U.S. M56 90mm Self-Propelled Gun Scorpion

U.S. M56 90mm Self-Propelled Gun Scorpion. . The M56 Scorpion was developed to provide American Airborne forces with a mobile, self-propelled, anti-tank gun that could be transported by helicopter or dropped by parachute. A total of 325 Scorpions were manufactured from 1953 to 1959 by the Cadillac Motor Car Division of General Motors of Cleveland. The vehicle was fielded with the 82nd and 101st Airborne Divisions. It went on to see combat service during the Vietnam War with the 173rd Airborne Brigade. With a crew of four (commander, gunner, loader and driver), the M56 was a fully tracked vehicle with rubber-tired, run-flat road wheels. The M56 was given a pneumatic tire arrangement that further served to lighten its combat weight. One of the drawbacks of the M56 design was that the crew sat completely exposed to the elements and critically exposed to battlefield dangers. The commander sat on top of the radio, and the loader's seat was on top of the right fender stowage box, leaving the gunner and driver as the only crewmen "in" the vehicle. The only protection was a forward fragmentation shield. During firing, the front of the vehicle would kick up violently usually obscuring the Scorpion in a cloud of dust., Caliber - 3.5 in. - 90 mm , Weight - 15,750 lbs. - 7,144 kg , Range - 1,640 yds. - 1,500 m , Shell Weight - 42 lbs. - 19 kg , Muzzle Velocity - 2,700 ft/sec. - 823 m/sec. , Elevation (-10 to + 15 degrees) - (-178 to +267 mils) , Traverse - 60 degrees - 1067 mils , Rate of Fire - 20 rpm , Maximum Speed - 28 mph - 45 kph , Cruising Range - 140 miles - 230 km , Engine - Continental AOI-402-5, 6-cylinder, 4 cycle, opposed, fuel injected gasoline, 200 hp, Allison CD-150-4 Transmission , CCN# 105453