General-purpose bomb
Encyclopedia
A general-purpose bomb is an air-dropped bomb
intended as a compromise between blast damage, penetration, and fragmentation
in explosive effect.
, or Tritonal
in NATO or United States service) composing about 50% of the bomb's total weight. The British term for a bomb of this type is "medium case" or "medium capacity", abbreviated to MC. The GP bomb is a common weapon of fighter bomber and attack aircraft because it is useful for a variety of tactical applications and relatively cheap.
General-purpose bombs are often identified by their weight (e.g., 500 lb, 250 kg). In many cases this is strictly a nominal weight, or caliber
, and the actual weight of each individual weapon may vary depending on its retardation, fusing, carriage, and guidance systems. For example, the actual weight of a U.S. M117 bomb, nominally 750 lb (340 kg), is typically around 820 lb (374 kg).
Most modern air-dropped GP bombs are designed to minimize drag
for the carrier aircraft.
In low-altitude attacks, there is a danger of the attacking aircraft being caught in the blast of its own weapons. To address this problem, GP bombs are often fitted with retarders, parachute
s or pop-out fins that slow the bomb's descent to allow the aircraft time to escape the detonation.
GP bombs can be fitted with a variety of fuse
s and fins for different uses. One notable example is the "daisy cutter
" fuse used on Vietnam-era American weapons, an extended probe designed to ensure that the bomb would detonate on contact (even with foliage) rather than burying itself in earth or mud, which would reduce its effectiveness.
GP bombs are commonly used as the warheads for more sophisticated precision-guided munitions. Affixing various types of seeker and electrically controlled fins turns a basic 'iron' bomb into a laser-guided bomb
(like the U.S. Paveway
series), an electro-optical guided bomb, or, more recently, GPS-guided weapon (like the U.S. JDAM). The combination is cheaper than a true guided missile (and can be more easily upgraded or replaced in service), but substantially more accurate than an unguided bomb.
During the Korean War
and Vietnam War
the U.S. used older designs like the M117 and M118
, which had a higher explosive content (about 65%) than most current weapons. Although some of these weapons remain in the U.S. arsenal, they are little used, and the M117 is primarily carried only by the B-52 Stratofortress
.
The primary U.S. GP bombs are the Mark 80 series. This class of weapons uses a shape known as Aero 1A, designed by Ed Heinemann
of Douglas Aircraft as the result of studies in 1946
. It has a length-to-diameter ratio of about 8:1, and results in minimum drag for the carrier aircraft. The Mark 80 series was not used in combat until the Vietnam War, but has since that time replaced most earlier GP weapons. It includes four basic weapon types:
Vietnam service showed the Mk 81 "Firecracker" to be insufficiently effective, and it was withdrawn from U.S. service. However, recently precision-guided variants of the Mk 81 bomb have begun a return to service, based on U.S. experience in Iraq
after 2003, and the desire to reduce collateral damage
compared to Mk 82 and larger bombs (e.g., when attacking a single small building in a populated area).
Since the Vietnam War, United States Navy
and United States Marine Corps
GP bombs are distinguished by a thick ablative
fire-retardant coating, which is designed to delay any potential accidental explosion in the event of a shipboard fire. Land-based air forces typically do not use such coatings, largely because they add some 30 lb (14 kg) to the weight of the complete weapon.
In the Mk 80 series bomb bodies is also used in the following weapons:
_in_flight_dropping_a_snake-eye_bomb_060922-f-1234s-005.jpg)
The 1000 lb MC was developed from 1942 to replace the existing 1000 lb GP (General Purpose) bomb. Initially using most of the components of the 1000 lb GP it was decide to give it a new tail and was built with a half-inch thick wall. Fillings could be Amatex
, Amatol
, Minol
, RDX
and others. Actual weight was around 1020 lb (464 kg).
It was introduced to service in 1943 and about a quarter of a million produced by the end of the war.
The Russian term for general-purpose bomb is fugasnaya aviatsionnaya bomba, abbreviated FAB and followed by the bomb's nominal weight in kilograms. Most Russian iron bombs have circular ring airfoils rather than the fins used by Western types.
In 1946 the Soviet Union developed a series of freefall bombs in four sizes 250 kg (550 lb), 500 kg (1,100 lb), 1,500 kg (3,300 lb), and 3,000 kg (6,600 lb) and sharing a single nose and a single tail fuze. The bomb could be dropped from up to 12,000 m (40,000 ft) and up to 1,000 km/h (625 mph). The original, 1946-series bombs had poor ballistic characteristics at supersonic
speed, and their construction was fragile. As an interim measure, upgraded versions of the bombs were built with thicker walls and no nose fuze. The thick-walled version of the bombs were built until 1956.
The 1954 series of high-drag bombs was built in six sizes: 250 kg (550 lb), 500 kg (1,100 lb), 1500 kg (3,300 lb), 3,000 kg (6,600 lb), 5,000 kg (11,000 lb), and 9,000 kg (20,000 lb). The smaller (less than 3,000 kg) bombs had a single nose and a single tail fuze, while the larger weapons shared a single nose fuze and two base fuzes. The FAB-9000 (9,000 kg / 20,000 lb) weapon was roughly comparable to the wartime
Grand Slam bomb
. Its use in the postwar era was apparently never seriously contemplated, but it was used by Russian aircraft designers as a substitute for early nuclear weapon
s when determining the size and clearances of bomb bays.
In 1962 a new series of streamlined, low-drag bombs was introduced, designed for external carriage by fighter-bomber
aircraft rather than in internal bays. They come in only two sizes, 250 kg (550 lb) and 500 kg (1,100 lb). Both bombs have a single nose fuze.
Both the 54 and 62 series designs remain in use. The most common of these are the FAB-100, FAB-250, FAB-500, FAB-750, and FAB-1000, roughly corresponding to the U.S. Mark 80 series. These have seen widespread service in Russia, Warsaw Pact
nations, and various export countries.
Larger bombs with less streamlined shapes also remained in the Soviet arsenal, primarily for use by heavy bombers. In Afghanistan
in 1988 Soviet Tupolev Tu-22M
bombers used massive FAB-1500 (1,500 kg / 3,300 lb) and FAB-3000 (3,000 kg / 6,600 lb) weapons to devastating effect.
and built by the Société des Ateliers Mécanique de Port-sur-Sambre (SAMP) are made in a variety of types with nominal weights from 50 kg (110 lb) to 1,000 kg (2,205 lb). The most common are the 250 kg (550 lb) EU2 and T25, 400 kg (882 lb) T200, and 1,000 kg (2,205 lb) BL4.
Bomb
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...
intended as a compromise between blast damage, penetration, and fragmentation
Fragmentation (weaponry)
Fragmentation is the process by which the casing of an artillery shell, bomb, grenade, etc. is shattered by the detonating high explosive filling. The correct technical terminology for these casing pieces is fragments , although shards or splinters can be used for non-preformed fragments...
in explosive effect.
Characteristics
General-purpose (GP) bombs use a thick-walled metal casing with explosive filler (typically TNT, Composition BComposition B
Composition B, colloquially "comp B", is an explosive consisting of castable mixtures of RDX and TNT. It is used as the main explosive filling in artillery projectiles, rockets, land mines, hand grenades, sticky bombs and various other munitions...
, or Tritonal
Tritonal
Tritonal is a mixture of 80% TNT and 20% aluminium powder, used in several types of ordnance such as air-dropped bombs. The aluminium improves the total heat output and hence impulse of the TNT - the length of time during which the blast wave is positive...
in NATO or United States service) composing about 50% of the bomb's total weight. The British term for a bomb of this type is "medium case" or "medium capacity", abbreviated to MC. The GP bomb is a common weapon of fighter bomber and attack aircraft because it is useful for a variety of tactical applications and relatively cheap.
General-purpose bombs are often identified by their weight (e.g., 500 lb, 250 kg). In many cases this is strictly a nominal weight, or caliber
Caliber
In guns including firearms, caliber or calibre is the approximate internal diameter of the barrel in relation to the diameter of the projectile used in it....
, and the actual weight of each individual weapon may vary depending on its retardation, fusing, carriage, and guidance systems. For example, the actual weight of a U.S. M117 bomb, nominally 750 lb (340 kg), is typically around 820 lb (374 kg).
Most modern air-dropped GP bombs are designed to minimize drag
Drag (physics)
In fluid dynamics, drag refers to forces which act on a solid object in the direction of the relative fluid flow velocity...
for the carrier aircraft.
In low-altitude attacks, there is a danger of the attacking aircraft being caught in the blast of its own weapons. To address this problem, GP bombs are often fitted with retarders, parachute
Parachute
A parachute is a device used to slow the motion of an object through an atmosphere by creating drag, or in the case of ram-air parachutes, aerodynamic lift. Parachutes are usually made out of light, strong cloth, originally silk, now most commonly nylon...
s or pop-out fins that slow the bomb's descent to allow the aircraft time to escape the detonation.
GP bombs can be fitted with a variety of fuse
Fuse (explosives)
In an explosive, pyrotechnic device or military munition, a fuse is the part of the device that initiates function. In common usage, the word fuse is used indiscriminately...
s and fins for different uses. One notable example is the "daisy cutter
Daisy cutter (fuse)
A daisy cutter is a type of fuse designed to detonate an aerial bomb at or above ground level. The fuse itself is a long probe affixed to the weapon's nose, which detonates the bomb if it touches the ground or any solid object....
" fuse used on Vietnam-era American weapons, an extended probe designed to ensure that the bomb would detonate on contact (even with foliage) rather than burying itself in earth or mud, which would reduce its effectiveness.
GP bombs are commonly used as the warheads for more sophisticated precision-guided munitions. Affixing various types of seeker and electrically controlled fins turns a basic 'iron' bomb into a laser-guided bomb
Laser-guided bomb
A laser-guided bomb is a guided bomb that uses semi-active laser homing to strike a designated target with greater accuracy than an unguided bomb. LGBs are one of the most common and widespread guided bombs, used by a large number of the world's air forces.- Overview :Laser-guided munitions use a...
(like the U.S. Paveway
Paveway
Paveway is a generic term for Laser Guided Bombs .Pave or PAVE is sometimes used as an acronym for precision avionics vectoring equipment; literally, electronics for controlling the speed and direction of aircraft...
series), an electro-optical guided bomb, or, more recently, GPS-guided weapon (like the U.S. JDAM). The combination is cheaper than a true guided missile (and can be more easily upgraded or replaced in service), but substantially more accurate than an unguided bomb.
British
- 40 lb General Purpose bomb - produced 1937 to 1941
- 50 lb General Purpose Bomb - not produced
- 120 lb General Purpose Bomb - abandoned project
- 250 lb General Purpose Bomb (1926 onwards) - replaced by 250 lb MC in 1942
- 500 lb General Purpose Bomb (1926 onwards) - replaced by 500 lb MC in 1942
- 1000 lb General Purpose Bomb (1939 onwards) - replaced by 1000 lb MC
- 1900 lb General Purpose Bomb (1941 onwards)
- 4000 lb GP (1943–1945)
Modern American GP bombs: the Mark 80 series
Korean War
The Korean War was a conventional war between South Korea, supported by the United Nations, and North Korea, supported by the People's Republic of China , with military material aid from the Soviet Union...
and Vietnam War
Vietnam War
The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...
the U.S. used older designs like the M117 and M118
Mark 118 bomb
The M118 is an air-dropped general-purpose or demolition bomb used by United States military forces. It dates back to the time of the Korean War of the early 1950s. Although it has a nominal weight of 3,000 lb , its actual weight, depending on fuse and retardation options, is somewhat higher...
, which had a higher explosive content (about 65%) than most current weapons. Although some of these weapons remain in the U.S. arsenal, they are little used, and the M117 is primarily carried only by the B-52 Stratofortress
B-52 Stratofortress
The Boeing B-52 Stratofortress is a long-range, subsonic, jet-powered strategic bomber operated by the United States Air Force since the 1950s. The B-52 was designed and built by Boeing, who have continued to provide maintainence and upgrades to the aircraft in service...
.
The primary U.S. GP bombs are the Mark 80 series. This class of weapons uses a shape known as Aero 1A, designed by Ed Heinemann
Ed Heinemann
Edward Henry Heinemann, was a noted military aircraft designer for Douglas Aircraft Company.-Biography:...
of Douglas Aircraft as the result of studies in 1946
1946 in aviation
This is a list of aviation-related events from 1946:- Events :* The American Section of the International League of Aviators resurrects the National Trophy, a Harmon Trophy awarded from 1926 to 1938 to the outstanding aviator of the year in each of the 21 member countries of the now-defunct League...
. It has a length-to-diameter ratio of about 8:1, and results in minimum drag for the carrier aircraft. The Mark 80 series was not used in combat until the Vietnam War, but has since that time replaced most earlier GP weapons. It includes four basic weapon types:
- Mark 81Mark 81 bombThe Mark 81 250 lb general purpose bomb was the smallest of the Mark 80 series of low-drag general-purpose bombs.-Development & deployment:...
- nominal weight 250 pounds (113.4 kg) - Mark 82Mark 82 bombThe Mark 82 is an unguided, low-drag general-purpose bomb, part of the U.S. Mark 80 series. The explosive filling is tritonal.-Development and deployment:...
- nominal weight 500 pounds (226.8 kg) - Mark 83Mark 83 bombThe Mark 83 is part of the Mark 80 series of low-drag general-purpose bombs in United States service.-Development & deployment:The nominal weight of the bomb is 1,000 lb , although its actual weight varies between 985 lb and 1,030 lb , depending on fuze options, and fin configuration...
- nominal weight 1000 pounds (453.6 kg) - Mark 84Mark 84 bombThe Mark 84 is an American general-purpose bomb, it is also the largest of the Mark 80 series of weapons. Entering service during the Vietnam War, it became a commonly used US heavy unguided bomb to be dropped, second only to the BLU-82 "Daisy Cutter" then in service and presently third only to...
- nominal weight 2000 pounds (907.2 kg)
Vietnam service showed the Mk 81 "Firecracker" to be insufficiently effective, and it was withdrawn from U.S. service. However, recently precision-guided variants of the Mk 81 bomb have begun a return to service, based on U.S. experience in Iraq
Iraq
Iraq ; officially the Republic of Iraq is a country in Western Asia spanning most of the northwestern end of the Zagros mountain range, the eastern part of the Syrian Desert and the northern part of the Arabian Desert....
after 2003, and the desire to reduce collateral damage
Collateral damage
Collateral damage is damage to people or property that is unintended or incidental to the intended outcome. The phrase is prevalently used as an euphemism for civilian casualties of a military action.-Etymology:...
compared to Mk 82 and larger bombs (e.g., when attacking a single small building in a populated area).
Since the Vietnam War, United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
and United States Marine Corps
United States Marine Corps
The United States Marine Corps is a branch of the United States Armed Forces responsible for providing power projection from the sea, using the mobility of the United States Navy to deliver combined-arms task forces rapidly. It is one of seven uniformed services of the United States...
GP bombs are distinguished by a thick ablative
Ablation
Ablation is removal of material from the surface of an object by vaporization, chipping, or other erosive processes. This occurs in spaceflight during ascent and atmospheric reentry, glaciology, medicine, and passive fire protection.-Spaceflight:...
fire-retardant coating, which is designed to delay any potential accidental explosion in the event of a shipboard fire. Land-based air forces typically do not use such coatings, largely because they add some 30 lb (14 kg) to the weight of the complete weapon.
In the Mk 80 series bomb bodies is also used in the following weapons:
- BDU-50 A practice (no explosive) version of the Mk 82Mark 82 bombThe Mark 82 is an unguided, low-drag general-purpose bomb, part of the U.S. Mark 80 series. The explosive filling is tritonal.-Development and deployment:...
bomb body - BDU-56 A practice (no explosive) version of the Mk 84Mark 84 bombThe Mark 84 is an American general-purpose bomb, it is also the largest of the Mark 80 series of weapons. Entering service during the Vietnam War, it became a commonly used US heavy unguided bomb to be dropped, second only to the BLU-82 "Daisy Cutter" then in service and presently third only to...
bomb body
Smart bomb kits
Dumb Mk 80 bombs could be smart bombs with attached kits:- GBU-12D Paveway II (Mk 82) laser guided.
- GBU-16B Paveway II (Mk 83) laser guided.
- GBU-24B Paveway III (Mk 84) laser guided.
- GBU-38 JDAM (Mk 82) INS/GPS guided.
- GBU-32 JDAM (Mk 83) INS/GPS guided.
- GBU-31 JDAM (Mk 84) INS/GPS guided.
Retarded versions
- Mk 82 Snake Eye was a standard Mk 82 with folded, retarding petals.
- Mk 82 Retarded was a standard Mk 82 with a balluteBalluteA ballute was invented by Goodyear in 1958. It is a parachute braking device that is optimized for use at high altitudes and high supersonic velocities. The original ballute was a cone-shaped balloon with a toroidal burble fence fitted around its widest point...
. - Mk 83 Retarded was a standard Mk 83 with a ballute.
- Mk 84 Retarded was a standard Mk 84 with a ballute.
Modern British GP bombs
The British describe general-purpose bombs as medium capacity (MC) bombs. The principal modern British bombs are 540 lb (245 kg) and 1,000 lb (454 kg), with a wide variety of fin, fuze, and retarder options.The 1000 lb MC was developed from 1942 to replace the existing 1000 lb GP (General Purpose) bomb. Initially using most of the components of the 1000 lb GP it was decide to give it a new tail and was built with a half-inch thick wall. Fillings could be Amatex
Amatex
Amatex is a military explosive consisting of 51% ammonium nitrate, 40% TNT, and 9% RDX....
, Amatol
Amatol
Amatol is a highly explosive material made from a mixture of TNT and ammonium nitrate. Its name originates from the words ammonium and toluene...
, Minol
Minol
The VEB Kombinat Minol, founded on 1 January 1956, was the state-owned gasoline and lubricant reseller of the German Democratic Republic.The marketing name MINOL was invented in 1949, when Die Deutsche Kraftstoff- und Mineralölzentrale and the German-Russian Naphta-AG founded the VEB...
, RDX
RDX
RDX, an initialism for Research Department Explosive, is an explosive nitroamine widely used in military and industrial applications. It was developed as an explosive which was more powerful than TNT, and it saw wide use in WWII. RDX is also known as cyclonite, hexogen , and T4...
and others. Actual weight was around 1020 lb (464 kg).
It was introduced to service in 1943 and about a quarter of a million produced by the end of the war.
Soviet / Russian GP bombs
In 1946 the Soviet Union developed a series of freefall bombs in four sizes 250 kg (550 lb), 500 kg (1,100 lb), 1,500 kg (3,300 lb), and 3,000 kg (6,600 lb) and sharing a single nose and a single tail fuze. The bomb could be dropped from up to 12,000 m (40,000 ft) and up to 1,000 km/h (625 mph). The original, 1946-series bombs had poor ballistic characteristics at supersonic
Supersonic
Supersonic speed is a rate of travel of an object that exceeds the speed of sound . For objects traveling in dry air of a temperature of 20 °C this speed is approximately 343 m/s, 1,125 ft/s, 768 mph or 1,235 km/h. Speeds greater than five times the speed of sound are often...
speed, and their construction was fragile. As an interim measure, upgraded versions of the bombs were built with thicker walls and no nose fuze. The thick-walled version of the bombs were built until 1956.
The 1954 series of high-drag bombs was built in six sizes: 250 kg (550 lb), 500 kg (1,100 lb), 1500 kg (3,300 lb), 3,000 kg (6,600 lb), 5,000 kg (11,000 lb), and 9,000 kg (20,000 lb). The smaller (less than 3,000 kg) bombs had a single nose and a single tail fuze, while the larger weapons shared a single nose fuze and two base fuzes. The FAB-9000 (9,000 kg / 20,000 lb) weapon was roughly comparable to the wartime
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
Grand Slam bomb
Grand Slam bomb
The Grand Slam was a 22,000 lb earthquake bomb used by RAF Bomber Command against strategic targets during the Second World War.Known officially as the Bomb, Medium Capacity, 22,000 lb, it was a scaled up version of the Tallboy bomb and closer to the original size that the bombs' inventor,...
. Its use in the postwar era was apparently never seriously contemplated, but it was used by Russian aircraft designers as a substitute for early nuclear weapon
Nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission bomb test released the same amount...
s when determining the size and clearances of bomb bays.
In 1962 a new series of streamlined, low-drag bombs was introduced, designed for external carriage by fighter-bomber
Fighter-bomber
A fighter-bomber is a fixed-wing aircraft with an intended primary role of light tactical bombing and also incorporating certain performance characteristics of a fighter aircraft. This term, although still used, has less significance since the introduction of rockets and guided missiles into aerial...
aircraft rather than in internal bays. They come in only two sizes, 250 kg (550 lb) and 500 kg (1,100 lb). Both bombs have a single nose fuze.
Both the 54 and 62 series designs remain in use. The most common of these are the FAB-100, FAB-250, FAB-500, FAB-750, and FAB-1000, roughly corresponding to the U.S. Mark 80 series. These have seen widespread service in Russia, Warsaw Pact
Warsaw Pact
The Warsaw Treaty Organization of Friendship, Cooperation, and Mutual Assistance , or more commonly referred to as the Warsaw Pact, was a mutual defense treaty subscribed to by eight communist states in Eastern Europe...
nations, and various export countries.
Larger bombs with less streamlined shapes also remained in the Soviet arsenal, primarily for use by heavy bombers. In Afghanistan
Afghanistan
Afghanistan , officially the Islamic Republic of Afghanistan, is a landlocked country located in the centre of Asia, forming South Asia, Central Asia and the Middle East. With a population of about 29 million, it has an area of , making it the 42nd most populous and 41st largest nation in the world...
in 1988 Soviet Tupolev Tu-22M
Tupolev Tu-22M
The Tupolev Tu-22M is a supersonic, swing-wing, long-range strategic and maritime strike bomber developed by the Soviet Union. Significant numbers remain in service with the Russian Air Force....
bombers used massive FAB-1500 (1,500 kg / 3,300 lb) and FAB-3000 (3,000 kg / 6,600 lb) weapons to devastating effect.
French GP bombs
France's GP bombs, marketed by MatraMatra
Mécanique Aviation Traction or Matra was a French company covering a wide range of activities mainly related to automobile, bicycles, aeronautics and weaponry. In 1994, it became a subsidiary of the Lagardère Group and now operates under that name.Matra was owned by the Floirat family...
and built by the Société des Ateliers Mécanique de Port-sur-Sambre (SAMP) are made in a variety of types with nominal weights from 50 kg (110 lb) to 1,000 kg (2,205 lb). The most common are the 250 kg (550 lb) EU2 and T25, 400 kg (882 lb) T200, and 1,000 kg (2,205 lb) BL4.