Submarine team torpedoes competition

BETHESDA, Md.—Engineering students from the University of Michigan propelled themselves to victory last weekend in a human-powered submarine competition. The team took first place among two-person submarines in the 6th International Submarine Races (ISR), held at the U.S. Naval Surface Warfare Center, June 11-15. The team also received third place for innovation in the design of their submarine, Neptune.

Sixteen teams participated in the competition, which was created by the Foundation for Underwater Research and Education and sponsored by the U.S. Navy. The submarines raced underwater along a 100-meter course in a 3,200-foot-long tank used to test ships and hulls. Neptune was the fastest two-person sub in the race, posting the fourth fastest speed overall at 4.905 knots, or about 5.7 miles per hour.

“The biggest challenges were stability and control,” said team captain Joseph Tilchen. “Once our driver learned how to control the sub, we could attempt faster speeds.” Successful competition required the team to master principles of buoyancy, propulsion, drag, hydrodynamics and life support systems for small sub-sea vehicles.

“We also lost our hatches a few times during the race, so another key was to keep them attached if we were to achieve a high speed,” added Tilchen.

Neptune is Michigan’s third human-powered submarine since 1996. Sixteen feet long and featuring counter-rotating propellers, Neptune weighs about 200 pounds dry or 3,500 pounds wet. Because the submarine is completely flooded during racing, the crew relies on scuba equipment to breathe. The crew members sit foot-to-foot in the submarine with a tandem bicycle pedaling system between them. Only one person steers the craft.

The team worked on the Neptune throughout the 2000-2001 school year, incorporating lessons learned from their prior submarine named Atlas.

“Neptune’s drivetrain is much more efficient and stabler at high speeds,” said Tilchen. “The hull was also made from the same molds as Atlas, although we removed two feet from the length to reduce the weight and drag.”

The team plans to race Neptune again next summer in Escondido, Calif., at a competition sponsored by the American Society of Mechanical Engineers. They will also be designing a new submarine to race at ISR 2003.

EngineeringU.S. NavyAmerican Society of Mechanical Engineers