The cover price is US$30.00. This book contains 144 pages.
Roman Candle Accident: Comet Characteristics |
|
This article is the second in a series addressing the nature, cause
and course of a most horrific accident caused by a large-bore Roman candle.
These articles are offered in the hope that through a sharing of what
was learned in this case, similar accidents might be avoided in the future. |
|
Reprint
Information: Number of pages = 5. Price for this reprint is the
minimum charge of $5.00.
|
Pyrotechnic Burn Rate Measurement: Interstitial
Flame Spread Rate Testing |
|
There are two general types of burning, sometimes described as parallel
burning and propagative burning. In the previous article in this series,
a method for determining parallel burn rate was discussed (strand testing),
and a simplified method of testing under ambient conditions was suggested.
In the current article, a method for determining one type of propagative
burn rate (interstitial flame spread rate) is discussed. |
|
Reprint
Information: Number of pages = 6. Price for this reprint is the
minimum charge of $5.00.
|
Aerial Shell Augmentation Effects |
|
This article provides information about a method of augmenting an
aerial shell’s aesthetic performance that is simple, high profit and
widely appreciated by display sponsors. This method was first discussed
many years ago by the authors as part of an article on electrically
fired displays. In that article, these effects were described as parasitic
firework effects. They were described in that way because the “parasitic”
firework effects (small shells, mine stars and other small components)
derived their lift energy from other “host” aerial shells. In the present
article, because it is more descriptive, these same effects will be
called augmentation effects. |
|
Reprint
Information: Number of pages = 4. Price for this reprint is the
minimum charge of $5.00.
|
Feasibility Study on the Use of Nanoscale Thermites
for Lead-Free Electric Matches |
|
Electric matches are
used in the pyrotechnic industry to electrically initiate devices
remotely and with precise timing. Unfortunately, most current commercial
electric matches contain lead compounds, which when burned produce
lead reaction products that may cause environmental pollution and
contamination of firing areas. These lead compounds, namely lead
thiocyanate, lead nitroresorcinate and lead tetroxide, are used
in electric match pyrotechnic formulations because a small diameter
resistive bridgewire can reliably initiate them. A possible alternative
to lead-containing compounds is nanoscale thermite materials, otherwise
known as Metastable Intermolecular Composite (MIC) materials. These
super-thermite materials can be formulated to be sensitive to thermal
stimuli, such as resistive heating. In the effort to produce a lead-free
electric match, a feasibility study was performed using nanoscale
aluminum and molybdenum trioxide mixtures in electric match formulations. |
|
Keywords: nanoscale, thermite,
lead-free, electric match, metastable intermolecular composite, performance
test, sensitiveness test
Reprint
Information: Number of pages = 11. Price for this reprint is $5.50.
|
Characterization of Pyrotechnic Reaction Residue
Particles by SEM / EDS |
|
Today the most reliable method for detecting gunshot residue is through
the combined use of scanning electron microscopy (SEM) and energy dispersive
spectroscopy (EDS). In recent years, this same methodology is beginning
to find use in detecting and characterizing pyrotechnic reaction residue
particles (PRRP) whether produced by explosion or burning. This is accomplished
by collecting particulate samples from a surface in the immediate area
of the pyrotechnic reaction. Suspect PRRP are identified by their morphology
(typically 1 to 20 micron spheroidal particles) using a SEM and then
analyzed for the elements they contain using X-ray EDS. This can help
to identify the general type of pyrotechnic composition involved. Further,
more extensive laboratory comparisons can be made using various known
pyrotechnic formulations. |
|
Keywords: pyrotechnic reaction
residue particle, PRRP, gunshot residue, GSR, scanning electron microscopy,
SEM, energy dispersive spectroscopy, EDS, morphology, X-ray elemental
analysis
Reprint Information: Number of pages = 12. Price for this reprint
is $6.00.
|
WARNING: Serious Product Malfunction |
|
In 2003 a fireworks display company experienced two serious malfunctions
of a product. The items were 5-inch White Tiger Tail shells under the
brand name of Flower Basket. These shells are spherical in shape and
at the time were thought to be solid masses of comet composition, without
a shell or other component inside the comet composition. The items were
received in January of 2003. Forty of the comets were fired in a display.
Two of these comets exploded with great violence within their HDPE mortars
as they were being fired, destroying both the mortars and the wooden
racks holding the mortars. (While there were no injuries in this instance,
given the apparent power of the explosions, that certainly was a possibility.) |
|
Reprint Information: Number of pages = 2. |
Flowerpots and Muzzle Breaks |
|
Flowerpot and muzzle break are descriptive terms for two types of
star shell malfunctions. There can be serious safety consequences from
these malfunctions, especially for manually fired displays. Some commonly
held beliefs as to the cause of these malfunctions are challenged by
the available data. This article summarizes some of that data and then
draws inferences from that data. |
|
Reprint
Information: Number of pages = 4. Price for this reprint is the
minimum charge of $5.00.
|
Report on the Initial Testing of Suspect Tiger
Tail Comets |
|
It was previously reported that two out of forty 5-inch White Tiger
Tail comet shells had explosively malfunctioned upon firing, destroying
their mortars and the racks that contained them. While traveling to
conduct display safety training, it was arranged to visit the display
company that experienced the problem with the comet shells. During that
visit, the damaged mortars were inspected, photographed and sampled
for pyrotechnic residues; the problem shells and some similar items
were dissected, their components weighed and photographed; and fifty
of the comet shells were test fired while being video taped. This article
reports on that work. |
|
Reprint
Information: Number of pages = 3. Price for this reprint is the minimum charge of $5.00.
|
The Effect of Reflected Blast Waves in HDPE Mortars
|
|
A recent article discussed a problem with some comet shells exploding
as they were being fired, and thus seriously damaging the HDPE mortars
being used. Included in the article were photographs of the two mortars
that had been damaged. In these photos, it was clear that, while both
ends of the mortars received serious damage, the middle section of the
mortars received less damage in one case and no damage in the other.
This raised a question in the minds of some readers, how could a single
explosion damage both ends of a mortar while leaving the middle of the
mortar essentially undamaged? The purpose of this article is to address
that question. |
|
Reprint
Information: Number of pages = 3. Price for this reprint is the minimum charge of $5.00.
|
Electric Match Lead Splatters |
|
A study of performance characteristics of some common electric matches
had been conducted. During the course of that study, a series of electron
micrographs were made of the residues produced upon firing the electric
matches. Those electric matches using lead mononitroresorcinate as a
significant ingredient of their composition produced some interesting,
albeit incredibly tiny, splatters of molten lead metal. In the thought
that it might prove interesting to users of electric matches, four of
these micrographs are shown in the accompanying figure. |
|
Reprint
Information: Number of pages = 1. |
Color Values and Spectra of the Principal Emitters
in Colored Flames |
|
The emission spectra of many of the more important emitters in pyrotechnic
flames were collected. For this purpose solutions and suspensions of
sodium, potassium, calcium, strontium, barium and copper salts were
aspirated into a propane gas flame as the excitation source. Performing
instrument corrections and using appropriate data reduction strategies
allowed the isolation of the individual spectra. Among these are the
monochlorides and monohydroxides of strontium, calcium, barium and copper.
The CIE color coordinates of the principal emitters were calculated
from the isolated spectra. In addition, a table of normalized band and
line intensities was produced for each of the successfully isolated
emitting species. |
|
Keywords: flame spectra, flame
color, color emitter, color coordinate, monochloride, monohydroxide,
barium, calcium, copper, strontium
Reprint
Information: Number of pages = 22. Price for this reprint is the
maximum charge of $10.00.
|
Further Report on the Testing of Suspect Tiger
Tail Comets |
|
In the hope of avoiding a serious accident, earlier issues of Fireworks
Business carried a report of the powerfully explosive malfunctions of
some tiger-tail comets, and then a brief report of an examination and
initial testing of a number of the suspect comets. Since that time,
samples from one of the suspect comet shells were provided for laboratory
analysis. This article reports on the results of that analysis. |
|
Reprint Information: Number of pages = 2. |
Shogun Electric Match Connectors |
|
The most common point of attachment of an electric match to a fireworks
aerial shell is via the shell leader, and most commonly the installation
of the electric match is performed by a display company when preparing
for a display. Because of the difficulty of performing that operation
with the safety shroud left in place, too often the shrouds are removed
prior to their installation. Unfortunately, while removing the safety
shroud is allowed under a US-DOT exemption, this greatly increases the
likelihood of an accidental ignition. Fortunately, now there is a simple
and effective solution to the problem; the Shogun Electric Match Connector. |
|
Reprint Information: Number of pages = 2. |
The Effect of Intentionally Caused Fire Leaks into
2-1/4-Inch Consumer Fireworks Shells |
|
A series of experiments are being conducted to more definitively establish
the difference between the causes of so-called flowerpots and muzzle
breaks. Testing was performed to document the effect of firing small
firework aerial shells after having intentionally provided fire leaks
into those shells. The idea for this testing originated from a conversation
that occurred during a break between paper presentations at the First
International Symposium on Fireworks. At that time, the authors were
engaged in research to determine the cause and mechanism of some types
of aerial shell malfunctions. This work focused on the time taken for
various size aerial shells to explode after the ignition of their contents
and the time for those same size shells to exit a mortar after ignition
of their lift charges. Based on this work, the authors had concluded
that relatively minor fire leaks (through small holes and cracks) would
be expected to preferentially produce muzzle breaks rather than flowerpots
and that flowerpots must be the result of more substantial fire leaks
into the shells. Part of the reason for the conversation was to solicit
input regarding the authors’ work from two persons highly knowledgeable
in the manufacture of aerial shells. |
|
Reprint
Information: Number of pages = 6. Price for this reprint is the
minimum charge of $5.00.
|
Typical Mortar Recoil Forces Produced When Firing
Spherical Aerial Shells |
|
One of the more common requests for information regards the recoil
force produced when aerial shells are fired from mortars. Generally
the concern is whether some support structure (e.g., roof top, platform
or barge deck) will safely accommodate the dynamic load produced as
shells of various sizes are fired from mortars placed upon the support
structure. Providing a precise answer can be a complex engineering problem,
requiring information that is not readily available. However, providing
reasonable estimates for the recoil forces produced by the firing of
typically performing aerial shells is a relatively easy matter. This
article provides those approximate values for typical 3- through 12-
inch (75- through 300-mm) spherical aerial shell firings. (These values
are only for single break spherical shells; they are not for cylindrical
shells or for so-called stacked, double-bubble, or peanut spherical
shells.) |
|
Reprint
Information: Number of pages = 5. Price for this reprint is the
minimum charge of $5.00.
|
Indoor Pyrotechnics-A Brief Cautionary Message
|
|
The forensic science community has had a long-standing interest in
the analysis of the residues deposited after the deployment of devices
whose operation involves a controlled explosion. For example, testing
for the residues of the compounds of lead, barium, and antimony, used
in the primer of small-arms ammunitions, may be required on the hands
and clothing of individuals to determine whether they may have discharged,
or otherwise had contact with, a firearm. As an extension of research
in the area of gunshot residue analysis, recent work dealing with the
examination of residues from various pyrotechnic devices has revealed
some trends in the chemical composition of the residues of pyrotechnic
devices. A survey of the composition of the starting components and
residues from 150 small, consumer grade pyrotechnic devices purchased
in the United States revealed that more than 30% of the devices contained
some proportion of lead, 5% contained antimony, and 80% contained barium.
These devices included fountains, wheels, and ground spinners that are
likely to be used in family fireworks displays in close proximity to
the spectators. |
|
Reprint Information: Number of pages = 2. |
Manual Firing Delay Times for Aerial Shells |
|
As used in this article, the definition of “manual firing delay time”
is the time interval between the manual ignition of the tip of the shell
leader delay element and when the aerial shell fires from its mortar.
This delay time is of interest in the context of the delay time requirement
in the National Fire Protection Association’s Code for Fireworks Displays
(NFPA- 1123). |
|
Reprint
Information: Number of pages = 4. Price for this reprint is the
minimum charge of $5.00.
|
A Brief Description of the Construction and Functioning
of Common Electric Matches |
|
A simple description of the construction and the physical principles
governing the function of common electric matches and some implications
of these principles for testing and firing them are presented.
Keywords: electric match, heat
resistance, current, volt, pyrogen
|
|
Reprint
Information: Number of pages = 7. Price for this reprint is the
minimum charge of $5.00.
|
A Report on the Fireworks Accident at Carmel, Western
Australia |
|
The investigation into an accident at Carmel, Western Australia in
March 2002 found that the magnitude of explosions occurring in licensed
and unlicensed storage areas was significantly greater than would have
been expected from the UN hazard classification of items stored within
them. Use of revised UN default classification tables for the items
in storage, instead of the previous classification, goes toward accounting
for the violence of the explosions. The official report into the accident
makes a number of recommendations that are of direct international relevance,
such as a minimum safety distance of 400 m (from residential housing
or defined vulnerable facilities) for licensed UN Hazard Division 1.1
magazines regardless of mass of contents (above 50 kg minimum), removal
of a concession that allows for the temporary storage of fireworks in
unlicensed areas for up to 14 days prior to a display, the adoption
of the UN default classification table throughout Western Australia
and the importation of incorrectly classified fireworks to be made an
offence. Keywords: Carmel explosion, UN
hazard classification, safety distance, unlicensed storage |
|
Reprint
Information: Number of pages = 10. Price for this reprint is $5.00.
|
As Defined in Regulation, What is Fireworks Flash
Powder? |
|
Although widely used, the term “flash powder” is poorly defined; there
is nothing even approaching universal agreement about exactly which
pyrotechnic formulations are and are not fireworks flash powders. This
would be of some concern under any circumstance; however, it is the
use of the term—flash powder—in regulations that greatly magnifies the
problem. One might expect that an agency choosing to use the term “flash
powder” in their regulations would have a responsibility to provide
a reasonably precise definition for it; if not providing a generally
applicable definition, then at least a definition for use within the
context of the regulations. Unfortunately, this is not the case. |
|
Reprint
Information: Number of pages = 3. Price for this reprint is the minimum charge of $5.00.
|
An Interesting New Design???? |
|
It is difficult to argue that the quality of Chinese fireworks has
not improved greatly over the past 25 years. However, that is not to
say that on occasion, one still does not encounter quality related problems,
sometimes so extreme that it is hard to believe. The photo in Figure
1 is of a 3-inch (75-mm) aerial shell and is such an example. (The authors
encountered this shell several years ago, while working briefly in Australia.)
Based on the location of the shell’s crossmatched time fuse and suspender
ring, the lift cup has clearly been attached to the side of the aerial
shell. One might suspect that this was an attempt at a cleaver new design,
were it not for the fact that this shell would not fit into a 3-inch
mortar, and that the other 71 shells in the case had been constructed
normally. Before seeing this shell, who would have believed that such
an incredibly obvious error could ever have been made by a worker attaching
lift cups, and if made, how could it have escaped the notice of the
worker packaging shells to make it through any quality control process! |
|
Reprint
Information: Number of pages = 1. |
Product Warning |
|
Display operators need to be aware of the potential for some tiger
tail comets to produce extremely dangerous fallout. The problem was
discovered only recently and was then investigated by the authors on
a visit to the display company’s facility. The shells in question are
4- and 5-inch (100- and 125-mm) White and Red Tiger Tail comets as shown
overall in Figure 1. While all of the shells have the same basic labels,
there were slight differences as noted in Table 1. However, in trying
to determine whether any particular tiger tail comets have the problems
found in the ones being discussed in this article, it is probably wise
to consider that Chinese manufacturers frequently subcontract work and
otherwise share production. Thus, it is possible that not all of the
items labeled and appearing as shown in this article may have a problem,
and it is also possible that items labeled and appearing differently
may have the same problem described in this article. |
|
Reprint
Information: Number of pages = 3. |
From a Technical Standpoint, What is Flash Powder?
|
|
In a recently published article on the regulatory definitions of firework
flash powder it was concluded that none of those definitions provided
sufficient information to objectively establish whether or not a pyrotechnic
composition is a flash powder. That is to say, those definitions are
all subjective to the extent that they depend on the intended use of
the composition and none provide a quantifiable measure that can be
used to determine whether a particular pyrotechnic composition is a
flash powder. The purpose of the present article is to suggest a general
approach that might be used as the basis for producing a quantitative
definition of flash powder. |
|
Reprint
Information: Number of pages = 5. Price for this reprint is the
minimum charge of $5.00.
|
Muzzle Breaks That Appear as Flowerpots |
|
As is sometimes the case when doing research: A) one occasionally
discovers something which was not being sought; B) the thing discovered
then seems intuitively obvious and one is amazed (and a little embarrassed)
not to have figured it out long ago; C) the thing discovered helps to
answer some other previously seemingly inexplicable observations; and
D) one finds there are some new questions for which no certain answer
is immediately available. All four of these happened recently while
the authors were investigating the size of hole in the casing of aerial
shells (of various sizes) that is needed to produce a fire-leak sufficiently
great to cause the shell to explode while it is still inside the mortar.
During the course of those studies, it was found that a number of events,
which visually appeared to definitely be flowerpots, were actually muzzle
breaks. |
|
Reprint
Information: Number of pages = 6. Price for this reprint is the
minimum charge of $5.00.
|
When Is Wind Speed Excessive for the Safe Display
of Fireworks |
|
While working on the 2006 edition of NFPA-1123 Code for Fireworks
Display, the Technical Committee on Pyrotechnics of the National Fire
Protection Association (NFPA) received a request for a “Formal Interpretation”
regarding the 2000 edition of the code. In effect, a request for a Formal
Interpretation is a request for the committee to provide clarification
or a ruling regarding one or more paragraphs in the code. According
to NFPA practice, a request for a Formal Interpretation must always
be phrased in such a way that it can be answered either “yes” or “no”.
This article addresses that request for a Formal Interpretation and
was written because: 1) the question being posed was reasonable and
important; 2) a simple yes or no will not meet the needs of the requestor;
and 3) to stimulate a discussion of the issue, such that the display
fireworks industry might then provide guidance to the committee before
they address the issue at their next committee meeting. |
|
Reprint
Information: Number of pages = 5. Price for this reprint is the
minimum charge of $5.00.
|
Warning Extremely Dangerous Directions for Firing
|
|
The title of this very short article is, in effect, a direct quote
from a label found on some display firework aerial shells. As it turns
out, the label is more literally correct than might have been intended.
Note that one of the instructions is to “LIGHT FUSE BEFORE PUT IN TO
MORTAR…” Few if any would argue that users should not be “warned” about
such “extremely dangerous directions for firing”. As regards this particular
label, it would definitely seem to be a good thing that many inexperienced
users of display fireworks fail to read (and in this case, rigorously
follow) the use instructions accompanying them. |
|
Reprint
Information: Number of pages = 1. |
The Effect of Intentionally Caused Fire Leaks into
3-Inch Display Firework Aerial Shells |
|
This article is the second report on a series of tests to more definitively
establish the difference between the causes of so-called flowerpots
and muzzle breaks. A previous article reported on a similar study using
2-1/4 inch (57-mm) plastic aerial shells (formerly classed as consumer
fireworks). The current article extends the earlier work by considering
relatively high quality, although small, display firework shells. To
conserve space and avoid needless repetition, some of the background
and supporting information presented in the earlier article will not
be repeated in the present article. |
|
Reprint
Information: Number of pages = 4. Price for this reprint is the
minimum charge of $5.00.
|
Fireworks Displays: When is Safe, Safe Enough?
|
|
At a recent meeting of the National Fire Protection Association's
Technical Committee on Pyrotechnics, there was a proposal to increase
the site size requirement for public fireworks displays from the current
70 feet (21 m) to 100 feet (30.5 m) radius per the largest shell size
in inches. It was the consensus of the committee that this was not needed
because fireworks displays using the current distances were “safe enough”.
However, no one was able to substantiate their opinion with data. As
part of that discussion the authors offered their own unsubstantiated
opinion that it was likely that people were at a significantly greater
risk while on the round trip drive to witness a fireworks display, than
from the fireworks in the display. After offering some background information,
this article presents a calculation of the comparative risks of driving
to and attending a fireworks display, estimating that people are at
least 7 times more likely to be killed or injured as a result of driving
to attend a public display than they are from the fireworks in the public
display. |
|
Reprint Information: Number of pages = 2. |
The Effect on Mortars of Explosions within Them
|
|
An earlier article that appeared a little over a year ago discussed
one type of mortar bursting explosion. The article described a process
whereby a sufficiently powerful explosion occurring internally near
the muzzle of a high density polyethylene (HDPE) mortar would not only
burst the top of the mortar, but could also burst the plugged end of
the mortar, frequently leaving the middle section of the mortar fully
intact. Since publishing that article, readers posed two questions:
1) do the conclusions of the earlier article apply equally to explosions
occurring near the plugged end of mortars; and 2) do the conclusions
of the earlier article apply equally to mortars made of other materials.
The simple answers to the two questions are no and yes, respectively.
However, before addressing these two questions, the current article
will very briefly summarize the observations made in the earlier article. |
|
Reprint
Information: Number of pages = 3. Price for this reprint is the minimum charge of $5.00.
|