The M42 40 mm Self-Propelled Anti-Aircraft Gun, or "Duster", is an armored light air-defense gun built for the United States Army from 1952 until December 1959. 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 December 1959 with 3700 examples made during its production run. The vehicle has a crew of six and weighs 22.500 kg (49.500 lb) fully loaded. Maximum speed is 72 km/h (45 mph) with a range of about 160 kilometres (100 miles). Armament consists of fully automatic twin 40 mm M2A1 Bofors, with a rate of fire of 2x120 rounds per minute (rpm) and either a .30 caliber Browning M1919A4 or 7.62mm M60 machine gun. The 500 hp, six-cylinder, Continental (or Lycoming Engines), air-cooled, gasoline engine is located in the rear of the vehicle. It was driven by a cross-drive, 2-speed Allison transmission. Although the M42 Duster was initially designed for an anti-aircraft role,
it proved highly successful when used in the Vietnam War against unarmored ground forces.
The Heeresgeschichtliches Museum (HGM) is a military history museum located in Vienna, Austria. It claims to be the oldest and largest purpose-built military history museum in the world. Its collection includes one of the world's largest collections of bronze cannons and focuses on Austrian military history from the 16th century to 1945. The museum is located in Vienna's Arsenal, in the Landstraße district, not far from the Belvedere palace.