University Place  Liese Pfeiffer The Art and Science of Hydro-Dynamic Design  February 12, 2014 UP980   cc >> Welcome, everyone, to Wednesday Nite at the Lab. I'm Tom Zinnen. I work here at the UW Madison Biotechnology Center. I also work for UW Extension Cooperative Extension, and on behalf of those folks and our other co-organizers, Wisconsin Public Television, the Wisconsin Alumni Association, and the UW Madison Science Alliance, thanks again for coming to Wednesday Nite at the Lab. We do this every Wednesday night, 50 times a year. Tonight it's my great pleasure to introduce to you Liese Pfeiffer with the Design Gallery here at the School of Human Ecology. She will be talking with you about the new exhibit there called Crafting Canoes. This is a remarkable topic for the state of Wisconsin given what the canoe means to the heritage and the current recreation here in Wisconsin. We have a city in this town that's called Portage, and it gives you an idea of how important canoes were in our history and our culture. Tonight we get to hear about canoes and designing. 

Please join me in welcoming Liese Pfeiffer to Wednesday Nite at the Lab. [APPLAUSE]  >> Welcome, everybody. I'm starting you off with a picture of a building right up the hill from where we are sitting right now. And feast your eyes on a different view than we are seeing in our wintry cold night. A time when you can actually be on the water. So tonight is because there is an exhibition that looks at canoe design in three different avenues. What we'll do tonight is I'll be speaking about two of those. Nick Molzahn from the UW Concrete Canoe Team will be covering one of those areas. And I will hand the program over initially to James Steiner to give us an umbrella of what this background of design thinking is. So with that, I'm going to have you come up. 

 >> Thanks, everyone, for being here. I'm going to start with kind of an overview because the exhibit and what Nick has done in actually crafting a canoe is all about design thinking. So it's a phrase that's been tossed around quite a bit on college campuses and in businesses, but a lot of people aren't really sure what it is. We thought we'd start tonight by talking about design process and design thinking and how designers solve problems in ways that are perhaps a little bit different than other more analytical, linear ways. We can begin with a definition of it. Design thinking is a human centered approach to innovation that draws from the designer's tool kit to integrate the needs of people, the possibilities of technology, and the requirements for business success. This is from Tim Brown, who is the president and CEO of IDEO, which is the design firm in Silicon Valley outside of San Francisco. They help innovate design thinking and with businesses, universities, and really help to get teams together to come up with innovative and creative ideas. So a couple of key words about design, the exciting reason I got into it as a landscape architect and also an architectural interior designer, is that design can truly transform the way we see the world and the way we see our environment. It always has a human point of view. 

And so being a person is always a part of design thinking, and how people use spaces and products and experiences is something that we as designers always try to infuse into this process. It is an actual set of creative tools that are used to specifically solve problems and hopefully some significant and complicated challenges.  Design thinking is thinking of it as a system of overlapping spaces rather than a sequence of orderly steps, which could be a little bit of a different way of thinking. As I teach design and visual communication in the landscape architecture department, I find that a lot of students come in from more linear analytical backgrounds, and when they're asked to think this way it's kind of a new and startling thought. Keywords that fall into the process, inspiration, ideation, and implementation. Inspiration is what gets creative people juiced up about solving a new problem. What is the inspiration we see just observing the world around us? And often that can come from just observing. Ideation is the generation of concepts. The big idea that gets a design going, and that to me has always been the fun part as a designer and as an artist in solving creative problems. Implementation is key because no matter how great an idea is in our head, we really need to apply it to people, to the world to see how it works and to test it out. 

We'll go with something really easy here. More of a simple process that all of use can relate to, especially around dinner time or lack of dinner time. It's just a recipe. A step by step way to solve a problem, in this case a delicious problem of creating cookies. If we follow the steps, measure correctly, if our oven is the right temperature, we pretty much will end up with that finished product. And like a recipe, the image is right there for us to follow. So it's not a lot of innovation there but it is solving a problem. Other linear problem solving diagrams such as those that are used in mathematics and sciences follow more of a linear process of actually step by step. In higher math and higher science, of course, there is innovation and discovery and creative problem solving, but with some simpler forms it is more right or wrong. The bottom blue boxes of hypotheses are false or partially true shows a little bit of the difference of the more black and white thinking of whether a problem is correct or incorrect, which is somewhat different in design thinking. 

Here's a diagram for design thinking. A little bit more of a spiral showing that the steps, while they're definitely a path, they aren't necessarily a linear path, and it takes a little bit of back forth, creating ideas, double checking. We call them in design class by feedback loops for you to go back and kind of toss out ideas and reevaluate and re-find. And then the idea as it evolves gets more and more refined and more and more implemented until it actually comes out as a finished product that can be tested and implemented. I like this diagram because this is kind of my brain as I solve problems. To more of an analytical thinker they would say this looks more like a noodle or a tangled ball of string. But really, this diagram of starting with a bunch of big ideas, the feedback loops, thinking about things, rejecting ideas, tossing them out, and then the decisions become more and more finite as you move through the design process. Notice at the end it is pretty much a linear process because you figured a lot of the bigger situation out, and now you're kind of going toward the end. And I do like the infinity symbol at the end there because I believe that design is really often never finished. You can think you're finished, give it to another designer, and they'll start all over with a whole other process. 

So it doesn't have oftentimes a complete and definitive end. Design thinking at UW Madison is ongoing in all of these different departments. I'm in landscape architecture. I work with engineering. We're doing a lot of collaboration now with the School of Human Ecology, interior architecture. Nick is in engineering, but all of these that were design thinking is happening on campus, scattered all over campus. So one of the interesting things about being a designer and a design thinker on campus is trying to find out where we all are and what we're doing. But all of these professions identify as design thinkers. Design Summit is an event that's coming up on February 20th. It's an annual event. 

And the purpose is to really get a lot of design thinking people on campus together in one room. I attended last year, and the interesting thing was how many people identified as a designer that are not in my fields of architecture, landscape architecture, and interior design. Soyeon Shim with the School of Human Ecology, which is where the Design Gallery is located, is really heading a campus-wide initiative to explore design thinking and try to create kind of a hub for all the design thinking people on campus and how we can get together and innovate. So that's exciting things that are on the way. This face is one that I've seen with a lot of my students when they come to me for more linear analytical backgrounds and we ask them to solve a design problem. And I literally have gotten this face in class where they're like, James, tell me the right answer to solve this problem. Just tell me the right design solution. And I have to patiently and kindly tell them that there is no right solution oftentimes in design. That the right solution is one that meets the project goals and actually meets the needs of the end user. All of us, if we were designing a problem, could come up with just that many different solutions, and they could all be right or they could all be successful. 

So just understanding that design is a process and it is subjective are key phrases. Some sample applications for design thinking, just to show how it can be applied in different ways.  A visual design problem, such as designing a logo for a business. A spatial design problem, which is more of what I do in architecture. Designing a new community center and a park for a neighborhood. Design thinking can also be applied to social design problems such as the example of eliminating childhood obesity at school. Using what they call ethnography to study how people act in situations could be then rethought and reevaluated and applied to create innovative ways to solve a social problem. Designing a new product. An innovative product example could aid in mobility for seniors could be developed. Lots of product design engineering is in the forefront of that. 

Experiences can be designed. I want to design an enhanced shopping experience for our consumers that will increase sales. It might sound a little farfetched, but there are teams of people doing this just now all over the place just to create experiences that we are reacting to in our environment. Lastly, designing a new identity such as designers in branding and marketing, changing our brand to appeal to a broader market. Lastly, before we get into the specifics of the exhibit, I'd just like to end with the idea that design is collaboration. Unlike some fine artists who could work alone creating their art, most everyone who is in the design profession learns very quickly that you must collaborate. It's about many voices, many people. Ideally it's about putting ego aside and learning from everyone else so that there is a combination of ideas put together to create the optimum and hopefully most innovative result. All right, with that quick overview, and it was quite quick, we're going to go a little bit more specific, and Liese Pfeiffer will now talk about the exhibit she put together at the Design Gallery. >> Thank you, James. 

Can you hear me all right? Is this working? Good. Good. Well, Crafting Canoes: Art and Science of Hydrodynamic Design is the name of this show, and what we're looking at here is the front window when you come into that beautiful building that we saw on our first slide. So inside the gallery, there is signage all around, and I'm really working with this exhibition so explore the art and science of canoe making, as specifically hydrodynamic design, and how design goals unfold for different people. I have to admit that I'm a bit of a closet paddler. I fell into marathon canoe racing when I turned 50 and am totally fascinated by this kind of niche group that's so passionate about what they do. And it was through that that I was exposed to the UW Concrete Canoe Team, which is a fascinating group with all kinds of odd characteristics to it. A canoe that goes fast and is made out of concrete fascinated me. So inside this gallery we have brought these different canoes together, and I love the overlapping aspects and there obviously are very, very different aspects as well. This is a shot of the exhibition itself. 

I'm going to start by talking about marathon canoes, which are the two that you see on the right of this slide. So, marathon canoe racing is not an Olympic sport but is something that many people do, I would call it citizen racing. People who have full-time jobs who do this for fun on the weekends. And a lot of what has happened in canoe design has come about from these weekend warriors. People who are just really passionate about the sport, have fun with it. You'll see on the left, the front image of a canoe that's made out of Kevlar I'm going to talk about that a little bit more. But what I want to talk about first is how you come about different design changes, and frequently this is done through building a wood strip boat. Wood strip is one of the more economical time efficient ways to come and examine design elements and how you might want to change it. So I'm going to spend a little bit of time going through the steps of how that is done, and thanks to Ken Koscik, who is a local canoe builder, kayak builder in our area for many, many slides that I've called down here. Obviously you're starting with strips. 

So we're cutting strips out of cedar wood. And then what's interesting about the slide on the right is it is a picture of gluing this ventilated gunnel, but what I want to point out is the frame. You'll see this on a later portion. Basically, you have to build that form for which you're going to put the wood strips around. I brought some show and tell up here. And at the end we can come up and handle some of this stuff. The wood strips are actually very flimsy. It would be very easy for me to snap this piece. You can see here how they're are beautifully aligned around that form. And you can even see staples in that. 

The staples hold the strips together while the glue sets. The glue holds it together long enough for the fiberglass to set. And I'll show you, this is a piece of the fiberglass woven cloth. Obviously a lot of sanding. That's going to be a reoccurring theme throughout this. And then we'll go on to the fiberglass going over that wood strip. You can see how the fiberglass actually disappears, becomes transparent, when the epoxy is put on. The beauty of the wood comes through, and you aren't even aware. It's amazing that difference. This is now the same thing coated with fiberglass on both sides. 

And if you have a chance to come up, it is stiff as can be. Very, very strong. So that combination really creates a strong boat. Now, my initial focus in looking at wood strip canoes was for that element of building it quickly, relatively cheaply in order to move onto the next design change. This particular boat on the right obviously was built for the beauty and love of the craft itself. It's amazing how many people in this area have actually built a boat. I had no idea. But this is an example of somebody, Ken has put a lot of time and effort into picking woods of different color, etc, to have a beautiful piece of art as well as a functional canoe. So, in the back of this slide, this installation shot of the exhibit is that shield-like form. That is the cutout of a kayak from Ken who was shown in the foreground. 

The boat that you see here is made out of carbon fiber. So, again, we're starting with that wood strip in order to come up with the shapes that are going to be most successful. It's because of some new materials that we've been able to really be more dramatic about some design changes. And it wasn't until 1971 that Kevlar became a commercially used fabric. Again, these are fiber fabrics, woven materials that really have a lot of flexibility to them, but just like what you see with the wood strip, when it's used with the resin it becomes an incredibly strong material. Stephanie Kwolek is the inventor of Kevlar and came across it while doing research trying to come up with improvements for synthetic tires. The polymers that she was working with formed an unexpected liquid crystal, and out of this discovery, instead of throwing this unwanted thing out, she asked her technicians to go ahead and put it through the machine that spins the material creating a thread and discovering that this was an unbreakable and amazingly strong thread. We have gone on to use Kevlar for bulletproof vests and many, many other things, but it has also been used in the sporting industry. So, in these, here are a couple examples. And I can't go very far in talking about canoe design without bringing up the name of Gene Jensen. 

In this hotbed of Wisconsin, Michigan, Minnesota is really a hotbed of canoe enthusiasts as well as designers and makers. Jensen was from Minnesota, and at an early age of 19, he got into canoe racing. It was through his desire to go faster that he kept trying out different things. Again, somebody who had a full-time job. He was doing this for fun, but his fellow was responsible, earlier Tom Zinnen brought and passed around this bent shaft paddle, Gene was the one who came up with that idea to bend that shaft. I'm going to talk a little bit about this particular boat made out of Kevlar shows a couple dramatic design changes. One of the unexpected outcomes of doing the research for this show, and I was very curious about how people came to their design decisions. Even though in the '70s Kevlar offered some abilities to change things because of this lightweight material, the most dominant shift came about because of a rule book. The United States Canoe Association embraced the recreational paddler and came up with specs for canoe racing. The designers then dug in and started building canoes that met these specs and still were pushing the limits of trying to go faster. 

We have an extreme taper on the bow of this boat. The 33-inch spec was achieved with this hipped wing, but that doesn't meet the water. So the part of the boat that's actually meeting the water is much thinner than that. Therefore, there's less friction, gaining more speed. He was also responsible for the tucked gunnels that allow a more efficient, more ergonomic stroke. This is really clearly seen on the tandem boat. If you get a chance to go into the gallery, there's really a swooping curve at that point. So this slide kind of shows some of the process of these marathon canoes. Again, we're starting with that wood strip boat, and then building a fiberglass mold. There's materials, whether it be Kevlar or carbon fiber. 

You'll see that there are ribs, and here is an example of what these ribs are. It's an amazingly lightweight material but strong. And when it's covered with the Kevlar or the carbon fiber, it becomes a structural point for the boat. You can see through the changes, another big innovation of probably the early '80s was vacuum bagging where the entire sheet that covers the interior of the boat is sucked into place through vacuum. I won't go through all the steps here, but ultimately your outcome is this carbon fiber boat that's got this curved inside for the stern paddler to be able to really ergonomically get the most power from their stroke. John Diller is a canoe designer and builder in this country, the one who gave me these slides, and he has an incredibly simple formula for his process. He said, quite simply, I just look at what's out there and then I imagine how a boat can get the skinniest path through the water, least disturbance of the water. And then he tells me that I use my experiential knowledge of having done this countless times, countless hours, and the ideas just come out of my head. So he's approaching this in a very matter of fact way and building on his experience. This is a big shift from another section in this exhibition which right now we're looking at some canoes from the anthropology department. 

These are from their storage area. These boats have not been in public since they were collected. So we're very happy to be able to bring them into the gallery and tell their story. And it's fitting to bring this conversation into the canoe because there's some wonderful correlations between how these boats are built. Both the boats that we have in the gallery from the anthropology department were built for hunting. They couldn't be more different in design. This particular one that we're looking at right here from the Canadian Caribou Eskimo is built for speed. Long, narrow, sometimes up to 30 feet. There was attention paid to being as lightweight, again, didn't have Kevlar but did really think about how to make this light. The sloping stern helps to keep downwind from the animals, and the front rides higher to guard against the waves. 

This is Eskimo subgroup, and this particular boat was collected at Ennadai Lake in northern parts of Canada. The materials of this boat were gathered, and you can see here that the ribs are pieces of driftwood that are shaped but also found as shaped. It's put together with sinew as well as some cotton thread very simply. The covering for it is caribou hide, which is much thinner and lighter than the other hide of choice that was used. Caribou can swim at four or five miles per hour, so they wanted a boat that would be able to keep up with that. Their method of hunting at that time was to herd the animals into the water using wolf calls to scare the animals, and then while it was in the water they would then jump in the boats and take care of gaining their meat and everything that they needed while the animal was in the water. The other boat is not long and thin but short and fat. This boat is from northwest Alaska from the Inupiat. They have built and designed boats for centuries. Again, the design choices were based entirely on the needs. 

These people lived on the water. They used what was in the water for their survival. The boat that we're looking at now has a bit of a wood frame, but they've used whale for the ribs of this. And it is covered, the hide that you see here is actually the animal they were hunting, a bearded seal. It's a very thick skin, not nearly as lightweight as that caribou was.  The little kayak, the qayapauraq is the name of this boat, and they had to transport it by dogsled and then were able to jump in and out of it. It's a design that came about after the gun started to be used. Baleen, I didn't know what that word meant. It's actually the name of a whale as well as a part of the whale, and it's a beautiful black material. Again, seal oil used for waterproofing. 

This exhibition is up until April 6th. Our hours are Tuesday through Friday 10:00 to 4:00 and Sundays noon to 5:00. I certainly hope you get a chance to see it in real life versus the pictures, and I'm always available by appointment. Coming into the gallery, we have installation shots from the concrete canoe, and I'd like to hand the program over to Nick Molzahn to tell you more about this part of the program. So, thank you, Nick. >> Well, hi, everybody. So, as you heard, I am Nick Molzahn. I am the current president of the UW Concrete Canoe Team. A little bit about myself. I am a fifth year senior in the chemical and biological engineering program. 

So I have been around for a little bit. I have been involved with the canoe team for the last three years, and we are really proud to have our boat from last year on display. We build a new boat every year, so we always get new ideas and we get to incorporate new thoughts into what we're doing, trying to always improve on the previous designs. So a little overview about the team. We're approximately 40 to 60 strong on the team. It's all undergraduates. We have advisors, but we do almost the entirety of the work ourselves. We're led by a group of three coaches. I have two other members of the team who help to lead it with myself. We're in charge of managing the team, the budget, the fund raising, getting industry to sponsor us, making sure that we have all of the proper materials that we need when we need them. 

Recruitment, we have to always try to replenish everybody who's graduating and moving on. We also then have to manage the actual construction of the boat, all of the analysis and the mix development that goes into it. All while still trying to maintain a full course load because we're all still full-time students. So we don't get any actual academic credit for this. This is all just based on our love for what we do. The boats themselves take approximately 2,500 to 3,500 hours. It always depends slightly on the complexity that you're going for every year. But suffice to say that we put in the time to come up with a product that we're very proud of. We're all disciplines of engineers. It's primarily civil engineering. 

Concrete is a very civil oriented building material. But we've got every single type of engineer represented. We've got chemical, mechanical, aerospace. The mechanical and aerospace guys like to do the CFD, the computational fluid dynamics for how the hull is going to flow. Computer engineering, nuclear. It's really all types, a big collaboration. So, how does the construction process work? Early in the year we have our early meetings that we go over the theme selection. So every year we choose a different theme. As you might have seen from some of the other pictures, last year's theme was a pyramid. It was based on the Egyptians. 

The first civil engineering feats were really based in Egypt. So that's where you had the great pyramids, Sphinxes, and we really tried to pay tribute to that last year. In previous years we've gone over the aurora borealis, the different elements that make up Earth, wind, and fire. We've gone a lot into the history of UW itself. So the history of the university. We've tried to make a nice memorial to it. This year's theme, well, actually, you'll have to come check it yourselves. I know this is being broadcast, so we'll keep that to ourselves for now. But suffice to say, it's a very strong tie to Wisconsin once again. We might say it helped to shape the landscape that we're built on. 

Going to this then. That's the theme selection. A little overview of the rest of this. We'll get into these separate aspects later. You have to go over your mix analysis and testing. So each of the different mixes that we develop, we create around 44 every year. And these are different ratios of different cements, different pozzolans, different add mixtures, different aggregate sizes. We'll get into all of that a little bit later. But you've got to test a lot of different things to always try to come up with the lightest and strongest. You can see here is a little cylinder here. 

This is just an example of one of the ways that we do that testing. I encourage you guys to all come up afterward and feel it. You'll feel how light it actually is. I guess we can pass it around, right? Yeah. We'll pass this around right now. There you go. So after we get our mix analysis and testing, we then go and do the hull design. The hull design captures the actual numbers that we need. A lot of the hardcore engineering that goes into it comes in at the hull design process. So that's where we go through and we figure out the strengths that we're going to need. 

Is our boat going to crack or is it going to survive the stresses of not only racing but racing with four people in it and the loads on it? After we have a hull design complete, we go through and we construct a prototype out of wood strips. We heard a little about that. We'll go and see how we actually do the construction of our prototype. With our prototype then we have to create a mold. So the mold is what the concrete is actually placed into. Once the concrete is placed, it's allowed to cure, and then we have to go through the finishing process which takes approximately three to four months. So the basic question that we always get is, how does it float if it's made out of concrete? I'm sure a few of you guys might be having that question floating around in the back of your mind right now. Well, Archimedes' principle states the buoyant force is equal to the weight of the fluid displaced. So, as you can see down in this little figure here, you've got a submerged solid. You've got the buoyant force pushing up on it, and you've got the force of gravity pulling down on it. 

Now, when these are balanced out exactly, you have a neutrally buoyant object that would neither float nor sink. Now, if you take a real boat made out of steel, you've got a big battleship is the one I typically think of, you've got all of that weight, but you're displacing even more water than even all of that weighs. The density of the water is quite, it's pretty dense stuff. So that's how you can make anything float if it's the right shape. Now, with our concrete boats, there's always the risk that they crack in half. It has happened, not to us fortunately, but we have seen it happen at some of the competitions. So for safety and environmental concerns, our canoes actually have to be positively buoyant. So that means that even when completely full of water, they must still be able to rise back up to the surface. So to do that, it has to be less dense than water which is not an easy feat to achieve with concrete. Exactly. 

How do we do that then? We use a lightweight glass bead aggregate. Now, an aggregate in the cement world, in the concrete world, is what is used to actually be the, I think of a glue and popsicle stick analogy. You have the glue that holds it all together is cement. So cementitious components include your Portland cement, you various pozzolans, your expansive concrete. You've got a lot of different things that actually form the chemical bonds. So what happens with those is when you get them wet, they get hydrated and you form long linkages that can connect other things together. In this case, the things that you are connecting together are known as aggregates. Now, in the concrete that's holding up this building, I hope is holding up this building, is sand and gravel and rocks. So those have very strong compressive strengths, but they're also very heavy. Just for comparison purpose, the density of normal concrete is right around 110 to 120 PCF. 

So PCF stands for pounds per cubic foot. So if you have one cubic foot of these normal concrete, you're weighing in at over a hundred pounds. Now, water is right around 62 to 64 depending on the temperature. So you've got 62 pounds is what you're trying to beat. Our concrete for the boat last year, Pyramidion, came in at right around 38 PCF. So that shows how it floats right there, but a lot of engineering has to go into that to get it to float. For our glass beads or for our aggregates then, we used expanded glass beads. This comes from Germany. It's a company called --. And what they do is they take glass beads and grind them up, expand them with air so they're actually hallow, and then use those and ship those over in various sizes. 

So we get different sizes that we bring all together, and that's how we get our gradation. So normally in concrete you've got sand, which is the really filler material in between it, you've got bigger gravel and bigger rocks. So we use glass beads of different diameters to achieve that same effect. The cement then goes in between and binds all of these glass beads together. So that's how you get the, I don't know where the cylinder is right now, but that's how you get the lightweight that you're felling right there. We also use partial replacement of the Portland cement. I don't know how many of you guys might be familiar with this statistic, but almost, I think it's 15% of the CO2 in the atmosphere comes from Portland cement creation. It's very damaging to the environment. It's not a very sustainable process. We rely on it because you need concrete. 

However, there are replacement agents available. One that we use is called VCAS. It's a byproduct of the fiberglass industry. So when they make fiberglass they get this powder leftover. This is also the case in power plants. They get fly ash. These are collectively known as pozzolans. So what pozzolans do is you're able to incorporate them into the mix. You get additional binding chemically from them, but in most cases they weigh less than the Portland cement. So you can reduce your weight and still get strong bonds in an environmentally sustainable fashion. 

So at UW Concrete Canoe we are all about trying to maintain environmental sustainability in every phase of the project. These are just two of the ways we are able to do that. Now, to make sure it doesn't crack, there should be a K under there, it's hidden by the picture, we do know how to spell most of the time. We use pre-stress steel cables going through there. That is kind of like the rebar of concrete that really pulls it together. As well as we use fiberglass and carbon fiber reinforcement. We'll see that later as we go through. Now, for the hull design, you can see here that we have a 3D analysis of it. You can see the bottom little dots on there, the red dots, that's where the knees are of the paddler. We're not allowed to use the 3D analysis every year, but when we can use it, we definitely take full advantage. 

This year is one of the years that we have to do it all by pen and paper. This is a picture taken from a few years ago. You can see that as they're paddling, the stresses on the hull are immense. This is a concrete boat. Typical thicknesses are less than half an inch. This year we were at three-eighths of an inch thick. So it's a 21-foot boat with three-eighths of an inch thick of concrete, it's going to take a lot of analysis that goes in there to make sure you're not going to crack it. There's a lot of dynamic stresses then too. Every time that you paddle, it's approximately 50 pounds that you're pulling backwards in the water. So that force all gets transmitted through the hull. 

So we always look to optimize our strength, make sure that it's not going to crack there. Now on to the actual construction of it. After we know what mix we're going to use, after we know the overall shape of it, we put it into a computer program that gives us 3D cross-sections of it. We take these cross-sections and we print them off and we cut out these I guess we call them cross-sections also at foot intervals. And we saw a few of these pictures before. This goes through and shows how universal this model is that you have these wood strip canoes at every level, this is how we get our initial shape. They're attached to a central strongback in the middle so you know that it's going to be perfectly aligned. After you have that, you start to wood strip it. So you have the wood stripping going on, which is where you take thin plywood strips, attach them to the strongbacks with removable nails, and you let the glue kind of hold the shape together. Now, as we were saying before, you've got to cover this thing in fiberglass because the glue itself does not have much strength. 

After you get the entire boat made, and it gets progressively more challenging to meet all of these curves, then you go on to the fiberglassing.  So, fiberglass is something that you have to definitely take precautions while using because it is a skin irritant. You can see here that everyone is covered with the full skin suits to make sure that they don't get any fiberglass irritating the skin. It's then covered with the reactive resin, and that resin provides approximately 90% of the strength that the wood boat actually has. We use this wooden boat then as a prototype to practice in. So just last night we rented out the Natatorium pool here on campus and had two hours of paddling practice in the middle of winter. So that's one thing that our geography here in Wisconsin makes us move indoors a little bit. Now then, the next step is to make a plaster and burlap mold. The plaster and burlap mold is what we actually place the concrete into. You can see here in the picture on the upper right that we have team members alternating layers of plaster and burlap in there so that you can create a strong mold. 

Now, the strength of the mold is important, and we'll get to that a little bit later, but in general this is where all of your aesthetics come together with your hull design. So we cut open the strips that are going to take the place of the concrete in some locations, and that's how we get different colors to match up so seamlessly It's almost a void space, that once the concrete hardens you pull out these linoleum strips which are present all throughout here. This the aurora pattern from two years ago. You pull that out and then you're left with a void you can pack with a different color of concrete. Now, in this mold it's important to have strength for the pre-stressed steel tie wires. When you have the tie wires in there, it conforms the shape of the boat when you pull the stress on them. So you have to have tie wires going through that actually secure to those pre-stressed wires to hold them in place. You place the concrete around it, and then you've got to make sure that your mold is strong enough that it's not going to crack. So we call this mix day or placement day where we actually place the concrete into the mold. It all happens on one day over approximately two to three hours. 

So all of our work really comes together for the first semester on that day. It's in the middle of December so we're all wearing Hawaiian shirts because it gets very hot in there. We have it in a humidity tent. Now, concrete relies on water for the hydration. So with the water to hydrate it, you'd want to make sure that you're not losing any to the atmosphere. So you keep it in a high humidity tent and that ensures all of your moisture content stays in the concrete to keep strengthening the bonds. Mixing it outside and bringing it into the tent then, you place it into the mold. You have different layers so you place them an eighth of an inch thick. Each eighth-inch layer is separated by either a layer of fiberglass reinforcement or carbon fiber Kevlar mesh. And those are highlighted here. 

The picture in the upper left shows some of the fiberglass reinforcement. The picture in the upper right shows some of the carbon fiber Kevlar reinforcement. These are there to provide strength inflection. So I have another plate here. We test these plates when we're doing the mix development. You've got to make sure the plates are strong enough to resist not only a compressive force on the cylinder but also a bending force that we call flexural stress. This is more indicative of actually the stresses that are endured during the race. So these are very important. I'll pass this around also. You can give it a little bit of a flex. 

Try not to crack it. [LAUGHTER] I don't think you will. So once you have that, then you let the concrete cure for 28 days, seven of them in this humidity tent. After it's removed from the mold then, the hull is sanded to the final shape. Now, the sanding process takes from January through our competition in April. So it's about three and a half months of just sanding the boat. Now, it does take a long time, but it's perfection that we're after. We're always after getting the best possible quality that we can, and to get that you have to sand for a long time. Normal concrete has a lot of pits in it, so you have to cover it multiple times. We go over every surface of the boat approximately 10 times with a special mix called a slurry mix that fills in the little holes, and then we sand it down again. 

So it's a very integrated process. To get the color right, we could use a sort of stain or paint on the hull, but we prefer dyed concrete. You can see a little bit of the dyed concrete in this picture right here. That's dyed concrete being placed into the holes left by the linoleum cutouts being removed. You can see that illustrated perfectly down here. That's one of the linoleum cutouts. That's the initial state of the hull. The slurry then fills in all of those gaps that appear there. This process takes thousands of person hours. So it's a very intensive process, but we're very proud of how it turns out. 

The final product that we get turns out like this. It's sanded to 2,000 grit, which is about as smooth as I can imagine. Think of like glass or something. It feels that smooth, and it's actually all concrete. We get the very consistent colors that you can see. Now, the competition is more than just the boat itself. You also have to create stands, displays, there's a technical presentation, and a technical paper that go into it. So it's really a process of weeding out and making sure that you have very well rounded engineers at the end of this. So you can see our canoe at the competition from last year, the one that's currently on display at the Design Gallery. Pyramidion weighs in at 124.7 pounds. 

It's 20 feet long, or 20 feet, two inches long. And we're very proud to have that. You can see the team down here. That is our team from last year. So you can see we were a very large group, very diverse group, and we really enjoy what we do. So I've got one last treat for you guys here. The real fun of this whole competition is the races. So we have a nice video here from 2008, which was coincidentally the last time that UW won its last of five consecutive national championships leading the nation. So let's see how these things actually race. About 200 schools across the nation compete in these competitions. 

So it's a pretty large event. We're very proud of the way that we've placed the last few years. So this was 2008's boat called Buckingham, and this is up in the national competition. >> Where is that? >> I am not exactly sure where this one was. >> Montreal. >> What was that? >> It was in Montreal. >> Oh, it was in Montreal at ETS? Okay. So you can see the races here. >> The Olympic basin. >> Okay. 

So a lot of the competition relies on how well your boat can turn. So you've got to know the hydrodynamic characteristics of your boat. We use a technique called a crossbow where the front two paddlers are going to insert their paddles into the water to execute a 180-degree turn around the buoy. So this is what we practice for. You can see how sharp these turns can become right around the buoy. [LAUGHTER] We get this guys paddling so they're starting right now so they're going to be ready for this. There's five different events, five different racing events. You have a two male sprint, two female sprint, two male endurance, two female endurance, and then the crown of all of them, the four person sprint race which you're viewing right now. It's very important for everyone to stay in sync. So everyone has to be able to be on the same beat to make sure that you minimize the rocking and make sure that you are getting the most out of every stroke. 

 So that was UW taking the title right there. So with that, that's what I've got. I would like to open the floor to any questions after this. I don't know how the question portion works, but I'll be around and will answer anything you have. Thank you very much. [APPLAUSE]