A shock tube detonator is a non-electric explosive
fuze
In military munitions, a fuze (sometimes fuse) is the part of the device that initiates function. In some applications, such as torpedoes, a fuze may be identified by function as the exploder. The relative complexity of even the earliest fuze de ...
or
initiator
An initiator can refer to:
* A person who instigates something.
* Modulated neutron initiator, a neutron source used in some nuclear weapons
** Initiator, an Explosive booster
** Initiator, the first Nuclear chain reaction
* Pyrotechnic initiator, ...
in the form of small-diameter hollow plastic
tubing used to transport an initiating signal to an
explosive
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An exp ...
by means of 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 ...
(also known as a percussive wave) traveling the length of the tube.
Shock tube is used to convey a detonation signal to a
detonator
A detonator, frequently a blasting cap, is a device used to trigger an explosive device. Detonators can be chemically, mechanically, or electrically initiated, the last two being the most common.
The commercial use of explosives uses electr ...
. Shock tube is a hollow extruded tube containing a thin layer of energetic material upon its inner diameter. Once it is initiated, the shock tube transfers a signal to a detonating output charge.
It was invented by Per Anders Persson of Nitro Nobel AB, patented,
and sold by them under the
registered trademark
The registered trademark symbol, , is a typographic symbol that provides notice that the preceding word or symbol is a trademark or service mark that has been registered with a national trademark office. A trademark is a symbol, word, or wo ...
Nonel
Nonel is a shock tube detonator designed to initiate explosions, generally for the purpose of demolition of buildings and for use in the blasting of rock in mines and quarries. Nonel is a contraction of "non electric". Instead of electric wires, a ...
,
[James T. Thurman, ‘’Practical bomb scene investigation’‘, p104]
/ref> containing a small quantity of high explosive
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An e ...
, but safer and more reliable than detonating cord
Detonating cord (also called detonation cord, detacord, detcord, primer cord, or sun cord) is a thin, flexible plastic tube usually filled with pentaerythritol tetranitrate (PETN, pentrite). With the PETN exploding at a rate of approximately , ...
with the same quantity of explosive.[ Another early product contained an enclosed combusting, non-detonating fiber.][
]
The most common product is 3 mm outer diameter and 1 mm inner diameter, with a tiny dusting of HMX
HMX, also called octogen, is a powerful and relatively insensitive nitroamine high explosive, chemically related to RDX. Like RDX, the compound's name is the subject of much speculation, having been variously listed as High Melting Explosive, H ...
/aluminum
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It h ...
explosive powder on the tubing's inner surface, which detonates down the tube at a speed greater than but does not burst the tube. Being non-electrical and non-metallic, shock tubes are less sensitive to static electricity
Static electricity is an imbalance of electric charges within or on the surface of a material or between materials. The charge remains until it is able to move away by means of an electric current or electrical discharge. Static electricity is n ...
and radio frequency energy and thus have replaced many uses of electric detonators and are safer to handle and store than detonating cord. A version containing an explosive gas mixture has the additional advantage of being entirely inert until the tubing is charged with the gas.
One manufacturer estimates that over of shock tube are used each year worldwide, in commercial blasting
Commercial may refer to:
* a dose of advertising conveyed through media (such as - for example - radio or television)
** Radio advertisement
** Television advertisement
* (adjective for:) commerce, a system of voluntary exchange of products and s ...
, military demolition
Demolition (also known as razing, cartage, and wrecking) is the science and engineering in safely and efficiently tearing down of buildings and other artificial structures. Demolition contrasts with deconstruction, which involves taking a ...
, theatrical special effect
Special effects (often abbreviated as SFX, F/X or simply FX) are illusions or visual tricks used in the theatre, film, television, video game, amusement park and simulator industries to simulate the imagined events in a story or virtual w ...
s, automobile airbags
An airbag is a vehicle occupant-restraint system using a bag designed to inflate extremely quickly, then quickly deflate during a collision. It consists of the airbag cushion, a flexible fabric bag, an inflation module, and an impact sensor. Th ...
, aircraft ejection seats, IED initiation and professional fireworks
Fireworks are a class of low explosive pyrotechnic devices used for aesthetic and entertainment purposes. They are most commonly used in fireworks displays (also called a fireworks show or pyrotechnics), combining a large number of devices ...
. Shock Tube Detonator is available with an optional patented in-line initiator consisting of a threaded adapter and a pre-installed percussion primer providing convenient and reliable initiation.
See also
* Detonating cord
Detonating cord (also called detonation cord, detacord, detcord, primer cord, or sun cord) is a thin, flexible plastic tube usually filled with pentaerythritol tetranitrate (PETN, pentrite). With the PETN exploding at a rate of approximately , ...
– another tubular explosive cord product with much more explosive and direct explosive effects and ability to directly initiate other explosive charges
References
Detonators
Pyrotechnic initiators
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