Staff Writer (Updated: 6/23/2015):
One offshoot of the original M24 light tank family became the "M19 Gun Motor Carriage" self-propelled, anti-aircraft platform mounting a pair of 40mm Bofors cannons in an open-topped traversing turret. While the M24 chassis it was built upon was no longer a viable solution to the revamping American Army, the turret system and its 40mm guns were still an effective short-ranged deterrent against low-flying enemy aircraft. As such, the decision was made to simply relocate the existing M19 turrets and their applicable arms to the newer all-welded steel hulls of the M41 Walker Bulldog light tanks - in effect creating an updated anti-aircraft weapon system and the new designation of "M42".
The M42 was powered by a single 6-cylinder air-cooled gasoline fueled engine with 500 horsepower output. Primary armament was the aforementioned pair of 40mm M2A1 Bofors anti-aircraft cannons with a single 7.62mm M1919A4 general purpose machine gun (or later, the M60 GPMG) fitted as secondary. The cannons would initially be tied to a radar-guided fire control system but this option was eventually dropped in lieu of ballooning project costs. Each cannon maintained a hefty rate-of-fire of 240 rounds per minute with a fully automatic firing action. As the M42 was based on the M41 light tank chassis, she reflected much of the latter's qualities including the torsion bar suspension, a well-sloped glacis plate and five road wheels per track side. Operational range for the M42 was listed at approximately 100 miles with a top speed nearing 45 miles per hour. Operational weight was in the vicinity of 49,500lbs. A standard operating crew would be between four and six personnel to include the driver and gunnery specialists.
The M42 entered production in 1952 out of the Cleveland Tank Plant of General Motors and entered service the following year. Production continued on through 1959 to which some 3,700 vehicles were delivered to the US Army and others. As missile technology advanced ever further in the burgeoning jet age, it became a common viewpoint that self-propelled anti-aircraft guns such as the M42 had already seen their best days. As such, the type was subsequently removed from active frontline service within time beginning in 1963, replaced by more modern advanced missile-minded systems such as the MIM-23 HAWK - a tracked surface-to-air, medium-range deterrent.