A punkin chunkin is a contest for machines, such as catapults, to see how far
they can throw a pumpkin. The machines don't use any electricity, engines or explosives. One class of punkin chunkin machine uses air power.
Recently, near the Stuff.dewsoftoverseas.com office in North Carolina, a local FM radio station, WDCG-FM, promoted a human-powered punkin chunkin competition.
Some of the promoter's official rules for this competition are quite interesting:
- Pumpkins must weigh between 8 and 10 pounds.
- Pumpkins must leave the machine intact.
- No part of the machine shall cross the starting line.
- For safety, only five people per machine are allowed during the actual contest.
- Absolutely no explosives!
- Machines may have either springs, rubber cords, counterweights, compressed air or any other device that uses the stored power of one human being in a maximum of 10 minutes.
- Machines must be able to reload and fire within 10 minutes.
Teams compete in classifications such as air, centrifugal, catapult, human power, youth unlimited and youth 11-17.
Many of the pumpkin throwing machines are mechanical in design, while the long-range ones use compressed air.
In the 1998 World Championships, an air-powered machine threw a pumpkin 4,026 feet (1.23 km)! In the North Carolina contest, Team Carbo's Onager catapult threw a pumpkin 1,032 feet (314.5 m). The distance is measured by a laser device, similar to what you may see land surveyor crews use along the highway.
Built of heavy timbers and nylon rope and bicycle-powered to help preload the mechanism, the Onager placed second in the national championship in 1999. Onager uses many mechanical devices to throw a pumpkin, as shown at this Web page, including a torsion spring. Torsion means twisting, and in the Onager, the torsion device is a heavy, thick bundle of nylon rope. When released, the device untwists and catapults the pumpkin. Team Carbo tightens the torsion spring bundle with a long lever, and then a winch cinches it down even more with pedal power.
In the photo below, Team Carbo's bicyclist is actually winding a boat winch with gear reduction pedal power. This winch is just above his right foot. Click on the picture to see a 5-second movie in mpeg format.
Below, Team Carbo preloads the heavy yellow nylon rope torsion spring:
Onager's winch is at the bottom; the yellow nylon rope torsion spring is
visible the middle:
Onager's sling is ready to throw the pumpkin, from a hole dug behind the machine. The hole helps keep the pumpkin in place and allows for a longer sling.
Special thanks to program director Chris Edge at WDCG-FM and his staff for their cooperation and assistance.
Here are some interesting links: