M-42 "Duster"
40 mm Self-Propelled Anti-Aircraft Gun

The M-42 weapon served with the Delaware National Guard from 1962-1970. The M-42
“Duster”, is a full-tracked, self propelled turret-mounted dual 40mm automatic M2A1
Bofors guns augmented with an air cooled 30 caliber machine gun.  

Early in 1966, a number of Army Guard enlisted specialists volunteered for six months
service as instructors at Fort Bliss, Texas, when the Army found it lacked men capable of
training new personnel on the intricacies of the M-42 "Duster". In this select force were
seven Delaware units - the five batteries of the First Battalion, 198th Artillery, the 116
MASH, and the 1049th Transportation Company, comprising about one-third of the
Delaware Army Guard strength.

The M42 40 mm Self-Propelled Anti-Aircraft Gun, or "Duster" as it is known, is an armored
light air-defense gun built for the U.S. Army from 1952 until December 1959. Production of
this vehicle was performed by the tank division of the General Motors Corporation. It used
components from the M41 light tank and was constructed of all welded steel. The 500 hp,
six cylinder, air-cooled, gasoline engine is located in the rear of the vehicle. A total of 3,700
M42s were built. The vehicle has a crew of six and weighs 22,500 kg (49,500 lb) fully loaded.
Maximum speed is 45 mph with a range of 100 miles. Armament consists of fully automatic
twin 40 mm M2A1 Bofors, with a rate of fire of 240 rounds per minute (rpm) and either a .
30 cal. Browning M1919A4 or M-60 Machine Gun.

Although the M42 Duster was initially designed in the anti-aircraft role, it found great
success when used in the Vietnam War against unarmored ground forces.

Development

During the course of the Korean War, the U.S. Army decided to phase out all vehicles based
on the M24 Chaffee chassis, such as the M19 Gun Motor Carriage 40mm Anti-Aircraft, in
favor of designs that utilized the chassis of the M41. Since the 40mm guns were still seen as
an effective anti-aircraft weapon, the turret of the M19 was simply mounted to the M41
chassis with few changes except a partial redesign to accommodate the larger turret ring of
the M41 and designated as the M42. Initially, the 40mm guns were aimed with the
assistance of a radar fire control system housed in a secondary vehicle of similar design, but
this idea was scrapped as development costs mounted.

Service history

Production of the M42 began in early 1952 at GM's Cleveland Tank Plant. It entered service
in 1953 and replaced a variety of different anti-aircraft systems in armored divisions. In
1956, the M42 received a new engine and other upgrades along with other M41 based
vehicles, becoming the M42A1. Production was halted in Dec. 1959 with 3700 examples
made during its production run. Sometime in the late 50s, the U.S. Army reached the
conclusion that anti-aircraft guns were no longer viable in the jet age and began fielding a
self propelled version of the HAWK SAM instead. Accordingly, the M42 was retired from
front line service and passed to the National Guard with the last M42s leaving the regular
Army by 1963, except for the 4th BN (Hawk-AW) 517th artillery in the Panama Canal
Zone, which operated two batteries of M-42s into the 1970s (http://www.517thartillery.org)

Vietnam War

Unfortunately, the HAWK missile system performed poorly in low altitude defense. To
ensure some low altitude anti-aircraft capability for the ever increasing amount of forces
fielded in Vietnam, the Army began recalling M42A1s back into active service and
organizing them into air defense artillery (ADA) battalions. Three M42A1 equipped ADA
battalions were sent to Vietnam, the first arriving in late 1966.

Despite a few early air kills, the air threat posed by North Vietnam never materialized, and
ADA crews found themselves increasingly involved in ground support missions. Most
often the M42 was on point security, convoy escort or perimeter defense. The "Duster" (as it
was called by U.S. troops in Vietnam) was soon found to excel in ground support. The
rapid firing 40mm guns could devastate massed infantry attacks or sweep away guerrillas
hiding in the jungle, with equal ease.

Post Vietnam

M42 used by German Bundeswehr
The last M42A1 equipped ADA units left Vietnam in 1972 and the Duster was returned to
the National Guard. The U.S. Army maintained multiple National Guard M42 battalions as
a corps level ADA asset until the system was retired in 1988.

Operators

United States of America: US Army, US National Guard
Germany
Greece: Hellenic Army, from surplus German stocks.
Japan: Japan Ground Self Defense Force
Lebanon: 15 M42A1 Dusters in service with the Lebanese Army (1958-1984), passed on to
the Army of Free Lebanon, Lebanese Arab Army, Tigers Militia, Guardians of the Cedars,
Kataeb Regulatory Forces, Lebanese Forces
Taiwan: Republic of China Army, Republic of China Marine Corps
Thailand: Royal Thai Army
Turkey: Will be replaced by a new FNSS 2x35mm ACV
Jordan
Venezuela: Venezuelan Army, retired from service in 1989, AMX-13/M41E1 Ráfaga since 1998
Pakistan: Pakistan Army, 123 In Service.[citation needed]

Variants

M42A1: received the AOSI-895-5 engine (500 hp).
Type 64: Taiwanese light tank variant produced by combining turrets of decommissioned
M18 tank destroyers with surplus M42 hulls. Compartments over the track guards for
spare Bofors gun barrels were replaced with storage boxes of the stock M41 tank. One
battalion worth (50+) of conversions were made.
AMX-13/M41E1 Ráfaga : Venezuelan Self-propelled AA gun variant produced by combining
turrets of decommissioned M-42A1 Dusters towers (M41E1) with surplus AMX-13M51
hulls. With improvements in fire control for night operations and on original chassis. One
AA-Battery +/-10 of conversions were made).
Delaware Military History