R. W. Bickes, Jr. and M. C. Grubelich[Sandia
Laboratories, Albuquerque, NM, USA]
Abstract: We have developed
a silicon semiconductor bridge (SCB) igniter which, when driven
with a low-energy current pulse, produces a plasma discharge that
ignites energetic materials. Our experiments have demonstrated that
SCB explosive devices function in a few tens of microseconds at
one-tenth the input energy of hot-wire devices. Despite the low
input energies for ignition, tests have demonstrated SCB devices
to be explosively safe, passing electrostatic discharge (ESD) requirements
and no-fire current levels. In fact, SCB devices can have better
no-fire characteristics than hot-wire devices, because of the intimate
bridge contact between the underlying thermally conductive substrate.
We have tested several different prototype explosive devices
. In addition, we have tested SCB actuators with breadboarded "smart"
firing sets that will fire the SCB actuators only after transmission
of a digital code, after a preset delay, or in a preprogrammed sequence.
M. A. Williams [Night
Musick, Inc., Denver, CO USA]
Abstract: Professional fireworks
displays, as well as those performed by volunteers, have for many
years relied on equipment designs and techniques that were established
before the turn of the century. The use of steel mortars, the hand
firing of individual aerial shells and the use of wooden racks
for chain firing of finale effects have until recently been the
industry standard. These techniques and designs are adequate for
the use intended, as long as the shells function normally, but
if a color shell "detonates" or a salute explodes in
a mortar, the results can be catastrophic. Since these designs
and techniques first came about, the severity of the legal repercussions
from accidents at displays has increased to the point where such
an event, however unlikely, now represents an unacceptable legal
risk to the display company. In this article, designs are presented
for finale racks and single shot mortars (for use in "dense-pack" style
rack systems) that were developed at Night Musick Inc., and which
significantly reduce the risk of catastrophic equipment failure
in the event of a shell malfunction.
Abstract: This is the second
in a series of tutorials that introduce the concepts of chemistry
to practicing pyrotechnists. The behavior of electrons in atoms
is given as the fundamental explanation for all pyrotechnic processes.
The periodic arrangement of the elements in a table and their tendencies
to unite in chemical bonds are attributed to electrons. Even the
production of heat, light, sound, and color in fireworks are ascribed
to electronic movements.
Lake City, UT, USA] and K. L. Kosanke[PyroLabs,
Inc., Whitewater, CO USA]
Abstract: All pyrotechnic compositions
present some hazard due to their ability to produce energy. However,
some compositions may pose an added hazard because of the combination
of incompatible materials. The use of such compositions may result
in more frequent accidental ignitions during processing or spontaneous
ignitions during storage. Other compositions pose an added hazard
because of their ability to produce especially large amounts of energy
with rapid reaction rates. The use of such compositions is likely
to result in especially powerful explosions in the event of an accidental
This article attempts an organized examination of some combinations
of commonly used pyrotechnic chemicals, which are believed to have
significantly increased hazard potentials.
J. E. Hay [Pittsburgh
Research Center, US Bureau of Mines, Pittsburgh, PA, USA]
Introduction: The treasury department's
Bureau of Alcohol, Tobacco and Firearms (BATF) requested the Bureau
of Mines to perform bullet impact sensitivity tests on a selection
of class B (display) fireworks shells and some ingredients thereof
(flash powder, "stars"), and also to establish that the
flash powder used in salute shells is a detonable material, something
which is widely presumed but apparently not documented.
The fireworks and ingredients to be tested were procured by BATF
from two different domestic suppliers and included a variety of
foreign as well as domestic shells, two different flash powder
compositions, and two different kinds of "stars."
Suppliers of the shells and ingredients are designated in this
report as Manufacturer K and Manufacturer M.
In most cases, there was only one shell of each kind; where more
than one shell of the same kind was available, the shell was impacted
in two different orientations: through the center of the lateral
surface when seated vertically, and through the center of the bottom
when lying on its side. In a very few cases there were more than
two shells, and in these cases a replicate shot using the shell
in one or the other of these orientations was performed. Manufacturer
K supplied shells in both the "lifted" and "unlifted" form. "lifted" refers
to the inclusion of a small charge (several grams to a few ounces
depending on the size of the shell) of coarse black powder which
serves as the propellant charge to eject the shell from the mortar
for aerial displays.
Please send comments and suggested corrections to: B. Kosanke,
Publisher, Journal of Pyrotechnics, Inc.
1775 Blair Road Whitewater, CO 81527 USA
You Can Help Keep Fireworks Legal
Did you know that efforts are underway in the United States at both State
and Federal levels to ban consumer fireworks and rocketry forever? You
can help turn the tide by joining the Fireworks Alliance.
It's free, and we need your voice today!