The M47 was another addition to the long line of main battle tanks stemming from the World War 2-era M26 Pershing "heavy tank". The Pershing, later downgraded to a medium tank, was bettered in the upcoming interim M46 Patton which became the first such tank to take on the "Patton" name - this after fabled American World War 2 General George S. Patton. The all-new M47 fell in line next only to be superseded by the much-improved M48 Patton just a short time later. The line eventually culminated in the capable M60 Patton main battle tank series of the 1960s.
With that said, the M47 was a further development of the M46 Patton, which itself was a development of the wartime M26 Pershing (externally, the entire tank family line shared many similarities in their design). Classified as a medium tank, the M47 formed the backbone of US Army and NATO forces during those critical early years of the Cold War with its escalating arms race and limited conflicts. Intended to replace both the M4 Sherman and M46 Patton classes, the M47 graduated to become the long arm of NATO for decades to follow and was ultimately produced in 8,676 examples and fielded by some 21 nations across the globe - primarily throughout Europe, Asia and the Middle East. While charged to replace the M46, the M47 itself was quickly replaced in US service by the improved M48 beginning in the mid-1950s. However, it is of note that the M47 represented America's first true "all new" tank system developed since the days of World War 2.
The T42 and the Korean War
By the time of the Korean War in 1950, the mainstay force of the post-World War 2 US Army were the M26 Pershing and the M46 Patton tanks. The M46 itself was an interim solution meant to improve upon the drawbacks of the M26 - mainly in its underpowered engine (basically the same as found on the lighter M4 Sherman) and limited mobility. While the M46 fitted a better engine and improved reliability, it was still seen as nothing more than an interim solution for an all-new medium tank design was then in the works to known as the "T42". The T42 showcased a shapely, single-piece, molded turret and five double-wheeled medium-size road wheels to a track side fitted to a wide body hull. However, the ongoing war across the Korean Peninsula brought about the need for a quicker main battle tank solution without those inherent delays as found in a "ground-up" tank design program like the T42.
The M47 is Born
As a result, the turret developed for the T42 was mated to the existing (and proven) M46 chassis with the main armament of the M36 90mm being the gun of choice. The design went under the pilot (prototype) designation of "M46E1" of which only one example was constructed. The new tank then became known under the production designation of M47 (though it was theoretically the "Patton II", the M47 was never officially reported as such). The M47 underwent production at the Detroit Tank Arsenal and American Locomotive Company beginning in June of 1951 almost immediately. Despite this expediency, the 50-ton M47 would arrive too late to see combat actions in the Korean War - the very war that brought about the tank's construction - for the armistice between the North and South was drawn up in 1953. American service units were taking on delivery of the M47 beginning in the summer of 1952. However, delays in receiving the M12 optical rangefinders for the 90mm main guns played a role in the tank missing the war. In fact, M47s were not delivered to the region until August of 1958 - these replacing the M46s stationed there.
M47 armor was all-cast for both the turret and hull with a transverse bulkhead separating the crew from the engine. The crew was made up of five personnel that included the driver and assistant driver (bow gunner) in the forward hull and the tank commander, gunner and loader in the turret. The bow gunner and driver were allowed entry/exit via a pair of top-mounted hatches along the forward hull while the turret featured a further two hatches for the turret crew therein. The oblong turret, with its pointed front end and overhanging rear, was set in the forward portion of the hull and featured full 360-degree rotation with -5 to + 19 traverse for the 90mm main gun. Each track side was characterized by six double-wheeled road wheels and three track return rollers. Suspension was of the torsion bar variety.
Armament centered around the 90mm M36 series main gun of which 71 x 90mm projectiles were allotted. Secondary armament included a .50 caliber heavy Browning M2 air-cooled machine gun for anti-aircraft defense on a pintle mount along the turret roof and manned by the tank commander. This was further complimented by a co-axially mounted .30 caliber M1919A4 machine gun (controlled by the gunner) and an additional .30 caliber M1919A4 machine gun in a bow-mount for anti-infantry defense (the latter was later removed to make space for additional 90mm projectiles, therefore making the M47 the last American tank to feature the bow-mounted machine gun and its extra crew position).
Power and Performance
Power was derived from a Continental AVDS-1790-5B V-12 air-cooled, twin-carbureted gasoline engine delivering up to 800 horsepower. The engine was mated to an Allison/General Motors CD-850-4 transmission allowing for two modes of forward travel and one mode of reverse travel. Performance specifications included a top speed of 30 miles per hour and an approximate range of 81 miles. Gradient traverse was limited to 60 percent and vertical obstacle crossing at 3 feet. Trench crossing was limited at 8 feet, 6 inches while onboard fuel capacity was a reported 232 gallons.
The M47 Lives on Through Export
The Military Assistance Program (MAP) of the Cold War ensured that the tank lived a hearty existence within the ranks of NATO allies throughout the 1950s. Once in foreign service, the type would survive well into the 21st Century thanks to special locally-introduced modernization programs - some introducing diesel engines and all-new transmission systems or proposed 105mm main gun armament. West Germany and Turkey were quantitative users of note, each receiving some reported 1,120 and 1,347 examples respectively. The Turkish examples were themselves made up of former American and West German M47 models no longer of value.
Combat Ultimately Finds the M47
Though missing out in American actions of the Korean War, the M47 was nonetheless fielded by other export nations in anger. The Pakistani Army unleashed the M47 on India in the Indo-Pak War of 1965 while Jordan used the type in the 1967 Six Day War with Israel. Iran used the M47 against Iraq in their cross-border war. In 1974, some 200 Turkish M47s were used in the invasion of the island of Cyprus. More recently, Croatian M47s were used against Serb forces in the Croatian War of Independence but did not fare well against the more-capable Soviet-produced T-55 main battle tanks. After all was said and done, the M47 became the only Patton-named tank in American service to never see direct combat actions for the United States.
Limited Production Equals Limited Variants
Despite the M47's "newness" at the time of inception, the system led a relatively short service life with the United States military for the excellent and all-new M48 tank design came online to quickly replace the type. Beyond the M46E1 pilot model, the Patton II was revealed in two major production forms. "M47" was used to note the base series designation and was essentially a re-turreted M46 with a revised hull and three track return rollers per track side (down from five). The tank was later improved in the "M47M" model of the 1960s which fitted the fire control system and engine of the M60A1 Patton main battle tank and deleted the bow-mounted machine gun position. None of these newer "M" models were utilized by the US Army, which had already moved on to other more capable main battle tank products by this time. The M6 became an M47 fitted with a bulldozer kit for battlefield excavation. The T66 was a proposed flamethrower tank but never placed into production.
The USMC and the M47
Beyond use of the tank in the US Army, the US Marine Corps operated the M47 for a time before these too were soon replaced by the M48A1 main battle tanks and M103 heavy tanks. USMC M47s were removed from service in 1959.