detail of the interior of the originally Lebanese M42 tower captured by Israel

Another large van of the M42 Duster , comprising 295 machines, traveled to Taiwan . Here, after being phased out of the air defense, the dusters underwent interesting reconstructions.The original tower was replaced by a tower of M18 Hellcat fighters . The resulting light tank bore the designation "Type 64". In total, about 50 pieces were built and formed the armament of one tank battalion. Other users in the area were units of South Vietnam and Thailand.

M42A1 Duster in Taiwanese camouflage

Further east, the M42 in the number of 22 pieces came into service in Japan . He was armed with the 5th Division of the 7th Anti-Aircraft Regiment of the 7th Mechanized Division, stationed on the island of Hokkaido . Dusters remained in the armament of the division until 1994. A total of 123 pieces of M42 Duster received by Pakistan , which used them in the first decade of the 21st century.

Venezuela received 30 M42 and armed with army and marine units. In the 1980s, the M42s were phased out, but the military did not want to say goodbye to effective firepower. Part of the towers were mounted on the chassis of 2.5-ton M35 trucks. The resulting gun truck was named "Phoenix". In 1998, there was another relocation of the towers - this time on the chassis of the French light tanks AMX-13M51. The resulting vehicle was designated "AMX-13 / M42E1 Rafaga". It is estimated that around 12 machines have been rebuilt.

Venezuelan M35 Phoenix with tower from M42 Duster

As an anti-aircraft vehicle, the M42 Duster was practically obsolete at the time when it began to come into service. However, it has proven to be a means of firing support and destroying ground targets and repelling infantry attacks.

Photo: DoD archive, www.valka.cz , author

Published with the kind permission of the author.
Published in Military revue 3/2015 by Naše Vojsko