M48 Patton American Main Battle Tank (MBT)

The M48 Patton is an American first generation main battle tank (MBT) introduced in February 1951. 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 AlCo, 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 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 through 1975 by many West German Army units. Numerous examples of the M48 saw combat use in various Arab–Israeli conflicts and the Vietnam War. Beginning in 1959, most American M48A1s and A2s 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 The M48 Patton-series saw widespread service with the United States and NATO until it was superseded by the M60 tank as well as being widely exported. The tank's hull also developed a wide variety of prototypical, 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 were used as targets for weapons and radar testing into the mid-1990s. Many M48s remain in service in other countries though most of these have been highly modified and had their firepower, mobility and protection upgraded to increase their combat effectiveness on the modern battlefield. The Turkish Army has the largest number of modernized M48 MBTs, with more than 1,400 in its inventory. Of these, around 1,000 have been phased out, placed in storage, or modified as armoured recovery vehicles. Chrysler began building the new Newark Tank Plant in Newark, Delaware in 1951 to produce the M48 while Chrysler Defense Engineering and ARCOVE continued advanced production engineering (APE) to evolve the design using the T48 prototypes at the OTAC Detroit Arsenal. In May 1952 Chrysler came to an agreement to take control on a Government Owned and Contractor Operated (GOCO) basis of the Newark Tank plant production facility with the US Government and to continue production design refinement of the T48 at the OTAC Detroit Arsenal. The first Chrysler production tank was unveiled on 1 July 1952 as the 90mm Gun Tank M48 and christened the M48 Patton by Mrs. Beatrice Ayer Patton, wife of the late General George S Patton.[28] To meet the urgent need for tanks, production contracts were also awarded to General Motors and Ford Motor Company to produce the tank in Michigan starting in 1952. Also in July 1952 the Army awarded American Locomotive Company a $200 million contract to start producing the tank in 1953 at the Schenectady Tank Plant in New York. All four companies were given initial production contracts in that same year for around 400 tanks each. The M48 featured a gasoline-powered engine, different models were used depending on availability and manufacturer. Originally the M48(Mod A) was built at the Chrysler Defense using the Continental AV-1790-5B coupled to a General Motors CD-850-4A or 4B cross-drive transmission as used for the M47. The M48(Mod B) used a Continental AV-1790-5C gasoline engine and either an Allison CD-850-4A or 4B cross-drive transmission. Most of these were built by the American Locomotive Company. Additionally a two-cylinder, gasoline, air-cooled engine (sometimes referred to as the "Little Joe" by tank crews) was provided to power a 28 volt, 300 ampere generator when the main engine was not needed. Fuel capacity was 200 gallons providing a cruising range of about 70 miles (110 km). The suspension consisted of six roadwheel pairs with a torsion bar suspension system and five return rollers. 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 as were the previous M46 and M47 tanks. It had hydraulic shock absorbers mount on the first, second and sixth roadwheel pairs (opposite of the M46 and M47). The bow mounted machine gun and its related crew station was eliminated thus providing more ammunition storage for the main gun. The driver's station was moved to the front center of the hull. The steering controls were redesigned. A large aircraft-styled steering wheel (replacing the wobble stick control of the M46 and M47) and placing the transmission range selector on the floor to the driver's right. Mod A hulls had a small oval overhead hatch for the driver. It 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. The vehicle did not have an NBC protection system for the crew and a fording depth of approximately 1.2 meters. The M48's turret consisted of a redesigned flat gun shield and standard pop-up hatch for the commander's station. The M48 Mod A turret design had a smaller roof hatches for both the commander and loader. A .50cal M2HB using a M1 remote control mount on a pedestal was available for the commander. When not in use, the machine gun mount could be stowed on a bracket welded to the turret roof in front of the loader. The M48's direct fire control system consisted of an M12/T41 stereoscopic rangefinder with a field of view of 5 degrees and magnification of x7.5, an azimuth indicator, an M20 gunner's periscope and a T13 superelevation actuator. Two main bearings are bolted to the mounting plate on the roof of the tank turret to support the range finder on steel radial ball bearings. A parallel gun linkage between the gun trunnion and the range finder assures that the line of sight of the range finder reproduces the exact motion of the gun in elevation. A .30 caliber M1919E4 machine gun was coaxially mounted to the main gun's right and was operated by the gunner. An M12 full field optical range finder was used, the same as the M47. The tank was not fitted with any night fighting or computerized fire control systems. It featured the 90 mm T139 main gun using a Y-shaped muzzle brake on the barrel and carried 53 rounds. Eight ready rounds were stored in the left side of the turret bustle for the loader, the rest were stored inside safe containers in the hull. Tank crews complained that the Y-shaped fume extractor was found to be prone to snagging brush. It was replaced with a T-shaped model early in production. These early M48 tanks suffered from engine, transmission, track, and suspension problems. The M12 rangefinder was too fragile and often broke. Army Field Forces (AFF) found these tanks to be unsuitable for combat use in Europe and was regulated to limited use by US Army CONUS units until numerous shortcomings were corrected. Furthermore, some 120 hulls were found to have insufficient hull armor. These were denoted as the M48C and relegated to the United States Army Training and Doctrine Command (TRADOC) for non-ballistic training use by the Armor School at Fort Knox to train crewmembers and maintenance personnel.