Will it float?
A Q&A with concrete-canoe-building engineers
By Jesse Tahirali
|The concrete canoe team of the Université de Laval placed second among 250 participating universities at the National Concrete Canoe Competition in Nevada, Reno in June 2012. (Photo courtesy of Sébastien Girard)
Modern canoes can be built a number of different ways, using anything from wood to aluminum to fiberglass to Kevlar. No matter the material, the goal is of course to make something that floats.
But for a team of engineering students from Laval University, building a regular boat is too easy. In fact, they’ve opted to build a canoe out of something that most people associate with sinking: concrete. And not only have they built a functioning canoe, they’ve also competed and won competitions held specially for teams of engineering students. Across North America, schools pit their concrete contraptions against one another to see who can design and build the best boat out of one of the most difficult materials.
Sébastien Girard, a graduate student in civil engineering at the Université de Laval who has been a part of the team since 2009, and Marc Jolin, a professor in the department of civil engineering and the faculty advisor for the project, explain the method behind the madness.
Q. The words “concrete” and “canoe” don’t generally mix — what are you guys doing building a concrete canoe?
Sébastien Girard: The competition started 30 years ago in the United States. A professor challenged a group of students to build a concrete canoe. After that, it spread to other universities in the United States, and in 1996 the competition spread to Canada.
Civil engineers are essentially concrete engineers, so we’re trying to match concrete with a thing that doesn’t have to do with concrete. Usually people think that concrete will sink, but it depends how you build it. The concrete we use isn’t the same kind of concrete you see in the streets — we’re actually designing concrete that is very light, and will stay afloat in the water.
Marc Jolin: There are a lot of these competitions for engineering faculties across the U.S. and Canada, and they’re always the craziest competitions you can imagine. The idea is just to push the creativity and the innovation of the students and see what they can come up with. Obviously a floating concrete canoe is a crazy idea, but that’s what the industry is looking for — they’ve seen very creative designs coming out of these things.
Q. Is the canoe made entirely from concrete?
SG: The canoe is made of concrete, but you have to reinforce it. The tensile strength of this kind of concrete is not very high, so we reinforce it with carbon fiber mesh. Between two layers of concrete, we put the mesh in the hull.
Q. And you actually get in these boats and race?
SG: We have three races — first we have the sprints, with two people in the canoe. We do this twice, one for men and one for women, and what they have to do is paddle 100 metres, turn around at the buoys, and race back to the departure line. The second one we have is the endurance, with two people again. They travel 600 metres. The last one is the co-ed. We have four people in the canoe, paddling together for 100 metres and turning around at the buoys to come back.
Q. This sounds like a big project — how long does a concrete canoe take to make, and how expensive is it?
SG: This is a 9,000 man-hour project; it’s a lot of time we spent on this. If you take that and look at it compared to a full work year, which is about 2,000 man-hours, it’s very, very time consuming — but it’s worth it. The budget is also high, about $55,000.
MJ: These guys are training in a freaking swimming pool in the winter because there are no lakes around here. We are very proud. To have a French-Canadian team going to Nevada that will probably finish in the top five — that’s not easy. They learn to work as a team, they learn to work together until 3 o’clock in the morning when they’re sanding that stupid thing, and it’s really impressive.
Q. What is the greatest engineering problem you have to overcome when making a canoe out of concrete?
SG: It’s different for everybody. For us, we’re very proud of our weight, because we were able to build a concrete canoe that weighs 75 pounds (34 kg). Most of the teams aren’t able to build that because their building techniques aren’t suited to this light of a canoe.
MJ: We’re not necessarily looking for something really strong, but we’re looking for something that will resist the propagation of cracks, because at the end of the competition, under the knees and on the side with the paddle hitting, there is damage. You don’t want it cracking into two pieces in the middle of the lake. You want those cracks to stay closed so you can manage to finish the race.
Q. Could you give us some insight into how Laval’s team stays so competitive each year?
MJ: Some teams are coming in with a very heavy canoe not because of bad construction, but because they don’t have the proper analysis. That’s one thing at Laval that’s been very strong. That analysis gets handed down year after year, so when time comes to analyze the stresses, and what you should expect in the water with two people paddling, we have a pretty good idea of what we need.
SG: Some years you lose a lot of veterans who have been on the team since their first year in the civil engineering program. When you lose them, it’s not good for us because you’re losing knowledge, so we have to transfer knowledge in order to keep the team afloat.
Q. Any stand-out moments from past competitions?
SG: Seeing a canoe break in half. I saw it at the conference level this year. What happens is the stresses are too high, and then the canoe breaks in the water.
Université de Laval won the 2012 Canadian competition in Moncton, New Brunswick. Laval also won the 2012 Northeast American competition, which qualified them for the U.S. finals competition in Reno, Nevada.