A bomb is any of a range of explosive weapons that only rely on the exothermic reaction of

an explosive material to provide an extremely sudden and violent release of energy (an explosive

device). 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.[1] A nuclear weapon employs chemical-based explosives to initiate a

much larger nuclear-based explosion. Bombs have been in use since the 11th century in Song

Dynasty China.[2]

The term bomb is not usually applied to explosive devices used for civilian purposes such

as construction or mining, although the people using the devices may sometimes refer to them as

"bomb". The military use of the term "bomb", or more specifically aerial bomb action, typically refers to

airdropped, unpowered explosive weapons most commonly used by air forces and naval aviation.

Other military explosive weapons not classified as "bombs" includegrenades, shells, depth

charges (used in water), warheads when in missiles, or land mines. In unconventional warfare,

"bomb" can refer to a range of offensive weaponry. For instance, in recent conflicts, "bombs" known

as improvised explosive devices (IEDS) have been employed by insurgent fighters to great

effectiveness.

The word comes from the Latin bombus, which in turn comes from the Greek βόμβος (bombos),[3] an onomatopoetic term meaning "booming", "buzzing".

A "wind-and-dust" bomb depicted in the Ming Dynasty bookHuolongjing. The pot contains a tube of gunpowder, and

was thrown at invaders.[4]

Contents

  [hide] 

1 History

2 Shock

3 Heat

4 Fragmentation

5 Effects on living things

6 Effects on structures

7 Types

o 7.1 Compressed Gas

o 7.2 Low Explosive

o 7.3 High Explosive

o 7.4 Nuclear Fission

o 7.5 Nuclear Fusion

o 7.6 Other

7.6.1 Concrete bomb

7.6.2 Inert bomb

8 Delivery

9 Blast seat

10 See also

11 References

12 External links

History[edit]

See also: History of gunpowder

An illustration depicting early bombs thrown at Manchu assault ladders during the siege of Ningyuan, from the

book Thai Tsu Shih Lu Thu (Veritable Records of the Great Ancestor) written in 1635. The bombs are known as

"thunder-crash bombs."[5]

Explosive bombs were used in China in 1221, by a Jin Dynasty army against a Song Dynasty city.

Bombs built using bamboo tubes appear in the 11th century.[2] Bombs made of cast iron shells packed

with explosive gunpowder date to 13th century China.[6] The term was coined for this bomb (i.e.

"thunder-crash bomb") during a Jin Dynasty (1115–1234) naval battle of 1231 against the Mongols.[6] The History of Jin 《金史》 (compiled by 1345) states that in 1232, as the Mongol

general Subutai (1176–1248) descended on the Jin stronghold of Kaifeng, the defenders had a

"thunder-crash bomb" which "consisted of gunpowder put into an iron container ... then when the fuse

was lit (and the projectile shot off) there was a great explosion the noise whereof was like thunder,

audible for more than a hundred li, and the vegetation was scorched and blasted by the heat over an

area of more than half a mou. When hit, even iron armourwas quite pierced through."[6] The Song

Dynasty (960–1279) official Li Zengbo wrote in 1257 that arsenals should have several hundred

thousand iron bomb shells available and that when he was in Jingzhou, about one to two thousand

were produced each month for dispatch of ten to twenty thousand at a time toXiangyang and

Yingzhou.[6] The Ming Dynasty text Huolongjing describes the use of poisonous gunpowder bombs,

including the "wind-and-dust" bomb.[4]

During the Mongol invasions of Japan, the Mongols used the explosive "thunder-crash bombs"

against the Japanese. Archaeological evidence of the "thunder-crash bombs" has been discovered in

an underwater shipwreck off the shore of Japan by the Kyushu Okinawa Society for Underwater

Archaeology. X-rays by Japanese scientists of the excavated shells confirmed that they contained

gunpowder.[7]

Shock[edit]

Explosive shock waves can cause situations such as body displacement (i.e., people being thrown

through the air), dismemberment, internal bleeding and ruptured eardrums.[8]

Shock waves produced by explosive events have two distinct components, the positive and negative

wave. The positive wave shoves outward from the point of detonation, followed by the trailing vacuum

space "sucking back" towards the point of origin as the shock bubble collapses. The greatest defense

against shock injuries is distance from the source of shock.[9] As a point of reference, the overpressure

at the Oklahoma City bombing was estimated in the range of28 MPa.[10]

Heat[edit]

A thermal wave is created by the sudden release of heat caused by an explosion. Military bomb tests

have documented temperatures of up to 2,480 °C (4,500 °F). While capable of inflicting severe to

catastrophic burns and causing secondary fires, thermal wave effects are considered very limited in

range compared to shock and fragmentation. This rule has been challenged, however, by military

development of thermobaric weapons, which employ a combination of negative shock wave effects

and extreme temperature to incinerate objects within the blast radius. This would be fatal to humans,

as bomb tests have proven.

Fragmentation[edit]

Main article: Fragmentation (weaponry)

An illustration of a fragmentation bomb from the 14th century Ming Dynasty text Huolongjing. The black dots represent

iron pellets.

Fragmentation is produced by the acceleration of shattered pieces of bomb casing and adjacent

physical objects. The use of fragmentation in bombs dates to the 14th century, and appears in

the Ming Dynasty text Huolongjing. The fragmentation bombs were filled with iron pellets and pieces

of broken porcelain. Once the bomb explodes, the resulting shrapnel is capable of piercing the skin

and blinding enemy soldiers.[11]

While conventionally viewed as small metal shards moving at super-

supersonic and hypersonic speeds, fragmentation can occur in epic proportions and travel for

extensive distances. When the S.S. Grandcamp exploded in the Texas City Disaster on April 16,

1947, one fragment of that blast was a two ton anchor which was hurled nearly two miles inland to

embed itself in the parking lot of the Pan American refinery. Fragmentation should not be confused

with shrapnel, which relies on the momentum of a shell to cause damage.

Effects on living things[edit]

To people who are close to a blast incident, such as bomb disposal technicians, soldiers wearing

body armor, deminers or individuals wearing little to no protection, there are four types of blast effects

on the human body: overpressure (shock), fragmentation, impact and heat. Overpressure refers to the

sudden and drastic rise in ambient pressure that can damage the internal organs, possibly leading to

permanent damage or death. Fragmentation includes the shrapnel described above but can also

include sand, debris and vegetation from the area surrounding the blast source. This is very common

in anti-personnel mine blasts.[12] The projection of materials poses a potentially lethal threat caused by

cuts in soft tissues, as well as infections, and injuries to the internal organs. When the overpressure

wave impacts the body it can induce violent levels of blast-induced acceleration. Resulting injuries

range from minor to unsurvivable. Immediately following this initial acceleration, deceleration injuries

can occur when a person impacts directly against a rigid surface or obstacle after being set in motion

by the force of the blast. Finally, injury and fatality can result from the explosive fireball as well as

incendiary agents projected onto the body. Personal protective equipment, such as a bomb suit or

demining ensemble, as well as helmets, visors and foot protection, can dramatically reduce the four

effects, depending upon the charge, proximity and other variables.