Just off the coast of Sunset Beach in Cape May, N.J. lies an empty concrete shell. These are not the remains of a pier or other building lost to the seas, but of a ship that once traversed the Atlantic Ocean in a time of war.
The final resting place of the S.S. Atlantis is both a curiosity and important part of U.S. history. In her life, she was a transport ship in the World War I Emergency Fleet. Now she intrigues tourists, often raising the question "how did a concrete ship manage to float?"
Students at the University of Wisconsin-Madison spend their nights shut in at the Engineering Centers Building answering this question year after year.
These students are members of the UW-Madison Concrete Canoe Team (UW-CCT) and are tasked each year with designing and building a canoe out of concrete.
It is not enough that the students must create something convention tells us will not float; they also compete with other schools across the country in the American Society of Civil Engineers National Concrete Canoe Competition, where teams are judged on an oral report, technical report, the race and the overall product.
Starting at the beginning of the academic year, around 40 engineering students gathered to begin work on creating a canoe for this year's competition.
But how does the UW-CCT go about making concrete that floats? In the minds of these engineers, making concrete float is no more difficult than getting the most common boat material, steel, to float.
"How do you get steel to not sink?" co-chair Reid Carlson asked. For steel or concrete, the overall concept is the same: it's all about buoyancy.
In order for the concrete to float, the weight of the concrete must be displaced by a force, buoyancy, created by the water. The concrete mixture, along with the design of the canoe, is the key to achieving this displacement.
Building a canoe out of concrete is not as simple as pouring store-bought cement into a mold and letting it set though.
The UW-CCT uses a mixture of cement, water, aggregate and an add-mixture that they develop to create the concrete. The aggregate is made of glass microfibers and the add-mixture can change the concrete depending on the focus of the mix. The mix the team developed this year is about two-thirds the density of water.
To ensure that the concrete binds, it is placed by hand onto a fiberglass mesh reinforcement. Individual fibers are also mixed into the concrete, adding extra strength as the concrete hardens.
This year's UW-CCT team placed their concrete two weeks before fall finals started, allowing the concrete to set over winter break. Upon returning for the spring semester, work began on sanding and finishing the canoe in time for the regional competition.
While the canoe is constructed, members are also preparing the oral and technical reports to be presented at the competition. In addition to the presentation, the team will participate in races at two different levels, regional and national.
Each school that enters the competition fields a team of 10 paddlers, five male and five female. Not every paddler will compete, but these are the only members allowed to participate in the races.
The UW-CCT competes in the Great Lakes Region with 17 other schools, many of which are located in Wisconsin, including UW-Milwaukee, Marquette and the Milwaukee School of Engineering. The team that takes first place at this regional competition advances to the national competition where they compete with the winner of the other 20 regions.
The UW-CCT has enjoyed a lot of success in recent years at the regional and national level. At the 2011 regional competition, the team placed first in all four categories and finished in second overall at the national level.
Carlson compared the success of the UW-CCT to that of the Wisconsin men's and women's hockey teams. He notes that the UW-CCT has claimed five national titles, winning in consecutive years from 2002 to 2007. The hockey teams have six and four national titles, respectively.
Aside from the success the UW-CCT has had at the competitions, co-chair Nicole Johnson emphasized the importance of participating in the event for the learning experience.
"The whole point of this competition is for engineers to learn about new techniques and then build off of those," Johnson said.
Many engineers cite the competition as a major factor in future opportunities.
"I have my co-op lined up this summer because of [UW-CCT]," co-chair Robert Arts said. "I didn't even talk to the people in the interview about anything they wanted to talk about. They got me started on canoe, and I just talked for a half an hour."
"It's a good talking point," Johnson added.
The UW-CCT will compete at the regional competition April 19-21 at Bradley University in Peoria, Ill. If the team takes first place overall at the regional competition, they will advance to the national competition June 14-16 in Reno, Nev.
For more information on the UW-CCT, visit http://canoe.slc.engr.wisc.edu/.
