Over five sweltering days in June, teams of submariners
donned wet suits and raced their craft through the cold waters
of the Navy's David Taylor Model Basin in Bethesda, Md. As part
of the 7th International Submarine Races for human-powered submarines,
19 teams of engineering students from universities in the United
States, Canada, and Mexico—along with students from a few high
schools—tried to overtake team "Omer 5" from
Ecole de Technologie Superieure in Montreal, holders of the current
world
speed record.
The biennial competition gives engineering students
the opportunity to apply their knowledge of hydrodynamic design,
buoyancy, propulsion, and underwater life support. They work for
months, sometimes years, on their craft. Though many team members
are mechanical engineering majors, students from multiple disciplines
were involved. "We worked with people from the art school,
mechanical engineering, electrical, and aerospace," says Eli
Rosenburg, co-captain of the University of Michigan's "Mercury" team.
From their staging area in the adjoining parking lot,
teams wheeled their one- or two-person subs to the loading platform.
Resembling an extremely long rectangular swimming pool, the 3,200-foot-long
basin yawned before them. After the inevitable last minute changes,
the subs were lowered into the chilly water and the pilots prepared
to enter their craft. Submarine size varied, with some not much larger
than their single crewmember to others measuring 16 feet to contain
their two-person crews. The brightly colored hulls, adorned with
names of school and corporate sponsors, were hand built and made
of fiberglass.
Once the pilots were inside, the hatch was closed
and the submarine flooded to send them toward the bottom. To get
moving, the pilots pedaled a bicycle crank, connected to a driveshaft,
to turn a propeller. But not every sub had a propeller. Virginia
Tech's "Specter 1" used a dolphin-like fin attached
to the pilot's legs to move. "We can't wait to
see what this baby can do," said race director Jerry Rovner.
That baby took first place in the one-person, nonpropeller division
with a speed of 4.05 mph.
A submarine's speed over the 328-foot course
is clocked at the starting line, a 32.8-foot-wide speed trap in the
middle, and the finish line. A team of Navy divers in an inflatable
boat tracked the submarines from above and divers occasionally jumped
out to check on a troubled sub. Not content to merely oversee the
races, the divers decided to try piloting Sussex County Technical
School's "Umptysquatch-1." It wasn't as easy
as the students' made it look after months of practice; none
of the Navy divers were able to complete the course.
The impromptu nature of the divers' attempt
aside, completing the race course wasn't easy. Technical glitches
abounded: propellers broke, shear pins snapped, hatches broke off,
and guidance fins failed. Even when everything held together, navigation
mishaps in the dimly lit waters of the tank were common. "They
all experienced the same problems," said chief judge Claude
Brancart. "It is gratifying [however] to see these teams react,
respond, repair and get back into the competition." And to
receive help from their competitors. Despite the serious competition,
interteam cooperation flourished. When the University of California
at San Diego's "Invicid" veered sharply during
a run and smashed its nosecone against the wall, other teams helped
with the repairs. Within hours it was racing again.
In the end, no one was able to end the Canadian team's
dominance. "Omer 5" registered a new world record of
7.84 mph. But there were surprises. Springstead High School's "Sublime
II" managed to edge out its collegiate competition by getting
into the water first on opening day. A technical glitch forced
its crew to surface but, unlike the Navy divers, they eventually
finished
the course.
Robert Gardner is an associate editor at Prism.
He can be reached at rgardner@asee.org.