ARTHUR - High school shop class used to be pretty pedestrian: Maybe you'd make a nice ashtray in those far-off days before the onslaught of nonsmoking political correctness. In more recent years, students drag home stuff like earnest shelving units or maybe a really useful magazine rack.

Few kids in the history of the world get to wow their mom with a medieval siege weapon.

But in the year of our Lord 2007, those most perfect and gentle Knights of Arthur were faced with a vexing dilemma: Other young squires wished to confront them on the field of honor and see how far they could hurl a humble pumpkin. Arthur, as in Arthur Junior-Senior High School, where sporting teams are known as the Knights, set forth a simple riposte to this insolent challenge: "OK, varlets, bring it on."

All of which led directly to the class-made siege weapon but, first, some more prolog to this epic saga would no doubt be helpful.

The actual lead-up to the great pumpkin chuckin' contest was a meeting between Arthur Principal Philip Hise and the principals of Arcola and Villa Grove high schools. As these high-power gatherings are wont to go, the subject of pumpkin projectile competitiveness inevitably arose, and it was agreed that teams from each school would gather at Rockome Gardens near Arcola on Oct. 27 to duke it out.

The method of lofting pumpkins was left up to the individual educational establishments, and Arthur's Knights put aside their shelving units to build a trebuchet - 10 feet tall and 20 feet long. "We figured go big or go home," said 18-year-old senior Corey Dowd who, perhaps not surprisingly, plans to pursue a career trajectory in civil engineering.

The trebuchet hit its stride as a war weapon in the 12th century and is basically a hot-rodded sling shot: A throwing arm has a sling attached that holds the projectile. A heavy weight on the other end of the arm is released to plunge the arm downwards, and the ensuing complex ballet of leverage and fulcrum physics accelerates the force applied to flinging the payload - or pumpkin - over and forward.

The biggest historical trebuchets could hurl 250-pound boulders 200 yards and punch them clean through castle walls. Richard the Lionheart, of psychotic Crusader fame, loved his trebuchets so much that he gave them names such as "God's Own Catapult" and "Bad Neighbor." They could also be used to fling rotting human or bovine corpses over the battlements to put defenders off their lunch and spread disease: the first example of biological warfare field artillery.

"Now, if we look at this computer model, we can see our pumpkin was going about 100 mph when it left the trebuchet," says life sciences teacher JD Graham, having just explained the bit about trebuchets and decomposing ammunition. He's actually wearing an Arthur trebuchet team T-shirt emblazoned with "Over Knight Delivery" that shows a dead red cow being fired through the air. "That velocity means our pumpkin was accelerating with a force of 100Gs," he continues. "A fighter aircraft can pull about 12Gs for a moment."

Graham only got to make stuff like ashtrays and shelves in his own school days, and his eyes gleam with the kind of enthusiasm rarely seen in the vicinity of any class-made shelving unit. "This trebuchet has kind of taken over my life," he says. "But it's really so exciting because of the kids' enthusiasm: They're the ones that worked on it before school, during school and after school."

In fact, the trebuchet project scored a bull's-eye with everyone. It wound up needing the creative and constructive efforts of 40 students, led by Graham, industrial technology teacher Michael Reynolds and math and physics instructor Mark Smith. There also were parents involved, school administration, school board members and all kinds of Arthur businesses that donated supplies and expertise as needed.

One student even found a program on the Internet that can be used to calculate the physics and mechanics of trebuchet operation. It took about four weeks of work to design and build the machine and, as it took shape, a sense of community spirit and achievement arose right along with it. "I've been teaching now for 31 years," says Reynolds. "And this is probably one of the most exciting things I've ever done."

When the day of the great challenge finally dawned, Dowd recalls the kind of festive, anticipatory atmosphere normally associated with a sports duel: Dozens of parents showed up to watch, and somebody even brought along a grill and cooked out. "We all tailgated; it was just like a football game," adds Dowd. "Nothing like this has ever happened in our small town."

How did this Knight's Tale end? Most perfectly. King Arthur kicked medieval butt when the team punched an 8-pound pumpkin an astonishing 450 feet; Arcola came in a distant second at 112 feet, using its own version of the trebuchet, while Villa Grove's giant catapult was good for a 97-foot lob.

Tony Reid can be reached at treid@herald-review.com or 421-7977.