HAMPSTEAD — North Carroll High School students Tom McVicker and Derrick Poznaniak have built themselves a bridge.
It's a bridge made of balsa wood. It spans just 290 millimeters and has a width of 50 millimeters -- wide enough, perhaps, for a Matchbox car to cross.
Roger Collins, the students' drafting teacher, described their work as a "flat, square-beam bridge." It doesn't have "super-overhead trestles" like the Chesapeake Bay Bridge.
"It looks like those little bridges going over small creeks on back roads," said Collins, who also teaches drafting at Francis Scott Key High School.
Carefully packed, the bridge is en route to Chicago, where the pair have entered their work in the International Bridge Building Challenge.
The contest will be held Saturday at the Illinois Institute of Technology.
The first-place winner will receive a scholarship to the institute.
Tom and Derrick placed second in the local Bridge Building Challenge for Region 6, which includes Carroll and Frederick counties andmost of Western Maryland.
Everybody in Collins' class participated in the local challenge, held in February, but only the first- and second-place winners advanced to the international contest, sponsored by the American Society of Civil Engineers.
Collins said he usually tries to get his students to enter contests. Sometimes classroom competitions are held so "students can understand how drawing relates to structure," he said.
Although the Maryland Society of Professional Engineers offered Tom and Derrick money to defray the costs of theChicago trip, neither chose to go.
The Chicago-bound bridge is the second the pair has made.
The first was destroyed in the local challenge. That's the purpose of the contest, though.
Pressure is exerted on the bridge to test its strength and efficiency, Collins said. In building their bridges, students were given a list of specifiedmaterials and parameters to follow.
"It's an ingenuity-type challenge," Collins said. "They had to leave holes in the bridge in order for the judges to use a stressing device."
Their bridge was able to hold 24 kilograms.
Tom, a 17-year-old junior, said he and Derrick started building their bridge and then came up with a design.
"Their bridge had a very high efficiency," Collins said. "Bridges were judged on the amount of weight they could hold versus the amount of weight of material that went in it. The object was to build the lightest bridge that will hold the most weight."
Tom and Derrick, both Hampstead residents, said they were surprised by their success.
"Wedidn't really expect to do so well," said Derrick, a 17-year-old sophomore. "It took us about a week to build. I had never built anythinglike that before."
By watching their bridge be destroyed, the students learned its weaknesses and made a stronger, more efficient bridge for the international challenge.
"The is a better design," Tom said. "We knew our flaws in the other one. We could fix what we did last time and build it better."
Added Derrick, "It should be betterthan the other one."
Collins said his students get a kick out of watching their bridges be destroyed. As they break, he said students are able to analyze their work.
"The days we test them, it's like having a football game in the classroom," he said. "Everybody cheers every time another weight goes on."