(upbeat music) - [Narrator] On a college campus known for sports like baseball, basketball, and football, most folks don't know about the team you can find in the old engineering workshop, the concrete canoe team.

- That's exactly what it sounds like.

We're making a canoe out of concrete.

- It seems crazy, but it's true.

- A lot of people, they just can't really grasp their head around it, but that's kind of the fun part about it.

(tool whirring) - 40 years ago, a bunch of civil engineers got together and said, " Hey, we need civil engineering, but sports!"

And so they came up with Concrete Canoe.

- It's a wild tradition.

- [Narrator] Every year, on college campuses across the country, civil engineering students take on an extracurricular challenge, building canoes out of concrete, that float, and racing them against other schools.

- We make concrete canoes because it is difficult.

- [Narrator] Concrete, like what you see in sidewalks and driveways, is basically a mix of cement with tiny rocks, called aggregate.

These rocks add strength, but also weight.

- 4.3754 pounds.

That's a little on the heavy side.

- [Narrator] A canoe, by its nature, is meant to float.

And concrete, as we all know, sinks like a stone.

So, making the concrete strong, but also light, is the first challenge for the students.

And this is where things get granular.

Literally.

- The stuff we make our concrete out of is not like you would find in any retail store.

It's all designed by us for our very niche, unique purpose.

- [Narrator] So, to make concrete that floats, the students add buoyant aggregates, like ground-up cork, tiny glass beads, and even feather-like flakes of fiberglass.

- As the mix crew mixes, the construction crew finalizes the shape of the canoe, the foam form to be used as the mold.

The thickness of the concrete is critical.

Too thick, and that's extra weight, which will slow the canoe on race day, but too thin, and the walls of the canoe become brittle, like ceramics, risking cracks and even sinking.

- That's the most quarter-inch of a quarter-inch I've ever seen.

- Yeah!

(tool whirring) - [Narrator] Each year is a chance for a new design, testing new concepts to make a better concrete canoe.

And any new idea is always an experiment that might not actually work.

- Will it break if we drop it or if we sit in it the wrong way?

I hope to never find out.

Oh, yeah.

That's getting better.

- [Narrator] After the mix is ready, it's time for pour day.

The concrete isn't exactly poured, per se.

More, it's smooshed and then smoothed, one handful at a time.

- Pour day is definitely the most important, because if anything goes wrong, there's no take backs and redos.

- We only have so much time to work with it before it starts curing, and then once it starts curing, we can't really overwork it at that point, so we'll go batch by batch.

- [Narrator] After the concrete is all poured, it needs to cure.

And this will take at least a month.

And to keep the concrete from cracking as it dries, the students design a DIY sprinkler system.

As the competition canoe is left to cure, the team heads to a local lake.

- One, two, three.

Everyone ready?

- [Narrator] This is their first attempt at a concrete canoe, a prototype, started in the fall term, and is now ready to try out.

- Lower the canoe.

- Okay, slow.

- [Narrator] It weighs a couple hundred pounds, and getting it into the water is where engineering theory, and a fair amount of guess work, get put to the real world test.

- A concrete canoe does not handle like your typical canoe.

I was not prepared to get in a concrete canoe, but then again, who is?

- [Narrator] The designs and calculations have tried to strike a balance.

To be fast in the water for the race, the hull should be long and slender, but that makes it unstable.

- I'm trying.

- And risks capsizing.

- [Alec] It's very hard to describe beyond it's "very tippy" and balancing is very challenging.

- See, it's just not going to go... - [Elaina] Oh, (beep)!

Ah!

(students chuckling) - [Narrator] With their tight term schedule and a full-class load, the students only get a weekend or two to practice paddling.

- There's not too much that goes along with the technique.

It's more of just practicing the techniques.

You know, making sure you know how to stay in a straight line, making sure you know how to, like, turn.

- There you guys go, you're going good.

I'd say about 30% of the teams can go in a straight line, so we're doing pretty good if we're there.

- Water is slowly but steadily coming into the canoe.

That's not a great sign but this is the practice canoe.

So, we won't be bringing this to the competition.

- Nice!

- Yeah!

- [Narrator] After allowing the competition canoe to cure for a month, it's the big moment of truth, pulling it off the form.

Has it dried completely?

Has it cracked?

- All right.

- If something has gone wrong, there's not enough time to make another canoe.

- [Ryan] Three, two, one, lift.

All right, we're going to rotate it towards my right.

- Oh, that's pretty.

- All right.

- Heck yeah.

- All right.

Let's get to patching.

- [Rachel] I really liked how it looks on the inside.

It's super smooth and the colors look pretty good, and it doesn't need too much patching, so, this is a good thing.

- [Narrator] They seal up the porous concrete to make it watertight, or, as watertight as concrete can get.

And with this last step, it's time to head to the races.

A different school hosts each year, and this year is Portland State University's turn.

Teams have come from across the Pacific Northwest, and students get their first chance to size up their competition.

And some of the canoes have already been patched with duct tape.

From fall to spring, the students have invested more than 1,000 hours to get to this point.

And for this extra-curricular challenge, race day is the final exam.

- [Students] Let's go!

- Good luck, Beavers!

- [Narrator] They line up for the first of many races.

- [Announcer] Ready, go!

- Row!

- And they're off.

- [Rower] Row!

(crowd applauding and cheering) - [Narrator] You didn't expect these races to be fast, did you?

- [Student] Yeah, you got it!

- [Narrator] Hard to tell if the ducks are in the race, and if they're winning.

And one canoe seems to have a significant list to one side.

One team's canoe breaks apart, and they cross the finish line with a swim.

But the spirit is high.

- [Crowd] O-S-U!

- [Narrator] OSU celebrates the first races of the day.

(crowd applauding) But already, the canoe is taking on water.

- [Student] There's a leak in it already?

- [Narrator] When the water's bailed out, the source of the leak is identified.

It doesn't look good, but it's a slow leak.

(cowbell ringing) - [Crowd] Let's go Beavers!

- [Narrator] The races go all day.

All day.

And everyone gets a chance to paddle.

And each race adds up to points toward the total school score.

- [Crowd] Let's go Beavers!

- [Narrator] But the real test of the canoes, and teamwork, comes at the end of the day, for the four-person co-ed race.

- [Announcer] Everyone, paddles up.

- [Narrator] The schools square off at the starting line.

- [Announcer] Get ready.

Go.

(crowd cheering) - [Narrator] OSU starts strong, and rounds the buoy back to the starting line.

Followed closely by the canoe called Cementitious Maximus, paddled by wizards.

Followed by the canoe that seems precariously on the brink of capsizing.

(crowd cheering) - Bring it in, come on!

- [Crowd] Let's go Beavers!

- [Narrator] It's about as neck and neck as a concrete canoe race comes.

- [Narrator] OSU is coming in fast to the finish line, but stalls.

(crowd yelling) - [Narrator] Ah, the thrill of victory and the agony of defeat.

- I got a little flustered seeing the other teams ahead of us, and I focused a little bit too much on trying to get us to go faster and not enough on getting us going straight.

So, not quite what I wanted to see in the last race, but really good for today.

- Okay, one, two, three!

- [Narrator] No glory of first place.

They don't even get a grade.

But getting to this moment calls for a victory celebration.

- At the end, it's a club.

It's for fun.

- Three, two, one!

(crowd cheering) - The competition to me is a celebration of engineering, a celebration of all of our efforts to make something that shouldn't work.

- [Narrator] And now it's time to load up the canoe.

- [Philip] You know, the whole time that we're working on this, there's so many people working really hard to make everything happen, and it won't work if you have just a few people.

But when you're moving the canoe, you get the physical manifestation of that, because you all physically have your hands lifting the same object up together, doing something that's really hard.

- Up and over.

- And I think that's quite beautiful.

(crowd cheering and applauding) - [Speaker] Congratulations, everybody.

- Thank you.

- Good job, team!

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