 Okay, Tech Talks. We're back. Two o'clock, Rock. You're going to give it Friday. We're Think Tech Tech Talks. And we have a special guest who has been with Think Tech for a long time. We'll play back in the radio days, too. That's Dr. Hans Krock. He's an energy engineer. And he was, what? The chair or the dean of the energy engineering department and... Ocean engineering. Ocean engineering department back in... Yeah, since 1980. And you're associated with Al Yee, another engineer. Yes. And you guys have worked together on various projects over the years. Yes. Yes, we have. And that area is mainly having to do with OTAG ocean thermal energy conversion. And of course, in the department of ocean and resources engineering, I was one that added resources to the title and included OTAG as part of the curriculum. So, I believe this was the only academic program in the United States that had OTAG ocean thermal energy conversion. Other countries, Japan has some academic program. And... It's in SOS then. Yes, it's in SOS. And I believe Taiwan and Korea. South Korea have programs that include OTAG. Both of those are headed up by doctoral graduates of our department. My students actually. Is that right? Yeah. Cover the whole Pacific world. Yeah. You guys have designed projects for every place, really. Yeah. Well, Al Yi, of course, is a world-famous structural engineer, expert in concrete structures, and especially marine structures, which require a different mix of concrete to survive. That's one of the reasons we got together in both an OTAG and these other things like the Natatorium, which we're going to talk about today. Yeah, let's talk about that. So it was in the paper yesterday in the Star Advertiser. There you were. I think it was the front page, no? No, it was the front page of the business. The business section, yeah. And it was about a new design that you guys had devised with some encouragement from the National Trust for Historic Preservation for the Natatorium, a really important national monument here in Hawaii. Can you tell us about the design and how it got to the level of news? Well, as most everybody knows, an auditorium has been on the possibility of redesign for, I believe, some 35 years, and we really haven't achieved it yet. We've gone through several iterations of alternatives, but it hasn't happened. And it's at a stage right now where some alternatives are being considered as alternatives to be covered by an environmental impact statement. And when the national people came by, none of those really satisfied them. And they had heard about Ali and myself having some expertise in this area. So we had a series of meetings, and I basically resurrected a design that I had 20 years ago with some graduate students. Really? An academic design then, yeah? Well, yeah, it was, and we experimented on it and whatnot. In any case, that wasn't accepted at the time because they wanted to go with something that, to my mind, wouldn't work. Nevertheless, it came up again now with the National Historic People. And they're backing this design? They are, and they're pushing something here specifically because they're interested in keeping a World War I memorial active, especially on the 100th anniversary of World War I, you know, the Armistice Day. Yeah, we can't tear down a monument like this on an anniversary that's over. Today is Armistice Day, isn't it? November 11th. Veteran's Day, Armistice Day. Yeah, yeah, yeah. So it's an important discussion for us to have today, actually. So it was a monument to the soldiers and sailors who had died in World War I. Yes, and Hawaii contingent, as I understand it, of course that was before either one of our times, was large for the population. In fact, when they sent the contingent of basically volunteers to the first World War, I believe it was the largest one of any of the states for the population of Hawaii at the time. And remember, at that time, Hawaii wasn't a state yet. That's right, it was just barely a territory. Yeah. And World War I was a real meat grinder, but the casualty rate was very high. Very, very, I mean, unsurpassed even now, you know, in terms of pro-battle, you know, huge amounts of history and changed the world. I'm somewhat involved, I mean, in my background somewhat involved in that, because I was born in Poland, incidentally. And prior to the end of World War I, Poland didn't exist for 140 years, if you remember. And only as a result of the, what, the disappearance of the three empires, the Russians, the Austrians, and the Russians, Poland suddenly popped up again and became an independent country until World War II, when all that changed. Nevertheless, it's again an independent country. Yes, it is. And that was the start of it. So here, the powers that were at the time, the end of World War I, they decided to build this monument to the fallen soldiers and sailors. And it was an unusual design at the time. It was advanced at the time. Well, it was unusual in a couple of ways. One, it was a trend that was also covered in other monuments in the U.S., for instance, Soldiers Field, you know, the baseball park. It was a trend to have a useful monument, not just a statue of somebody on a horse, you know, but actually to have some use out of it. And this was a pool for swimming. And that's useful, you know. And so it was a national monument that everybody knew about. Really? On the mainland, too. On the mainland, yeah. It was advertised, I mean, you know, written about. And so it was an important thing from that standpoint. And of course, all of Hawaii knows that many people learn to swim there, do kanamoku. Do kanamoku. That's where he did his swimming. Exactly. And what Tarzan, you know, on the Weissmuller and whatnot, there were lots of associations. And it basically fell into decay. Now, it was one of only, well, you didn't find a lot of salt water swimming pools in those days. I'm not sure how many there were, but you could probably count them in one hand or even less. So, and it was actually built with some of that in mind because it was built to the dimension of an Olympic-sized pool, you know, 100 meters long. And so they set some records in there. But of course, finally, records are kept separately for salt water and freshwater because you float and solve a little better. Yeah, about the same. So it's not the same, yeah. Well, I can see Waikiki at the time. Waikiki with Kapi Lenny Park. There were horse races around that time in Kapi Lenny Park. The ladies would come out with their finery on a Sunday and everybody would attend these great horse race-type events. And the kids were surfing. Everybody was surfing in those days was, I guess, just as popular, if not more popular. And all this within a few feet of the Natatorium. So it was part of a complex of sport and athletic activity right there. It was probably a great center, drew a lot of people. Yeah, and I understand that the local kids came from school and, you know, considered it, I mean, it was free. So, you know, and it was a safe place to learn to swim. You weren't exposed to, you know, waves. You know, although, of course, we all swim in waves, but it was a good place to learn, you know. So let's talk about the original design, because this was unprecedented in so many ways. How did they want to... We have pictures. Let's look at some pictures. Okay. There's a picture of the... Is that a picture of it as it was built or as it is now? No, no, that says it was originally built. And you can see that it's relatively enclosed. And here, I believe, you can't see the color in this case, I don't think. But this is what the present situation is. I mean, the original design really hasn't changed in terms of its gross outline. And the area around the swimming pool there is now blocked off because it is unsafe. The concrete has deteriorated and there are holes all over the place, and the water is in poor quality there. And some of the original assumptions about the design didn't work out. How could the water be of poor quality? What's going on to make it of poor quality? Yeah, there are two things that make it poor quality. And one has to do with the bottom sand, the bottom sediment in there, and the other one has to do with the rate of exchange of water. Inside and outside? So it's stagnant inside? Yeah, it's a poor exchange rate So originally, there were pukas on the side walls over here, which assumed that there was a current that would push the water through there. But that doesn't really happen. It doesn't really happen, and in any case, those pukas are fairly small. There were four on each side, and the pukas on the downstream side here by Kamana Beach became filled with sand, because before the Natatorium was built there was no Kamana Beach. And sand changes position all the time? Well, it changes, but it accumulates when you have a barrier like the side wall over there. So it accumulates, and now we have a beach, and we have people that enjoy the beach and want the beach to stay there. So the alternative of tearing down the Natatorium completely is not a good alternative. In other words, going back to the original shoreline condition, because the beach is there, and so people don't want that thing to be torn down. So that's one of the alternatives. Well, it's in the National Trust for Preserved Monuments. Can it be torn down as a national monument? You have to jump through a bunch of hoops if you want to do that, and it would be difficult. And like I say, especially on the 100th anniversary of the First World War, excuse me. Well, we're going to take a short break. We have Hans Krak, energy engineer, talking about his plan. With Al Yee for the redevelopment of the Natatorium. We'll be right back. Aloha, everybody. My name is Mark Shklav. I'd like you to join me for my program, Law Across the Sea, on thinktechhawaii.com. Aloha. Looking to energize your Friday afternoon? Tune in to Stand the Energyman at 12 noon. Aloha Friday here on Think Tech Hawaii. Hey, everybody. My name is David Chang, and I'm the new host of the new show, The Art of Thinking Smart. I'm really excited to be able to share with you secrets on giving yourself a smart edge in life. We're going to have awesome guests and great mentors of mine from the political, military, business, nonprofit. You name it. So it's something for everybody. Okay, we're back. We're live with Think Tech Talks, with Hans Krak, an energy engineer who's spent what, many decades in the engineering, in the marine, the ocean engineering department in the UH. And he and his colleague, Al Ye, devised a new plan to save the Natatorium. And it was in the newspaper, the Star Advertiser yesterday and other media too, I think. And now we're here to go into some detail today. So we have some more slides, and I'm hoping we can show them, and Hans can describe what we see here. Yeah, I want to show right now the existing walls, the outer wall and the side walls. And the thing to note here is that these walls are solid and don't allow waves to come through, a wave break through there. And the bottom is sand. So we talked a little bit previously about the lack of exchange of water. And so the idea is to allow the waves to push some water through here. That's the idea that I have. And the lack of the exchange of water means that it's stagnant. Yeah. And it's not healthy. Right. The water stays in there long enough to grow phytoplankton, and they accumulate in there, and they cause the water to be cloudy. And additionally, they change the pH, which is the amount of acid that's in the water. And that's significant because of the sand on the bottom, which in Hawaii, it comes from coral, which is chemically calcium carbonate. And if you go to acidic conditions because of the accumulation of organic material, that sand tends to dissolve. And so you get finer and finer particles, and they come into the water and become turbid. And so that's the condition. It's not clear water anymore. And it won't be clear unless you do two things. One, get rid of the sand, either by replacing it with some sand that doesn't dissolve or with a solid bottom. Another material, not calcium carbonate. So now what you're talking about is to solve the problems that you have found with this lack of exchange, but that would be as part of a larger project to rehabilitate the entire netatorium. All of the structures and infrastructure around to make it a workable athletic stadium as it was. Yeah, it makes no sense to just say, oh, this thing's deteriorating, but let's just replace the walls with new walls and not solve the problems that made it usable, unusable to begin with. And that's the difference here. In the past, we have talked about just rebuilding it with the same system, but that's a waste. If you're going to rebuild it, you want to improve it and you want to deal with these problems you identified. So what's your system? Well, I want to first of all say that one of the objections to the present system is that the health department has come up with rules about pools. So pool regulations. And that is applicable to saltwater pools, but not applicable to areas that are freely exchanging with the ocean. And so in solving this problem, we want to make the conditions so that this doesn't meet the definition of a pool according to the health department. So there are other examples in Hawaii where you have areas where you in fact have exchange that's driven by waves and you have a pool and the health department doesn't apply saltwater pool rules to them. That's Magic Island. That's Magic Island right now. And the water is pushed through the gaps there and those are waves. That's one way to use wave energy. And the water inside is not terribly turbid. People use it and they do a lot of swimming and whatnot in there. And the health department doesn't get to exercise about that. Similarly, there's the Cahuillo Beach right in Waikiki, very close to an auditorium, where in that case there's an outer wall that's relatively low and the waves break over that and push water into that area. And again, the pool rules by the health department don't apply here, although ostensibly you've got walls and you've got people swimming and it's very similar. It's very similar and you can swim a lot easier in a structure like that. Yes, exactly. You have exchange. You don't have static water conditions. And the next one in the Corolina Lagoon these are completely artificial. Nothing was there before. And this was dredged out. And again, although it's not immediately obvious, this is again wave-driven exchange. And that is each one of these lagoons has a configuration on its mouth where the waves break on the two outer channels, push water in and the outflow goes through the center channel which is deeper. So the wave comes through and goes out. And again, there's a swimming area. People recreate in there and the health department doesn't apply salt water. That's very clever. So you use the depths of the in and the out to achieve the exchange. Well, right. Waves are source of energy or water movement. And normally people don't really realize that but out in the ocean when you don't have breaking waves the water doesn't move forward. It just moves in a circle. And only until you break the wave or until you allow movement only in one direction do you actually get water movement. So water in a breaking wave washes up on the shore. That's water movement. And so by cleverly designing something that allows you to take advantage of the energy which is the movement of water in design. You can then design the thing to exchange water. And that's what I've done. I've come up with this little thing. Although if somebody says, oh, we don't want that, we can use any of these other methods here. It's the same thing. It's the same thing. The essential thing is you use the energy of the water itself of the waves to achieve the exchange. Then you can avoid stagnant water and have a flow in and out. And that's the essence of the thing. So in one case, in that case, you solve the problem with the stagnant water. In the other case, you first of all pull out the sand, the calcium carbonate, you suck that out, and then replace it in my design anyway with gravel first of all, not calcium carbonate, but gravel, and then shape it however you want it or put whatever depth you want in the pool. It's not hard to do this. No, it's what you would do in any case. And then you put slabs of concrete. They don't have to be a contiguous thing, but slabs of concrete to shape the bottom and basically cover up any sand that's further down so that you don't have sand dissolving and causing turbidity in a thing. I don't know if we have a slide of that, but that's the existing condition that we're going to improve. See, it identifies a restricted water flow on the outer wall and shows that the deteriorating deck, the concrete and whatnot is in bad shape. And it says about the pipe that was originally thought to provide adequate circulation, but doesn't. And then the descriptor of the poor water quality, which is due to those two factors, poor circulation and the sand on the bottom. And then the solution is, in my mind, is the next thing which is... This is the important one. This was the one in the newspaper yesterday. Right, that's right. This is going to correct the problems. That's correct. Basically, this outer wall over here is replaced by a wall. I mean, you're still going to have a wall over there, but basically it's a two rows of chevrons which allows the wave energy to push in, but not... If you just have a wall, the wave goes to the wall and then reflects back out. What's a chevron? A chevron is just a V-shape of concrete and it's probably what, five or six or eight feet deep? Oh, it's the entire depth of the... Which is more than five or six feet. Yeah, it's not much more than that. And of course, this is fully tidal, so you have basically two feet of range, of the tidal range over here. And the chevrons are pointing outward. They just point out to C. Yeah, C is the J. See, if you get the pointy end outward... You see, if you look at the chart there, it's on the left-hand side. You can see the chevrons. If you got the pointy end outward, it's like the front of a boat. So if a boat goes sideways to the waves, the wave hits a wall and reflects it, and they say, oh, man, we're all going to get seasick. So you say, oh, we're going to put the pointy end into the waves, so it slices through the waves and the waves don't break. They just slice it. Come around the chevron. And this is like a valve, because it allows the water to come in, but not get out. That's right. You got it now. And the second row of chevrons actually further diverts the water and tells it, if you want to come back out, all you're going to see is a trap. You can't get out anymore. And then further inside over there, you've got a gap of a series of vertical walls with a gap in between and the wave, what remnants of the wave you have, which is going to get all confused by going through all these chevrons, and it's going to hit that wall and try to bounce back and see the closed ends of the chevrons, and turbulence ensues like a breaking wave, and you basically have a rise in water level, which then flows through the gaps in the vertical thing into the pool, and now it's in the pool. It's fresh. It's new. It's new there, and the only place that can get out of that pool is through these pucas here on the side walls. So it flies all the way through. Can we see that chart one more time? On the side walls. Showing the relief holes in the back. And the side walls are hollow. So it flows back out, and it goes back to the ocean near the front. You see those arrows going out. So it strikes me that this is actually pretty close to the original configuration. You're just replacing the one wall and expanding the relief holes at the back. Ostensibly, when you go back to the original thing, you wouldn't be able to tell the difference because it's still the walls. You can't really see the chevrons very well because they're below water, and so there it is. So the National Trust for Presentation is going to like this. They are already delighted. They've reviewed this, and they say, hey, let's do this. That's what it is. It's great, creative, and it's with you and Al Yee you've been doing for years concrete, marine concrete, and it's easy to make these things, right? You have a form, you pour it in, and they just put them out there. And in fact, you could even make them the same size as the bottom slabs. You wouldn't even see them. But they would be doing a job creating an exchange that you need to have. And from an engineering standpoint, you're just utilizing nature's energy that's available to you. And anybody knows it's easier to work with nature than it is to fight against it. There you go. It's easier to work but don't fight with mother nature. I've heard that before.