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March 27, 2007
To the Edge and Back: Grand Canyon Engineering
The Grand Canyon's much-hyped Skywalk is touted as a million-pound engineering marvel. In March, the U-shaped and glass-bottomed walkway that rests more than 4,000 feet above the canyon floor was inaugurated and opened to the general public.
For $25 plus other fees, you can step off the edge of the Grand Canyon and look down to the canyon floor 4,000 feet below, a vantage point more than twice as high as some of the world's tallest buildings.
The Skywalk is the first-ever cantilever-shaped glass walkway to suspend more than 1,220 meters (4,000 feet) above the canyon's floor and extend 21 meters (70 feet) from the canyon's rim. Steel-nerved visitors can look down through the horseshoe-shaped glass walkway's clear glass to view the spectacular scenery below: the Colorado River Valley. This is Grand Canyon West, 90 miles downstream from Grand Canyon National Park, on land owned by the Hualapai Indian tribe.
Image source: Grand Canyon West
Construction crews spent two years building the walkway. Mark Johnson, of Las Vegas-based MRJ Architects, has been working on the Skywalk for about three years, beginning with a lengthy design phase. He and a team of tribal consultants, engineers and geologists moved through several design concepts before settling on a U-shaped walkway. The walkway was structurally engineered by Lochsa Engineering, LLC.
At 1.07 million pounds, the anecdote offered by many is that the Skywalk is "about as heavy as four Boeing 757 jets stacked atop one another." According to Grand Canyon West, the skywalk is able to hold the weight of 71 fully loaded Boeing 747 airplanes and contains more than one million pounds of steel.
Earlier this month, the Skywalk was perched at the canyon's edge using four tractor-trailers and an elaborate system of pulleys. Underneath, hydraulic "shoes" lifted the Skywalk above a concrete track, rolled it across a bed of metal rods, and set it onto four steel anchors that were drilled 12 meters (40 feet) into the canyon's limestone rim. Once in place, workers welded the walkway to the anchors. (While it was pushed out, the walkway was not anchored to the canyon wall. To keep it from tipping over the side, engineers loaded the back end with a half-million pounds of steel cubes as counterweight, according to The Associated Press.)
The Skywalk is able to hold 70 tons of weight, allowing for 800 people weighing 175 lbs. each to stand on the bridge, though no more than 120 people will be allowed on it at any given time. According to Johnson, the Skywalk can withstand winds of up to 100 mph. The observation deck has been embedded with shock absorbers "to keep it from bouncing like a diving board as people walk on it."
Its walls and floor are built from glass four inches (10.2 cm) thick.
According to The Arizona Republic, "the glass used in the new Grand Canyon Skywalk has a connection to French kings and the Palace of Versailles."
Saint-Gobain, a three-centuries-old Paris firm that apparently supplied the glass in 1682 for the palace's famed Hall of Mirrors, manufactured the durable, ultra-clear glass for the floor of the Skywalk bridge. The low-iron Diamant glass was manufactured at a plant in Cologne, Germany, and was then processed into laminated glass. The deck, approximately 10 feet wide and 70 feet deep, is made of laminated tempered glass more than two inches thick, produced in 46 pieces, each of which is held in place by connectors specifically designed by Saint-Gobain for the bridge. The floor glass includes structural interlayers of DuPont SentryGlas Plus "for optical clarity and strength."
The tempered, laminated Skywalk glass contains less iron oxide than regular glass, increasing clarity. It is capable of withstanding a magnitude 8.0 earthquake and heavy winds. All visitors will be provided with shoe covers to protect them from slipping and to prevent scratching of the glass floor.
The Hualapai (pronounced WALL'-uh-pie), an impoverished tribe of 1,500-2,200 members who live near the rim about 90 miles west of the national park, allowed a Las Vegas developer to build the $30 million Skywalk in hopes of creating a unique attraction on their side of the canyon. Tribal leaders are betting that people will flock there, braving the rugged terrain of twisty, unpaved roads to walk its transparent surface. The Skywalk, they hope, will become the centerpiece of a budding tourism industry.
The Skywalk is scheduled to open to the public tomorrow (March 28), yet it has already become the center of controversy both on and off the reservation. Many Hualapai worry about disturbing nearby burial sites, and environmentalists have blamed the tribe for transforming the majesty of the canyon into a tourist trap. Hualapai leaders say they weighed those concerns for years before agreeing to build the Skywalk. With a third of the tribe's members living under the poverty line, the tribal government realized it needed the money.
Moreover, while the Skywalk is being touted as an engineering marvel, yet there are many who are skeptical that the tourist contraption will stand the test of time.
Delores Honta, a Hualapai tribal member, believes the walkway's lifespan is only 15 to 20 years. "Our ground is very dry. It will not stay together. You're drilling holes and letting hot and cold air into it," she told National Geographic News.
In the same article, MRJ Architects' Johnson said the rock wall, not the walkway's design, is the wild card that could determine the Skywalk's life span: at that height, the wall is made of 350-million-year-old limestone — porous material that is highly prone to erosion.
Millions of years of erosion, of course, is what has created much of the unspoiled beauty of the Grand Canyon.
What do you think: engineering marvel or tourist-trap eyesore?
Earlier: A Bit on the Bark-at-the-Moon Side of Mental (5th item down)
Resources
Tribe Puts Bridge on Grand Canyon's Edge
by Chris Kahn
The Associated Press, March 25, 2007
First steps on skywalk over Grand Canyon
The Associated Press (via CNN), March 20, 2007
Skywalk's glass made for clarity, durability
by Russ Wiles
The Arizona Republic, March 21, 2007
Grand Canyon's Glass Walkway to Open Next March
Anne Minard
National Geographic News, Dec. 15, 2006
Astronaut's aerial stroll launches Grand Canyon Skywalk
Reuters (via CNet), March 21, 2007
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15 CommentsEngineering marvel -- not really.
Cool factor -- very cool!!
Would I drive out to it and pay $25 to experience -- You bet my next vacation to the Grand Canyon will include this. I just might make the Grand Canyon my next vacation.
March 27, 2007 3:34 PMI would not go to the Grand Canyon just to walk out on the Skyway. It would not enhance the marvelous view just to be able to look down.
March 27, 2007 4:03 PMOf course it's an engineering marvel. Where else on the entire Earth can you look 4000 ft straight down between your feet? My next trip to AZ will include the Skywalk for sure!
March 27, 2007 4:23 PMI believe it's obvious that the Skywalk helps to de-spoil the natural beauty of the area.
A fraction of the creativity that went into the design could have figured out a better way to help the indigent tribe.
But hey, at least the developer got well. And ain't that the way it always works.
Prediction: no one involved in this will be around to clean up the mess when the Skywalk, in time, takes its 4000-foot dive.
There is No shame anymore.
March 27, 2007 5:15 PMLets review. The Hualapai tribe needs funds to get beyond the poverty line and give its people better lives. The site is off the main tourist site, so most visitors will pre-qualify themselves as being somewhat "environmentally sensitive" as they journey to the site. Less environmentally sensitive will turn back or become environmentally sensitive by need.
Hualapai worried about disturbing nearby burial sites raise a valid concern that is best addressed by protecting and honoring the burial site, letting visitors know how they've respected the site for generations. Establish protection zones and setback zones to keep it sacred. Proper kiosk presentations combining Hualapai history and tourist education focused on reverence will preserve ancestral honor. Ancestors that've fought hard to protect their heritage will be given great respect. This is a win-win situation if handled properly.
Yes -- the technology has a life cycle, as all technology does. If properly handled throughout its life cycle, the project will leave less of a negative impression than most other enterprises the tribe could embark on to raise its quality of living. As Hualapai utilize the funds correctly that accrue from tourism, (both real and virtual tours) and create eco-educational materials, they'll have a highly unique tourism/teaching tool and great security for future generations. They would be wise to establish a series of visitor "noise decompression" zones that would keep traffic back (except allowing for ADA needs) and give visitors to the site an aural spectacle as well as visual.
March 27, 2007 6:24 PMIt is refreshing that this Indian group did not go into the Casino industry as so many others have. Not only do they have a one-of-a-kind marvel, but they can build around that tourist attraction and have more control as to what other attractions are linked to it. My hat is off to them for their innovation and foresight.
I would definitely want to see this in person if I ever get back to that area.
March 28, 2007 2:49 PM.....Wretched excess....
March 30, 2007 12:18 AMMarvelous piece of engineering and foresight on behalf of the band. In your height comparison you neglected to include the CN Tower in Toronto, Ontario Canada. The worlds tallest freestanding building at 1,815ft.
April 19, 2007 2:21 PMWhile reading the article, I was wondering if the Canyon rock would hold the Skywalk in place. I hope no catastrophe happens one day in the future. The engineering of the structure, wow! The consideration of the canyon rock, questionable.
I felt it appeared to be an eye sore surrounded by the natural beauty, yet cool to be able to walk out there at the same time.
I actually seen this on TV last month. The statement of $25 plus other fees you talk about must be the additional $50 to get onto the Hualapai reservation. How many people would change their minds about going out of the way to walk on it now that it just tripled in price?
April 21, 2007 6:54 AMNo one complains about the environmental impact of the pyramids, the Coliseum in Rome, or the Parthenon in Athens. Is this really any worse? At least it will benefit the native tribes. Will I see it? Of course. It will be something new to show visitors who come to see me here in Arizona. Believe me, Arizona has plenty of pristine natural scenery to view.
April 22, 2007 1:27 AM$75? Per person? (Is the additonal $50 fee per vehicle, or per person?) I think I will avoid this area; and find an uncrowded area in the main National Park where we can carefully lean out, and look down over the edge. (But even the main National Park wants $25 per vehicle to get into the main park. Are the national parks really "for the enjoyment of the public" anymore?)
Even though we have a four-wheel-drive and enjoy exploring back roads, the extra hassle of driving several hours round-trip over bumpy dirt roads decreases the expectation of enjoyment even further. They need to put in a paved road, and charge a more reasonable price; if they expect to get more visitors.
The CN Tower now costs about $31.99 Canadian (about $28.47 US, currently). The exact price depends on whether you want to go all the way to the very top, and other options. Considering the factor of the overall less hassle involved, and the spectacular view of Toronto and the surrounding countryside; the CN Tower would seem to be a better deal.
April 23, 2007 2:08 PMReminds me of the mindless excesses of the Roman Empire before its destruction from within.
Waken up America!
October 30, 2007 4:13 PMI am not from USA, am from Manila, Philippines. I believe in the modern technology especially if it is done by Americans fused by European modernists. Just can see how brilliant the human brain is; however, only less than a per cent is yet being used for such exploits.
October 31, 2007 3:01 AMI would stand in awe of the view. It is a marvel that the bridge could be put in place and suspended in mid air. I get a queezy, panicky feeling just looking at the picture of the glass bridge so I know I could never walk out on it. It's amazing to me still.
October 31, 2007 8:02 AMWhat catastraphe when that rock holding the skywalk gives away... as all rocks do at some point or another.
April 3, 2008 4:43 PM
