It's one thing to design a human-powered underwater craft. But 16 teams are putting their ideas to the test through trial, failure and tinkering in the water.

In competition, students' hopes rise, sink with their submarines

July 01, 2005|By Dennis O'Brien | Dennis O'Brien,SUN STAFF

CARDEROCK - Schoolteacher Chris Land emerged from a Navy test pool here, dripping in a wetsuit as he offered up a smile and a list of what had gone wrong with the human-powered submarine built by his students.

"Let's see. The windshield cracked, we lost a rudder and we still have to fix the hatch. At this point it's kind of like Apollo 13 in that maybe we should talk about what does work instead of what doesn't," he said.

During a week of underwater racing in competition with more than a dozen other teams, a lack of buoyancy sent the submarine plunging to the bottom of the 22-foot-deep pool. Propeller malfunctions sent it crashing into the walls.

But Land's students at Sussex County Technical School in Sparta, N.J., learned from each of the nine failed attempts to propel their two-man sub.

And that was the point of the eighth annual International Human Powered Submarine Race, sponsored by the Foundation for Underwater Research and Education, a nonprofit group.

The event is intended to teach the importance of teamwork, the need to correct mistakes and the difficulty of creating a watercraft that is seaworthy and submersible.

"What we're trying to do is capture the imagination of these kids," said John Hussey, a group spokesman.

Designing an underwater craft means solving complex engineering problems involving hydrodynamics, propulsion and life support, experts say.

"There's about 200 things, and they all need to work right at once. It can get really complicated," said Wayne Neu, a professor of aerospace and ocean engineering at Virginia Tech and an adviser to a team from the university.

The rules require all submarines to be human powered and free flooding, which means cockpits are open to the pool's 64-degree water. Contestants use oxygen and scuba gear while on board.

Sixteen teams from the Netherlands, Canada and the United States - most made up of college engineering students - paid a $1,000 entry fee and took turns racing against a clock to cover the length of the 100-meter (328-foot) course. The race is held in the David Taylor Model Basin, a 3,000-foot pool the Navy built in Montgomery County to test hull designs.

Before entering the race, the teams had to satisfy a panel of judges that they understood a range of technological basics related to hydrodynamics and safety.

Most of the subs are shaped like torpedoes. They seat one or two people and are driven by either propellers or winglike flaps. Safety hatches are mandatory.

Each team was allowed to run the timed course as many times as it wanted. Cash and other prizes will be awarded in eight categories, including fastest time, best overall performance and best technological innovation. Cash awards range from $250 to $1,000.

Winning teams will be selected later today based on performances throughout the week. As of late yesterday, the leading entry was Omer 5, a two-person, propeller-driven craft created by students from the University of Quebec. It zipped through the water at 7 knots (about 8 mph).

Neu, of Virginia Tech, has had student teams enter the race routinely since 1995. But he said each time was like starting from scratch.

"They all want to build their own boat. They have their own ideas and they want to see if they'll work," he said.

He said most of the students are studying to be engineers, so they may have some basic knowledge about design and what makes a craft go through water.

But that doesn't ensure that the craft will stay upright as it plows through the water, or that the on-board computer - used to control a pivoting propeller - will function as designed.

Virginia Tech's entry this year included an on-board computer designed to automatically control the direction of a pivoting propeller system, which is meant to reduce drag. But the computer seemed to have a mind of its own, malfunctioning during early runs.

"When you have innovation, it can mean a whole new set of challenges," Neu said.

The Sussex County team members could attest to that. They went with a propeller with seven blades designed by Matthew Diemer, a 17-year-old senior at the school, and manufactured in the school's metal shop.

The team's resulting craft, named Umptysquatch II (last year's entry was Umptysquatch), was a sleek craft with counter-rotating twin propellers.

In a competition dominated by colleges, Sussex County is one of two competing teams with high school students. The kids from New Jersey raised about $28,000 for the necessary materials.

By late yesterday, they had made one successful run in the 11-foot-long craft, clocking the course at a respectable 2 knots (about 2 mph).

"We just wanted to see if we could do this," said Diana Lulek, a graduate who is attending the University of Massachusetts in Amherst this fall.

After completing repairs on the propulsion system late yesterday, they were optimistic about their chances of improving on that time.

"We keep dragging along the wall, but we can do it," said Trevor Boyer, 16, who designed the craft.

To ensure buoyancy, the team used ping-pong balls encased in nets - a late addition to the overall design made after the students saw a television documentary that described how ping-pong balls helped raise a sunken yacht.

Every run in the pool was recorded by underwater video cameras and watched by family and friends on monitors.

Tinkering to correct defects spotted in the water was not only allowed but encouraged.

"You can study all you want in a classroom. But you come out here and it's all practical learning about things like propulsion, hull design and buoyancy," said Roy Diemer, father of the Sussex team member. "The best thing is when something doesn't work, you see these kids' reaction and the first thing they say is, `How can we fix it?'"

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