M103 Heavy Tank

The M103, the Heavy Tank variant of the M48 series, was designed to counter to the Soviet's JS III heavy tanks, which outclassed all other US tanks during the immediate period following World War II. At nearly 65 tons, it was by far the heaviest tank placed in service by the US Army prior to the advent of the M1 Abrams. When the M103 was introduced, it completed the Army’s “Family” of tanks which included the M41 light tank, M47 Medium tank, M48 medium tank and the M103 Heavy tank.

The T43 design represented the pinnacle of U.S. Army tank engineering of the late 1940s. The heavy tank proved fairly popular with its crews, who above all respected the powerful armament it carried. The outbreak of war in Korea brought a rush order in December 1950 which led to a complete production run of 300 vehicles. After 1951, the Marine Corps alone retained confidence in the heavy tank program, investing its scarce funds in the improvements necessary to bring about its fielding after a hurried production run in midst of the 'tank crisis' of the year 1950-51.

The IS-3 heavy tank was first seen by the Western Powers during the Sept. 7, 1945, Allied victory parade when 52 of the new tanks rumbled through Berlin. The IS-3s belonged to 71st Guard Heavy Tank Regiment of 2nd Guards Tank Army. This new Soviet tank clearly came as a significant surprise to American and British leaders. A photograph taken during the parade highlighting a very concerned GEN Dwight D. Eisenhower may have been an indicator of things to come. The IS-3 was a game-changer. The Soviets had developed a tank that was far more advanced than anything in the American and British arsenals. The message was loud and clear: the new Soviet IS-3 represented the first volley in the “action-reaction” tank-development cycle that became a defining characteristic of the Cold War. The reaction caused by the appearance of the IS-3 was significant, pushing the Americans and British to develop their own heavy tanks as quickly as possible to counter this new threat. The resulting heavy tanks were the American M103 and the British Conqueror.

The strong family resemblance to the M48 was based on the components common to both vehicles. The suspension was similar to that of the M48, though modified to carry the increased weight. The M103 had one additional road wheel on each side, though unlike the M48 most of the M103's torsion arms had shock absorbers. Six return rollers were fitted, and the final-drives had much larger exposed gear-boxes.

While the M103 hull was similar in shape to the M48, it was longer and wider, and had thicker armor with better ballistic shape in the forward hull. The engine deck was unlike that of the M48. The turret was totally different, with a large bustle to enable the 120mm gun to recoil. The ballistic shape was excellent from the front, but poor from the rear. The machine gun mount was used to allow the gun to be trained, elevated, and fired from within the vehicle.

This massive vehicle is armed with a M58 fully rifled 120mm cannon which is the same bore diameter as the contemporary M1A2. The difference is that the M256 cannon on the M1A2 is a smooth bore and much more powerful. The gun barrel pretty much equals the length of a telephone pole. Weighing in at 65 tons, this vehicle represents the largest armored casting ever to enter into American tank production.

One of the peculiarities of the M58 is that it used separate charge and projectile ammunition, as on naval artillery guns . On the other hand, the charges were not bagged, but in a brass cartridge , which was safer in case of fire. There were two magazines in the turret, one placed to the right of the gun took care of the projectiles and the other to the left of the propellant cartridges. The charges were stored individually in double-walled tubes while the projectiles were placed in single tubes equipped with a spring-loaded expulsion system. The tank’s massive four-man turret accomodated two loaders, one gunner and one tank commander. The fifth man drove the tank and was located in the forward hull. Two loaders were required because the tank’s ammunition was loaded in two part (propellant and projectile) and had 68 storage locations dedicated to the two part munitions. The tank commander sat in a small caged-in area directly behind the main gun and operated a very large stereoscopic rangefinder which provided critical ranging data to the gunner.

The new heavy tank was not well received by American tankers. Indeed, the M103 turned out to be full of faults, such as an engine / transmission assembly whose reliability did not exceed 800 kilometers, or an insufficient ammunition endowment of 33 rounds. In addition, its 810 horsepower Continental AV-1790 gasoline engine with a maximum torque of 2169 N m at 2200 rpm struggled to move its 56 tons, whose range was limited to 130 kilometers and the speed to 33. km / h . The M103A1 differed slightly from the M103, having improved fire-control devices that resulted in minor changes in the turret shape. The M103A2 was the Heavy Tank variant of the M60 series. It had the large bulged rear engine deck, typical of the diesel engined M48 and M60. It saw service, with a few being around into the 1970's.

Today such armor technology is obsolete. The modern M1A2 tanks weigh about the same as the M103 but the newer Armor of the Abrams represents a quantum leap forward in crew protection and survivability. The eventual retirement of the M103 in 1972, over 20 years after manufacture and after 14 years of operational service, demonstrated the soundness of its engineering. It may have been the unwanted 'ugly duckling' of the Army, which refrained from naming the M103 alone of all its postwar tanks. For the Marine Corps, it served the purpose defined for it in 1949 until the automotive and weapons technology of the United States could produce viable alternatives.

M103 heavy tank
Service	1957-1963 (U.S. Army)	1957-1974 (U.S. Marines)
Production
Designer	Chrysler Corp
Builder	Detroit Arsenal Tank Plant & Red River Army Depot
Production	300	208 vehicles were reequipped
Modifications	T43E1 - tanks produced in 1951-1954. M103 - tanks after being adopted for service, modernization and standardization in 1956 (the ammunition load for the gun was 35 shells). M103A1 (T43E2) - 219 tanks, modernized in 1958-1959. It features an increased (up to 38 shots) ammunition load and an improved fire control system. M103A1E1 (M103A2) - 159 tanks, upgraded in 1964. Differs in the installation of the diesel engine AVDS-1790 "Continental", respectively, the modernized power train, aluminum fuel tanks of increased capacity and some suspension elements of the M60 tank. As a result, the tank's cruising range was increased to 480 km, and the maximum speed was up to 37 km / h. As practice has shown, the maximum speed was almost impossible to achieve,
Main Features
Crew	5 (driver, gunner, tank commander and 2 loaders)
Length	11.32 m (6.99 m without the barrel)
Width	3,76 m
Height	2.88 m (3.55 m with the commander cupola)
Mass in battle	M103 : 56,6 t	M103A2 : 58,05 t
Armor (thickness / inclination)
Type	12 to 178 mm steel
hull forehead	100 - 130 mm steel
hull side	76 mm steel
turret front	180 mm steel
turret side	76 mm steel
gun mask	250 mm steel
Armament
Main armament	1 120 mm M58 gun (33 rounds in the M103, 38 from the M103A1)
Secondary armament	1 machine gun heavy M2 HB of 12.7 mm, 1 machine gun M57 or M1919A4E1 of 7.62mm
Mobility
Engine	M103 & M103A1 : Continental AV-1790-5B, 7, 7B ou 7C à essence	M103A2 : Continental AVDS-1790-2A diesel
Power	M103 & M103A1 : 810 ch (595 kW) at 2800 tr / min	M103A2 : 750 ch (551 kW) at 2400 tr / min
Transmission	M103 & M103A1 : Allison-General Motors CD-850-4A ou 4B Cross-drive
Allison-General Motors CD-850-6 ou 6A Cross-drive
Suspension	torsion bar
Road speed	M103 : 34 km / h on the road	M103A2 : 37 km / h on the road
Specific power	~ 12 hp / ton
Autonomy	M103 : 130 km	M103A2 : 480 km

The experimental T57 heavy tank, developed in the United States in the mid-1950s, is a slightly modified T43 tank. On October 12, 1951, it was decided to create experimental heavy tanks with the main armament in the so-called "swinging" turret and with an automated loading system. The idea of ??a "swinging" turret was borrowed by American engineers in France, where by this time similar turrets were already installed on the AMX-13 and AMX-50 tanks. The new American tank, designated T57 (in American post-war terminology - "120-mm cannon tank T57"), was to be based on the chassis of the T43 tank and at the same time have a "swinging" turret with a 120-mm gun on heavy outer trunnions. The hull of the T57 was borrowed almost unchanged from the M103, but the turret ... The tank was equipped with an oscillating turret - a type of tank turret, in which the gun is fixedly mounted in the upper half of the turret, swinging on trunnions relative to the rotary lower half. Such a turret has a number of specific advantages and disadvantages over traditional turrets. The main advantage of the swinging turret over the turrets of the traditional scheme is the immobility of the upper part of the turret relative to the gun, which makes it possible to use the simplest loading mechanism in it. The turret consisted of two cast parts, hinged together. The lower one rested on a roller shoulder strap and provided horizontal guidance of the weapon, as in traditional designs, but the upper part, which was actually a turret and contained weapons, jobs for three crew members and part of the ammunition was performed swinging on a horizontal transverse axis, to ensure vertical guidance. The automatic loader was located in the massive rear of the turret and consisted of a feeder and a drum for 8 unitary rounds, which was under the bolt of the gun. The drum, driven by a hydraulic rammer, could be loaded with three types of ammunition, the choice of which was carried out by the gunner or tank commander. The shell casings were thrown out through a special hatch on the turret roof. For loading, the projectile was first removed from the store back and up, into the rammer tray, then the tray was brought into the loading position, coaxial with the barrel bore, and sent the projectile into the breech. The magazine, rammer and gun swayed together, so it was not required to move the barrel to a certain position and the loading process did not depend on the vertical guidance angle. The gun was a 120 mm T123E1 rifled gun, but modified to use unitary rounds. It was unusual to have a rigid mount for a gun of such a large caliber in the turret, without any recoil devices. Therefore, a hydraulic drive was used to open the shutter, which was automatically triggered after the shot. The role of the loader was to replenish the magazine from the stowage in the hull, which contained an additional 10 rounds, thus providing an ammunition load of 18 pieces. In the opinion of the American military, this was clearly not enough. A 7.62 mm machine gun (left) was paired with the gun, and a telescopic sight was located on the right. The large size of the moving part in the oscillating turret created a number of problems. One of them was the additional area, and, accordingly, the mass of the armor required to provide protection at any elevation angles of the gun, compared to the turrets of the traditional design, where this role is played by a relatively small gun mantlet. The turret aft niche, swinging along with the gun, also limited the maximum elevation angle of the gun, resting on the roof of the rear of the hull. In addition, the relatively large gap between the top and bottom of the turret made it difficult to seal it to overcome deep fords or to protect against weapons of mass destruction, which became an important requirement for tanks in many countries in the 1950s and 1960s. An equally serious drawback over time was the extreme difficulty of stabilizing the gun in the vertical plane, The location of the crew's seats in the turret is standard for American tanks - the gunner is to the right of the gun, the tank commander is behind him and the loader is to the left of the gun. Above the commander's seat is a small turret with six T36 prismatic observation devices and a turret for a 12.7 mm anti-aircraft machine gun. The second hatch is for the loader. Both hatches were mounted on a large slab that formed the middle of the turret roof, which could be opened with a hydraulic lift to facilitate access to the turret mechanisms. The driver's workplace remained unchanged. Taking into account the innovativeness of the T57 project, work progressed slowly, and by the time two turrets were ready (one of them was installed on the T43E1 chassis), interest in the project had cooled. Although the construction of prototypes had begun by the mid-1950s, all work on them was stopped in 1957, even before the completion of prototype assembly. After the negative results shown by the completed prototypes of medium tanks on tests, the military's interest in the concept of a swinging turret dropped significantly. A shift in priorities in favor of developing small, air-transportable tanks led to the cancellation of the project in January 1957, before the prototype reached operational status and could be tested. Not a single photograph of the assembled T57 prototype has survived. Combat weight, t: 54.4 Crew, pers .: 4 Overall dimensions, mm: length 6992 length with a cannon forward 11412 width 3632 height 2654 ground clearance 457 Armor, mm: hull forehead 127 hull side 51 turret forehead 127 turret side 137 Armament: 120 mm T179 cannon, one 7.62 mm M1919A4E1 machine gun, one 12.7 mm M2HB anti-aircraft machine gun Ammunition: 18 shots 3425 7.62 mm cartridges 3000 12.7 mm cartridges Engine:carburetor, "Continental" AV-1790-5C power 810 hp Speed ??on the highway, km / h: 35.2 In store on the highway, km: 128 https://en.topwar.ru/6486-kak-vymirali-dinozavry-poslednie-tyazhelye-tanki-chast-6.html http://catainium.blogspot.com/2016/01/t110-heavy-tank.html https://thearmoredpatrol.com/2015/07/04/chrysler-t110-heavy-tank/ the M103 Heavy Tank, the Americans were still not satisfied with its performance on the battlefield. Thus, it was decided to recreate it again with 2 methods – evolutionary and revolutionary ones. The former was an attempt to improve its performance by mounting an autoloader system, eventually resulting in the development of the T57 (120 mm) and T58 (155 mm, also a derivative from the T30 Heavy Tank). And the latter was an attempt to create the tank from scratch. The T110 series’ history began in June 1954, when Detroit Arsenal had a conference concerning the further development of heavy tanks. The conference presented several options for development, including projects named TS-2, TS-5, TS-6 and TS-31. The TS Tank Concepts were supposed to achieve the most optimum design of a heavy tank, which was planned to bring them to the prototype stage within 2 years. The first basis on this matter was the TS-31, originally built as a combat vehicle armed with the 120 mm T123E1 gun, and it didn’t have a fully rotating turret. The TS-31 idea was picked up by Chrysler Corporation to unfold the production of the M103 Heavy Tank. As a result, Chrysler Corporation and Detroit Arsenal cooperated to develop a new heavy tank, and it received the index “T110 Heavy Tank”. It should be noted that the US Heavy Tank designation was very conditional at the time, because the original T110 looked like this: It’s fairly recognizable with (Seb: looking like) one of the US experimental super-heavy tanks known as T28/T95. The basic design specifications that were required by the US Army were to enable the vehicle to cross an railway-sized tunnel such as Berne Tunnel. It was intended to use a 700 HP Continental AOI-1490 engine, combined with a XTG-500 transmission system. The engine would be placed in the rear section of the tank, while the transmission system was placed in the frontal section of the tank. The armor scheme was rather arbitrary, but the maximum thickness value was as high as 9? (228.6 mm) from the gun mantlet. The initial project was slightly updated. As the width of the current tank hull was still too big to fit in a tunnel, especially concerning its cupola position, they offered another change by repositioning the cupola to the center, thus making the commander to sit on the top of the motor bulkhead and experience the running 700 HP engine, and also positioning the driver to operate the tank with the other crew members in a single interior section. After a very short time, they changed the design again. This time, the driver position was returned to its initial place again, but the commander position was very, very unconventional and cramped. The rear section of the tank was made smaller, to accommodate more space for the engine compartment. As such, the concept didn’t last for long either. Due to very cramped space of the commander area, it had been repositioned again to the far right side of the tank. At the same time the engine was turned by 90 degrees, putting it lengthwise. As a result, its rear section became “higher”. After the lengthy development of failed projects, the tank engineers were tired of developing the tank while maintaining the original T110 design, so they decided to act in a more radical way. By ignoring the length limit, they lengthened the hull, shifting the rear transmission system from directly below the engine to the rearmost section of the tank while making a standard engine compartment. The tank interior was also changed radically, at the same time returning back the whole crew positions in a single section again. It’s believed that this tank is the fourth variant of the T110 Heavy Tank series, designated as T110E4 (which is erroneously called T110E3 in World of Tanks). Even though by considering the number of the illustration, it’s at least the fifth variant of the T110. It’s the fourth variant of the T110 because the original T110 isn’t counted, as nearly every US Tank, with their respective initial variants, they didn’t receive any number indexes, such as M48, M60, and M103 (all initial variants, not the base or “one-for-all” designation) ). Instead, in World of Tanks, the original 120 mm T123E1 gun mount is replaced by the 155 mm T7E2, a completely unhistorical gun, and an “improvement” from the 155 mm T7E1 which was mounted on the T30E1 Heavy Tank. Surprisingly, at the same time, Detroit Arsenal planned to make another M103 variant armed with an 155 mm gun mount, even more so with an autoloader system (T58 Heavy Tank). In addition, there was another T110E4 variant with a separated superstructure from the hull, which is resembling the in-game T110E4, but without a 180° rotary turret: The T110E4 layout scheme (It was clearly seen that the separation of the hull and turret virtually turned it into a non-rotating turret): As you can see, the gunner had his own seating area located directly behind the gun mount while traversing: At some point, one of the Chrysler’s engineers had a perfect concept for a T110 “Heavy Tank”. It was designated as T110E5: The finished concept was very similar with the M103 Heavy Tank, but more technically sophisticated, and of course protected better. The mock-up models (which looked very different than the current T110E5 available in World of Tanks): The T110E5 layout scheme: As a result, it was decided to launch the concept of the T110E5, but there was some little trouble. In February 1956, the T110E5 was cancelled, as the test site was already attended by the T43E2 Heavy Tank for trials, which was later put into service as the M103A1 Heavy Tank. Although it was not as perfect as the T110E5, it was already classified as suitable for the US Army and ready for production. Name: T110 Type: Heavy Tank Origin: United States Year: 1954 Produced: 0 Crew: 5 Length: 5.5 Meters Width: 2.9 Meters Height: 2.8 Meters Weight: ??? Speed: ??? Primary Armament: -120 mm T123E1 Secondary Armament: -what appears to be a machine gun of unknown caliber Armor: -unknown 2. Name: T110E1 Type: Heavy Tank Origin: United States Year: 1954 Produced: 0 Crew: 5 Length: 5.5 Meters Width: 2.9 Meters Height: 2.8 Meters Weight: ??? Speed: ??? Primary Armament: -120 mm T123E1 Secondary Armament: -what appears to be a machine gun of unknown caliber Armor: -unknown 3. Name: T110E2 Type: Heavy Tank Origin: United States Year: 1954 Produced: 0 Crew: 5 Length: 5.7 Meters Width: 2.9 Meters Height: 2.8 Meters Weight: ??? Speed: ??? Primary Armament: -120 mm T123E1 Secondary Armament: -what appears to be a machine gun of unknown caliber Armor: -unknown 4. Name: T110E3 Type: Heavy Tank Origin: United States Year: 1954 Produced: 0 Crew: 5 Length: 6.0 Meters Width: 2.9 Meters Height: 2.8 Meters Weight: ??? Speed: ??? Primary Armament: -120 mm T123E1 Secondary Armament: -what appears to be a machine gun of unknown caliber Armor: -unknown 5. Name: T110E4 Type: Heavy Tank Origin: United States Year: 1954 Produced: 0 Crew: 5 Length: 6.5 Meters Width: 2.9 Meters Height: 3.1 Meters Weight: ??? Speed: ??? Primary Armament: -120 mm T123E1 Secondary Armament: -7.62 mm MG -12.7 mm MG Gun Flexibility: 20° Elevation 10° Depression 15° Left 15° Right Armor: -Hull 127 mm Front -Upper Structure 127 mm Front (229 mm Gun Shield) 6. Name: T110E5 Type: Heavy Tank Origin: United States Year: 1954 Produced: 0 Crew: 4 Length: 4.3 Meters Width: 3.1 Meters Height: 2.6 Meters Weight: ??? Speed: ??? Primary Armament: -120 mm T123E1 Secondary Armament: -what appears to be a machine gun of unknown caliber Armor: -unknown