Compressed Air Firing Systems

Discussion in 'Fireworks Forum Chat And Discussion' started by Salute, Aug 25, 2003.

  1. A bit ago, DJ Liam made a reference to Disney using a compressed air firing system for their daily fireworks displays at Disney World. I found this intriguing (as did several others) and researched it. Here is what I dug up:

    1. Disney World engineers actually designed and patented this technology out of necessity. Their daily displays were producing a lot of smoke that had local residents worried about toxins and decreased visibility. By cutting out the lift charges which are all black powder, ground level smoke was virtually eliminated. There is also greater control over height, placement of shells and consistancy.

    2. Controlling the pressure of the compressed air determines how high the shell will reach. A sensor is attached to the shell which allows technicians to control when it is to ignite and explode. This allows the bursts to be timed exactly with the music. This is usually governed by software linked through a radio transmitter that can tell the chips in the shells when to let 'er rip. The chips cost about 10 cents each and have to be installed in the shells at production, eliminated the need for quickmatch and a time fuse. The chip does it all.

    3. 2,800 fireworks shells are used for each show and are launched from 750 mortar tubes and 56 firing modules at 34 locations around the lagoon. So, it costs Disney about $280.00 per day to outfit their shells with the chips. Not bad considering.....:O

    4. The military has been using compressed air for years to fire torpedoes (I refer you to Gerry). As little as 50 psi can fling a torpedo out of a submarine.

    Click here IllumiNations Link to read more.
     
  2. Well, we do use it Salute, but not to fling out the topedo, in fact the compressed air is used to fire a water ram, water is used to launch the torpedo from the tube these days.

    Compressed air used to be used, but was a sort of giveaway when it reached the surface as to where you were, and it made a lot of noise.

    The air is now vented back into the boat after firing, lots of popped ears [​IMG]

    Gerry
     
  3. Andy_P

    Andy_P Pro Firer/Crew

    I still cannot get my head round the mechanics of this.

    A normal shell is ignited by either an electric igniter or by conventional fuse and flame. The lift charge sends it on its way, and after whatever delay is built in to the main shell, that bursts too.
    If the shell is launched by compressed air, it still has to be ignighted somehow, either while it is still in the tube, or once it is in the air. If its done in the tube that’s fine but you still have all the variables in the timing as usual.
    To my mind, IF it is done in the air, then you need two things:
    1) the "10cent chip" has to have an energy source, battery or chemical reaction, to ignite the shell, as well as intelligence to do so.
    2) Each of the 2,800 shells would need a separate radio receiver programmed to a particular digital code, (just like car alarms have)

    I cannot imagine that these two requirements could be achieved in a package much smaller than a key fob, which would cost much more than 10c.

    Also there would need to be a fairly powerful transmitter, to reliably broadcast over the distances involved, designed with some epic fail safe features

    I’d love to be proved wrong, anyone got more details or ideas
     
  4. djliam

    djliam Pro Firer/Crew

    Air-launch is a simple idea; instead of launching fireworks shells with black powder explosions, like a cannon shot, you use compressed air.  By varying the pressure, you can control the height.  Along with that simple idea comes one very complicated problem: in a conventional firework shell, it is that launch explosion that ignites the time fuse, and the time fuse is what eventually causes the shell to explode.  When you do away with the initial ignition, you have to have an alternate method of lighting the shell once it gets up into the air.  Disney developed a teeny-tiny computer chip that carries not only the charge for igniting the shell, but also the timing information that allows the ignition to be up to 500 times more accurate than a conventional shell.  With such precise control over altitude and ignition time, all kinds of new creative effects are possible.  

    With conventional shells, you just stick some pipes in a ditch filled with sand and you have a launch site.  Air-launch requires a "launcher" consisting of air tanks, a compressor, a power supply, and a computer.  It's a more expensive setup, which has been the reason it has not been widely adopted.  Air-launch enabled the "shooting star" effect used in "Holiday IllumiNations" and has been used in a limited fashion at Disneyland for testing.  Currently it is used for the opening effect of "Reflections of Earth" which is the "shooting star" effect plus a secondary effect of a pair of shells, which meet up with it at a precise point in the sky over the lagoon.  Both the "shooting star" and "Mickey Ears in the Sky" are effects I developed with the air-launch team in Florida, which are used in Disneyland's "Believe – There's Magic in the Stars" show.

    Taken from http://themeparkadventure.com/OLFMillennium1.htm

    Probably isn't much more help, but...........

    DJ
     
  5. Chesterfield Fireworks

    Chesterfield Fireworks Pro Firer/Crew

    I there huge cost in setting this kind of system up initially?? and is it more suited to "static" firing sites such as the theme parks.???



    just wondered why it was not more widely used if it offered such flexibility
     
  6. wouldnt you need a licence for compressed gas using this system, as well as a whole set safety guidelines