The Miraculous Floating Airport | Super Structures | Spark

Off the coast of Japan, there is a superstructure so immense it can be seen from space. The world's first airport in the midst of the sea. The largest man-made island of its day. The longest bridge of its kind. And one of the world's architectural masterpieces. But its brilliant design could not conquer a hostile Earth. A low-tech ingenuity saves its high-tech engineering. Is Kansai the airport of the future? Or is it doomed to sink beneath the waves? Where modern skyscrapers dwarf the monuments of ages past. Where timeless serenity mingles with industrial might. And one of the world's engineering marvels rises from the sea. A superstructure for the 21st century. The mile-long terminal at Kansai International Airport hovers like a giant silver bird atop a man-made island in Osaka Bay. Graceful in design, Japan's aerodynamic airport is a triumph of construction and a technological wonder. It was quite extraordinary to me that when the building first opened it was getting 10,000 visitors a day who were not there to fly, they were there to look at the building. And that says something. To build the world's first ocean airport, architects and engineers probed deep into the laws of nature, searching for answers to the awesome challenges before them. Thousands of workers labored seven years building the biggest man-made island of its day, more than three miles from shore in water 60 feet deep. Then crowning it with the world's longest building, the biggest public works project of the 20th century. The airport is the first place and last place people normally see at your city. So you want it to represent something about your city. You want it to look good. You want them to have a favorable impression when they arrive and when they leave. We don't build big cathedrals anymore, but we build big airports. Today, Kansai International is a glittering masterpiece, widely regarded as one of the world's most beautiful airports and one of modern history's most daring engineering projects. Before Kansai, no one had ever built an island in water so deep or so far from land. From steel girders to workers' lunches, everything had to be transported to the construction site by boat. To create the island, work crews had to move 750 million cubic feet of earth, pound a million steel columns into the ocean floor, and labor over 10 million man-hours. I scouted the location by helicopter, and I thought, oh, my God, this might be a big challenge. Why did Japan take on the challenge of building an airport on the sea? Because daunting as that challenge was, building Kansai International Airport on land would have been next to impossible. Kansai is a 10,000-square-mile region in central Japan, straddling the island of Honshu, some 300 miles southwest of Tokyo. Within its boundaries lie two of Japan's most important cities, the sprawling industrial centers of Osaka and Kobe. In the 1960s, Kansai's cities were losing ground. Japan's imports and exports flowed through Tokyo. To compete with Tokyo, Kansai needed a new international airport. This airport was not only very important for Kansai, but also for the whole Japanese economy. Before Kansai Airport, manufacturing companies based in Kansai had to send their cargo all the way to Tokyo to ship it out of the country. That was very inconvenient. Osaka's airport, Itami, sat in the middle of a residential neighborhood, dangerously hemmed in by buildings. The constant roar of jet engines disturbed its neighbors. There's no way that you can get around it. The airplanes fly over, they make noise, they have particles of emission from the jet engines, and those end up in people's yards and people's roofs, and in people's ears when they're trying to watch television or have a barbecue. Too many families lived in that area, so the potential, therefore, was a dangerous one. If something ever went wrong, thank goodness it didn't. At the far end of the runway, just on the approach, there was a school. We were always cognizant of the school being there, which is not the greatest thing. Expanding Itami was out of the question, but so was finding land for a new airport. In heavily populated Japan, there was little empty land and few people willing to give up land they owned. In 1969, Tokyo began construction of an international airport at Narita, a distant suburb largely populated by farmers. When the government confiscated farmland to build the airport, protests exploded. Outraged farmers besieged the Narita construction site. Leftist radicals fired rockets across the runway. Police arrested more than 3,000 activists. Seven people died. Protests delayed construction of Narita Airport for nearly a decade. In the Narita case, the government carried the plan forward without giving much information to the people. You might say the government forced its plan on the people, and that caused a strong movement against the construction. The best way to deal with noise pollution and angry neighbors was to avoid them altogether. Kansai decided to build its new airport on the waters of Osaka Bay. There's nobody out there to suit them in the middle of Osaka Bay. Maybe a marlin here or there or something like that. With no neighbors to disturb, a water airport could stay open 24 hours a day, making it even more competitive with Tokyo. But the plan had other perils. Osaka's fishermen might oppose a water airport as bitterly as Narita's farmers had battled an airport on land. Fish travel their own routes, which the fishermen know. If there's any change in those routes, it's very difficult for the fishermen to catch fish. It's not like the fish travel along marked highways. To find them again is very difficult. To avoid another Narita, authorities offered the fishermen a huge fee as compensation for disturbing their fishing grounds. The fishermen accepted. Politically, the path was now clear. But the project's troubles were only beginning. By locating their airport on water, Kansai's planners had avoided battles with outraged citizens over land. Yet they would soon find themselves battling a far more powerful force, the force of nature itself. Japan's four main islands have been called the most geologically treacherous real estate on earth. Nine major earthquakes greater than magnitude 7 struck in the 20th century alone, killing over 150,000 people. Thousands of smaller temblors shake Japan every month. An earthquake's worst damage is often to structures built on landfill, which liquefies when shaken. When it isn't shaking, Japan is reeling from some of the deadliest storms on the planet. Since World War II, hundreds of typhoons have ravaged the Japanese coastline, killing nearly 7,000 people. A typhoon's cyclonic winds can whip up what meteorologists call a storm surge, a dangerous rise in sea level. On September 21, 1934, a storm surge raised the level of Osaka Bay 10 feet for several hours. That typhoon killed 3,000 people. Three miles from shore, the new Kansai Airport would be fully exposed to a typhoon's fury. Would a typhoon someday tear the new multibillion-dollar airport apart? Would its foundations dissolve in an earthquake? Would storms or earthquakes sever its lengths to land? The new Kansai Airport had to survive some of nature's most powerful onslaughts. Engineers designed an island 2.5 miles long and nearly 4,000 feet wide, framed by a huge rectangular seawall, whose perimeter would be 7 miles long. Into this massive frame, they would pour 750 million cubic feet of earth. It seemed like a simple plan, a larger version of other projects Japanese engineers had successfully completed many times before. In land-starved Kansai, the shore is lined with industries built on man-made land. But three miles from shore, conditions were very different. The seabed is something like 100 meters or so depth of soft clay, so soft, in fact, that if you could drain the sea away, you wouldn't be able to welcome it as a marsh. Tests showed that the airport island would rest on two levels of ocean-bottom clay. The upper layer, called alluvial clay, didn't worry engineers. They had built on it many times before. But three miles from shore, there was a deeper, older stratum called diluvial clay, extending 1,000 feet below the alluvial layer. Engineers had never built anything on this diluvial clay. No one was sure how it would react when the world's largest man-made island began pressing down on it. That's, I think, the first case in human engineering history. In order to know the condition of the foundation ground, we developed a method of sampling the clay itself. We calculated things like strength and pressure-density correlation to learn the characteristics of the ground. Scientists analyzed core samples from the ocean floor and gave differing predictions of how far the airport might sink into the clay. Some believed it would sink only 19 feet. Others insisted it could sink as deep as 25 feet. Officials made a fateful decision. To save money, they rejected the predictions of deeper sinking and planned an airport that would sink only 19 feet. January 1987. With prayers for the safety of the workers, construction of Kansai International Airport begins. The first task is to strengthen the soft ocean floor clay so it can support the airport's immense weight. To strengthen the seabed, engineers use a well-tested method known as sand draining. Specially designed ships float over the construction site, first spreading a five-foot layer of sand over the ocean floor, then hammering one million pipes deep into the clay. It's a fully automated process controlled by shipboard computers. Next, enormous barges equipped with pile drivers force sand into each pipe. Finally, the computer-controlled ships pull out each pipe, leaving a million columns of sand. When the finished airport presses down on the waterlogged clay, its weight will squeeze the water from the clay into the sand piles, draining the clay to make it harder. But the sand drains cannot reach the deeper diluvial clay. Nothing can be done to stabilize it. With sand drains in place, work on the seawall begins. To keep waves from washing away its rubble slope, seawall workers must armor its surface with massive stones. Sixty feet below the surface, divers guide these armor stones into position. The divers are veterans of many underwater construction projects, but none as deep and as far from shore as Kansai Airport. They face deadly hazards in the turbulent ocean depths. At this place, we set stones that are about one to two tons each in the water. It was far from the shore, so there were bigger waves. It was a challenge for us. We did it even in tough situations like in bad weather. One guy had his leg amputated at the thigh because the waves moved a stone and it smashed into his leg. We were always close to death in a way. Despite the dangers, work on the seawall continued as workers maneuvered 69 gigantic steel chambers into place. Each of these mammoth casings was 75 feet high, 75 feet in diameter, and weighed over 200 tons. Piledrivers pounded them into the ocean floor to form the corners of the seawall. Workers placed 48,000 four-pointed concrete blocks along the seawall's south and western edges where the sea was strongest. These strange-looking blocks are designed to dissipate the force of breaking waves. By June 1989, two and a half years after work began, the seawall was finished. Now, the airport builders had to find enough soil to fill it. On the mainland, crews worked round the clock excavating three entire mountains. Huge barges transported the excavated soil to the airport site. For three years, a fleet of 80 ships dumped earth inside the seawall until it rose over 100 feet above the ocean floor. Global positioning systems directed each barge through its onboard computers telling it exactly where to dump each load. The island fill combined three different sizes of coarse rock and gravel. Engineers hoped this mixture would resist liquefaction in an earthquake. Slowly, the airport island emerged from the sea, despite violent protests. The same leftist radicals who assaulted Narita Airport launched a mortar attack on one of the quarries supplying the island's fill. No one is hurt, but the exploding mortar rounds ignite a forest fire which rages for hours. It is only one of more than two dozen attacks on the airport project during construction. Planting bombs, firing rockets, and setting fires, the radicals destroyed equipment and injured four people. But work never faltered. While some workers built the island, other crews were busy linking it to land. In the fall of 1987, giant floating cranes brought the first pre-assembled bridge pier to Osaka Bay, anchoring it on pilings driven into the seabed. By the spring of 1989, 29 of these piers stood in line between the airport island and the mainland. The gigantic cranes returned with enormous steel modules, each over 500 feet long and weighing over 4,000 tons. Bolted together, they formed a double-decked truss bridge over two miles long, one-third longer than the Golden Gate Bridge, with a price tag of over a billion dollars. Its upper deck was a highway, its lower deck a railroad track. Flexible joints connected its spans, so the giant bridge would bend, not break, in a typhoon's deadly winds. By March 1990, the bridge was built, and the airport island was nearly complete. This man-made island was created by the effort, sweat, blood, and tears of over 10,000 people who worked very hard. But the island builders' celebration was a muted one. By then, they had discovered a new and relentless threat, an enemy so powerful it could defeat them. Spring 1990, Kansai Airport's man-made island is nearly finished. Construction firms prepare for the monumental task of building the passenger terminal. But in March, engineers make an alarming discovery, which threatens to destroy the project. Kansai Airport is sinking into the sea. Airport officials had expected the island to settle some 19 feet into the soft seabed. But by March 1990, it had sunk 27 feet and was still sinking over two inches every month. No one knew when, or if, the sinking would stop. No one knows exactly what to do, because it's quite different from our past experience. This big size and very heavy load, these two factors combined give rise to the effect of waking up the sleeping lions. The revelation stunned Osaka and the nation. The international press dubbed Kansai Japan's sinking airport. Some compared it to history's most notorious engineering blunder, the Leaning Tower of Pisa. After 20 years of planning, three years of construction, and billions of dollars, it appeared that Kansai Airport might never be built. What had seemed genius now appeared to be merely hubris. As public outrage grew, the president of Kansai Airport resigned. Engineers scrambled to find a solution, if there was one. We cannot stop the compression of this type of soil, because we can cope with the soil with various new techniques, down to 50 or 60 meters depth. But now the soil in question is 200 meters deep, so we cannot apply any sort of artificial techniques. To keep the airport above sea level, workers piled an extra 11 and a half feet of soil atop the island, at a cost of $150 million. They dropped a 20-ton weight 100 feet onto the runway to compact its soil. They decided to pave the runway with asphalt, because asphalt would absorb earth movements better than concrete. Yet their greatest problem remained unsolved. It was time to construct Kansai International's passenger terminal. But how could they build it on a sinking island? While engineers debated, the terminal's architects perfected its design. Noriaki Okabe had spent 25 years in Europe, working with world-renowned Italian architect Renzo Piano. Together, they had created some of the world's most remarkable buildings, including the famed Pompidou Center in Paris. But at Kansai, they faced the challenge of their careers. The Kansai terminal had to be small enough to fit on a man-made island, yet big enough to house all the complex functions of a modern international airport. High enough to inspire passengers with its beauty, yet low enough to allow air traffic controllers an unrestricted view of every airplane on the tarmac. It seemed an architectural paradox. Architects usually get stimulated by looking at the site before the work starts. This project was unique because there was no site yet. There was no ground. Seeking new sources of inspiration, the architects turned to the structures of nature. Nature's geometries solved their most difficult problem. How to make the terminal both high and low? Answer? The toroid. The remarkably versatile shape of magnetic fields, convection currents, bicycle tires, donuts, and fruits. In its architects' eyes, the enormous Kansai terminal is only the small, visible portion of an immense toroid over 20 miles in diameter, circling through the earth. The toroid shape allows the building's center to soar 85 feet high, while its wings taper to 20 feet, inspiring visitors, giving the control tower a clear view of aircraft and making architectural history. It is the most pervasive form in the natural world, the toroid. And so far as I know, this was the first time it had been used, certainly the first time it had been used in a big structure. Since Kansai was designed, the toroid has become a very fashionable form, particularly architects working with British engineers who have mastered how to use this form. But it was innovatory at its time. The toroid solved the problem of designing the passenger terminal. But still unsolved was the biggest problem of all, how to construct one of the world's biggest buildings on an island sinking into the sea. By the spring of 1990, an international team of architects and engineers had created a cutting-edge design for Kansai Airport's passenger terminal. The blueprints were ready, but the terminal could not be built until the builders solved a puzzling problem. The completed terminal would weigh only half as much as the vast amount of earth excavated for its foundation from an island that was sinking into the sea. The lighter terminal would not sink as fast as the heavier island. As island and terminal pulled apart, the massive structure was certain to crack. The problem is not that the building is sinking into the ground, but that the ground is sinking faster than the building. People don't realize, but the building actually floats in the earth. That's one of the reasons they have to have basements. They're like ships. And that's particularly true of New Earth. So Kansai Airport has a ballast of a quarter of a million tons of very dense iron ore in it. As they prepared to build the terminal, engineers lined its foundation with an eight-foot thick layer of crushed iron ore, hoping the extra weight would help the terminal sink as fast as the island. On April 24, 1991, terminal construction began. It would take nearly three years to complete. Following the architects' blueprints, workers erect some 30 steel trusses to support the roof. Each of these massive trusses weighs over 200 tons. Workers assemble the terminal's skeleton of 250 ribs, each forged in England and carried by ship to Japan. They install nearly 5,000 panels of glass on its sweeping front, carefully encasing each panel in a rubber frame so it will move, not break, if an earthquake or a typhoon sways the building. They cover the roof with 90,000 stainless steel tiles, tested to withstand fierce typhoon winds and violent seismic shaking. With painstaking effort, workers lay each of these tiles individually by hand. High ocean winds make their task even more difficult, and sometimes impossible. By 1993, the terminal's enormous shape rose above the airport island. Over a million architects, engineers and workers around the world had contributed to its construction. Today, Noriaki Okabe wanders with pride through a superstructure, widely proclaimed as one of the most brilliantly designed airport terminals in the world. It's a very big building, Kansai. It's possibly the longest building in history that is not a factory, but one huge room occupied by people. But what's very striking is the very intimate relationship it sets up between you, the person moving through, and the building that is making way for you, leading you through, guiding you through. This is a very extraordinary sense, to get in what's a highly technological, enormous building. I think that's one of its most extraordinary achievements. Arriving by car, rail or hydrofoil, passengers enter what the architects call the canyon, a vast open space 100 feet high and nearly 1,000 feet long. Four cavernous stories linked by humming escalators and whirring elevators, designed to impress, but also to inform. The reason why this space is so huge is so that people can see where they are going. Any spaces in this structure can be seen from wherever you are. As they move beyond the canyon, passengers don't have to navigate a sprawling multi-terminal complex as in many other airports. Domestic and international arrivals and departures are vertically stacked on the four floors of the terminal building. Passengers travel up and down a central set of escalators, which carries them to arriving and departing domestic and international flights. Finally, they emerge into the terminal's spectacular departures area, a kind of aviation cathedral stretching over a mile long, making Kansai Terminal the longest building in the world. Automated trains whisk passengers to its 41 aircraft gates. Travel time from the central terminal to the end of each wing is only 90 seconds. An ingenious system solves a baffling problem. How do you air condition the world's longest building? If you blow a big air jet into a very large space, it travels so far. Now what we did on Kansai, which I think is quite innovative, was to create a shape of ceiling which was similar to an air jet shape, and to stick the jet to the ceiling. If you make a jet of air stick to the ceiling, then it travels up to twice as far as it would if it was in free space, and it will cause a much bigger circulation current. Gigantic yet graceful, 18 nozzles send air flowing along the ceiling into sheets of smooth fabric which keep it circulating. Colorful mobiles reveal the moving air. It's the first time it had been done at such a big scale, and it's the first time in which the shape of the roof and structure was exactly shaped to the decelerating air jet. It's a building that is most in step with what is happening in the sciences and must herald the future. But when it was finished, Kansai Terminal's future remained in doubt as the island beneath it continued to sink. Even with its iron ore ballast, the terminal would almost certainly crack as the heavier island beneath it sank. Engineers devised a surprisingly simple solution. In the basement, 900 concrete columns support the building's massive weight, but that's not all they do. As the terminal sinks, sensors on the columns alert computers in the central control room. Technicians scan the computer screens looking for trouble spots. This screen shows the current subsidence of the terminal building. The areas in red have less subsidence, and those in blue have more. When the computers warn that the sinking island threatens to crack the terminal, workers raise or lower the columns in the endangered area to keep it level with the ground. They use powerful hydraulic jacks which can move columns up to 15 inches if necessary. Workers slide iron plates under the jacked-up pillars to hold them up after the jacks have been removed. It's no different than sliding a matchbook under the leg of a wobbly coffee table. But Kansai Terminal has 900 legs and weighs nearly 3 million tons. It's a solution which, as I understand it, has been used before in Japan, and it might seem a bit primitive, but I have no reason to suspect that it's anything but perfect for the problem. In fact, everything in the Kansai Terminal's basement is designed to move up and down. Air conditioning and other systems are bolted to the ceiling instead of the floor. Doorways feature several inches of extra room overhead. In their zeal to save the Kansai Terminal, engineers tried to think of everything. This terminal building is being adjusted at all times. I'm on the stairs which connect the first floor and the basement. The step where I'm standing right now was the height of the floor when the airport opened. In the last four years, we jacked it up three times, and as a result, we added two more steps here. Measures like these helped the airport cope with its sinking island, but they also delayed its completion by over a year. On September 4, 1994, Kansai International Airport finally opened for business. The emperor's son, Crown Prince Naruhito, and his wife, Princess Misako, attended the opening ceremonies. 11,000 police stood guard in case radicals attacked. As they celebrated, the airport's proud builders could not know that nature's fury would soon assault their masterpiece. January 17, 1995. Kansai International Airport has been open 15 months. As this day begins, it will be severely tested. 5.46 a.m. on January 17, a devastating 7.2 earthquake rocks the Kansai region. The massive temblor is the deadliest quake to strike Japan since the Great Tokyo earthquake of 1923. I was still in bed because it was quite early in the morning. It was a very huge, up-thrusting movement. Dishes jumped out of the cupboard in my house. I had never experienced an earthquake that big before. The hardest hit is the city of Kobe. The city's wharf rises 10 feet. Cranes topple, and a harbor breakwater sinks. Rail lines and major highways buckle. The quake kills more than 5,000 people and injures over 25,000. More than 300,000 people lose their homes. Kansai International Airport is only 18 miles from the epicenter. When the earthquake hit, the first thing I thought about was my family. Then I thought about the Kansai Airport. Maybe the glass has broken. Fearing the worst, officials rush to the airport. Outside the terminal, they find a cracked sidewalk and few other signs of damage. I raced to the airport in my car and arrived before 7 o'clock. When I rushed into this control room, all the machines were operating properly. The airport had survived one of nature's deadliest assaults, or had it? With so much devastation nearby, it seemed too good to be true. When I came to Kansai Airport, we could see Kobe was burning. Although you couldn't see anything wrong, I had great anxiety about the airport's invisible parts. The inspections confirmed that the airport's anti-earthquake measures had worked. Engineers had used a mixture of large rocks to build the airport island. When the earthquake hit, this coarser landfill absorbed the shaking. Had the fill rocks been smaller, the island's soil might have liquefied. Airport buildings would have collapsed, as so many other structures did. Instead, the delicate-looking passenger terminal proved as tough as its architects had hoped, thanks to its ingenious design. For example, at this bridge, that side of the building is fixed, and this side has a sliding system to absorb the shock. At the time of the Kobe earthquake, this point moved almost four inches. Even the terminal's massive glass walls were intact. It was important not to transmit the movement of the roof in an earthquake to the glass wall below. We designed a system which absorbed all movements between the two structures by using sliding or rotating joints. During the Kobe earthquake, this system worked so well that not a single pane of glass was broken. Kansai International remained open throughout the crisis, serving as a staging area for arriving rescue teams and supplies. The building was, in fact, the building closest to the epicenter of the earthquake that destroyed Kobe. That doesn't mean to say it was hardest hit, because the buildings in Kobe were equally hit hard. But because it had been designed to cope with all these things, it rode it out without any damage at all. Surviving the Kobe quake was a triumph for Kansai's beleaguered engineers. The airport had passed a significant test of its engineering and design. Three years later, it would face another, as nature struck again. September 22, 1998, a powerful typhoon slams into the Japanese coast, killing 10 people and injuring more than 200. Winds clocked at 130 miles per hour roar across Osaka Bay, whipping up dangerous waves and slashing rains. By noon, the storm's full fury reaches Kansai Airport. The typhoon had increased speed to the point of where we were arriving at the same time, and we did have quite strong winds. But the difficult part was that people who tried to park us on the ground, keep them from getting blown away, literally. Right after we landed, in fact, the airport authority closed the airport because of the difficulty on the causeway between the mainland and the island. It became unusable for vehicular traffic. When we were crossing the causeway going to the mainland, there was a motorcycle who went down, and there was a couple of accidents that we had seen. So it was smart of them to discontinue. By evening, the typhoon had passed, and Kansai Airport resumed normal operations. The terminal's roof had suffered minor damage, but airport officials felt lucky. The typhoon might have threatened the sinking island, now standing only 17 feet above sea level. Kansai's ingenious jacking system keeps the terminal building level, but it cannot stop the island from sinking. Every year, the airport sinks a foot deeper into the sea. Scientists debate how much farther the island will sink, but some believe that if it keeps sinking, a typhoon's waves will someday swamp the airport. The next countermeasure is how to prevent the invasion of water. We are going to start with this sort of countermeasure maybe five or ten years' time from now. If the top elevation of the man-made island goes down beyond some special value, in high tide time or typhoon time, it's quite easy for seawater to flush inside the island. That's our greatest concern at the moment. Airplane cannot land in the pond, so runway must be dry all the time. To keep out storms, engineers must build a higher seawall around the airport. But this is not the only challenge they must meet. If Kansai Airport is to survive economically, it must expand. Since it opened in 1994, its volume of international flights has nearly doubled. Its single runway can handle 160,000 takeoffs and landings a year. By the year 2007, it will reach that number. Without a second runway, Kansai will choke on its own traffic. The airport plans to build a second runway and terminal on a parallel island connected to the original airport. But this island must be built in water even deeper than the first. The seabed is even softer. Scientists believe the second island could sink even farther than the first. At the new site, we have to construct the island on a bad, soft foundation. Since it is impossible to do away with subsidence, we are thinking of constructing a second terminal building between the old and the new islands, which will float on the sea like a ship. Then we won't have to worry about it settling at all. But sinking isn't the only obstacle to expanding Kansai International. Battling the sinking problem drove the airport's price tag to $15 billion, 40% over budget. Interest alone on the airport's debt is $560 million a year. Building a second runway will cost an estimated $14 billion more. Even if it never slides beneath the waves, Kansai International may sink beneath the crushing burden of its debt. And yet the second runway must be built. The airport's future, and perhaps the lives of its passengers, depend on it. If you're going to be a major hub airport, you're going to really have to have two runways. Because what happens if something goes wrong? What happens if you have an airplane that blows a tire, and you're really a hub? A hub brings in a lot of airplanes at one time. When you're considering the number of tires on each 747, if you blow one tire, as far as the airplane is concerned, you'd never even know it until you cleared the runway. However, the carcass is on the runway, and you certainly wouldn't want an aircraft following you to encounter that. It could be a major disaster, both landing gear and or engine-wise. So they'd have to sweep the runway. And that takes time. And when you have, you know, 10 airplanes or 12 airplanes waiting for arrival, it gets to be a very ticklish affair. So a second runway is very, very important. Though surrounded by water, Kansai International Airport finds itself between a rock and a hard place. Hong Kong and Singapore now have new state-of-the-art airports. Tokyo's Narita is building a second runway. To hold its own in the highly competitive world of Asian aviation, Kansai must expand. Engineers need the second island as much as airport officials do. They want to build higher sea walls to keep typhoons from someday swamping the first island. To build those walls, they must temporarily close the original runway. Yet the immense cost of saving the airport, added to its already huge debt burden, may cripple its future. Kansai International Airport may never fulfill its builders' dream of becoming one of Asia's leading aviation hubs. But somehow, it's not Kansai's troubles most people remember. It's Kansai's achievement. Its landmark design has won the praise of critics the world over, and earned the approval of the thousands of awestruck travelers who pass through it each year. I think it will be some time before what has been achieved there will be fully understood. The lessons will be learned probably in the 21st century more than in the next few years from Kansai. People will understand more deeply what's been achieved there. I believe that the legacy that people are going to remember about the airport is that they built something that was never heard of before for an airport, and that even though they had problems, they found very good solutions to make it work, and in fact became an engineering marvel in several aspects. Number one, that they were able to fill it, and then when it didn't settle at the rate that somebody had calculated, that they were able to solve that problem and continue to operate. Whatever its future holds, Kansai International Airport will always be a monument to a bold vision. A vision that dared to accomplish something no one had ever tried before. A vision that literally moved mountains, created land in the midst of the sea, and graced Japan with one of the world's most beautiful airports.