Squib (explosive)

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Pyrotechnic charges from ejector seat of MiG-21F-13 fighter in the Aviation Museum of Central Finland

A squib is a miniature explosive device used in a wide range of industries, from special effects to military applications. It resembles a tiny stick of dynamite, both in appearance and construction, although with considerably less explosive power. Squibs consist of two electrical leads, which are separated by a plug of insulating material, a small bridge wire or electrical resistance heater, and a bead of heat-sensitive chemical composition, in which the bridge wire is embedded.[1] Squibs can be used for generating mechanical force or to provide pyrotechnic effects for both film and live theatrics. Squibs can be used for shattering or propelling a variety of materials.[2]

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.[3] Squibs range in size, anywhere from 0.08" up to 0.6" (~2 to 15 millimeters) in diameter.[2]

History[edit]

Squibs were originally made from parchment tubes, or the shaft of a feather, and filled with fine black powder.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 a cannon.[4]

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".[5]

The famous "Squib Case"[edit]

Squibs are mentioned in the prominent tort case from eighteenth-century England, Scott v. Shepherd, 96 Eng. Rep. 525 (K.B. 1773). A lit squib was thrown into a crowded market by Shepherd and landed on the table of a gingerbread merchant. A bystander, to protect himself and the gingerbread, threw the squib across the market, where it landed in the goods of another merchant. The merchant grabbed the squib and tossed it away, accidentally hitting Finlay Harrison in the face, putting out one of his eyes.

Squibs in films[edit]

The first documented use of squibs to simulate bullet impacts in movies was in the 1955 Polish film Pokolenie by Andrzej Wajda, 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. The creator of the effect, Kazimierz Kutz, used a condom with fake blood and dynamite.[6]

However, the American western, River of No Return, filmed in 1953 and released in 1954, used a blood squib to simulate realistic bullet impact in the story's climax, when the story's antagonist is shot dead. As such, this film precedes Run of the Arrow (1957) – often credited with being the first to use blood squibs – by three years, and Pokolenie by one.

Origin of the phrase "damp squib"[edit]

While most modern squibs used by professionals are insulated from moisture, older uninsulated squibs needed to be kept dry in order to ignite, thus a "damp squib" was literally one that failed to perform because it got wet. Often misheard as "damp squid",[7] the phrase "damp squib" has since come into general use to mean anything that fails to meet expectations.[8] The word "squib" has come to take on a similar meaning even when used alone, as a diminutive comparison to a full explosive.[9]

Film industry[edit]

In the film industry, the term squib is often used to refer variously to electric matches and detonators (used as initiators to trigger larger pyrotechnics). Squibs are generally (but not always) the main explosive element in an effect, and as such are regularly used as “bullet hits”.[10] Conventional squibs fire once, with the exception of eSquibs (proprietary), which fire 200 or more times before depletion.[11]

Today, squibs are widely used in the motion picture special effects industry and theatre productions to portray bullet impacts on inanimate objects or on actors. Simulants such as sand, soil, wood, splinters or in the case of the latter, fake blood, dust,[12] down feathers[13][14] (for the desired stylistic gunshot effect on a down jacket as the costume worn by the actor), water [15] (for rehearsals) or other materials to simulate shattered bone and tissue, may be attached to the squib to simulate the impact that occurs when bullets pierce through different materials.

Automotive industry[edit]

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.

Aerospace industry[edit]

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.[3]

Other uses[edit]

Squibs are also used in automatic fire extinguishers, to pierce seals that retain liquids such as halon, fluorocarbon, or liquid nitrogen.

See also[edit]

References[edit]

  1. ^ Thibodaux, J. G. (July 1, 1961). "Special Rockets and Pyrotechnics Problems". Langley Research Center. NTRS. Retrieved 20 May 2019.
  2. ^ a b "Top 10 Frequently Asked Questions". Fantasy Creations FX.
  3. ^ a b US 5411225  “Reusable non-pyrotechnic countermeasure dispenser cartridge for aircraft”.
  4. ^ Calvert, James B. "Cannons and Gunpowder". University of Denver. Archived from the original on 2007-07-01.
  5. ^ Wallace, Anthony F. C. (1988). St. Clair, a nineteenth-century coal town's experience with a disaster-prone industry. Cornell University Press. p. 50. ISBN 978-0-8014-9900-5.
  6. ^ "Pokolenie". Gazeta Wyborcza. 2008. Archived from the original on 2012-06-03.
  7. ^ "Damp Squid: The top 10 misquoted phrases in Britain". The Daily Telegraph. London. 24 February 2009.
  8. ^ "Definition of damp squib". Allwords.com.
  9. ^ "squib: Definitions, Synonyms". Answers.com.
  10. ^ Fantasy Creations FX. "Top 10 Frequently Asked Questions".
  11. ^ LDI 2014 Award Winners Announced. Nov 22, 2014, livedesignonline.com, accessed 20 May 2019.
  12. ^ "Professional Bullet Hit Effects". Roger George Special Effects. Retrieved 2021-02-06.
  13. ^ Sara Down Jacket Shot, retrieved 2021-08-19
  14. ^ FX (1996). "Fargo (1996) Kill Count". YouTube.
  15. ^ Duerr, Seth; Kirby, Jared (2021). Staging Shakespeare's Violence: My Cue to Fight: Domestic Fury. Pen and Sword History. p. 276. ISBN 1526762439.