Anyone who has ever watched a gangster movie in which someone drowns wearing a pair of cement overshoes knows that concrete doesn’t float. Think again wise guy. A group of University of Washington civil engineering students will compete April 27 in concrete canoe races on Lake Sammamish.
These concrete canoes not only float but will carry two paddlers in sprint and long- distance races set to begin at 9 a.m. from Issaquah’s Vasa Park at the south end of the lake. (Take exit 13 off I-90 and go one mile north on West Lake Sammamish Parkway.) The races, which will be open to the public, are being hosted by the UW and the University of Alaska-Anchorage as part of the annual American Society of Civil Engineers regional student conference. Teams from 10 universities throughout the Pacific Northwest are expected to participate, with the winner advancing to the national competition in Cleveland in June.
The UW has never won the regional competition. In fact, last year’s canoe sank. But the 1997 team has instituted several design changes and renamed the canoe “UW Positive Flotation” in hopes of ending up on top.
“We want to start a winning tradition,” says Dawn McIntosh, a senior from Ogdensburg, N.Y., and leader of the UW canoe design team. “The UW has never really been in contention of winning the regional competition, so we really wanted to do something different.”
UW Positive Flotation has a wider bottom than last year’s entry and a larger freeboard, which is the part of the canoe that stays above the waterline. UW team members believe these changes will make their canoe faster, more stable and less likely to be swamped by the paddlers. Perhaps the biggest change, however, is in the concrete mix.
Concrete usually is comprised of Portland cement, water, rock and fly ash (a coal- burning byproduct that binds the cement to the rock and makes the concrete more solid). The UW team used a different combination of ingredients to make the canoe lighter and more buoyant, McIntosh says. The team experimented with the ingredients to come up with a mix that yields the best combination of strength and low weight. Team sponsors Stoneway Concrete of Renton and Crutcher Lewis contractors of Seattle provided materials and funds for the project.
“We did our research and got good technical advice, so we’re confident we came up with the best materials and design,” says Laura Olsen, a senior from Vancouver, Wash., who is technical director for the UW student chapter of the American Society of Civil Engineers and a key member of the UW canoe design team. Other members of the team are: Lily Bui of Olympia, Wash.; Eric Blumhagen of Seattle; Dan Morrow of Sacramento, Calif.; and Steve Resnick of Philadelphia. Professor Fred Mannering is the faculty advisor.
To build the canoe, team members first constructed a wooden form overlaid with metal nuts and wire mesh. The concrete mix was pressed through the mesh and up against the form, with the nuts serving as spacers. After drying four days, the canoe was detached from the form and now is being sanded and painted as the concrete continues to cure.
In the meantime, the UW team members had hoped to hone their unpolished paddling skills. But classes, final exams and spring break have interrupted the practice schedule. “I feel good about the canoe itself; I’m not so sure about our paddling,” McIntosh says.
Win or lose, Olsen adds, the team members have learned as much about concrete design and construction on the canoe project as they have learned in some of their classes.
“It’s an incredible learning experience because it’s hands on,” she explains. “And you have to figure it out; it’s not like the lake will give you partial credit on a canoe.”
For more information, contact McIntosh at (206) 641-9399 or Olsen at (206) 520-1685.
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