Ceilidh

Michael Zey
futurist3000@aol.com

Give a kid a beach and he'll make a sandcastle; give a man a billion dollars and he'll build the world's tallest building. The urge to engineer big is elemental. "The same aspirations to celebrate and uplift the spirit that drove the Egyptians to build the pyramids are still driving us," says Henry Petroski, a professor of history and civil engineering at Duke University and the author of To Engineer Is Human. "The things we're doing differ only in magnitude."

But new technology always ups the magnitude ante. Italy plans to shatter the suspension-bridge record, held by Japan's Akashi Kaikyo Bridge, with a nearly 2-mile span. Taiwan finished the world's tallest building in 2003 -- and Dubai announced a scheme to surpass it by hundreds of feet.

Building higher and farther requires an enormous, conspicuous marshaling of resources. Extreme engineering projects -- real and speculative -- thus offer picture-window views into the collective aspirations of societies that would undertake them.

"Does Dubai really need the world's tallest building?" Petroski asks. "These things take great will, and you have to ask, Why are they being built?" One reason: Because they can be built by the nations that undertake them. Meanwhile, nations with a long history of superbuilding move on. The United States has skyscrapers and bridges galore. Now it's embarking on the world's most ambitious ecosystem restoration and the world's first long-term nuclear waste storage facility.

Of course, far more superprojects are dreamed of than built. Here, a look at big engineering schemes -- some under way, some in the dream stage.
Carl Hoffman is a frequent PopSci contributor based in Washington, D.C.
TRANS-ATLANTIC MAGLEV
What: Submerged OCEANIC tunnel and supersonic train
WHERE: New york - London
Cost: $88 billion - $175 billion
Crux: Neutrally buoyant vacuum tunnel submerged 150 to 300 feet beneath the Atlantic's surface and anchored to the seafloor, through which zips a magnetically levitated train at up to 4,000 mph.
The idea is as wondrous as it is audacious: Get on a train at New York City's Penn Station and hit Paris, London or Brussels just an hour later. "From an engineering point of view there are no serious stumbling blocks," says Ernst Frankel, retired professor of ocean engineering at MIT.
As envisioned by Frankel and Frank Davidson, a former MIT researcher and early member of the first formal English Channel Tunnel study group, sections of neutrally buoyant tunnel submerged 150 to 300 feet beneath the surface of the Atlantic, then anchored to the seafloor -- thereby avoiding the high pressures of the deep ocean. Then air would be pumped out, creating a vacuum, and alternating magnetic pulses would propel a magnetically levitated train capable of speeds up to 4,000 mph across the pond in an hour. As Frankel and Davidson say, it's doable. "We lay pipes and cables across the ocean every day," says Frankel. "The Norwegians recently investigated submerged, floating tunnels for crossing their deep fjords, and were only held back by the costs."
Ah, the costs: Estimates range from $25 million to $50 million per mile. Another hurdle: safety. But Davidson believes a test case might mitigate concerns. "Maybe a tunnel across Lake Ontario would show how it reacts to dynamic conditions and give us a better understanding of the costs," he muses. "A transatlantic tunnel will be done. We just have to be as interested in it as we are in getting to the Moon."
The Route: One proposed route for the transatlantic maglev train passes through northeastern Canada before barreling toward the British Isles and continental Europe, briefly kissing terra firma on Greenland and Iceland. Because aboveground sections would be cheaper to build than their underwater counterparts, such a route would be more economical than a direct shot through the Atlantic.
Magnetically Levitated Train: Propulsive magnets on the sides of the track rapidly switch their polarity to provide a steady push. For example, consider a fixed "north" magnet on the train. Since north magnets are attracted to south magnets, the track's magnets will rapidly switch polarity to ensure that there is always a south magnet directly in front of the north magnet on the train, pulling the train along even when it's moving at 4,000 mph.
Anchor Tether: To prevent drift from currents or storms, neutrally buoyant tunnel sections will be anchored 30 to 40 feet into the seafloor. Sections of the tunnel could be manufactured in drydock, then hauled to the site.
PALM AND THE WORLD ISLANDS
What: The largest man-made offshore islands
Where: dubai, united arab emirates
Cost: $3.5 billion
Crux: Two islands built in the shape of giant palm trees. The "trunks" are 5 miles long, each topped by 17 "fronds" up to 330 feet long. A third island group is shaped like a flat map of the globe. Materials: 4.2 billion cubic feet of dredged sand and 50 million tons of rock.

In 1975 there wasn't a single high-rise in the sleepy fishing village of Dubai. But, flush with oil riches and grand ambitions, the business capital of the United Arab Emirates is now sparing no expense to reinvent itself as a Middle Eastern Oz. Exhibit A: Two islands being built 3 miles offshore in the outline of giant recumbent palm trees. Each 5-mile-long trunk sprouts 17 fronds up to 330 feet long, on which a mind-boggling collection of villas, hotels, marinas and shopping complexes will be built. Everything is to be connected by high-speed monorail.
The first island was completed in late '03 after two years of work. Engineers mapped the island's shape via GPS surveys accurate to 2 centimeters. Seven dredgers, 20 miles out to sea, each filled a 5,200-to-22,000-cubic-yard hopper every hour. The hoppers in turn deposited more than 2 billion cubic feet of sand in the appointed areas. "We had to start before there was any protection from the breakwater," says Mark Lindo, engineering manager for the Dutch marine contracting firm Van Oord ACZ, "so we built it 13 feet below sea level." When 9 million tons of rock in 5-ton chunks finally sheltered the palm, Lindo raised it to its final height of 13 feet above sea level.
Even as Lindo begins Palm Island No. 2, he's about to start an even bigger project, an archipelago of 250 islands, called the World, laid out to mimic Earth's land masses. It will be 5 miles across and require 200 million cubic feet of sand, and 30 million tons of rock. "It's enormous," says Lindo. "In Europe or America it would take 10 years of planning and studies to do something like this. But in Dubai it's the other way around. We just do it as we go."
SPACE ELEVATOR
What: An "elevator" that carries heavy loads into space
Where: equatorial pacific ocean
Cost: $10 billion
Crux: A 62,000-mile cable -- one end "anchored" in space and the other attached to a platform in the Pacific -- that acts as a rail for laser-powered lifters carrying up to 5 tons.

Thirty-four years after the first human step on the Moon, cheap and reliable access to orbital space remains a seemingly distant dream. When it's flying, the shuttle costs $500 million per trip; lofting unmanned payloads still costs at least $12,000 a pound. Science fiction writers have long touted an elevator into the heavens, but pesky physics has always gotten in the way; there's simply no material that's light and strong enough to stretch to orbital heights without collapsing under its own weight.

Physicist Brad Edwards was researching at the Los Alamos National Laboratory in the late '90s when he overheard a colleague say that such an elevator couldn't be built for 300 years. Edwards, though, was familiar with carbon nanotubes -- nanoscale carbon structures 60 times stronger than steel. He did some calculations and hasn't yet found a reason why a space elevator can't be built. Last year Edwards became director of research at the Institute for Scientific Research in Fairmont, West Virginia, and received $500,000 from NASA's Institute for Advanced Concepts to flesh out a plan.

Edwards's design: Rockets blast off to 22,000 miles, launching an "anchor" satellite that uncoils a ribbon made from carbon-nanotube composite fiber as it ascends to 62,000 miles. The ribbon flutters to the ground, where technicians attach it to a platform floating at the equator. The centripetal forces at the space end keep the ribbon taut and maintain it in a geosynchronous orbit. Electric elevators powered by ground-based lasers and carrying as much as 5 tons in payload would climb up and down.

The biggest challenge: The longest nanotube ever created is just microns in length. But by combining nanotubes with an epoxy resin and then extruding the mixture like monofilament fishing line, "you can already make strands as long as you want," Edwards asserts. Two other great obstacles remain: maintaining the elevator despite hurricanes, meteorites and corrosive atomic oxygen, and building the laser system. "It's a big engineering challenge," Edwards says. "There will be difficulties. But there's absolutely no physics reason why it can't be done."


SPACE ELEVATOR (Illustration, left)

Most of a rocket's fuel is spent blasting through Earth's thick atmosphere and out of the planet?s strong gravitational field. But here's an alternate strategy for getting payloads up to space: Construct a 62,000-mile-long cable jutting straight out from the equator, hold it in place with centripetal force, then lift satellites and spacecraft out of the atmosphere with a giant freight elevator. One major hang-up: Cable strong enough to support the system does not yet exist, though it could be made from carbon nanotubes.

The Space Anchor
Launched to a geosynchronous orbit, the 45-ton anchor deploys its carbon-fiber-filament payload to Earth's surface. Engineers attach the filament to a base station floating west of the Galapagos Islands. The anchor keeps itself in place using fuel stored in its 8-foot- diameter propellant tanks.

The Climber
Once the filament is in place, it must be strengthened. More than 200 "climbers" will add layers of carbon-nanotube fiber to the tether, until it widens into a 3-foot-diameter cable. An infrared laser fired from Earth will beam energy to the climbers.

The ISS
By comparison, the International Space Station orbits a measly 250 miles above Earth's surface.





THIRD DELTA CHANNEL
What: A huge man-made canal that counteracts coastal erosion

Where: Louisiana coast
Cost: $2 billion - $3 billion
Crux: A 1,000-foot-wide, 60-foot-deep channel off the Mississippi River capable of carrying 200,000 cubic feet of water per second over 100 miles.

What years of engineering efforts have destroyed, engineers will now endeavor to repair. For eons the great muddy Mississippi River deposited sediment at its delta, replenishing any eroded areas and creating a rich incubator of barrier islands and bayous that nourished shrimp and shellfish and protected the low-lying coast from hurricanes and flooding. But oil and natural-gas industries dug channels throughout the delta to lay pipe, and the Army Corps of Engineers built levees along vast stretches of the river to control its water levels. The channels caused swifter-than-natural erosion, and the levees limited any chance of recovery by diverting much of the river's silt to a single outlet. Today millions of tons of sediment simply vanish off the continental shelf deep in the Gulf of Mexico, and, no longer nourished, Louisiana's famed bayous are disappearing faster than any other ecosystem on Earth.

The proposed fix is, ironically, another ditch: the Third Delta Conveyance Channel, a 30-to-40-foot-deep, 350-foot-wide, 100-mile-long channel off the Mississippi that will transport 20,000 cubic feet of water per second into the Gulf. Over 20 to 60 years, the channel is supposed to erode until it's 1,000 feet wide, 50 to 60 feet deep, and flowing at 200,000 cubic feet per second, delivering enough sediment to rebuild the marshes around Louisiana's barrier islands. "Most diversions drop sediment along their route rather than carry it to where it needs to go," says Bob Roberts, Louisiana State Department of Natural Resources manager for the project. "That's why we need such a big, high-velocity channel. Will this thing erode like we want it to, and then can we control it? We still don't know."


BURJ DUBAI
What: The world's tallest building
Where: dubai, united arab emirates
Cost: $1 Billion - $2 billion
Crux: A 2,000-foot-high building capable of withstanding 120-mph winds.

What good are islands in the shape of palm trees and maps of the world if you can't see their outline from high above? Dubai so yearns for tallest-building bragging rights that the Burj Dubai's developers are attempting to thwart any potential competitors by keeping secret its exact height and number of stories (as well as a precise estimate of its price). Suffice it to say, the Burj will be "comfortably higher than anything out there or on the drawing boards," says William F. Baker, a partner at Skidmore, Owings & Merrill and the Burj's lead structural engineer.
Early designs placed the massive residential and hotel tower well above 2,000 feet. At that height, "vortex shedding" -- eddies of wind, like the wake behind a boat -- develops at a building's top stories. As air whips around the tower at speeds reaching 120 mph, low-pressure zones occur on one side, then the other, setting up vibrations, known as resonant frequencies, that can literally shake the structure to death -- which is what happened to Washington State's infamous Tacoma Narrows bridge in 1940, when high winds snapped a cable and sent the third longest suspension bridge in the world crashing into Puget Sound. Older skyscrapers like the Empire State Building are immune because they are built out of heavy steel. But to erect a tower more than twice as high requires a construction with even greater damping qualities. The Burj will be made of poured concrete that contains blast furnace slag and microsilicates -- a material that's almost as strong as cast iron, yet more resistant to damage due to vibrations because the natural cracking in concrete dissipates the energy.

The taller a building is, though, the more it flexes, increasing its likelihood of flexing to its breaking point. Abetted by extensive computer and wind-tunnel testing, SOM designed a building with numerous setbacks and wings to scatter the wind. "The wind sees 18 different sections," says Baker, "each with a different vortex-shedding frequency. If we didn't do that, the building would just fall down sideways."

Keeping the building standing is only the first of a complex series of problems in a tower so high. The Burj's relatively small footprint requires a single 11,000-voltage power line routed through a series of transformers throughout the building; Dubai's burning sunlight necessitates coating the windows with special glazing; water pressure must be enhanced with a series of zoned pumping stations; and, to minimize commuting time, the elevators will zoom at 3,600 feet per minute. Going up, that is. "Coming down has to be a lot slower," says Raymond J. Clark, SOM's partner in charge of mechanical and electrical engineering, "or else you'd blow out people's ears."

STRAIT OF MESSINA BRIDGE
What: The world's longest suspension bridge
Where: connecting sicily to mainland italy
Cost: $5 billion
Crux: A single 2-mile-long span. The 10-lane bridge would be capable of flexing 30 feet during earthquakes of up to 7.1 on the Richter scale.

During the Punic Wars, Roman consul Gaius Cecilio Metello wanted to march elephants into Sicily across a wooden bridge; in 1870 a 2-mile tunnel was proposed to link the island with the mainland; and in 1971 a fixed link was declared a "prevailing national interest." But the area's 100 active seismic faults -- including four directly through the Strait of Messina itself -- and powerful winds and ocean currents have long been formidable engineering obstacles.

Italian prime minister Silvio Berlusconi pledged in June 2002 to build the bridge at last, but its construction remains a huge undertaking. Advances in computer modeling mean structures can be designed lighter and stronger, making possible a single 2-mile-long, 10-lane span suspended from 4-foot-diameter cables hanging from 1,000-foot towers built on the mainland and the island. The span would beat the current world-record holder, Japan's Akashi Kaikyo suspension bridge, by 66 percent. The land-based towers eliminate the problem of building support bases in the turbulent water; a suspension bridge allows the span to flex up to 30 feet during earthquakes. But the wind remains treacherous to the bridge and to large trucks and trains crossing it, says Khaled Mahmoud, director of long-span bridges at Hardesty & Hanover, a New York engineering firm that first began sketching Messina designs in 1969. Using computer and wind-tunnel models, engineers have designed steel box bridge sections that will act like giant aircraft wings to deflect the wind, mitigating the same vortex shedding that bedevils tall buildings. The bridge project remains stalled, however; the Italian government can't manage the enormous expense on its own, and private investors fret there won't be enough traffic to recoup their outlay.

NUCLEAR WASTE REPOSITORY
What: A 10,000-year storage facility for radioactive nuclear waste
Where: yucca mountain, nevada
Cost: $58 billion
Crux: Approximately 60 miles of access and emplacement tunnels to house stainless-steel waste casks. A robotic transport system of gantries, cranes and railcars.

It's an engineering challenge that dwarfs all others: disposing of 70,000 metric tons of highly radioactive nuclear waste for 10 millennia. Already, some 43,000 metric tons of this dangerous waste are in temporary storage, and America's 103 operating nuclear powerplants are generating another 3,000 metric tons a year. And the 10,000-year figure, daunting as it sounds, is conservative; the half-life of plutonium is 24,000 years, which means it'll actually take 240,000 years before you can hold a chunk in your hand without being poisoned by radiation.

More than two decades ago, U.S. scientists found what seemed the perfect place for the stuff: Yucca Mountain, a dry, remote and geologically stable desertscape 100 miles northwest of Las Vegas, conveniently owned by the federal government. But in the ensuing years, scientists and engineers have dug and prodded and modeled every piece of the mountain's geology and hydrology, spending some $5 billion, and the puzzle only grows more complex (and political opposition more heated). One important discovery: There could be more water than originally thought in the mountain, which could corrode the waste containers and allow waste to reach the water table. That makes engineered barriers almost as important as the natural mountain bulwark itself.

If the Nuclear Regulatory Commission licenses Yucca Mountain in 2009, the first stage of a 300-year project will commence in 2010: the boring of 60 miles of access and emplacement tunnels 250 feet apart and up to 25 feet in diameter, 1,000 feet underground. When waste arrives by truck or train, it will be placed in 19-foot-long, 7-foot-wide stainless-steel casks, then coated with a corrosion-resistant high-nickel alloy called C22. But even thus encoffined, the 80-ton "waste packages" will be highly radioactive and around 180�F. Which means a robotic system of gantries, cranes and railcars will transport the packages down the tunnels to their final resting place (where, by law, they must be retrievable for 50 years should something go awry). When a tunnel is full, it will be monitored for 300 years, then sealed forever.

 

 
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