Repackaging the computer parts will be the latest in a long list of modifications and redesigns that began with Shadow I in 1998. Shadow has become an annual senior design project in UA's Mechanical Engineering Department, and is entirely designed and built by undergraduates, with the exception of some computer programming done by a graduate student a couple of years ago.

The project received NSF funding in 2000 and has made great progress since then. Vincent anticipates that it will be ready to track octopuses next year.

Before that happens, this year's student design team will build a wireless communications system to free Shadow from the mother boat. Currently the sub and a computer on the mother boat are linked by a 100-foot-long coaxial cable. "We want to get rid of that tether from the boat and have it come to the surface at a buoy," Vincent said. "Then there will be a wireless link between the buoy and the boat."

The team also will modify Shadow's buoyancy system. Water flows into a ballast ring that circles the center of the sub. The amount of water that it takes on determines the sub's buoyancy, allowing it to submerge to any depth. Compressed air tanks on the sides of the sub blow this water out to bring Shadow to the surface.

"Right now the buoyancy system is under manual control, but we hope to have it under automatic control next time," Vincent said. "We'll just type in the depth we want on the computer and Shadow will automatically submerge to that depth."

Sub Will be Operational Next Year

Although the submarine will begin shadowing octopuses next year, Vincent has plenty of ideas to keep senior design teams busy for a long time.

"The way it is now, we'll still be on the surface watching images from Shadow's video camera and waiting for something to happen," Vincent said. "We'l
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Contact: Tom Vincent
Vincent@u.arizona.edu
520-621-2325
University of Arizona
17-Sep-2004