The Big 10 Inch (BTI) pneumatic cannon holds the Guinness Book of World Record for launching pumpkins over a mile at speeds that approach the local speed of sound. It is set to compete again at the World Champion Pumpkin Chucking (that’s pronounced “Punkin Chunkin”) competition this year. The BTI set the record in Moab, Utah in 2010 by launching a 9-lb, 12-oz Las Estrellas pumpkin over a distance of 5545.42 ft.
The World Champion Pumpkin Chucking event this year will take place in Bridgeville, Delaware on November 4, 5, and 6. There, world class competitors including Big Red and Death Star will make attempts to launch their pumpkins as far as they can. The event expects to see more than 2-dozen air cannons.
While in previous years, the BTI team has tried growing pumpkins in a round mold, this year, they will choose six of the roundest, densest gourds from a sample of over 1000 naturally grown pumpkins from local farmer in Delaware. The perfect pumpkin will be as close to the 10-lb. limit as possible, and will be small so as to minimize surface area for lower drag.
The pumpkins exit the 100-ft. cannon at speed exceeding 1000 feet per second, or 680 miles per hour. It uses a two-stage 3000-lb. ASME-code pressure tank run by a 25 horsepower motor that compresses air to 300 pounds per square inch. When decompressed, this runs a refrigeration cycle that builds ice around the exit of the compressor.
At such high speeds, the pumpkin are subjected to about 500 G. Team leader, Ralph Eschborn,puts this into perspective by saying pilots black out at about 6 or 7 G, while 50 G can kill someone in a car crash, and 501 G makes pumpkin pie-- which means that the pumpkin explodes upon exiting the cannon. With a 10-lb. pumpkin approaching speeds close to the speed of sound, the momentum transfer to the system is enormous.
When asked if the team foresees breaking another record this year, Eschborn says that the outcome depends mostly on the weather and air quality. The record in Moab was partially due to the thinner air at high elevation. Still, the specs are impressive and powered by compressed air. People interested in seeing the World Champion Pumpkin Chucking event can purchase tickets here.