Squib (explosive)

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A squib is a miniature explosive device used in a wide range of industries, from special effects to military applications. They resemble tiny sticks of dynamite, both in appearance and construction, although with considerably less explosive power. Squibs can be used to generate mechanical force, as well as to provide pyrotechnic effects for both film and live theatrics. Squibs can be used for shattering or propelling a variety of materials.^[1]

A squib generally consists of a small tube filled with an explosive substance, with a detonator running through the length of its core, similar to a stick of dynamite. Also similar to dynamite, the detonator can be a slow-burning fuse, or as is more common today, a wire connected to a remote electronic trigger.^[2] Squibs range in size, anywhere from 2 to 15 millimeters in diameter.^[1]

Squibs are sometimes confused with electric matches, as well as with detonators. While those are specifically used to trigger larger explosions, squibs are generally (but not always) the main explosive element.^[1]

Contents 1 Uses 2 History 2.1 Origin of the phrase "damp squib" 3 See also 4 References

[edit] Uses

Squibs were once used in coal mining to break coal away from rock. In the 1870s, some versions of the device were patented and mass-produced as "Miners' Safety Squibs".^[3]

Today, squibs are widely used in the motion picture special effects industry to simulate bullet impacts on inanimate objects. Items such as sand, soil, or wood splinters may be attached to the squib to simulate the "splash" that occurs when bullets pierce different materials.^[1]

Although squibs were once used even for the simulation of bullet hits on live actors, such use has been largely phased out in favor of more advanced devices that are safer for the actor, such as miniature compressed gas packs. These alternate devices are often still referred to as "squibs" even though they don't actually utilize explosive substances. The devices (whether explosive or not) are coupled with small balloons filled with fake blood and often other materials to simulate shattered bone and tissue.^[4]

Squibs are used in emergency mechanisms where gas pressure needs to be generated quickly in confined spaces, while not harming any surrounding persons or mechanical parts. In this form, squibs may be called gas generators. One such mechanism is the inflation of automobile air bags. In military aircraft, squibs are used to deploy countermeasures, and are also implemented during ejection to propel the canopy and ejection seat away from a crippled aircraft. They are also used to deploy parachutes.^[2] Squibs are also used in automatic fire extinguishers, to pierce seals that retain liquids such as halon, fluorocarbon, or liquid nitrogen.

[edit] History

Squibs were originally made from parchment tubes, or the shaft of a feather, and filled with fine black powder. They were then sealed at the ends with wax. They were sometimes used to ignite the main propellant charge in cannons.^[5]

Squibs were first used to simulate bullet impacts in the 1957 film Run of the Arrow, where for the first time audiences were presented with a realistic representation of a bullet impacting on an on-camera human being, complete with blood spatter.^[4]

[edit] Origin of the phrase "damp squib"

While most modern squibs used by professionals are insulated from moisture, older uninsulated squibs needed to be kept dry in order to ignite, so a "damp squib" was literally one that failed to perform because it got wet. The phrase "damp squib" has since come into general use to mean anything that fails to meet expectations.^[6] The word "squib" has come to take on a similar meaning even when used alone, as a synonym for dud.^[7]

[edit] See also

• Firecracker

[edit] References