AFAP (Artillery Fired Atomic Projectile)

The preferred employment options of the principal NATO Allies as a precursor of preferred TNF force structuring held four requirements to be essential to the employment of the TNF. They were early resort to tactical nuclear weapons to counter massive conventional attack. Nuclear weapons should not be used for purely political or psychological reasons without striking at meaningful military targets; they opposed demonstration use. An in-theater capability to strike non-Soviet Warsaw Pact territory and , if necessary , the Soviet Union itself. Nuclear weapons should be used in such a way as to minimize collateral damage.

NATO’s theater force should be postured so that Russian planners are assured that NATO was capable of responding to a first or subsequent use of nuclear weapons in such a manner that they would be forced to choose between a negotiated withdrawal or escalation to a strategic nuclear exchange. Confronted by such forces, Soviet planners who might miscalculate NATO’s capability for conventional defense could not ignore the prospect of conventional conflict escalating to the nuclear level.

Artillery’s favored position as that nuclear delivery system which best met NATO’s tactical needs was reaffirmed by Secretary Schlesinger: "Artillery’s high accuracy, low yield, rapid responsiveness and ease of control by local commanders should provide for effective attacks against targets in proximity to friendly troops. Because of its inherent limitations in range, etc. use of nuclear artillery in limited nuclear conflict probably has less chance of resulting in escalation to theater-wide nuclear war than longer range SSMs or tactical aircraft.

Lending credence to that view is the inherent survivability of artillery. Their existence in large numbers throughout the battle area makes it virtually impossible for an adversary to disarm the nuclear capability. Indeed, every battery becomes a nuclear delivery unit capable of launching a tactical nuclear strike with impressive responsiveness if nuclear projectiles are available. Therefore, it was logical to conclude that the mainstay of the American TNF force ought to be cannon artillery.

The nuclear war would be fought by the Corps Commander who would plan corps packages designed to decisively terminate the battle and would employ those packages, upon receipt of release authority, to defeat the total tactical threat facing the Corps. The authority to approve uses of nuclear weapons will be retained by the NCA.

But tactical nuclear weapons employment doctrine appeared contradictory and inadequate. Doctrine directed that nuclear weapons be employed selectively and with restraint, yet doctrine similarly notes that “the number of weapons in a corps package will usually be 100 to 200 depending on the threat, the mission, the terrain, and population characteristics.” The employment of a hundred or more weapons in a short pulse hardly augured a Warsaw Pact perception of NATO restraint except in the very broadest sense that the strike is something less than theater-wide war or strategic exchange.

In 1939, J. Robert Oppenheimer had first proposed a uranium hydride nuclear fission bomb to utilize the deuterium hydrogen isotope in a U235 metal-deuterium compound. The design used uranium-hydride 235, which featured the absorption of low-velocity neutrons by uranium, providing a lower critical mass. But the hydrogen slows the process, possibly to impermissibly long periods of time. Weapon efficiency is adversely affected by the slowing of the neutrons, since it gives the bomb core more time to blow apart. The nuclear fission chain reaction would be the result of slow (thermal energy) neutron fission, with a predicted energy yield of 1,000 tons TNT equivalent.

After the war Edward Teller remained interested in the development of the uranium hydride bomb. Ruth and Ray were both uranium hydride experimental devices designed by Edward Teller and Ernest Lawrence at UCRL, later the Lawrence Livermore National Laboratory (LLNL). Ruth was the first device fielded by UCRL and was detonated 31 March 1953; Ray was detonated 11 April 1953. Both yielded an energy of explosion equivalent to 200 tons of TNT.

Lawrence Livermore National Laboratory was less than a year old when the first nuclear-explosive device designed entirely by Livermore scientists was fired at Mercury, Nevada. RUTH, the Laboratory's first nuclear test, explored a new design for fission devices that offered hope for smaller, more efficient bombs and provided information about certain thermonuclear reactions. The experiment exemplified Livermore's commitment to be a "new ideas" laboratory. RUTH was fired on March 31, 1953-just six months after Livermore opened.

The device, Hydride I, weighed 7400 lb, was 56 inches in diameter and was 66 inches long. It was installed on a 300-ft tower, and Laboratory researchers stood back at the outlying observation station with their dark glasses on waiting for the device to go off. When it was fired, all that was visible was a small speck of light on the horizon - no mushroom cloud. Normally during a test, the detonation is seen about a minute before the sound reaches the observation station, and there is an announcement over the loudspeaker system warning to brace for the shock. According to Wally Decker, a young Laboratory engineer involved in his first field test, the shot went "pop." The predicted yield was 1.5 to 3 kt, while the 200 ton yield was a fraction of that. As the dust cleared, dismayed engineers and scientists peered through their field glasses and saw the tower was still standing. As Decker walked away he passed a guard who asked in all innocence, "When is the sound going to get here?"

While Livermore researchers were trying to find out what went wrong with the shot, Los Alamos personnel were busy taking a picture of the barely damaged tower. The Los Alamos contingency kidded Livermore about the shot, and even about the shipping boxes, which were painted a bright silver instead of the military olive drab that Los Alamos used.

A few months later the Laboratory prepared for another event with a slightly different design, and chose a 100-foot tower instead of a 300-foot one. Like Ruth, Livermore's second hydride test, Ray, on April 11, 1953, also fizzled. The explosion, however, at least managed to level the bomb's 100-tower. The tower had an open platform and the device was set up on a blustery day around Easter during rain, snow, and a dust storm. To protect the device from the weather, a large canvas tarpaulin was used to cover it. The device was fired with the same dismal results. The guard at the site commented, "Gee, you shouldn'tve put that canvas over it."

The research led to the Laboratory's first weapon-development assignments, including the W48 155-mm howitzer atomic projectile and other tactical nuclear weapon systems.

The problem of shells of the "cannon" scheme was their low relative efficiency and high cost, caused by the use of expensive enriched uranium in them. Nevertheless, more effective and cheap plutonium bombs on the implosion scheme for a long time could not be made compact enough to be placed in the gun barrel. Only in the 1960s, with the development of linear implosion technologies, it became possible to create an artillery shell based on implosion - the W48 under a standard caliber of 155 millimeters. In view of the small TNT equivalent (no more than 70-100 tons), the main striking factor of this projectile was a powerful neutron flux. More than 1,000 such shells were in service until 1992.

With the improvement of rocket weapons, the development of artillery nuclear systems in the US Army was pushed to the background. In the late 1960s, two new types of projectiles were developed - the W-74 for the 155-mm caliber and the W-75 for the 203-mm caliber - but in 1971 their development was canceled. These projectiles were to become neutron munitions with a TNT equivalent of about 100 tons.

The last nuclear projectile of the US Army was the W79 , developed in 1976. Created under the caliber of 203 millimeters, this projectile used a deuterium-tritium mixture to increase the power of the nuclear reaction and was produced in two modifications; Mod 0 had a controlled capacity from 100 tons and up to 1.1 kilotons, and Mod 1 had a fixed capacity of 0.8 kilotons. There was also an optional injection function for an additional deuterium boost, which increased the yield of neutrons and turned the munition into a neutron weapon. More than 550 shells of this type were in service until 1992. The planned development of a similarly designed projectile W-82 for the 155-mm caliber was suspended several times and was canceled in 1990.

The US Navy in the early 1950's adopted the 406-mm nuclear projectile W23 . According to the design, this projectile was a version of the army 280 mm W19 shell, placed in a larger body. The projectile was intended for use from the Iowa type battleships, the magazines of which were converted for the storage of nuclear munitions. However, onboard battleships, these shells never used, and in 1962 were written off. The Navy did not show much interest in nuclear artillery, believing that missile weapons - including anti-aircraft missiles with nuclear warheads, used by all US missile cruisers - would be more effective if tactical nuclear strikes were required.

AR 50-102 Army safety rules for the 155 required two-person access AT ALL TIMES. The tech manual REQUIRED minimum exposure to the round itself. That meant the crew member did their task and stepped back 3 feet. As long as the task could be seen by the 2nd individual, example setting the timer (e.g. assuring correct procedures were being performed, another safety rule), then the 2nd person could stand at the 3 foot mark. Obviously this was easy with the 155, not so when ones hands had to go inside a weapon, then a closer look was required by both individuals. An example where two individuals were always used was when the projectile was raised to a vertical position in the M467 container, the thing was rather heavy even if only 119.5 lbs.

In 1992, the US Army withdrew its nuclear artillery ammunition. At present, there are no plans for such development, although potentially modern nuclear technologies allow the creation of much more compact and effective artillery nuclear munitions than in the 20th century.