Fireworks guru going after world record with 62-inch shell

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Winston

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Fireworks guru going after world record with 62-inch shell

https://www.steamboattoday.com/news...-going-after-world-record-with-62-inch-shell/

Borden will launch the 62-inch diameter shell, which weighs an estimated 2,400 pounds, a mile into the air for detonation. It will be traveling at 300 mph when it leaves the ground.

It will be lofted to one mile altitude and the burst will be about one mile in diameter.

Borden is a fireworks nut, who, for several years, through his bank, Yampa Valley Bank, has donated the fireworks for Winter Carnival.

Borden once bought the town of Lay, Colorado, so he could obtain a federal license to manufacture fireworks. Today, he manufactures the big shells at his Steamboat ranch.

Experts Jim Widmann and Eric Krug will come to Steamboat this month to begin building the 62-inch shell.

The job will take 12-hour work days over a three-week period.

The shell will be launched from a mortar tube. The engineering designs for the tube were 60 pages long. The basic tube was built in Washington, and Steamboat Springs welder Rollin' Stone did the finishing work.
Steamboat Springs welder Rollin Stone helped build the mortar tube that will be used to launch the 62-inch shell.

"I spent two weeks in there," Stone said. "It gets hot." The tube is 26 feet long, its walls are 2 inches thick, and it weighs seven tons.

In February 2017, he launched a 48-inch shell, which was the biggest shell ever launched in North America. The 48-inch shell which weighed 1,271 pounds:


fireworks1-620x413.jpg


The mortar for the 62-inch shell:

firework-sbt-060418-1-413x620.jpg
 
The reaches a height of 1 mile and has a burst width of 1 mile....so the bottom stars of the shell will hit the ground?
 
The reaches a height of 1 mile and has a burst width of 1 mile....so the bottom stars of the shell will hit the ground?

Er, no.... Height of a mile. Burst width is 1 mile... So you're still 1/2 mile away from the burst.
 
Unfortunately these very big shells are far less impressive than one would think. In the US the required setback distance for the viewing public is so large that the functioning of the shell is not a big thrill. Think of witnessing the burst then not hearing the boom for 5-6 seconds and it is muffled considerably.
Most FW enthusiasts would much rather be underneath a well made 8 or 10" shell. The close proximity allows for full enjoyment of the sharp break and functioning of the contents.
 
"Borden will launch the 62-inch diameter shell, which weighs an estimated 2,400 pounds, a mile into the air for detonation. It will be traveling at 300 mph when it leaves the ground."

Launch at 300 MPH will reach a maximum altitude of 3011 feet, even with no air resistance considered.
 
Hmmm...I hate to be 'that guy'...but suppose that shell fails to explode in flight? 2400lbs of black powder could make quite a hole, or set quite a fire...Oh well, I will trust they know what they are doing and be glad it's nowhere near my house.
 
My money is on the casing failing during launch...and it explodes in the tube. From what I understand, this is a common mode of failure for shells this big.
 
My money is on the casing failing during launch...and it explodes in the tube. From what I understand, this is a common mode of failure for shells this big.
Yes, it is. Here's why. To reach 300 mph within the 26 ft of the mortar requires 115g acceleration. A 2,400 lb shell would experience 276,000 lb of force. Even if the shell wall can take that, consider the internal components (just "stars" if this is a chrysanthemum shell) mashing against each other under that force. Any pyrotechnic mixture even slightly friction sensitive could ignite or, if it just fragments, produce a mix with a far greater surface area and, therefore, a far greater rate of pressure buildup when the shell is burst at apogee. I'll have to search on how these problems are avoided since even his 48 inch shell would have had these issues as do beautiful Japanese shells that work properly on a regular basis. I know that TIGHT packing of internal components is a way to avoid the friction and fragmenting problem since this avoids movement and allows force distribution and division throughout the contents.
 
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