Warhead

A B61 nuclear bomb in various stages of assembly; the nuclear warhead is the bullet-shaped silver canister in the middle-left of the photograph.

The term warhead refers to the explosive material and detonator that is delivered by a missile, rocket, or torpedo.

Etymology

During the early development of naval torpedoes, they could be equipped with an inert payload that was intended for use during training, test firing and exercises. This was referred to as a "peacehead". The explosive payload carried by weapons intended for use in combat became known as a warhead. The term "peacehead" subsequently fell out of use.

Classification

Types of warheads include:

• Explosive: An explosive charge is used to disintegrate the target, and damage surrounding areas with a shock wave.
  • Conventional: Chemicals such as gunpowder and high explosives store significant energy within their molecular bonds. This energy can be released quickly by a trigger, such as an electric spark. Thermobaric weapons are something of a special case.
    • Blast: A strong shock wave is provided by the detonation of the explosive
    • Fragmentation: Metal fragments are projected at high velocity to cause damage or injury.
    • Continuous rod: Metal bars welded on their ends forming a compact cylinder of interconnected rods, which is violently expanded into a contiguous "zig-zag" shaped ring by an explosive detonation. The rapidly expanding ring produces a unique planar "guillotine" effect that is particularly devastating against military aircraft, which are designed to be resistant to traditional shrapnel.
    • Shaped charge: The effect of the explosive charge is focused onto a specially shaped metal liner to project a hypervelocity jet of metal, to perforate heavy armour.
      • Explosively formed penetrator: Instead of turning a thin metal liner into a focused jet of metal plasma, the shaped charge is directed against a concave metal plate at the front of the warhead, propelling it at super high-velocity while simultaneously deforming it into a dense ogive projectile
  • Nuclear: A runaway nuclear fission or nuclear fusion reaction causes immense energy release.
• Chemical: A toxic chemical, such as poison gas or nerve gas, is dispersed, which is designed to injure or kill human beings.
• Biological: An infectious agent, such as anthrax spores, is dispersed, which is designed to sicken or kill humans.
• Kinetic: Collides with the target at high speed. A detonation is not necessarily required.

Often, a biological or chemical warhead will use an explosive charge for rapid dispersal.

Detonators

The types of detonators are:

• Contact: When the warhead makes physical contact with the target, the explosive is detonated. Sometimes combined with a delay, to detonate a specific amount of time after contact.
• Proximity: Using radar, sound waves, a magnetic sensor, or a laser the warhead is detonated when the target is within a specified distance. It is often coupled with directional explosion control system that ensures that the explosion sends the shrapnel primarily towards the target that triggered it.
• Remote: remotely detonated via signal from operator (Not normally used for warheads except for self-destruction)
• Timed: Warhead is detonated after a specific amount of time.
• Altitude: Warhead is detonated once it falls to a specified altitude. See air burst.
• Combined: Any combination of the above.

See also

• Guidance system
• List of aircraft weapons
• List of missiles
• Nuclear weapon yield
• Missile and

References

1. The Nuclear Weapon Archive. The B61 (Mk-61) Bomb - Intermediate yield strategic and tactical thermonuclear bomb. [1]
2. GlobalSecurity.org The B61 thermonuclear bomb. [2]
3. The Brookings Institution. B61 Nuclear Gravity Bomb. [3]
4. Stephen I. Schwartz. Atomic Audit - The Costs and Consequences of U.S. Nuclear Weapons Since 1940. Brookings Institution Press 1998 c. 700pp. [4]
5. Ogden Air Logistics Center at Hill AFB, Utah. B61 THERMONUCLEAR BOMB. [5]
6. National Nuclear Security Administration (NNSA). NNSA Achieves Significant Milestone for B61 Bomb. June 30, 2006. [6]
7. Chuck Hansen, U.S. Nuclear Weapons: The Secret History, (New York: Orion Books, 1988), pp. 162-164.