July 3, 2013
The Booming Business Of Fireworks
I know that creating fireworks displays is a complex endeavor. I didn’t realize quite how involved it is until I started doing a little research. The basic shell components are not all that difficult to put together, but you don’t want to make a careless mistake! The fuse on the firework ignites a lift charge and an additional time fuse. When the shell reaches the desired height, the time fuse lights the bursting charge which releases the colorful sparkles that light up the sky. The boom is caused by the rapid release of energy into the air.
The appearance of a particular burst depends on many things. The black powder used in fireworks is composed of three things: saltpeter, sulfur and charcoal. According to a NOVA program on fireworks, the ways these chemicals are ground and combined determines how they burn. To produce the lifting charge, the fireworks maker grinds these ingredients for many hours, presses them into cakes and breaks them up into a coarse powder. Mixing the grains so that the individual ingredients are still distinguishable produces a slower burning product that makes up the sparkly part. This powder is also pressed into marble-sized balls called stars. The number of these in the shell and the way they are packed determines the shape of the firework burst.
By replacing the traditional potassium nitrate of gunpowder with potassium chlorate, the fireworks creator increases the temperature of the reaction from 1700̊ Celsius to 2000̊ Celsius. This temperature increase allows the use of mineral salts that won’t burn at lower temperatures. These mineral salts create the colors. Copper produces blue, strontium produces red, barium produces green, sodium produces yellow, etc. This innovation was added in the 1830’s. Prior to that time all fireworks were silver and gold.
The length of the shell determines how high the firework will rise into the sky. Each inch correlates to a 100-foot rise into the air. The shell blasts into the air within 15 milliseconds of igniting the powder, traveling upwards at 300 miles per hour.
The method of ignition is the one part of the process that has seen dramatic changes in recent years. The ignition is now computer generated, which allows for extremely precise firing and coordination with music, lasers and other features of a modern show. Most shells are shot from mortars packed in sand and racks for stability.
Most, but not all, of the fireworks used in America today are made in China. Even so, fireworks in America is a billion-dollar industry. Two of the largest fireworks producers in the United States can be found in one town, New Castle, Pennsylvania. The companies are Zambelli and Pyrotechnico. Between the two, they produce nearly 5,000 fireworks displays a year, a quarter of which are held around the Fourth of July.
New Castle calls itself The Fireworks Capital of America. In fact they trademarked the name in 2006. There was an influx of Italian immigrants to New Castle around the 1890’s. Five of these families set up fireworks companies. One of these immigrants was Antonio Zambelli who arrived from Naples in 1893. He kept his fireworks recipes in a small, black book that is still locked in the safe at the Zambelli company.
The Zambelli company can create around 640 fireworks a day by hand. They may pack as many as 16 features into one shell. Less complicated shells come from China.
Nearly two million fireworks are stored year-round at the Zambelli plant. This number includes 3,200 varieties. The plant is 200 acres, surrounded by a chain-link fence with guards stationed to watch over the loading of trucks. There are 70 small buildings at the plant, limiting the number of fireworks stored in one building. Each building has concrete walls filled with sand, so that if there should be an explosion. the building would blow up, not out. There is nothing in these buildings that could create a spark. There are no exposed nails. All the employees must wear only cotton clothing, down to the underwear. They wear no hardhats and no gloves.
Six packers begin to assemble fireworks for the July Fourth shows in February. In May, another 20 workers come on board to help load. The factory operates 12 to 15 hours a day, seven days a week until July 4. 1,300 technicians do the shows. Pyrotechnico operates much the same way.
Organizing and setting up a huge display is a massive production. Fireworks technicians have to coordinate with the fire department and all appropriate law and property management agencies. These could include local and state police, park rangers, the Coast Guard (if the show is over water), city and county officials, etc. It can take as long as a week to set the wiring for a large show. They also have to keep an eye on the weather. Damp powder won’t light. Lightning or static electricity could set off a firework at an unplanned time. Fireworks techs have to be cautious, vigilant, and fearless.
Fireworks shows can cost anywhere from $15,000 to more than $100,000. The display put on by the Boston Pops every year uses 3.5 tons of explosives shot from 5700 mortars.
Another new feature of a major fireworks display is a command center filled with live monitors. From this vantage point the technicians can keep track of weather radar and link to police helicopters with cameras and thermal sensors aboard as well as viewing the show itself from several angles. The techs in the center can communicate with the field techs using two-way radios.
That’s a lot of effort for something that may only last for 20 minutes, but it is certainly worth it. Ooooh, aaaah!
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