M48 Patton
The M48 Patton is an American first-generation main battle tank introduced in February 1952, being designated as the 90mm Gun M48, armored, full-tracked, combat vehicle of the medium-gun tank class. It was designed as a replacement for the, M4 Sherman, M46 and M47 Patton tanks, and was the main battle tank of the and U.S. Marine Corps in the Vietnam War. Nearly 12,000 M48s were built, mainly by Chrysler and American Locomotive Company, from 1952 to 1961. The M48 Patton was the first U.S. medium gun tank with a four-man crew, featuring a centerline driver's compartment and no bow machine gunner. As with nearly all new armored vehicles it had a wide variety of suspension systems, cupola styles, power packs, fenders and other details among individual tanks.
The early designs, up to the M48A2C, were powered by a gasoline engine. The M48A3 and A5 versions used a diesel engine. However, gasoline engine versions were still in use in the US Army National Guard through 1968 and by many West German Army units through 1975. Numerous examples of the M48 saw combat in various Arab–Israeli conflicts and the Vietnam War. Beginning in 1959, most American M48A1s and M48A2s were upgraded to the M48A3 model.
The M48 Patton-series saw widespread service with the United States and NATO until it was superseded by the M60 tank. It was widely exported. The tank's hull also became the basis for a wide variety of experimental, utility and support vehicles such as armored recovery vehicles and bridge layers. Some M48A5 models served into the mid-1980s with US Army National Guard units, and M48A3s were used as targets for weapons and radar testing into the mid-1990s.
Many M48s remain in service in countries other than the US. Most of these have been modified and their firepower, mobility and protection upgraded to increase their combat effectiveness on the modern battlefield. Turkey is the largest operator with over 750 units in service, Taiwan is second with approximately 500 upgraded variants, and Greece is third with 390 in service.
History
After the conclusion of World War II, the United States Ordnance Tank-Automotive Command drastically slowed or canceled many tank development and design programs. On 7 November 1950, the Ordnance Technical Committee mandated a change in the nomenclature for tanks in the US military. It was decided that weight designations were no longer applicable due to changes in the way tanks were developed and employed on the battlefield, and the varying calibers of main guns now available. Thus the caliber of the gun replaced its weight designation. For example, the M103 Heavy Tank was redesignated as the 120 mm Gun Tank M103 and the Light Tank M41 Walker Bulldog as the 76 mm Gun Tank M41 Walker Bulldog.The M47 Patton entered production in 1951 and was used by the United States Army and Marine Corps but ongoing technical and production problems kept it from serving in the Korean War. This forced the US to field older tank models, such as the M26 Pershing and M46 Patton. In response, the Army launched several design projects for a replacement of the M46 and M26. The United States entered a period of frenzied activity during the crisis atmosphere of the Korean War, when the U.S. seemed to lag behind the Soviet Union in terms of tank quality and quantity.
Testing and development cycles occurred simultaneously with production to ensure speedy delivery of new tanks. Such rapid production caused problems but the importance given to rapidly equipping combat units with new tanks precluded detailed testing and evaluation prior to its quantity production. Notable among these were the T42, T69 and T48 projects as well as continuing to pursue further improvements to the M47.
Compromise was inevitable, but not always welcomed, as General Bruce C. Clarke ironically observed: "We know exactly what we want. We want a fast, highly mobile, fully armored, lightweight vehicle. It must be able to swim, cross any terrain, and climb 30 degree hills. It must be air-transportable. It must have a simple but powerful engine, requiring little or no maintenance. The operating range should be several hundred miles. We would also like it to be invisible".
T48 project
The T48 project was to focus on improving the turret of the M47 Patton and upgrading performance with a more powerful yet more efficient gasoline engine. and scale design mockups of the turret were constructed during May 1950 using the T119 90mm main gun of the M47 Patton. The design study was accepted by the Army in December and a contract for the advanced production design and engineering of a 90mm armed tank was awarded to the Chrysler Defense.Hull redesign included moving the driver's station to the front center and removal of the bow-mounted machine gun and its associated crew station, which was converted to safe container storage for additional main gun ammunition. The front glacis was sloped to offer much better ballistic protection than former welded and rather flat designs. An aircraft style steering wheel replaced lever steering. The power pack consisted of the Continental AV-1790-5B gasoline engine producing 704 brake horsepower coupled to an Allison CD-850-4A cross-drive transmission with 2 forward and 1 reverse ranges. The hull armor was increased to on the front glacis of rolled homogeneous steel. It had six roadwheel pairs per side and five return rollers, a torsion bar suspension system, and used T97E2 steel tracks. A new hemisphere-shaped turret eliminated the M47s noted shot traps and lowered the vehicle's height.
T48 pilot #1 was constructed by Chrysler Engineering to begin testing at the OTAC Detroit Arsenal Test Center in December 1951. Six prototypes were built in all.
On 27 February 1951, shortly after the outbreak of the Korean War, the Ordnance Technical Committee Minutes #33791 initiated the simultaneous production and design refinement of the new tank, designating the production tanks as the 90mm Gun Tank M48. The Army planned to produce some 9,000 M48s within three years of development. Chrysler Corporation became the principal producer of the tank. Expected production and teething troubles led to the creation of integrating committees to coordinate tank and component development. These Army Combat Vehicle committees included military and industrial representatives who provided early warning of defects and recommended remedies.
Testing trials of the T48 tanks began in February 1952 and continued until the end of 1955. However, the perceived immediate threat of Soviet aggression in Western Europe and the ongoing Korean War impelled Army senior leadership to rush the T48 tank into series production before the inevitable bugs could be worked out of the new tank design. Instead, it was decided that any needed design changes uncovered by the continued testing and evaluation of the T48 tanks at the OTAC Detroit Arsenal Test Center would be incorporated into the M48 series production vehicles as quickly as possible.
T48 pilot #1 was designed and constructed by Chrysler Engineering to begin the APE design development at the OTAC Detroit Arsenal Test Center in December 1951. This tank was provisionally armed with the M36/T119 gun using a Y-shaped deflector and a muzzle brake. This gun was not used for production M48 tanks. It used the Mod A hull and turret designs with smaller diameter crew hatches. The driver's hatch incorporated a mechanism that dropped his three periscope heads to provide clearance for the hatch door as it swung to the right, and the driver then had to reposition the periscopes by hand once the hatch was closed again. It had 5 return rollers, 6 roadwheel pairs per side with the drive sprocket at the rear and a torsion bar suspension system.
Pilot #2 was built in February 1952 and also used the early Mod A design with small hatches. It was fitted with the T139/M41 90mm gun replacing the muzzle brake with a cylindrical blast deflector. A T-shaped deflector was used for production M48 tanks. This vehicle had two machine guns installed, a.30cal M1919E4 mounted coaxially to the left of the main gun and a.50cal M2HB mounted on the commander's cupola. The full image stereoscopic T46E1/M12 rangefinder was placed in the central section of the turret.
Pilot #3 was constructed in November 1952 and used the Mod B hull and turret designs with a simplified, larger diameter hatch that was easier for the driver to operate. Also the front vision block was removable and allowed for the future use of IR vision blocks by the driver. It also had 5 return rollers, 6 roadwheel pairs per side with the drive sprocket at the rear and a torsion bar suspension system. The Mod B turret also had larger hatches for the commander and loader. An additional three hulls were constructed in 1953. These tanks were used into 1955 for the component development of the M48A2 production tanks including fire control systems, turret cupolas, suspension configurations and powerpacks. At least one of these hulls was fitted with experimental silica glass composite armor panels.
Components
Armor
In conjunction with the development of the T48 project there was some discussion regarding armor. The weight of conventional armored steel needed to provide protection against the emerging large-caliber high-velocity main guns and improved APDS kinetic energy penetrators was making its continued use impractical. Composite applique armor panels made with fused silica glass was envisioned to be fitted to the hull. It was also desired that a turret be constructed using this special armor. The OTAC and Carnegie Institute of Technology began development of the armor in November 1952 at Fort Belvoir VA as Project TT2-782/51. This composite armor offered protection against HEAT, HESH, and HE rounds. Its overall slow development limited its use to the T48 and was dropped from consideration in the M48 by 1953, however its development was continued with the T95 Medium Tank until 1958.There were two different hulls used for the M48 series. The M48 hull had a wedge-shaped front glacis compared to the M46's rather flat design. Early Mod A hulls had smaller diameter driver's hatches. The suspension consisted of six roadwheel pairs per side with a torsion bar suspension system and five return rollers. The engine exhaust vents were located on the top of the rear deck. There was a dual compensating idler arm at the front, and dual auxiliary track tension wheels behind the last road wheels, using the T97E2 track assembly. The drive sprocket was located at the rear of the hull. Shock absorbers were mounted at the first two and last roadwheel arms. This hull design was manufactured for the original M48 and M48A1 versions of the M48 series. Many Mod B hull designs used for the M48A1 were further upgraded to the A2 hull design standard but retained their original 5 return roller configuration.
The M48A2 hull design saw several modifications including a reduction from five to three return rollers per side. The suspension system was simplified, a more compact powerpack compartment and additional fuel cells, with large louvered grill access doors replaced the complicated grill work of the rear engine decks of the M48/M48A1 hull designs. This hull was used on newly constructed M48A2 and M48A3 tanks of the M48 series.
The turret used for the M48 series was hemispherical in shape and was made from cast homogeneous steel. It had a flat gun shield and a standard pop-up styled hatch for the commander and an additional hatch for the loader's station. Early production Mod A models of the turret had somewhat smaller diameter hatches. The gunner was provided with an M37.30 cal machine gun with 5,900 rounds of ammunition.