Aerial Shells
Safety First
First a few safety guidelines:
Always keep your body parts away from the muzzle of the mortar once it is loaded.
Be weary of cutting the quickmatch if there is an electric match in it. This WILL set if off if you cut through the e-match.
Remember, they are explosives, some more sensitive than others, treat them ALL with respect.
How do you drop and wire an aerial shell for an electrically fired display?
First, unwind the electric match. Lower the shell down into the mortar with the lift charge on the bottom. Make sure the
shell reaches all the way down to the bottom, otherwise the shell will not reach the desired height. Then apply a strain
relief to the wire, and plug it into the appropriate cue number. When plugging in the wire, I typically bend the end of the
wire into a "horseshoe" type shape so that I get that much more metal on metal contact at the cue terminal. Make sure you
crimp the connector down on the wire to ensure proper contact.
Click here to
watch a video explaination of how to drop and wire an aerial shell.
How do I apply a strain relief on the electric match wire?
All methods of wire strain relief have the primary goal of keeping the wire which is hooked into a cue from being pulled
violently away during firing of the shell. If the wire is pulled away (since it is attached to the shell) at high speeds,
it has the potential of prematurely pulling out adjacent cues, rendering them un-fired. A good strain relief will allow the wire
to break on the shell end instead of being pulled out of the cue.
There are quite a few methods for strain relieving a wire, however, I will discuss the two best in my opinion. Namely,
Quick Release Method
Half Hitch Method
Quick Release Method - The quick release method strain relieves the wire, at the same time allowing for an
extremely simple removal of the wire from the mortar at the end of the night. You are literally tying a slip knot. The
knot will not give when the wire is being tuged on during firing, but when pulled from the other end, it comes out with no
effort at all. This method requires a small hole just big enough for the wire to fit through at the top of the mortar.
Click here to
watch a video explaination of how to strain relief a wire on a mortar (same video as above).
Half Hitch Method - This method is used when there is no hole available at the top of the mortar. It is not
as reliable as the Quick release method, however still very effective when done properly. This method consists of creating
a "half-hitch" with the wire, and placing this over the mortar. See picture to the right.
An additional backup technique is to pass the electric match wire between the mortar and the rack it is placed in on the way to
the slave module your going to plug it into. This is of
course after it has been strain relieved by one of the above techniques. See quick release picture to the right.
Do I have to remove the plastic bag that some aerial shells come in?
No. This is really up to you, as it does not effect the performance of the shell. The heat created by the lift charge
literally makes the bag disapear during firing. Just load the shell with the bag still around it. This eliminates the
amount of trash you generate at a show. See picture on the bottom right.
The shell barely fits, will it come out when fired?
Yep. The general rule of thumb is that if you can get the shell to the bottom of the mortar, it will come back out.
Mortars, especially those made of HDPE tend to warp over time. This is ok as long as the shell can still be loaded to the
bottom. It's ok if the shell is a little tight, as this should not effect it's performance. In actuality, it will increase the
height the shell reaches. Now, if you have to cram the
shell down by hammering it in with a stick, that's no good. The shell must be able to slide freely down the gun with a
minimal amount of assistance. In most cases, the shell slides down the gun under it's own weight. Aside from the danger factor, keep in mind that most shells utilize
cardboard for their casing. This cardboard must be able to hold up during the violent process of firing. This is most likely not the case if the shell has to
really force it's way out of the mortar, especially if you have potentially damaged it by ramming it down there in the first place.
If it's raining, can I fire through plastic sheeting?
Yes! You may worry that during a good storm when you have all your guns covered with plastic sheeting that this will impead
the performance of your shells. Nope. Your shells will blow right through the plastic as if it wasn't there. However, it is
reccommended that your plastic be secured to the mortar racks in a very tight fashion. Beleive it or not, if you have the plastic
loose and just drapped over your guns, this will tend to reduce the overall height that the shell reaches. Reason? Simple
physics. If the plastic is left loose, the entire weight of the plastic sheet can contribute to the reduction of momentum
of the shell as the plastic is lifted a short distance before the shell penetrates, instead of the shell just needing to overcome
the structural integrity of the plastic as in the case of the
plastic being secured tightly around the guns. Yes, this is picky picky stuff, but something to consider.
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