A bomb is an explosive weapon that uses the exothermic reaction of an explosive material to provide an extremely sudden and violent release of energy. Detonations inflict damage principally through ground- and atmosphere-transmitted mechanical stress, the impact and penetration of pressure-driven projectiles, pressure damage, and explosion-generated effects. Bombs have been utilized since the 11th century starting in East Asia.
Operation Argus was a series of United States low-yield, high-altitude nuclear weapons tests and missile tests secretly conducted from 27 August to 9 September 1958 over the South Atlantic Ocean. The tests were performed by the Defense Nuclear Agency.
Overpressure is the pressure caused by a shock wave over and above normal atmospheric pressure. The shock wave may be caused by sonic boom or by explosion, and the resulting overpressure receives particular attention when measuring the effects of nuclear weapons or thermobaric bombs.
Operation Crossroads was a pair of nuclear weapon tests conducted by the United States at Bikini Atoll in mid-1946. They were the first nuclear weapon tests since Trinity on July 16, 1945, and the first detonations of nuclear devices since the atomic bombing of Nagasaki on August 9, 1945. The purpose of the tests was to investigate the effect of nuclear weapons on warships.
The effects of a nuclear explosion on its immediate vicinity are typically much more destructive and multifaceted than those caused by conventional explosives. In most cases, the energy released from a nuclear weapon detonated within the lower atmosphere can be approximately divided into four basic categories:
Operation Wigwam involved a single test of the Mark 90 "Betty" nuclear bomb. It was conducted between Operation Teapot and Project 56 on May 14, 1955, about 500 miles (800 km) southwest of San Diego, California. 6,800 personnel aboard 30 ships were involved in Wigwam. The purpose of Wigwam was to determine the vulnerability of submarines to deeply detonated nuclear weapons, and to evaluate the feasibility of using such weapons in a combat situation. The task force commander, Admiral John Sylvester, was embarked on the task force flagship USS Mount McKinley. Wigwam was the first atomic test in the deep ocean, and it remains the only test that has been conducted in water deeper than 1,000 ft (300 m).
Operation Blowdown was an explosives test carried out in the Kutini-Payamu jungle of Australia's Cape York Peninsula in 1963, to simulate the effects of a nuclear weapon on tropical rainforest. It was conducted by the Australian Army, the Department of Supply, and the Defence Standards Laboratory with participation from the United Kingdom, Canada and United States. In addition, blast effects on military material, field fortifications, supply points, and foot and vehicle movement were examined in a rain forest environment.
Operation Hardtack I was a series of 35 nuclear tests conducted by the United States from April 28 to August 18 in 1958 at the Pacific Proving Grounds. At the time of testing, the Operation Hardtack I test series included more nuclear detonations than the total of prior nuclear explosions in the Pacific Ocean. These tests followed the Project 58/58A series, which occurred from 1957 December 6 to 1958, March 14, and preceded the Operation Argus series, which took place in 1958 from August 27 to September 6.
There have been many extremely large explosions, accidental and intentional, caused by modern high explosives, boiling liquid expanding vapour explosions (BLEVEs), older explosives such as gunpowder, volatile petroleum-based fuels such as gasoline, and other chemical reactions. This list contains the largest known examples, sorted by date. An unambiguous ranking in order of severity is not possible; a 1994 study by historian Jay White of 130 large explosions suggested that they need to be ranked by an overall effect of power, quantity, radius, loss of life and property destruction, but concluded that such rankings are difficult to assess.
The explosive yield of a nuclear weapon is the amount of energy released such as blast, thermal, and nuclear radiation, when that particular nuclear weapon is detonated, usually expressed as a TNT equivalent (the standardized equivalent mass of trinitrotoluene which, if detonated, would produce the same energy discharge), either in kilotonnes (kt—thousands of tonnes of TNT), in megatonnes (Mt—millions of tonnes of TNT), or sometimes in terajoules (TJ). An explosive yield of one terajoule is equal to 0.239 kilotonnes of TNT. Because the accuracy of any measurement of the energy released by TNT has always been problematic, the conventional definition is that one kilotonne of TNT is held simply to be equivalent to 1012 calories.
Minor Scale was a test conducted on June 27, 1985, by the United States Defense Nuclear Agency involving the detonation of several thousand tons of conventional explosives to simulate the explosion of a small nuclear bomb. The purpose of the test was to evaluate the effect of nuclear blasts on various pieces of military hardware, particularly new, blast-hardened launchers for the MGM-134 Midgetman ballistic missile.
Explosives safety originated as a formal program in the United States in the aftermath of World War I when several ammunition storage areas were destroyed in a series of mishaps. The most serious occurred at Picatinny Arsenal Ammunition Storage Depot, New Jersey, in July, 1926 when an electrical storm led to fires that caused explosions and widespread destruction. The severe property damage and 19 fatalities led Congress to empower a board of Army and Naval officers to investigate the Picatinny Arsenal disaster and determine if similar conditions existed at other ammunition depots. The board reported in its findings that this mishap could recur, prompting Congress to establish a permanent board of colonels to develop explosives safety standards and ensure compliance beginning in 1928. This organization evolved into the Department of Defense Explosives Safety Board (DDESB) and is chartered in Title 10 of the US Code. The DDESB authors Defense Explosives Safety Regulation (DESR) 6055.9 which establishes the explosives safety standards for the Department of Defense. The DDESB also evaluates scientific data which may adjust those standards, reviews and approves all explosives site plans for new construction, and conducts worldwide visits to locations containing US title munitions. The cardinal principle of explosives safety is expose the minimum number of people for the minimum time to the minimum amount of explosives.
USS LSM-60 was a World War II era landing ship, medium (LSM) amphibious assault ship of the United States Navy. It was notable for being used as the float to suspend a fission bomb underwater during the Operation Crossroads BAKER test, becoming the first naval vessel to deploy a nuclear weapon.
On 29 July 1967, a fire broke out on board the aircraft carrier USS Forrestal after an electrical anomaly caused a Zuni rocket on an F-4B Phantom to fire, striking an external fuel tank of an A-4 Skyhawk. The flammable jet fuel spilled across the flight deck, ignited, and triggered a chain reaction of explosions that killed 134 sailors and injured 161. At the time, Forrestal was engaged in combat operations in the Gulf of Tonkin, during the Vietnam War. The ship survived, but with damage exceeding US$72 million, not including the damage to aircraft. Future United States Senator John McCain and future four-star admiral and U.S. Pacific Fleet Commander Ronald J. Zlatoper were among the survivors. Another on-board officer, Lieutenant Tom Treanore, later returned to the ship as its commander and retired an admiral.
Misty Picture was a test conducted on May 14, 1987 by the United States Defense Nuclear Agency involving the detonation of several thousand tons of conventional explosives to simulate the explosion of a small nuclear bomb.
A sympathetic detonation, also called flash over or secondary/secondaries (explosion), is a detonation, usually unintended, of an explosive charge by a nearby explosion.
A transient condensation cloud, also called a Wilson cloud, is observable surrounding large explosions in humid air.
Nuclear testing at Bikini Atoll consisted of the detonation of 24 nuclear weapons by the United States between 1946 and 1958 on Bikini Atoll in the Marshall Islands. Tests occurred at 7 test sites on the reef itself, on the sea, in the air, and underwater. The test weapons produced a combined yield of 42.2 Mt of TNT in explosive power.
Operation Snowball was a conventional explosive test to obtain information on nuclear weapon detonations run by the Defence Research Board with participation from the United Kingdom and United States. A detonation of 500 short tons (450 t) of TNT was used to study the resulting phenomena. The test was held at the Suffield Experimental Station in Alberta and was the largest ever man-made, non-accidental explosion in Canada. The test was also the first of its kind using a stacked TNT block hemisphere of such magnitude, a method repeated in six subsequent tests such as Operation Sailor Hat and Prairie Flat. The test allowed verifying predicted properties of shock and blast and determining its effect on a variety of military targets at varied distances from ground zero.
Operation Prairie Flat was a test involving the detonation of a 500-short-ton (450 t) spherical surface charge of TNT to evaluate airblast, ground shock and thermal effects of nuclear weapons.
