Laydown delivery is a mode of delivery found in some

nuclear Nuclear may refer to: Physics Relating to the nucleus of the atom: *Nuclear engineering *Nuclear physics *Nuclear power *Nuclear reactor *Nuclear weapon *Nuclear medicine *Radiation therapy *Nuclear warfare Mathematics *Nuclear space *Nuclear ...

gravity bombs: the bomb's descent to the target is slowed by

parachute A parachute is a device used to slow the motion of an object through an atmosphere by creating drag or, in a ram-air parachute, aerodynamic lift. A major application is to support people, for recreation or as a safety device for aviators, w ...

so that it lands on the ground without

detonating Detonation () is a type of combustion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations propagate supersonically through shock waves with s ...

. The bomb then detonates by timer some time later. Laydown delivery requires the weapon to be reinforced so that it can survive the force of impact. Laydown modes are used to make weapon delivery survivable by aircraft flying at low level. Low-altitude delivery helps hide the aircraft from

surface-to-air missile A surface-to-air missile (SAM), also known as a ground-to-air missile (GTAM) or surface-to-air guided weapon (SAGW), is a missile designed to be launched from the ground to destroy aircraft or other missiles. It is one type of anti-aircraft syst ...

s. The

ground burst A ground burst is the detonation of an explosive device such as an artillery shell, nuclear weapon or air-dropped bomb that explodes at ground level. These weapons are set off by fuses that are activated when the weapon strikes the ground or som ...

detonation of a laydown delivered weapon is used to increase the effect of the weapon's blast on built-up targets such as

submarine pen A submarine pen (''U-Boot-Bunker'' in German) is a type of submarine base that acts as a bunker to protect submarines from air attack. The term is generally applied to submarine bases constructed during World War II, particularly in Germany and ...

s, or to transmit a

shock wave In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a me ...

through the ground to attack deeply-buried targets. An attack of this type produces large amounts of

radioactive fallout Nuclear fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and the shock wave has passed. It commonly refers to the radioac ...

Weapons with laydown delivery options

United Kingdom

The issue of aircraft survivability lead to laydown being selected for the

Vickers Valiant The Vickers Valiant was a British high-altitude jet bomber designed to carry nuclear weapons, and in the 1950s and 1960s was part of the Royal Air Force's " V bomber" strategic deterrent force. It was developed by Vickers-Armstrongs in respon ...

bomber of the

Royal Air Force The Royal Air Force (RAF) is the United Kingdom's air and space force. It was formed towards the end of the First World War on 1 April 1918, becoming the first independent air force in the world, by regrouping the Royal Flying Corps (RFC) an ...

, as the design became increasingly vulnerable to Soviet weapons, especially the SA-2 missile. The low-level laydown delivery was referred to as "Equipment 2 Foxtrot" in RAF parlance; alternatives included "2 Echo"

toss bombing Toss bombing (sometimes known as loft bombing, and by the U.S. Air Force as the Low Altitude Bombing System, LABS) is a method of bombing where the attacking aircraft pulls upward when releasing its bomb load, giving the bomb additional time of f ...

and "2 Hotel", a particular climbing delivery method used by the

Avro Vulcan The Avro Vulcan (later Hawker Siddeley Vulcan from July 1963) is a jet-powered, tailless, delta-wing, high-altitude, strategic bomber, which was operated by the Royal Air Force (RAF) from 1956 until 1984. Aircraft manufacturer A.V. Roe an ...

.Kristan Stoddart
"Losing an Empire and Finding a Role"
Palgrave Macmillan, 2012, pp. 104–106.

United States

B28 bomb The B28, originally Mark 28, was a thermonuclear bomb carried by U.S. tactical fighter bombers, attack aircraft and bomber aircraft. From 1962 to 1972 under the NATO nuclear weapons sharing program, American B28s also equipped six Europe-based ...

— Only in the RE (retarded external), RI (retarded internal) and FI (full-fuzing internal) versions of the weapon. The RE and RI versions of the weapon used the W28 mod 1 warhead and were an interim weapon only capable of laydown delivery at altitude, while the FI version using W28 Mod 2 and later warheads was capable of delivery. * B53 bomb — Full-fuzing option (FUFO) weapon with laydown. The weapon later lost FUFO in its B53-1 upgrade in 1988, having only laydown fuzing. * B61 bomb — Full-fuzing option (FUFO) weapon with laydown. Capable of laydown delivery at altitude. * B83 bomb — Full-fuzing option (FUFO) weapon with laydown.

References

Nuclear weapons Aerial warfare strategy Aerial bombing {{nuclear-weapon-stub

Weapons with laydown delivery options

United Kingdom

United States

See also

References