In the late forties, work began in the United States on artillery systems of special power capable of using shells with a nuclear warhead. The first example of this kind to come to service was the M65 cannon. The gun, nicknamed the Atomic Annie, was not built in a large series, but it took a special place in the history of American artillery.
In the interests of the army
The first prerequisites for the emergence of American nuclear artillery took place at the final stage of World War II. Faced with German railroad artillery, American forces wished to have their own weapons with similar characteristics. At the end of 1944, the development of a promising long-range 240mm T1 gun began.
In 1947, the air force was separated from the army into a separate branch of the army, as a result of which the ground forces were left without their own nuclear weapons. After lengthy disputes in 1949, it was decided to start developing special ammunition for ground artillery and guns for them. In May 1950, the T131 project was launched, providing for the creation of a new 280-mm transportable gun using the T1 developments. In parallel, the creation of a special ammunition was carried out.
The development of the T131 gun was carried out in the Picatinny arsenal with the participation of several other organizations. When designing, the specialists had to solve a number of specific design problems, and some of their proposals were of great interest. For example, a part from T1 was taken as the basis for the T131 barrel. The existing 240mm barrel had a sufficient margin of safety and could be drilled out to a larger caliber.
The 280 mm gun needed a special gun carriage and specific means of transportation. This task was solved with the help of two standard tractors of a special design. With their help, the gun could move between positions. Deployment took less than half an hour. The means of transporting the guns were borrowed from the finished project with serious modifications.
The design process of the T131 coincided in time with the outbreak of the Korean War, which was the reason for the acceleration of work. The technical project was completed at the end of 1950, and just a few months later the first prototype of the gun appeared. Then the tests started.
Operation of serial guns began in the first half of the fifties, but they officially entered service only in 1956. The gun was assigned the official army index M65. There was also the nickname Atomic Annie ("Atomic Annie") - an allusion to the name Anzio Annie, coined by the Americans for the German high-power K5 guns.
Artillery complex
In fact, within the framework of the T131 / M65 project, a whole artillery complex was created, which included all the necessary devices and systems - from guns and ammunition to transportation and communication systems. The complex also includes separate vehicles for the calculation and ammunition.
The T131 / M65 gun was a 280 mm rifled gun. The barrel was 38.5 ft (11.7 m) long. The breech was equipped with a piston breech that was retracted downward. The barrel was fixed on a swinging part with developed hydropneumatic recoil devices. With the help of a hydraulic drive, vertical guidance was carried out in the range from 0 ° to + 55 °. The barrel could move on its mounts along its axis. For transportation, it was lowered to a horizontal position, after which it was retracted, shifting relative to the mountings. After that, the barrel did not protrude beyond the gun carriage.
The swinging part with the gun was fixed on a special carriage of the T72 type. It was made in the form of a solid frame with developed side walls, between which the swinging part was suspended. Under the attachment point of the gun was a base plate with a diameter of approx. 3 m. A smaller slab was located at the other end of the carriage. The main support had an axis on which the carriage rotated for horizontal guidance within a 15 ° wide sector.
The T72 was equipped with its own power plant, which ensured the operation of the drives. The hydraulics were responsible for aiming in two planes and for feeding the shot components into the barrel. There were also backup manual drives. A characteristic feature of the T72 gun carriage was the presence of additional buffers that extinguished the remnants of the recoil impulse.
The carriage with the gun was transported using a pair of special tractors developed by the Kenworth Truck Company. The M249 and M250 machines, using special restraints, had to pick up and lift the T72 product. At the same time, a structure with two joints was formed, having sufficient mobility, maneuverability and maneuverability.
The "leading" M249 was a front cab tractor with a 375 hp engine. and a 4x4 wheel arrangement. The M250 "closing" machine had the same composition of units, but differed in the rear cab, in front of which was placed a fork for lifting the carriage.
Before firing, the M65 complex had to arrive at a position, after which the T72 carriage was lowered to the ground, the tractors retreated, and the gun was transferred to a firing position. To leave the position, it was necessary to lay the barrel and hang out the carriage between the tractors.
The total length of the "Atomic Annie" in the stowed position reached 26 m, in the combat position - less than 12 m. Height during transportation - no more than 3, 7 m. The total mass of the complex reached 83, 3 tons, of which 47 tons was a gun carriage. The maximum speed of the complex on the highway is 45 miles per hour (over 70 km / h).
Shells for M65
The task of the promising weapon was to destroy important enemy targets at operational-tactical depth using conventional and nuclear shells. For the M65, only one conventional ammunition was intended - the high-explosive T122. This product weighed 272 kg and carried 55 kg of explosives. The initial velocity of the projectile reached 760 m / s, the maximum firing range was 28.7 km.
In the early fifties, the first American artillery shell with a nuclear warhead was created - the W9. The 280-mm product had a length of 1.38 m and weighed 364 kg. In the body of the projectile was placed a nuclear device of a cannon scheme with 50 kg of enriched uranium. The calculated explosion power was 15 kt TE. The projectile accelerated in the barrel up to 630 m / s and could fly 20-24 km.
In 1955, the W19 projectile appeared, which was an upgrade of the previous W9. It was slightly longer, but weighed 270 kg and carried a charge of similar power. By reducing the mass, the initial speed was increased to 720 m / s, and the range was increased to 28 km.
Cannons in service
Testing of individual components of the M65 system began in 1950-51. In the spring of 1951, a full-fledged artillery complex, built as part of the cooperation of several organizations, was sent to the training ground in Nevada. For some time, the tests consisted of checking the components of the system, and firing was carried out only with practical and high-explosive shells.
On January 20, 1953, the T131 gun was first shown to the public. It took part in the parade marking the inauguration of President Dwight D. Eisenhower. The new weapon has expectedly attracted attention both in the United States and abroad. The published data about him became an additional incentive for foreign projects of atomic artillery.
In May of the same year, one of the M65 cannons was involved in the Upshot – Knothole nuclear tests. On May 25, a test detonation with the Grable code took place - "Atomic Annie" sent a real W9 projectile to a conditional target at a distance of 11 km. This was the first and last case of the use of a special power weapon with a nuclear projectile in American practice.
By this time, the serial production of guns was launched. In just a few months, only 20 artillery complexes were built at a cost of $ 800,000 each (about $ 7.6 million in current prices). The built guns were distributed among several artillery units of the ground forces.
In October 1953, the M65 cannons appeared in Europe. They arrived in Germany as part of the armaments of the American 868th Field Artillery Battalion. Soon, guns of special power went to South Korea. At that time, nuclear artillery was seen both as a real tool for use in war and as a means of demonstrating strength and intentions.
End of service
Already in the mid-fifties, barreled artillery began to lag behind modern and promising missile systems in terms of its characteristics. High-powered weapons such as the M65 did not have much promise and had to leave the scene in the near future.
In the case of atomic artillery, it was not only about tactical and technical characteristics. The military-political consequences of the presence of such weapons, as well as issues of prestige, were of great importance. For this reason, the army was in no hurry to abandon the Atomic Annie, even when obsolescence became apparent.
The M65 was withdrawn from service only in 1963. By this time, the army received new, more advanced models of tactical nuclear weapons, showing obvious advantages over the cannon. Advances in technology have made it possible to create new nuclear missiles of smaller calibers, compatible with existing weapons. As a result, "Atomic Annie" became the first and last cannon, originally created for special ammunition.
After decommissioning, the fate of the M65 guns evolved in different ways. More than half of the items were melted down. Seven guns have been preserved in museums. Some of them are shown only with a gun carriage, but several complete complexes with standard tractors have survived. Of greatest interest is the cannon from the Fort Sill base museum. It was she who, in 1953, participated in the Grable tests and fired a single shot with a real nuclear projectile.
The M65 cannon occupies a special place in the history of US artillery. It was the result of the only attempt to create a specialized weapon for a nuclear projectile. The resulting product had limited prospects and quickly became outdated. For this reason, the concept of a separate atomic weapon of special power was abandoned. It turned out to be much more profitable to introduce special shells of smaller calibers into the ammunition load of other guns and self-propelled guns.
