I chose to explore the world of aerial fireworks primarily because I have experience with them. Most towns around Alaska celebrate the Fourth of July with a large firework display; this is especially true in the Capital. My father is a retired Fire Chief for the Douglas Volunteer Fire Department which allocated me to be part of the fireworks crew for the Annual festivities. The volunteer crew does not get paid to do the work; however the name would suggest that any one could help out, this is not completely accurate because the crew is primarily local fire fighters who have done this work for several years. I’ve helped set up and take down the firework mortar tubes for over 5 years, and, because of insurance reasons, I wasn’t allowed to be on the barge when the ‘powder’ was loaded until I was 18 years old. What barge am I talking about? The fireworks are set up on a large barge and pulled into position downtown in front of the wharf before the show starts.
On average, the number of fireworks set off on the Fourth of July in Juneau is about 800 - 1000 fireworks. The show usually last about 15 minutes with the grand finale at the end. The crew usually spends a combined total of over 500 man hours for the complete show. The crew first gets together before the 1st of July and wires ‘squibs’ to the fuses on the fireworks. A few days later, the barge is ready to be assembled; this involves unloading the mortar tubes and setting up the layout for the barge. There are usually five rows, two wide, of mortar tubes running the length of the barge. Each tube is then loaded with the correct size of shell and effect. So far, this has been the easiest thing to do. The most complicated and time consuming part of the set up is the wiring. Because of the explosive power of the fireworks, these are not ignited by hand. An electrical charge is sent through the wires which ignites the squibs. The squibs are a longer wire that connects to the fuse, when the charge gets to the end of the squib, there is an ignition of the aerial shells fuse.
As an example, the wire used to connect all these fireworks is like a large phone line. If you have ever looked at the inside of a phone wire, there are several smaller lines that are color coded. Each of the colored wires are connected to the squib and then to a control box. The control box is a device that sends a current through each wire when the user completes the circuit.
Okay, enough of the technical stuff….I want to give you an idea of how strong these aerial shells are. I had an experience with a 12” shell exploding in the mortar tube. The mortar tube was ¾” steel and was about five feet tall; obviously if a 12” shell was in the tube, the diameter of the tube was about 12”. The steel tube was placed in the center of a 55 gallon drum, and sand was compressed between the tube and drum. The shell exploded in the tube, blew the 55 gallon drum in half, and shattered the steel tube. Only once piece of the tube was ever found. That piece of tube is still around for a safety reminder. So, an explosive charge from an aerial shell is enough to break ¾” steel.
Also, I’ve seen what happens when a 6” shell hits someone. After
the grand finale, the tubes that did not launch get a flare dropped down
the tube to set the lifting charge off. A person I know ended up getting
a 6” shell across the front of his ‘turnouts’ (fire coat)
which ended up missing his head, but tearing the front of the coat. Anyone
who has ever felt the material on a fire coat can tell you that it would
be very difficult to do damage like that to fire coat in a split second.