Rule No. 1 when you win a bridge-building contest: Don't burn any bridges.
That explains why there was absolutely no gloating last week when three teen-agers from South-Central Los Angeles unexpectedly licked the competition in a Popsicle-stick construction tournament involving Los Angeles County's brightest physics students.
The victory by 17-year-olds Carlos Enllanche, Pedro Garcia and Victor Preciado of Jefferson High School was unexpected because California's most famous professional bridge builder had predicted that a rival entry would be the hands-down winner.
Contractor Clinton C. Myers--who earned national acclaim after last year's earthquake by rebuilding a pair of destroyed Santa Monica Freeway bridges in only 66 days--had praised the sturdy look of a stick bridge designed by a trio of students from private Oakwood School in North Hollywood.
Myers was among seven builders and engineers judging the contest, conducted by the American Society of Civil Engineers at Loyola Marymount University in Westchester as part of National Engineers Week. Nearly 300 students from 27 high schools competed.
Enllanche, Garcia and Preciado had listened silently as Myers predicted that the Oakwood entry would "take a tremendous load"--more than 500 pounds--when each of the 45 stick bridges was subjected to a crush test in the final judging.
"Some of these others won't hold 100 pounds," Myers said.
Pointing to the Oakwood bridge's unusual V-shaped supports, he added: "It will take the most load. Of course, it depends on how it was glued together."
After Myers and the other judges evaluated the bridges on the basis of their looks, civil engineer Joe Foyos loaded each into a computer-controlled hydraulic press to test its strength.
Soon, the room was filled with loud snapping sounds and flying pieces of Popsicle sticks.
Sixteen-year-old Lorraine Levers of St. Lucy's High School in Glendora threw her hands over her head and ran for cover when her bridge popped under 82 pounds of pressure and sticks flew in every direction.
Eric Liu, 15, of Diamond Bar High turned away when his bridge started to buckle at 35 pounds. "I can't watch this. It's going to explode!" he yelled.
Cristina Mendoza, 18, of Sylmar High School grimaced as her bridge twisted like a dishrag under just seven pounds of pressure.
There were gasps from the crowd when pressure was applied to the Jefferson High entry. When the test ended at 833 1/2 pounds, the bridge was still intact.
There was another gasp from onlookers when the V-shaped Oakwood structure was tested--and cracked apart under 33 1/3 pounds of pressure.
"The glue didn't hold," said designer Denny Oppenheimer, 16, of Encino--who spent five hours building the bridge with classmates Jesse Wordin of Woodland Hills and Suzie Vatz, also of Encino.
Jefferson High's 833-pound-bearing entry won in both the strongest and greatest-load-to-weight-ratio categories.
Jefferson students were modest when they picked up their winners' plaques and scientific calculator prizes from contest chairman Andy Hui, a Metropolitan Water District engineer.
Garcia credited tiny "dowels" made from slivers of Popsicle sticks for helping stiffen the bridge's joints.
The peg-like reinforcements were almost invisible to the casual observer.
And Enllanche--who plans to become an engineer--would not criticize the early contest forecast.
"Sometimes," he said delicately, "something can look strong but it's not."