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San Diego's Fireworks Show Over In 15 Seconds
First time accepted submitter fotoguzzi writes "Garden State Fireworks is investigating how the entire Fourth of July show was launched after a signal was sent to the barges that would set the timing for the rest of the show after the introduction. Can anyone suggest how such a trivial step could go so disastrously wrong?" It's not the first time such a thing has happened, either.
When I was in college I saw something similar. It was a sticky hot 4th of July evening. Just as the show was starting a big thunderstorm moved in. When they shot the first couple of rockets up, big flashes of lightning arced through the clouds in response. It was pretty impressive. They decided to shoot everything off at once, one after another; fireworks, thunder claps, lightning, all at once. It was totally awesome. Then it started to rain and all the braless coeds in tee-shirts had to walk back to campus. One of the better displays I've ever seen.
I have designed the electronics and software of a fireworks firing system for a company that does regular shows here in Catalonia/Spain.
Believe me, experienced people are very cautious in everything they do, but unexperienced people can make big mistakes if they are overconfident in a black box system that will do everything for them.
In one point specifications said:
-The firing system must make an autotest for each circuit for the team to check all connections are in place.
They test the firing circuits of the fireworks several times before the show to fire all the material. In our case it was done exciting the fuses (sorry I'm not native english) with a safe very low current to see if the fuse is electrically present, and the inspections does a check of a circuit every 0.05s, so you can check the entire show in a few seconds.
For me this seems the check was done with full current on the circuits which fired all the fireworks during this test procedure.
It's quite surprising to have someone design a system that lets this happen from my point of view, in our case we made the circuits impossible (due hardware to redundant hardware switches and circuits) to excite to fire during the test (there are various physical limiter).
So... it seems someone who had not enought experience with fireworks managed to build his system and convince this people to use it... but its surprising, it's a pretty conservative people, at least the ones I know.