Steamboat Springs — Steamboat Springs fireworks enthusiast Tim Borden is ready to make history again Saturday when he launches what is believed to be the heaviest firework ever launched in North America.

“We’re sure that there’s going to be an explosion in the mortar, and then what happens after that is exciting for all of us to see,” said Borden, who buys the Winter Carnival fireworks every year on behalf of Yampa Valley Bank.

The monster 48-inch shell weighs in at 1,271 pounds.

Fireworks experts Jim Widmann, Eric Krug and Dan Ramsauer were at Borden’s fireworks manufacturing facility Thursday putting the finishing touches on the shell.

It took Widmann a month to build the shell, which will be launched at the end of Saturday’s Night Extravaganza at Howelsen Hill.

The experts learned from last year’s Winter Carnival, when they first launched a 48-inch shell.

“There were a lot of successful things that happened last year,” Krug said. “It’s really about minor adjustments.”

Last year, they were conservative with the amount of explosive they used to launch the shell into the air. They did not want it to go too high or risk having the shell disintegrate from the blast.

The shell could have gone higher though, and they are upping the amount of explosive to more than 50 pounds. The exact amount is a closely-guarded secret.

Another adjustment the team has made ensures the shell fits tighter into the mortar, which is permanently buried in Emerald Mountain.

On Thursday, Widmann was using his custom-built machine to wrap additional layers of tape around the shell.

Something special was embedded into the firework, as well.

During a hunting trip in Africa, Borden spent $50 to buy five “lucky beans.”

“They claim they give you good luck over there, and they’re hard to find,” Borden said.

On Friday, three fuses were inserted into the shell.

“If one fails, the other two will make sure,” Widmann said.

On Saturday, the firework will be loaded onto a trailer, equipped with skis rather than wheels, and taken to the launch site.

Right after a 24-inch shell is launched, Borden will stand 1,000 feet away and push the magic button that will blast the 48-inch shell into the air. Once the fuses run down, the shell should explode, shooting a gold color that will turn to silver. There will also be a ring of gold that will turn to red.

To reach Matt Stensland, call 970-871-4247, email mstensland@SteamboatToday.com or follow him on Twitter @SBTStensland