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120mm Gun M1

1940 COLD WAR KOREAN WAR WORLD WAR 2

History of the 120mm M1 Gun

The emergence of aircraft as an effective tool of warfare in World War I resulted in the need for ground artillery to pursue and ultimately strike and destroy these enemy targets in the air. The U.S. Army began working on the weapon, but the end of the war marked a sharp slowdown in demand, and the program developed at a snail's pace until a new world war seemed almost inevitable when Hitler, Mussolini and Stalin landed in Europe . North Africa and Japanese conquest of Pacific territories.

The U.S. Army began its search for a modern anti-aircraft solution again in 1938, and the result was the "4.7-inch M1"a 120mm gun specifically designed to counter the newly discovered threat to the U.S.

Axis Air Forcethat is, The metal-clad monoplane was designed with greatly improved high-altitude capability and greater defensive maneuverability compared to the outdated wooden biplane designs of the previous World War.

The 120mm M1 gun, or "120mm" as most people call it (also known as "the Stratogun"), was the largest anti-aircraft gun built by the United States for the U.S. Army during World War II. It was first used in 1940, before the United States was formally involved in the conflict. Anti-aircraft guns are used to deter enemy aircraft from invading airspace by firing heavy explosive shells at predetermined altitudes. This defense was employed by all the major powers involved in WWII and proved as deadly to pilots as it was to enemy fighter jets.

The Germans' 88mm "FlaK" guns also had double success in anti-tank defense, and the "88s" excelled against enemy tank armor.

The M1 is traditionally mounted on a tractor, using eight large wheels placed in pairs at each corner of the chassis. These are necessary to support her massive shipping weight of 31 tons (62,000 pounds). The M1 barrel can be adjusted to fire vertically at targets up to 18,000 m (60,000 ft) and can fire at a rate of 10 rounds per minute with a trained crew. Experienced aircrews can fire up to 12 rounds per minute at the target, while battle-hardened crews can hit 15 rounds per minute.

The M1 used a 50-pound projectile with an internal fuze delay of 30 seconds. The weapons system requires 13 operators, consisting of an officer, weapons commander, an artillery sergeant, an ammunition sergeant (responsible for two ammunition operators), and seven other support personnel.

Typically, a combination of four 120mm M1 systems are deployed together to form a complete anti-aircraft battery and provide a protective net near critical installations.

For stability when firing powerful 120mm rounds, the M1 platform is designed with three hydraulically actuated "leg rests" with a base plate attached to each end. This three-point arrangement acts as a recoil damping system to counteract the enormous force required to fire a 120mm grenade against gravity.

These accessories can then be lifted and folded along the sides and front of the M1 system for easy transport. When the struts are fully lowered to the ground, the wheels are raised and out of contact with the ground, reducing the pressure on the pneumatic tires. Along the rear of the gun mount were two large folding platforms that provided the gunner with a "stage" from which to operate the gun's lift and roll system.

These platforms are supported by smaller hydraulically driven leg supports.

Accuracy in attacking incoming air targets has always been an issue with any ground fire system. Therefore, the SCR-268 (later SCR-584 series) microwave radar system was developed and incorporated to locate the position of enemy aircraft in the sky. The later SCR-584 itself became the primary antiaircraft gun positioning system for the U.S. Army's M1 series, and was so large due to the technology of the time that it required its own transporter and operator.

To illuminate enemy aircraft during the dark hours of the day, a powerful aerial searchlight was also assigned to an M1 artillery battalion. Since the radar system was detecting targets, the operator also needed a computer that could efficiently calculate and triangulate the gun firefighter's firing solution - which inevitably became the M10 auxiliary predictor, allowing targeting of moving aircraft. Associated with this predictor is the M4 Weapon Data Computer, which further assists the predictor by changing its recommendations based on the type of ammunition used and the total distance to the target.

Like the SCR-584 radar system, the M4 artillery data computer system is bulky, known as the size of a large vertical freezer. All in all, the Collective M1 kit is bulky and bulky, making mobility an issue throughout its lifespan.

The projectiles used in the M1 series come in two basic forms - fragmentation and high-explosive (HE). Shrapnel projectiles throw a barrage of metal blocks through the detonation zone, while HE projectiles, as the name suggests, simply detonate - both are designed to damage or completely destroy enemy aircraft and their crews. Since the inherent chance of direct contact with the enemy aircraft with the 120mm projectile is still small, the grenade is equipped with a time fuze to allow delayed detonation of the air blast despite accessories to improve accuracy. The grenade itself is not always accurate due to the different burning rates of the contained powder, especially due to changes in atmospheric pressure. Therefore, different fuses have been used to reduce this problem.

However, if the timer does not work as expected, unexploded shells can adversely affect friendly ground forces. Shooting vertically at a target can reach the stratosphere of the atmosphere, and the M1 was the only anti-aircraft gun in the war to exhibit this "range".

The limitation of this weapon is that muzzle velocity depends on the ammunition and shooting environment, so rain and winter conditions will have an effect. Having said that, the real ultimate limit to the M1's maximum range is its projectile's 30-second timed fuze.

Although the M1 120mm anti-aircraft gun was powerful and relatively accurate when paired with the best fire control computers of its time, its design had one notable major flaw. It turned out not to be very maneuverable, had to be towed by an M6 tractor and was limited to 20 mph on the road and 5 mph off-road.

As a result, the weapon proved unsuitable for tactical use during island hopping in the Pacific theater, while later in the war in the European theater, where mobility was a major advantage, the M1 system suffered. As a result, most of these weapons remained within the actual U.S. borders to protect the U.S. West Coast from an anticipated Japanese attack, which was never enacted. About 15 M1 guns were sent to the Panama Canal Zone, and several batteries were deployed in and around Allied London to protect British civilians from Hitler's V1 rocket retaliatory weapons. Despite its service in these active theaters, the M1 never fired on enemy aircraft throughout the war.

In 1944, the name "4.7" M1 gave way to the now more accepted standard and recognizable naming convention "120mm Gun M1".

After World War II, these guns were brought back into service during the upcoming Korean War (1950-1953) as the Communist North invaded the Democratic South. These M1s were fairly successful in their role, but with the advent of jet-powered mounts like the MiG-15 and F-86 Saber, the era of low-flying, piston-powered aircraft was coming to an end. This makes artillery-based air defense systems like the M1 obsolete in terms of actual air defense.

In response to the new Soviet air threat, a large number of anti-aircraft missiles for air-to-air operations and ground-based-to-air batteries were quickly developed. Like the anti-aircraft guns before them, these missile launch systems can be deployed together to form a cyber defense mechanism against any incoming air threat, be it bombers or fighter jets.

Not surprisingly, the Soviet Union - and all other world powers at the time - were followed by similar missile-based developments.

Only 550 examples of the 120mm M1 gun were made in total.