Predecessor of the M48, and standard equipment in the armies of over 20 countries, the M47 Patton is a descendent of the M26 Pershing Tank. The M46 got a new turret, 90mm gun, and fire control system to become the second Patton tank, the M47. The 1948 M46 Pershing was a variant of the original M26 Pershing with a more powerful engine. Except for a few vehicles, all M45 tanks were converted to the M46 Patton model in 1949-51. No M45 were recorded in the US Army inventory by 01 July 1954.
The Pershing got a new name -- dubbed the Patton - in 1950. It was an obvious naming choice with GEN George S. Patton Jr., a Blackjack Pershing protégé, transformed by death into an icon. Patton died in a freak automobile accident in December 1945, at the age of 60. He was probably ready to go. He had achieved his fate, his destiny. He was famous, a hero. He had earned the recognition and applause he had sought. Subsequent models through the M60 would retain the Patton name.
Early evaluations of the M26 medium tank focused on the fact that the forty-six-ton M26 used essentially the same engine as the thirty-three-ton Sherman. The underpowered M26 suffered from mechanical reliability problems related to its engine deficiencies. Even during the Second World War, the issue of modernizing the serial M26 became acute. The troops complained about everything: low speed, poor maneuverability, and poor armor. Since there was neither time nor money for the development and production of a new tank, starting from 44, the M26 underwent many modifications designed to improve its characteristics. The case of the installation of additional armor plates cut off from the padded Panther is widely known. In parallel, full-fledged projects of heavy tanks based on the M26 were developed in the United States. In addition, various options for enhancing weapons were considered. But the main problem of the tank was a weak engine, which provided a specific power of 10.8 liters. s./t., which was clearly not enough for a 40 ton medium tank. But the war ended, and along with it, funding began to decline.
Design work to improve the power and reliability of the M26 began in January 1948. Designers married an improved power plant and transmission with the existing M26 chassis and turret to create the M46 variant of the Pershing tank. In May 1948, the prototype, designated M26E2, finally made it to military trials at the Aberdeen Proving Ground. The final prototype differed from the usual M26 by replacing the engine compartment covers with louvers (to improve cooling), installing a powder gas ejector, a muzzle brake and a new optical sight. In addition, the shape of the exhaust pipe and its location were changed, mufflers were added. There was also 1 roller to improve track tension and prevent them from dropping. In all other respects the M46 medium tank resembled the M26 medium tank.
The M46 Patton had a classic layout: the engine and transmission were located in the rear of the vehicle, the fighting compartment was in the middle, the control compartment was located in front, where the driver and his assistant were located (he was also the gunner from the course machine gun). In the control department, the units were located quite freely, which cannot be said about the engine compartment, which was packed so tightly that to flush the fuel filters, adjust the ignition system, service generators, change gasoline pumps and other components and assemblies, it was necessary to remove the entire power plant and transmission unit.
The M46 is very similar to its predecessor and serves as a prime example of what can happen when designers work under tough financial constraints. Having received, in comparison with the "Pershing", a more perfect chassis and a more powerful engine, "Patton" was not spared such "diseases" of its predecessor as poor mobility and extremely low autonomy. Contemporaries noted that the tank was difficult to climb. As for the power reserve, the powerful gasoline engine consumed fuel in excessive quantities, and the M46 could expect to travel on a full tank, according to various sources, from 120 to 145 kilometers. This was not enough for full participation in maneuvering operations. These problems were aggravated by the fact that the Patton had almost 44 tons of combat mass - not every bridge in Europe could withstand it. Finally, the overall dimensions of the tank exceeded both European and Soviet railway standards. However, here the overkill was not so significant, and in some cases it could be neglected. Those who were involved in logistics simply had to remember that the M46 loaded onto the railway platform would not "crawl" everywhere.
The gun, as in the case of the well-known German "Tiger", was a rework of the anti-aircraft gun. This was done quite often, because it was not rational to develop armament for a tank from scratch in war conditions if serial samples of anti-aircraft guns with sufficiently high characteristics were already at hand. An early version of the gun was on the M26 and M36, while on the Patton it was decided to install a gun modified by a powder gas ejector and a new muzzle brake. The gun has an ejection device blowing the barrel; Electro-hydraulic turret with manual drive; duplicated lifting mechanism of a screw-type gun; the gunner and tank commander have telescopic and periscopic sights; when shooting with a roll, the lateral correction is automatically entered into the telescopic sight. The turret, the front and aft of the hull are cast, of medium-hard armor.
The Patton cannon ammunition consisted of 70 unitary rounds, which were located in the fighting compartment below the level of the turret ring: 10 of them in the vertical stacking of the first stage on the left side of the turret, 3 each in clamp stowage on the sides of the hull, and the remaining 54 in boxes on the floor fighting compartment.
The armament and armor protection of the new American tank was also ambiguous. Its 90mm cannon was weaker than its British and Soviet counterparts. And if it was still effective against medium tanks of the final period of World War II, then with new models of armored vehicles of a potential enemy, Patton was already struggling. In particular, the frontal armor of the Soviet T-54 tank of the 1949 model was invulnerable to standard M46 armor-piercing projectiles, and pierced with subcaliber shells only from short distances and at an angle close to normal. In turn, the armor of the M46 could not protect it from Soviet shells of 100 mm caliber, and 85-mm shells, although they did not provide a reliable hit in the forehead, did an excellent job of penetrating the Patton's side and stern projection. In order not to delve into the jungle of numbers, let's just say: the only Soviet tank, for which the M46 was a deadly enemy is the T-34-85. To defeat heavier or more modern vehicles, "Patton" would have to work hard, finding a tactically advantageous position for firing on the sides and stern, or firing expensive sub-caliber shells.
The main armament was supplemented by two 7.62-mm machine guns, one of which was paired with a cannon, and the second was installed in the frontal armor plate. A 12.7 mm anti-aircraft machine gun was located on the roof of the tower. The gun ammunition consisted of unitary rounds, most of which were located on the bottom of the tank hull under the fighting compartment, and the rest were removed from the lower ammunition rack and placed on the left side of the turret and on the sides of the fighting compartment.
Thanks to the new AV-1790-5A engine with a capacity of 810 hp, the tank's mobility improved significantly, the army finally received a maneuverable medium tank not only on paper, but also in combat units. The engine is four-stroke, 12-cylinder, V-shaped, carburetor, air cooling; hydromechanical transmission with double power flow of the “Cross-drive” type; engine and transmission in a single unit; individual suspension, torsion bar, with hydraulic telescopic shock absorbers; caterpillars with rubber mount.
The engine weight was only 1058 kg. However, the 6.5-fold compression ratio, which was large for those times, required the use of 80 gasoline, and the use of air cooling caused frequent engine overheating. In connection with the alteration of the tank for the air vent, the roof of the engine compartment was also changed, which turned into one continuous grille.
The gearbox and the turning mechanism were controlled by one lever, which served both to shift gears and to turn the tank. The undercarriage of the M46 tank differed from the undercarriage of its predecessor M26 in that one additional small-diameter roller was installed on the M46 between the drive wheels and the rear road wheels to ensure the constant tension of the tracks and prevent them from dropping. In addition, second shock absorbers were installed on the front suspension nodes. The rest of the Patton a's chassis was similar to the M26's. Tank ?46 was adapted for operations in low temperature conditions and had special equipment for overcoming water obstacles. The chassis design had also undergone changes. As a result, the tank became heavier, but its speed remained the same.
The M46 had differential armor protection. The armored hull of the tank was assembled by welding from cast and rolled parts of homogeneous armor steel. The frontal part of the hull and the roof of the control compartment were a one-piece casting. The thickness of its upper part was 102 mm at an angle of inclination of 46 ° to the vertical, and the protrusion in the fan area was 140 mm at an angle of inclination of 25 °. At the bottom, the part was 76.2 mm thick with a 53 ° tilt. The turret ring and the upper part of the sides in the fighting compartment were also assembled from several cast parts, while the rest of the sides were assembled from rolled armor plates. The sides of the hull, both in the cast and rolled parts, had a thickness of 76.2 mm in the area of ??the control compartment and the fighting compartment and 50.8 mm in the area of ??the engine compartment.
The rear of the hull consisted of two rolled armor plates: a vertical upper one with a thickness of 50.8 mm and a lower one with a thickness of 20.32 mm and an inclination of 62°. The bottom of the hull had a trough-like shape along its entire length and was assembled of rolled sheets 25 mm thick under the control compartment and 12.7 mm under the engine compartment. The roof of the hull was 22 mm thick.
For embarkation and disembarkation, the driver and assistant driver had individual hatches in the roof of the control compartment, the commander and gunner had a common hatch in the commander's cupola, and the loader had an oval hatch in the turret roof. In addition, in the floor of the control compartment there was a hatch for emergency leaving the tank. A round hatch for firing personal weapons was located in the left side of the turret, which could also be used by the loader to eject spent cartridges. Access to the engine and transmission assemblies was through folding plates in the roof of the engine compartment and three round hatches in the upper rear plate; removal and installation of the engine was carried out with the roof of the engine compartment removed and the tower deployed along the side.
The one-piece M46 turret had a cylindrical shape with a slight taper, a developed aft niche and a lure all along the sides and stern. The frontal part of the tower had a reduced thickness of 101.6 mm, the sides and stern - 76.2 mm, with insignificant angles of inclination: 0 ... 5 ° for the left side, 5 ... 8 ° for the starboard and 0 ... 5 ° for the stern. The roof of the tower was 25.4 mm thick. The cast gun mantlet consisted of a fixed part bolted to the forehead of the turret and movable, cylindrical in shape and 4.5-inch (114.3 mm) thick.
The first combat experience was not long in coming, the M46 were sent to Korea. At the front, the situation in the tank units was extremely deplorable, the existing M24 and M26 showed themselves not in the best way. The M24 had a too weak cannon, and the M26 suffered from a lack of engine power and, as a result, poor mobility in the difficult Korean landscape. By the time the Korean War broke out 319 M26 tanks had been converted to M46 tanks. Conversion would continue throughout the war and US armored forces continued using both Pershing versions throughout the war. The new "General Patton" could not only effectively destroy any enemy tanks with its 90mm gun, but also support the infantry in the offensive in hard-to-reach sectors of the front.
Among the first armored units to be rushed to Korea to repel the North Korean offensive was the US Army's 6th Medium Tank Battalion. On August 7, the 6th battalion arrived in South Korean Busan and was attached directly to the 8th Army. In the battles for Gimcheon in September 1950, the 6th battalion lost 10 M46 tanks. With the subsequent retreat of US troops in late November and early December 1950, the 6th Battalion abandoned almost all of its tanks on the railroad near Pyongyang. At the initial stage of hostilities, the American-South Korean troops were rapidly retreating, many tanks were abandoned by their crews. One of them was even brought to the USSR for testing. Despite this, the M46 showed high efficiency in the fight against the North Korean T34-85 (12-19 destroyed units). A little later, the 64th Tank Battalion, attached to the 2nd Infantry Division on 13 August 1950, also arrived in Korea, armed with the M46.
By June 1951, maneuvering fighting had ceased, and the front line had stabilized. But even here "General Patton" showed high efficiency. A powerful high-explosive projectile made it possible to fight well-fortified enemy firing points, and the presence of an azimuth indicator on the tank helped to fire from closed positions. The tank was often used as mobile artillery. The Korean War was the only armed conflict in which the Pattons were involved.
By 1950 the M46 Patton was the standard tank for the US Army , but limited production meant that some armor units had either the obsolescent M4E8 Sherman or the limited standard M26 Pershing. With the advent of the new M47 and M48 tanks after the Korean War, Pattons began to be withdrawn from the regular army and sent to the reserve or transferred to the armament of the National Guard. A number of vehicles remained to serve as part of a contingent of American troops in South Korea. In 1957, the tank was declared obsolete and began to be removed from service. After that, it had limited use as a target and crew training machine.