Engineering marvel could be tribe’s savior

Sights at 4,000 feet to beckon thrill seekers

By Greg Lavine
Salt Lake Tribune

HUALAPAI INDIAN RESERVATION, Ariz. - One of the world's largest natural wonders will soon be home to an engineering marvel.
    In late March, the Hualapai Nation plans to open the $30 million Skywalk, a glass-bottomed bridge that will jut 70 feet over the Grand Canyon's edge.
    The massive U-shaped steel structure now sits 20 feet from the cliff's edge. It will take up to 18 hours to ease the million-pound, horseshoe-shaped walkway into place, said Mark Johnson, Skywalk's architect.
    Skywalk, located at Grand Canyon West, will allow visitors to peer 4,000 feet straight down through the floor to the canyon's bottom. The attraction is part of the Hualapai tribe's effort to become a tourist destination. Going on the Skywalk will be a $25 add-on to all Grand Canyon West tour packages. The cost is included in some of the premium tour options.
    "This will feed our tribe," said Robert Bravo, a member of the Hualapai tribe and part of Grand Canyon West. "This will support our children."
    Visitors to the reservation, which is about a three-hour drive from Las Vegas, must take a 14-mile, winding, unpaved desert road. Grand Canyon West now relies on generator power, must truck in all water and has limited phone services.
    While other Arizona tribes rely on gaming income, the Hualapai, a tribe of about 1,500, were not successful in this venture. Most of the 250,000 visitors to Grand Canyon West each year come from Las Vegas, where they are able to take care of all their gambling needs.
    The few slot machines that once sat in the Hualapai Reservation's airport were no match for the nearby natural beauty of the Grand Canyon.
    Las Vegas businessman David Jin, founder of Grand Canyon Skywalk Development, came up with the idea of the Skywalk nearly a decade ago. Jin and the Hualapai have worked jointly over the past several years to refine the design of the structure, Johnson said.
    Bravo said tribal members consulted with their elders before proceeding with the Skywalk plan.
    "We're creating a new way of looking at something," Johnson said, "where you feel like you're almost floating."
    Original drawings called for a glass structure with a wisp of steel supporting the bridge, but engineering realities forced the base to become thicker.
    The base of the bridge is made up of two, 5-foot-tall U-shaped steel walls, made by Mark Steel, a Salt Lake City firm. A series of support beams connects the inner and outer walls of the bridge, leaving many open areas for visitors to look down through.
    "This is the most exciting thing we've ever done as far as I'm concerned," said Fred Elmen, director of projects for Mark Steel.
    The company shipped the 40- to 60-foot-long steel segments to the site, on the Hualapai reservation, which covers about 1 million acres. Another company welded the pieces into the massive horse-shoe-shape that will become Skywalk.
    Mark Steel has worked mostly on more traditional structures, such as the E Center, but has also done boat-building work. Skywalk was seen as a challenge.
    "We pride ourselves on doing things that are a little bit different," Elmen said.
    Crews must eventually move the steel skeleton 75 feet, which will place half the structure over the side of the cliff.
    Once in place, the bridge will have no visible means of support; it will appear to emerge from the cliff. But only half of the structure's total mass will be visible, Johnson said.
    The bulk of the support system will be hidden under a gift shop/restaurant. A series of eight box beams, each anchored 40 feet vertically into the cliff, will hold most of the bridge's load.
    Moving the bridge toward those critical connection points will pose a challenge.
    Johnson said it will involve a process called "jack and roll." Hydraulic jacks will lift the bridge onto a steel track, and a series of rollers will help move the structure.
    Once on the steel tracks, crews will add 500,000 pounds of weights on the back end of the structure to prevent it from tipping over into the canyon.
    Four trucks, including two with winches, will use a pulley system to slowly move the bridge inches at a time toward the cliff.
    Once Skywalk is in place, a team will weld the structure to the eight box beams. These connections will bear the brunt of the bridge's support needs.
    Johnson said engineers have studied the wind patterns of the canyon and have altered the design as necessary. The bridge is also designed to withstand a magnitude 8 earthquake within 50 miles.
    "It's first-time technology," said Allison Raskansky, president of Destination Grand Canyon, which markets Grand Canyon West. "It's an incredibly complex process."
    While Skywalk literature claims the bridge could hold a fleet of jumbo jets - totalling 71 million pounds - the actual loads will be significantly lighter.
    Only a handful of people will be allowed on the bridge at any given time.
    All Skywalkers will have to wear booties to protect the 4.5-inch-thick glass floor. A thin top layer of glass will be replaceable to maintain scuff-free views.
    The glass is a special high-strength material from Germany made by Saint-Gobain. Five-foot-tall glass walls will line the sides of the bridge, allowing full view of the Grand Canyon and its surroundings.
    The wall windows will be in panels that can be removed as necessary should they break. A trolley system on the bottom of the bridge will be used for cleaning and repairs.
    When Skywalk opens in the spring, the Hualapai hope more curiosity seekers will trek out to northern Arizona to see the Grand Canyon from a new perspective. While some visitors may not dare to tread on the engineering feat, thrill seekers will take in a view that once required wings to see.