The M48 Patton is an American first generation main battle tank (MBT) introduced in February 1952, being designated as the 90mm Gun Tank: M48. It was designed as a replacement for the M26 Pershing, M4 Sherman variants and M46 Pattons used in the Korean War, and as the successor to the M47 Patton. Nearly 12,000 M48s were built, mainly by Chrysler and American Locomotive Company, from 1952 to 1961. The M48 underwent many design modifications and improvements during its production life. This led to a wide variety of suspension systems, cupola styles, power packs, fenders and other details among individual tanks.
The A3 model incorporated a diesel engine which greatly improved its cruising range. Because many M48A3 tanks were conversions from earlier models many details varied among individual examples of this type. M48A3 tanks could have either three or five support rollers on each side and might have either the early or later type headlight assemblies, some retained their earlier Mod A turrets and different cupola styles. During the Hungarian Revolution of 1956, a Soviet T-54A medium tank was driven onto the grounds of the UK's embassy in Budapest by the Hungarians. After a brief examination of this tank's armor and 100 mm gun by a British military attache, the UK decided that their 20 pounder (84mm L/66.7) was apparently incapable of defeating it. There were also rumors of an even larger 115 mm gun in the works. In response to this the US Army started development of the XM60 to replace the M48 tank series and incorporating the ARCOVE recommendation of a more powerful main gun, the 105mm T254. Instead of immediately getting a 105mm main gun, the M48A3 tanks were to retain their existing M41 90mm main guns due to funding shortfalls that made it impossible to supply enough 105mm main gun rounds for all the planned converted tanks. Secondly, there were still large stockpiles of 90 mm main gun rounds on hand.
The M48A3 was withdrawn from Europe by October 1961, being replaced with the M60 tank. As US armored and cavalry units rotated out of combat deployments to South Vietnam most of their M48A3 tanks were either directly transferred to the South Vietnamese Army or to Thailand. FORSCOM withdrew the M48A3 from combat service with both the US Army and US Marine Corps in 1973 replacing them with the M60A1 tank. Some M48A3s continued in service with National Guard units until 1979.