W33 (nuclear warhead)
The W33 was an American nuclear artillery shell, fired from an eight-inch M110 howitzer and M115 howitzer. A total of 2,000 W33 projectiles were produced, the first of, manufactured in 1957; the W33 remained in service until 1992. The warhead used enriched uranium as its nuclear fissile material and could be used in two different yield configurations; this required the assembly and insertion of different pits, with the amount of fissile materials used controlling whether the destructive yield was low or high. The highest-yield version of the W33 may have been a boosted fission weapon. Information regarding the W33 has suggested that it was either a double gun and/or that it may have used an annular barrel assembly; the device's internal mechanism was code-named Fleegle. A double gun mechanism reduces the required velocity of each projectile by half, which reduces the gun system weight by a factor of 8. An annular bore. Titanium was used to reduce weight of some components. Judging by the remaining photographic evidence, it is that the exterior casing of the artillery shell itself was made of titanium.
This is logical, given that the copper-alloy driving band around the base of the shell is the only part of the shell which engages with the rifling on the artillery piece's barrel. The W33 mechanism has been reported to have comprised two critical nuclear parts which were required to assemble a complete W33 warhead; the initial disassembly of stockpiled W33 warheads in 1992 proceeded first by disassembling all existing parts for one of the components, disassembling the other one in following years. The W33 is the third known model of gun-type fission weapons to have been detonated as a test; the W33 was tested twice, first in Operation Plumbbob Laplace, on September 8, 1957, the TX-33Y2 in Operation Nougat Aardvark on May 12, 1962, with a yield of 40 kilotons. Neither test involved firing a W33 from an actual howitzer. Laplace Plumbob was test fired with the device hanging from a balloon at an altitude of 750 feet. Nougat Aardvark was test fired underground, at a depth of 1,424 feet. Prior gun-type detonations were the Little Boy Mark-1 nuclear weapon used on Hiroshima in World War II, a test firing of the W9 11-inch nuclear artillery shell in test shot Upshot-Knothole Grable on May 25, 1953.
List of nuclear weapons W79 Allbombs.html list of all US nuclear weapons models at nuclearweaponarchive.org Historical nuclear weapons list at GlobalSecurity.org
W25 (nuclear warhead)
The W25 was a small nuclear warhead developed by the United States Air Force and Los Alamos Scientific Laboratory for air-defense use. It was a fission bomb with a nominal yield of 1.5 kt. Development of the weapon began in 1954 at the behest of Douglas Aircraft for use against enemy bombers; the W25 was used for the MB-1 "Ding Dong", an unguided air-to-air rocket used by the Northrop F-89 Scorpion, F-101B, F-106 interceptor aircraft. The MB-1 entered service in 1957, was redesignated the AIR-2 Genie; the only non-U. S. User was Canada, whose CF-101 Voodoos carried Genies until 1984 via a dual-key nuclear sharing arrangement. Limited numbers were still used for Air National Guard F-106 aircraft until December 1984; the W25 is 17.4 inches in 26.6 inches long, with a reported weight of 218-221 pounds. The W25 was described as a composite pit and the first US sealed pit design. A sealed pit means that a solid metal barrier is formed around the pit or nuclear material components inside a nuclear weapon, with no openings.
This protects the nuclear materials from environmental degradation and helps reduce the chances of their release in case of an accidental fire or minor explosion. List of nuclear weapons
The W48 was an American nuclear artillery shell, capable of being fired from any standard 155 mm howitzer, e.g. the M114, M198 or M109. It was manufactured starting in 1963, all units were retired in 1992; the W48 was 6.1 inches in 33.3 inches long. It came in two models, Mod 0 and Mod 1, which are reported to have weighed 118 pounds and 128 pounds respectively, it had an explosive yield equivalent to 72 tons of TNT, small for a nuclear weapon. The W48 was a small diameter linear implosion nuclear fission weapon. An implosion weapon needs less nuclear material than is required to form a critical mass, at normal pressure and configurations, compared to a gun-type assembly, it uses precise explosive assemblies to collapse the material to many times normal density in order to attain critical mass. A bare critical mass of plutonium at normal density and without additional neutron reflector material is 10 kilograms; this amount of alpha-phase plutonium takes up 657 cm3, giving a sphere of radius 5.4 cm ).
To achieve a large explosive yield, a linear implosion weapon needs somewhat more material, about 13 kilograms. The mass, known as the "pit", is configured in a lower density non-spherical configuration. A tamper or reflector could be used to reduce the mass, but the overall diameter of the fissile material plus tamper/reflector increases compared to the volume required for an untamped, unreflected pit. To fit weapons into small artillery shells bare pits are required. On firing the weapon, small to moderate amounts of high explosive collapse and reshape the nuclear material into a supercritical mass which begins a chain reaction, goes critical, explodes in a small nuclear blast. Three methods are known to compress and reshape the nuclear material: collapsing hollow spaces inside the nuclear material. Linear implosion weapons have much lower efficiency due to low pressure, require 2-3 times more nuclear material than conventional implosion weapons, they are considerably heavier, much smaller than conventional implosion weapons.
The W54 nuclear warhead used in the Davy Crockett nuclear artillery unit was about 11 inches diameter and weighs 51 pounds. The W48 is 6 inches in diameter and weighs over twice as much, requires twice as much plutonium. Independent researchers have determined that one model of US conventional implosion fission weapon cost $1.25 million per unit produced, of which $250,000 was the total cost for all non-nuclear components and $1 million the cost of the plutonium. Linear implosion weapons requiring 2-3 times more plutonium are proportionally more expensive; the W82 was the most successful, but not complete, replacement for the W48. Nuclear weapon design List of nuclear weapons On page 10'A heavy spring is used to hold the pit in place'; as there are no pits in a gun system like that of, it is likely the W48 was most an implosion type device, not a gun type. Denotes a spherical implosion system, for an artillery piece. Allbombs.html list of all US nuclear weapon models at nuclearweaponarchive.org Linear Implosion in the Nuclear Weapons FAQ at nuclearweaponarchive.org
Trinity (nuclear test)
Trinity was the code name of the first detonation of a nuclear weapon. It was conducted by the United States Army at 5:29 a.m. on July 16, 1945, as part of the Manhattan Project. The test was conducted in the Jornada del Muerto desert about 35 miles southeast of Socorro, New Mexico, on what was the USAAF Alamogordo Bombing and Gunnery Range, now part of White Sands Missile Range; the only structures in the vicinity were the McDonald Ranch House and its ancillary buildings, which scientists used as a laboratory for testing bomb components. A base camp was constructed, there were 425 people present on the weekend of the test; the code name "Trinity" was assigned by J. Robert Oppenheimer, the director of the Los Alamos Laboratory, inspired by the poetry of John Donne; the test was of an implosion-design plutonium device, informally nicknamed "The Gadget", of the same design as the Fat Man bomb detonated over Nagasaki, Japan, on August 9, 1945. The complexity of the design required a major effort from the Los Alamos Laboratory, concerns about whether it would work led to a decision to conduct the first nuclear test.
The test was directed by Kenneth Bainbridge. Fears of a fizzle led to the construction of a steel containment vessel called Jumbo that could contain the plutonium, allowing it to be recovered, but Jumbo was not used. A rehearsal was held on May 7, 1945, in which 108 short tons of high explosive spiked with radioactive isotopes were detonated; the Gadget's detonation released the explosive energy of about 22 kilotons of TNT. Observers included Vannevar Bush, James Chadwick, James Conant, Thomas Farrell, Enrico Fermi, Richard Feynman, Leslie Groves, Robert Oppenheimer, Geoffrey Taylor, Richard Tolman; the test site was declared a National Historic Landmark district in 1965, listed on the National Register of Historic Places the following year. The creation of nuclear weapons arose from political developments of the 1930s; the decade saw many new discoveries about the nature of atoms, including the existence of nuclear fission. The concurrent rise of fascist governments in Europe led to a fear of a German nuclear weapon project among scientists who were refugees from Nazi Germany and other fascist countries.
When their calculations showed that nuclear weapons were theoretically feasible, the British and United States governments supported an all-out effort to build them. These efforts were transferred to the authority of the U. S. Army in June 1942, became the Manhattan Project. Brigadier General Leslie R. Groves, Jr. was appointed its director in September 1942. The weapons development portion of this project was located at the Los Alamos Laboratory in northern New Mexico, under the directorship of physicist J. Robert Oppenheimer; the University of Chicago, Columbia University and the Radiation Laboratory at the University of California, Berkeley conducted other development work. Production of the fissile isotopes uranium-235 and plutonium-239 were enormous undertakings given the technology of the 1940s, accounted for 80% of the total costs of the project. Uranium enrichment was carried out at the Clinton Engineer Works near Tennessee. Theoretically, enriching uranium was feasible through pre-existing techniques, but it proved difficult to scale to industrial levels and was costly.
Only 0.71 percent of natural uranium was uranium-235, it was estimated that it would take 27,000 years to produce a gram of uranium with mass spectrometers, but kilogram amounts were required. Plutonium is a synthetic element with complicated physical and metallurgical properties, it is not found in nature in appreciable quantities. Until mid-1944, the only plutonium, isolated had been produced in cyclotrons in microgram amounts, whereas weapons required kilograms. In April 1944, physicist Emilio Segrè, the head of the Los Alamos Laboratory's P-5 Group, received the first sample of reactor-bred plutonium from the X-10 Graphite Reactor at Oak Ridge, he discovered that, in addition to the plutonium-239 isotope, it contained significant amounts of plutonium-240. The Manhattan Project produced plutonium in nuclear reactors at the Hanford Engineer Works near Hanford, Washington; the longer the plutonium remained irradiated inside a reactor—necessary for high yields of the metal—the greater the content of the plutonium-240 isotope, which undergoes spontaneous fission at thousands of times the rate of plutonium-239.
The extra neutrons it released meant that there was an unacceptably high probability that plutonium in a gun-type fission weapon would detonate too soon after a critical mass was formed, producing a "fizzle"—a nuclear explosion many times smaller than a full explosion. This meant; the Laboratory turned to an alternative, albeit more technically difficult, design, an implosion-type nuclear weapon. In September 1943, mathematician John von Neumann had proposed a design in which a fissile core would be surrounded by two different high explosives that produced shock waves of different speeds. Alternating the faster- and slower-burning explosives in a calculated configuration would produce a compressive wave upon their simultaneous detonation; this so-called "explosive lens" focused the shock waves inward with enough force to compress the plutonium core to several times its original density. This reduced the size of a critical mass, it activated a small neutron source at the center of the core, which assured that the chain reaction began in earnest at the right moment.
Such a complicated process required research and experimentation in engineering and hydrodynamics before a practical desi
W9 (nuclear warhead)
The W9 was an American nuclear artillery shell fired from a special 11 inch howitzer. It was produced starting in 1952 and all were retired by 1957; the W9 was 11 inches in diameter, 55 inches long, weighed 850 pounds. It had an explosive yield of 15 kilotons; the W9 was a gun-type nuclear weapon, using around 50 kilograms of enriched uranium in one large rings assembly and one smaller "bullet", fired down a tube by conventional explosives into the rings assembly to achieve critical mass and detonate the weapon. The W9 units which were retired in 1957 were recycled into lower yield T-4 Atomic Demolition Munitions; these were the first man-portable nuclear weapons. The W9 is only the second gun-type nuclear weapon known to have been detonated; the W9 artillery shell was test fired once, fired from the "Atomic Annie" M65 Atomic Cannon, in Upshot-Knothole Grable on May 25, 1953 at the NTS. Yield was the expected 15 kilotons. Subsequently, the W33 nuclear artillery shell was test fired twice during its development.
These four detonations are the only identified gun-type bomb detonations. Nuclear artillery List of nuclear weapons Allbombs.html list of all US nuclear weapons models at nuclearweaponarchive.org
United States Air Force
The United States Air Force is the aerial and space warfare service branch of the United States Armed Forces. It is one of the five branches of the United States Armed Forces, one of the seven American uniformed services. Formed as a part of the United States Army on 1 August 1907, the USAF was established as a separate branch of the U. S. Armed Forces on 18 September 1947 with the passing of the National Security Act of 1947, it is the youngest branch of the U. S. Armed Forces, the fourth in order of precedence; the USAF is the largest and most technologically advanced air force in the world. The Air Force articulates its core missions as air and space superiority, global integrated intelligence and reconnaissance, rapid global mobility, global strike, command and control; the U. S. Air Force is a military service branch organized within the Department of the Air Force, one of the three military departments of the Department of Defense; the Air Force, through the Department of the Air Force, is headed by the civilian Secretary of the Air Force, who reports to the Secretary of Defense, is appointed by the President with Senate confirmation.
The highest-ranking military officer in the Air Force is the Chief of Staff of the Air Force, who exercises supervision over Air Force units and serves as one of the Joint Chiefs of Staff. Air Force components are assigned, as directed by the Secretary of Defense, to the combatant commands, neither the Secretary of the Air Force nor the Chief of Staff of the Air Force have operational command authority over them. Along with conducting independent air and space operations, the U. S. Air Force provides air support for land and naval forces and aids in the recovery of troops in the field; as of 2017, the service operates more than 5,369 military aircraft, 406 ICBMs and 170 military satellites. It has a $161 billion budget and is the second largest service branch, with 318,415 active duty airmen, 140,169 civilian personnel, 69,200 reserve airmen, 105,700 Air National Guard airmen. According to the National Security Act of 1947, which created the USAF: In general, the United States Air Force shall include aviation forces both combat and service not otherwise assigned.
It shall be organized and equipped for prompt and sustained offensive and defensive air operations. The Air Force shall be responsible for the preparation of the air forces necessary for the effective prosecution of war except as otherwise assigned and, in accordance with integrated joint mobilization plans, for the expansion of the peacetime components of the Air Force to meet the needs of war. §8062 of Title 10 US Code defines the purpose of the USAF as: to preserve the peace and security, provide for the defense, of the United States, the Territories and possessions, any areas occupied by the United States. The stated mission of the USAF today is to "fly and win...in air and cyberspace". "The United States Air Force will be a trusted and reliable joint partner with our sister services known for integrity in all of our activities, including supporting the joint mission first and foremost. We will provide compelling air and cyber capabilities for use by the combatant commanders. We will excel as stewards of all Air Force resources in service to the American people, while providing precise and reliable Global Vigilance and Power for the nation".
The five core missions of the Air Force have not changed since the Air Force became independent in 1947, but they have evolved, are now articulated as air and space superiority, global integrated intelligence and reconnaissance, rapid global mobility, global strike, command and control. The purpose of all of these core missions is to provide, what the Air Force states as, global vigilance, global reach, global power. Air superiority is "that degree of dominance in the air battle of one force over another which permits the conduct of operations by the former and its related land, sea and special operations forces at a given time and place without prohibitive interference by the opposing force". Offensive Counterair is defined as "offensive operations to destroy, disrupt, or neutralize enemy aircraft, launch platforms, their supporting structures and systems both before and after launch, but as close to their source as possible". OCA is the preferred method of countering air and missile threats since it attempts to defeat the enemy closer to its source and enjoys the initiative.
OCA comprises attack operations, sweep and suppression/destruction of enemy air defense. Defensive Counter air is defined as "all the defensive measures designed to detect, identify and destroy or negate enemy forces attempting to penetrate or attack through friendly airspace". A major goal of DCA operations, in concert with OCA operations, is to provide an area from which forces can operate, secure from air and missile threats; the DCA mission comprises both passive defense measures. Active defense is "the employment of limited offensive action and counterattacks to deny a contested area or position to the enemy", it includes both ballistic missile defense and air-breathing threat defense, encompasses point defense, area defense, high-value airborne asset defense. Passive defense is "measures taken to reduce the probability of and to minimize the effects of damage caused by hostile action without the intention of taking the initiative", it includes warning.
Mark 12 nuclear bomb
The Mark-12 nuclear bomb was a lightweight nuclear bomb designed and manufactured by the United States, built starting in 1954 and which saw service from until 1962. The Mark-12 was notable for being smaller in both size and weight compared to prior implosion-type nuclear weapons. For example, the overall diameter was only 22 inches, compared to the prior Mark-7 which had a 30 inches diameter, the volume of the implosion assembly was only 40% the size of the Mark-7's. There was a planned W-12 warhead variant which would have been used with the RIM-8 Talos missile, but it was cancelled prior to introduction into service; the complete Mark-12 bomb was 22 inches in diameter, 155 inches long, weighed 1,100 to 1,200 pounds. It had a yield of 12 to 14 kilotonnes of TNT; the Mark-12 has been speculated to have been the first deployed nuclear weapon to have used beryllium as a reflector-tamper inside the implosion assembly. It is believed to have used a spherical implosion assembly, levitated pit, 92-point detonation.
Though the weapon went out of service in 1962, it resurfaced in a fictional role in Tom Clancy's 1991 book The Sum of All Fears and the 2002 film, where the plot included an Israeli copy of the Mark-12 being lost by accident in 1973 during the Yom Kippur War in southern Syria near the Golan Heights, recovered by a terrorist organization. Nuclear weapon design Mark 7 nuclear bomb The Sum of All Fears The Sum of All Fears allbombs.html list at nuclearweaponarchive.org Historical nuclear bombs list at globalsecurity.org