Subsidence craters left over after underground nuclear (test) explosions

Bunker-busting nuclear weapons, also known as earth-penetrating weapons (EPW), are a type of nuclear weapon designed to penetrate into soil, rock, or concrete to deliver a nuclear warhead to a target. These weapons would be used to destroy hardened, underground military bunkers buried deep in the ground. In theory, the amount of radioactive nuclear fallout would be reduced from that of a standard, air-burst nuclear detonation because they would have relatively low explosive yield. However because such weapons necessarily come into contact with large amounts of earth-based debris, they may, under certain circumstances, still generate fallout. Warhead yield and weapon design have changed periodically throughout the history of the design of such weapons. The crater-scarred landscape of the Nevada Test Site. ... The crater-scarred landscape of the Nevada Test Site. ... Post-shot subsidence crater and Huron King test chamber, which was less than 20 kilotons (1980) A subsidence crater is the crater left on the surface of an area which has had an underground (usually nuclear) explosion. ... The mushroom cloud of the atomic bombing of Nagasaki, Japan, 1945, rose some 18 kilometers (11 mi) above the hypocenter. ... Loess field in Germany Soil horizons are formed by combined biological, chemical and physical alterations. ... The rocky side of a mountain creek near Orosí, Costa Rica. ... Concrete being poured, raked and vibrated into place in residential construction in Toronto, Ontario, Canada. ... Bunkers in Albania A bunker is a defensive military fortification. ... Radioactive decay is the set of various processes by which unstable atomic nuclei (nuclides) emit subatomic particles. ... Map of hypothetical fallout dispersal after a large-scale nuclear attack against the United States. ... // The explosive yield of a nuclear weapon is the amount of energy discharged when the weapon is detonated, expressed usually in the equivalent mass of trinitrotoluene (TNT), either in kilotons (thousands of tons of TNT) or megatons (million of tons of TNT), but sometimes also in terajoules (1 kiloton of... A warhead is an explosive device used in military conflicts, used to destroy enemy vehicles or buildings. ...

Methods of operation

Penetration by explosive force

Concrete design remains little changed since 60 years ago. The majority of protected concrete structures in the US military are derived from standards set forth in Fundamentals of Protective Design, published in 1946 (US Army Corps of Engineers). Various augmentations, such as glass, fibers, and rebar, have made concrete less vulnerable, but far from impenetrable. Raymond T. Moore [1] was able to create a "human sized hole" in 18 inch (45 cm) thick reinforced concrete in less than 48 seconds with a mere 20 lb (9 kg) of explosive and a bolt cutter. Concrete being poured, raked and vibrated into place in residential construction in Toronto, Ontario, Canada. ... Glass can be made transparent and flat, or into other shapes and colors as shown in this sphere from the Verrerie of Brehat in Brittany. ... Fiber or fibre[1] is a class of materials that are continuous filaments or are in discrete elongated pieces, similar to lengths of thread. ... Rebar is common steel reinforcing bar, an important component of reinforced concrete and reinforced masonry structures. ...

When explosive force is applied to concrete, three major fracture regions are usually formed: the initial crater, a crushed aggregate surrounding the crater, and "scabbing" on the opposite side of the crater. Scabbing, also known as "spalling," is the violent separation of a mass of material from the opposite face of a plate or slab subjected to an impact or impulsive loading (this does not necessarily mean that the barrier itself must have been penetrated at this point). Very high speed photography of a small projectile impacting a thin aluminium plate at 7000 m/s. ...

The crater volume varies approximately inversely with the square root of the concrete's compressive strength. Therefore, increasing the compressive strength of the concrete by 50% will yield an approximately 25% smaller crater.

As the compressive wave propagates to the opposite side of the concrete and is reflected, the concrete fractures, and scabbing occurs on the interior wall. As such, an asymptotic relationship exists between the strength of the concrete and the damage that will be done between the crater, aggregate, and scabbing. In mathematics and applications, particularly the analysis of algorithms, asymptotic analysis is a method of classifying limiting behaviour, by concentrating on some trend. ...

While soil is a less dense material, it also does not transmit shock waves as well as concrete. So while a penetrator may actually travel further through soil, its effect may be lessened due to its inability to transmit shock to the target. Introduction The shock wave is one of several different ways in which a gas in a supersonic flow can be compressed. ...

Penetration with a hardened penetrator

A secant ogive

Further thinking on the subject envisions a penetrator, dropped from service height of a bomber aircraft, using kinetic energy to penetrate the shielding, and subsequently deliver a nuclear explosive to the buried target. Image File history File links Secant_ogive. ... Image File history File links Secant_ogive. ... A bomber is a military aircraft designed to attack ground targets, primarily by dropping bombs. ...

The problems with such a penetrator is the tremendous heat applied to the penetrator unit when striking the shielding (surface) at hundreds of meters per second. This has partially been solved by using metals such as tungsten (with a much higher melting point than steel), and altering the shape of the projectile (such as an ogive). General Name, Symbol, Number tungsten, W, 74 Chemical series transition metals Group, Period, Block 6, 6, d Appearance grayish white, lustrous Atomic mass 183. ... An ogive is a curved shape, figure, or feature. ...

Additionally, altering the shape of the projectile, to incorporate an ogive shape has yielded substantial results. Rocket sled testing at Eglin Air Force Base has demonstrated penetrations of 100 to 150 feet in concrete when traveling at 4,000 ft/s. The reason for this is liquefaction of the concrete in the target, which tends to flow over the projectile. Variation in the speed of the penetrator can either cause it to be vaporized on impact (in the case of traveling too fast), or to not penetrate far enough (in the case of traveling too slow). An approximation for the penetration depth is obtained with an impact depth formula derived by Sir Issac Newton. An ogive is a curved shape, figure, or feature. ... A rocket sled is essentially a small railroad car with rockets attached. ... Eglin Air Force Base is a base of the United States Air Force that belongs to the Air Force Materiel Command; the Air Armament Center is the host unit. ... Liquefaction may refer to: Soil liquefaction, the process by which sediments are converted into suspension, as in earthquake liquefaction, quicksand, quick clay, and turbidity currents. ... The physicist Sir Isaac Newton first developed this idea to get rough approximations for the impact depth for projectiles travelling at high velocities. ... Sir Isaac Newton, President of the Royal Society, (4 January 1643 – 31 March 1727) [OS: 25 December 1642 – 20 March 1727] was an English mathematician, physicist, astronomer, alchemist, chemist, inventor, and natural philosopher who is generally regarded as one of the most influential scientists and mathematicians in history. ...

Combination penetrator-explosive munitions

Another school of thought on nuclear bunker busters is using a light penetrator to travel 15 to 30 meters through shielding, and detonate a nuclear charge there. Such an explosion would generate powerful shock waves, which would be transmitted very effectively through the solid material comprising the shielding (see "scabbing" above).

Criticism and controversy

The neutrality of this article is disputed. Please see the discussion on the talk page.

The main criticism of Nuclear bunker busters is nuclear fallout and nuclear proliferation. The purpose of an earth-penetrating nuclear "bunker buster" is to reduce the required yield needed to ensure the destruction of the target by coupling the explosion to the ground, yielding a shock wave similar to an earthquake. For example, the United States retired the B-53 warhead, with a yield of 9 megatons, because the B-61 Mod 11 could attack similar targets with much lower yield (400 kilotons) because the latter can penetrate into the ground. Thus the fallout of a B-61 Mod 11 would likely be less than that of a B-53. Supporters note that this is one of the reasons Nuclear bunker busters should be developed. Critics claim that developing new nuclear weapons sends a proliferating message to non nuclear powers, undermining non-proliferation efforts by established nuclear powers. Image File history File links Unbalanced_scales. ... Map of hypothetical fallout dispersal after a large-scale nuclear attack against the United States. ... B53 W53 physics package The B53 with a yield of 9 Mt is one of the most powerful nuclear weapons built by the United States, and one of the last very high-yield thermonuclear bombs in U.S. service. ... B61 bomb in various stages of assembly. ...

Fallout from any nuclear detonation is increased with proximity to the ground. While a megaton class yield will inevitably throw up many tons of (newly) radioactive debris, which falls back to the earth as fallout, critics contend that despite their relatively miniscule explosive yield, Nuclear bunker busters create more fallout per kiloton yield.

The scientific group, Union of Concerned Scientists, points out that at the Nevada Test Site, the depth required to contain fallout from an average yield nuclear test was over 100 meters, depending upon the weapon's yield. They contend that it is improbable that penetrators could be made to burrow so deeply. With yields between 0.3 and 340 kt of TNT, they contend, it is unlikely the blast would be completely contained. The Union of Concerned Scientists (UCS) is an advocacy organization based in Cambridge, Massachusetts, United States. ... November 1951 nuclear test at Nevada Test Site. ... Preparation for an underground nuclear test at the Nevada Test Site in the 1980s. ... A megaton or megatonne is a unit of mass equal to 1,000,000 metric tons, i. ...

Another criticism is that bunkers can be built more deeply to make them more difficult to reach. The target's vulnerability is then limited to openings like the ventilation system, which don't require nuclear warheads, it is contended. Proponents of Nuclear bunker busters respond that the more deeply buried, the more expensive to construct, limiting the potential enemies who can withstand Nuclear bunker busters.

Politically, as well, such nuclear bunker busters are unpopular. Most targets are near cities, they argue, and even minimal fallout will inflict unacceptable levels of collateral damage. Furthermore, they state, the testing of new nuclear weapons would be prohibited by the proposed Comprehensive Test Ban Treaty, although the United States has refused to agree to be bound by this treaty. Comprehensive Test Ban Treaty Opened for signature September 10, 1996[1] in New York Entered into force Not yet in force Conditions for entry into force The treaty will enter into force 180 days after it is ratified by all of the following 44 (Annex 2) countries: Algeria, Argentina, Australia...

Finally, the need to use nuclear weapons in this role is questioned by critics. They argue that conventional ground penetration weapons are able to destroy enough buried or strengthened sites to lessen or even remove the need to use nuclear technology. Other conventional weapons such as thermobaric weapons have proven effective in defeating buried targets which have not been hardened. Thermobaric weapons distinguish themselves from conventional explosive weapons by using atmospheric oxygen, instead of carrying an oxidizer in their explosives. ...

Development of bunker-busting weapons

B61 nuclear bomb

As early as 1944, the Wallis Tallboy bomb and subsequent Grand Slam weapons were designed to penetrate deeply fortified structures through sheer explosive power. These were not designed to directly penetrate defences, though they could do this (for example the Valentin submarine pens had ferrous concrete roofs 7 metres (23 feet) thick which were penetrated by two Grand Slams on 27 March 1945), but rather to penetrate under the target and explode leaving a camouflet (cavern) which would undermine foundations of structures above, causing it to collapse, thus negating any possible hardening. The destruction of targets such as the V3 guns at Mimoyecques or with the first operational use of the Tallboy, one bored through a hillside and exploded in the Saumur rail tunnel about 18m (60 ft) below, completely blocking it; show that these weapons could destroy any hardened or deeply excavated installation, and modern targeting techniques allied with multiple strikes could unquestionably perform a similar task.^[1][2][3] B-61 gravity bomb from http://www. ... B-61 gravity bomb from http://www. ... B61 bomb in various stages of assembly. ... 1944 (MCMXLIV) was a leap year starting on Saturday (the link is to a full 1944 calendar). ... Tallboy bomb The Tallboy was an Earth Quake bomb developed by Barnes Wallis and brought into operation by the British in 1944. ... A British 22,000 lb (10,000 kg) Grand Slam bomb The Grand Slam ( Earth Quake bomb ), was a very large bomb developed by the British aeronautical engineer Barnes Wallis in late 1944. ... Reinforced concrete at Sainte Jeanne dArc Church (Nice, France): architect Jacques Dror, 1926–1933 Reinforced concrete, also called ferroconcrete in some countries, is concrete in which reinforcement bars (rebars) or fibers have been incorporated to strengthen the material that would otherwise be brittle. ... March 27 is the 86th day of the year in the Gregorian Calendar (87th in leap years). ... A Camouflet is military science term to describe an artificial cavern created by an explosion to undermine a structure. ... Like the V-1 flying bomb and the V-2 rocket, V-3 cannon was one of the three vengeance weapons (German: Vergeltungswaffe) built by Nazi Germany during World War II. Unlike the V-1 and the V-2, however, the V-3 was not a guided missile, but a... Mimoyecques was a German fortification in Europe during World war 2,consisting mainly of large cement bunkers, mainly built for testing of the newly built jet propelled aircraft and small versions of the v-2 rocket. ... Saumur is a small city and commune in the Maine-et-Loire département of France on the Loire River, with an approximate population of 30,000 (in 2001). ... In civil engineering, earthworks are engineering works created through the moving of massive quantities of soil or unformed stone. ...

Development continued, with weapons such as the nuclear B61, and conventional thermobaric weapons and GBU-28. One of the more effective housings, the GBU-28 used its large mass (4,700 lb) and casing (constructed from barrels of surplus 203 mm howitzers) to penetrate 20 feet of concrete, and more than 100 feet of earth. The B61 Mod 11, which first entered military service in January 1997, was specifically developed to allow for bunker penetration, and is speculated to have the ability to destroy hardened targets a few hundred feet beneath the earth.[1] B61 bomb in various stages of assembly. ... Categories: Air-dropped bombs ... Loading a WW1 British 15 in (381 mm) howitzer A howitzer or hauwitzer is a type of field artillery. ...

While penetrations of 20–100 feet were sufficient for some shallow targets, both the Soviet Union and the United States were creating bunkers buried under huge volumes of soil or reinforced concrete in order to withstand the multi-megaton thermonuclear weapons developed in the 1950s and 1960s. Bunker penetration weapons were initially designed out of this Cold War context. The Cold War was the point that people liked chilli peppers. ...

Mountainous terrain in Afghanistan

The weapon was revisited in the post-Cold War during the 2001 U.S. invasion of Afghanistan, and again during the 2003 invasion of Iraq. During the campaign in Tora Bora in particular, the United States believed that "vast underground complexes," deeply buried, were protecting opposing forces. While a nuclear penetrator (the "Robust Nuclear Earth Penetrator", or "RNEP") was never built, the DOE was allotted budget to develop it, and tests were conducted by the Air Force Research Laboratory. Such complexes were not found. Image File history File linksMetadata Download high resolution version (1600x1200, 830 KB) Summary This image is a work of a U.S. military or Department of Defense employee, taken or made during the course of an employees official duties. ... Image File history File linksMetadata Download high resolution version (1600x1200, 830 KB) Summary This image is a work of a U.S. military or Department of Defense employee, taken or made during the course of an employees official duties. ... This article is about the year 2001. ... Combatants al-Qaeda, Taliban Northern Alliance, United States, United Kingdom, Canada, Australia, France, New Zealand, Italy, Germany Commanders Mohammed Omar Osama bin Laden Tommy Franks Mohammed Fahim Strength Casualties {{{notes}}} The United States invasion of Afghanistan occurred in October 2001, in the wake of the September 11, 2001 attacks on... Combatants Coalition Forces: United States United Kingdom Poland Australia South Korea Romania Spain Portugal Italy others. ... Tora Bora Tora Bora (black dust) (Persian: تورا بورا ) is an area located in the White Mountains in eastern Afghanistan, southeast of Kabul and southwest of Jalalabad, near the Pakistan border. ... The United States Department of Energy (DOE) is a Cabinet-level department of the United States government responsible for energy policy and nuclear safety. ... The United States Air Force Research Laboratory with headquarters at Wright-Patterson Air Force Base, Ohio, was created in October 1997. ...

As well, it has been stated [2] that Iran may have such deeply buried bunkers to guard its nuclear program. This article is about Irans nuclear power program. ...

The Bush administration removed its request for funding of the weapon in October 2005. Additionally, US Senator Pete Domenici announced funding for the nuclear bunker-buster has been dropped from the Department of Energy's fiscal 2006 budget at the department's request. George Walker Bush (born July 6, 1946) is the 43rd and current President of the United States, inaugurated on January 20, 2001. ... The United States Senate is the upper house of the U.S. Congress, smaller than the United States House of Representatives. ... Pietro Pete Vichi Domenici (born May 7, 1932) is a powerful Republican United States senator from New Mexico. ... The United States Department of Energy (DOE) is a Cabinet-level department of the United States government responsible for energy policy and nuclear safety. ...

While the project for the RNEP seems to be in fact cancelled, Jane's Information Group speculates work may continue under another name. Janes Information Group (often referred to as Janes) was founded by John F.T. Jane in 1898. ...

See also

• Thermobaric weapon
• Tsar Bomba
• Fail-deadly
• No first use
• Nuclear strategy

Thermobaric weapons distinguish themselves from conventional explosive weapons by using atmospheric oxygen, instead of carrying an oxidizer in their explosives. ... A Tsar Bomba-type casing on display at Chelyabinsk-70 . ... Fail Deadly is a concept in military strategy which encourages deterrence by guaranteeing an immediate, automatic and overwhelming response to an attack. ... This article or section does not cite its references or sources. ... Nuclear strategy involves the development of doctrines and strategies for the production and use of nuclear weapons. ...

References

• Barrier Penetration Tests, Moore, R. T. National Bureau of Standards, ASIN B0006CHZT6
• Penetration Resistance of Concrete: A Review, James R. Clifton, The Physical Security and Stockpile Directorate, Defense Nuclear Agency, ASIN B0006E76U2
• U.S. Nuclear Weapons: Changes In Policy And Force Structure, Woolf, Amy F., ISBN 1-59454-234-1
• Nuclear Weapon Initiatives: Low-yield R&D, Advanced Concepts, Earth Penetrators, Test Readiness, Ernest, Jonathan V., et al., ISBN 1-59454-203-1

Asin is a Pinoy rock and folk rock band from the Philippines. ... Asin is a Pinoy rock and folk rock band from the Philippines. ...

External links

• Earth Penetrating Weapons by Lisbeth Gronlund, David Wright and Robert Nelson, Union of Concerned Scientists, May 2005
• Bunker-busters set to go nuclear by David Hambling, New Scientist, 07 November 2002
• Low-Yield Earth-Penetrating Nuclear Weapons by Robert W. Nelson, Federation of American Scientists, January/February 2001, Volume 54, Number 1

Footnotes

1. ^ Grand Slam raids
2. ^ RAF web site: RAF Bomber Command: July 1944 (See V-3 July 6 The photograph shows clearly the camouflet effect)
3. ^ RAF web site: RAF Bomber Command: saumur