In the basement of his Kennett Township home, Tom Burns constructed a medieval siege weapon. But he wasn't planning an attack. His trebuchet was built with one goal in mind -- hurling pumpkins great distances.

The Sanford School senior and his team won third place in the age 11 to 17 youth division at the 2006 World Championship Punkin' Chunkin' in Millsboro, Del., on Nov. 3 through 5. His home-assembled trebuchet launched its best chunk on the last day, when it really counted. The 4-pound pumpkin flew 587 feet, two feet short of second place. The first place winner chunked 729 feet.

Burns was thrilled with their success. This was his third year in the contest and this was a big improvement over the previous years. He is captain of the Sanford Punkin' Chunkin' club team, president of the science club and an advanced placement physics student. But he is most proud of his distinction as designer and builder of the "Arbiter" -- his best trebuchet yet.

A lot of science, engineering and physics go in to the design that derives its energy from counter weights on a lever arm. To the uninitiated the trebuchet in action is somewhat reminiscent of a mechanized hammer throw. Burns' design has been evolving for the past three years. As a sophomore he began to learn how not to build a trebuchet when the Sanford team pumpkin only went 250 feet. As a junior he designed the team trebuchet and it was even worse. "We regressed in distance," he said. "Only 133 feet. The winner was 750 feet. We were way off."

At the 2005 event, Burns made a lot of contacts, took a lot of photos and learned a lot about chunkin' pumpkins, and zeroed in on a "whipper" design. He went home and over the winter built a 5-foot high prototype that hurls baseballs and proved he had a whipper that worked. In the summer he created the Arbiter using lumber donated by Danby Lumber. He used 45-pound bench press weights. The maximum weight his design could use was 360 pounds. He made it in pieces in assembled it outside the family's Bayard Estates home. From the base to the tip of the arm measures 17 feet and it is 13 feet long.

Once the device was assembled in the Burns' driveway, the problem was where to do a test launch. A neighbor who owns and farms the land behind their development was intrigued and provided the solution, even mowing a swath of his hayfield for the launch area. Without the availability of pumpkins in mid-summer, Burns filled soccer balls with sand and launched them across the field. The Arbiter was ready; it worked perfectly.

The Sanford team disassembled it, loaded it on to a flatbed and took it to school to reassemble and demonstrate. At an all-school event in front of the lower school, middle school, upper school, faculty, staff, administrators and parents they launched the Arbiter. And because high school is supposed to be embarrassing, the four-pound orange missile went backwards.

"But," Burns said, "it went backwards impressively. It went more feet backwards than it had gone forwards in the years before."

Their next stop was Sussex County, Del. Burns said 100 teams participated in the enormous World Championship Punkin' Chunkin' event that includes divisions for centrifugal, catapult, trebuchet, human power, torsion and compressed air launches. There were 10 teams in the youth trebuchet division. About 35,000 spectators attended with tailgating extravaganzas and wild costumes. Fans of the Sanford team came to cheer on the Arbiter.

There was a launch each day with a free fire each night. The team would film their launches, study the replays and refine the technique for the next launch. The first day the Arbiter pumpkin flew 374 feet. The second day it flew 469 feet. On the third day the team held nothing back and loaded on the maximum 360 pounds of weight and came through with a 587-foot third place chunk. That final throw broke the arm and bent the axel. But, that no longer matters.

The Arbiter's job was done and Burns will leave the rising seniors in the Sanford club to improve on his design. By next year's event Burns will be 18 and have to compete as an adult. He hopes to study civil engineering in college next year, hopefully at either Lehigh University, Pennsylvania State University, Virginia Tech or the Coast Guard Academy.

For more information on Punkin' Chunkin' visit the Web site Toview video of the Arbiter chunk, search Arbiter trebuchet on

UTo contact Prue Osborn, email

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