Content Team 
Every year on July 4th a huge display of pyrotechnic wonder rumbles over the 700,000 people that annually make their way to the National Mall in Washington, D.C. for the Capitol Fourth event. And every year it seems to get bigger and better with the fireworks lighting up the sky longer and more brilliantly than in years past. But who is behind this marvel of technical accomplishment, what tools do they use, and how do they do it year in and year out? We have dug into the details and will take a look into the science, tech and people behind the annual visual extravaganza.
Who is behind these explosive firework shows?
This year the honor went to the protechnic professionals from Garden State Fireworks from New Jersey who have a long history of working in the firework industry with over 4 generations of experience dating back to 1890. An honor they have had every year since 2013 and each year they seem to rise to the challenge to provide something new and exciting.
Not only are they in charge of the fireworks display the night of the show, but are in charge of planning and choreographing the entire event. This year’s show took months of planning and nearly a week of setup to get the close to 2400 individual firework shells included in the incendiary exhibit ready to go.
And it is worth noting that prior to Garden State Fireworks current run of 11 straight Capitol Fourth events, another prominent company in the pyrotechnic industry from Tennessee named Pyro Shows ran the event from 2012 back through 2003 consecutively (and was chosen for the honor 13 times between 2012 and 1995).
With the magnitude of the show, in both the number of fireworks included as well as their overall size (i.e, firepower), it is not surprising that this responsibility is only given to those at the top of the firework display and pyrotechnic world.
Where do the fireworks come from?
The fireworks used in the Capitol Fourth show consist entirely of shells, launched from automated mortar systems and come in three distinct sizes, 6 inches, 8 inches and 10 inches. And it may be a surprise for many to learn that every shell is handmade in a very laborious process.
The first step involves creating the outer papershell which are made primarily from cardboard, and then manually filling it with powder (the explosive ingredient) and a lot of paper filling usually waded up into small balls. Once the papershell is nearly filled and close to a ball shape, the final step consists of wrapping these balls with wet paper over and over. A shell is considered completed when enough wet paper has been wrapped around the shell to create a snug and formed sphere. The process is very similar to paper mâché.
While most shows limit their largest shells to 6 inch, that is the starter size for the fireworks show on the Capitol Fourth, as a 6 inch shell is capable of traveling 600 feet in the air and dispersing its explosive and beautiful payload outward another 600 feet. This is the bare minimum required for each shell fired in the 4th of July show and is to ensure it can outreach the Washington Monument which stands at near 560 feet tall.
The overall size of the shells included in the Capitol Fourth show is what separates it from other shows as most of the show includes the larger 8-inch and 10-inch shells which have a viewing distance of over a mile.
What is involved with the firework setup?
Each shell is loaded into its own mortar shute which is first covered with plastic to waterproof it, then with metal foil to fireproof it. Each prearranged group of mortars and their shells are set about in rows and grouped together by size. The largest and most powerful of the fireworks are placed as far away from the crowds as possible. Each group and mortar is finally tarped and covered to eliminate any elemental interference that may come before or during the show.
The last steps are taking the electric match signal cables from each individual firework shell and matching them up with their appropriate terminal module (i.e., local hub) which then routes the cables to a central software system. The electric match is what lights the fuse on each shell and is signaled through its cable by the local terminal or hub which does contain its own local processor and timing programs. With each local terminal also being connected to the central software system, master control is always available for additional flexibility. In the past this was handled through analog switches manually turned by hand on a master firing board, but now it is all done electronically through a pre-programmed software controller.
While people are completely in control, the system is much more hands off now and plug-n play than in the past. This allows for more focus to be paid to big picture processes and more conducting or orchestrating of the show rather than simply firing each shell in its course. This also has the benefit of improved flexibility with increased electrical rather than mechanical control and allows for allowing for more eyes to be on matters like safety, which is always a plus.
What planning is required and what tools are used?
While much technology and science goes into the setup of the firework performance, even more is utilized during its preparation and planning stage. Since each and every shell launched is required to fit into a very specific role in an overarching program, forecasting becomes an important part of the process and an important tool to rely on.
Computers programs are used to assist in calculating things such as shell launch time, fuse light time, explosive burst size and shape to allow them to all fit together into a continuous seamless routine. A routine that not only needs timing but specific spatial coverage to allow all onlookers over a large area to be able see and enjoy the show from all angles and perspectives.
Chemistry is also used to not only improve the fireworks themselves (i.e., components), but knowledge of how specific elements produce different effects and colors at different temperatures is required. Using tools that enable accurate forecasting provides for the necessary planning that allows for the whole to end up greater than the sum of its parts.
At 9:09pm on Tuesday evening, a large boom and a flood of flashing and sparking lights signified the start of the show which, according to the National Park Service (N.P.S), the entity responsible for the overall show, lasted for 17 minutes and 30 seconds. This year’s show, like year’s past, was an amazing and wondrous experience. And I appreciate the people, and the science and tech that make it possible to be even better next year.
If you missed it, you could still watch it using the PBS channel website here: WATCH: A Capitol Fourth 2023 | PBS NewsHour
