Glass provides new view of natural wonder

March 27, 2007
COMMERCIAL

Grand Canyon Skywalk bridge set to open

Photos by Saint-Gobain

Tomorrow, the laminated glass bridge over the Grand Canyon will open to the public, allowing visitors to pay $25 for an unobstructed view 4,000 feet down to the Colorado River.

“You stand on the bridge and look out and don’t notice that there’s any glass there. It’s sensational,” says Roger Watson, vice president of sales and marketing for the glass supplier, Saint-Gobain of France.

The u-shaped Grand Canyon Skywalk extends 70 feet from the rim, and is the first cantilevered walkway over the canyon.

Saint-Gobain supplied its Diamant low-iron glass for the floor as well as the surrounding balustrades.

The balustrades feature laminated bent glass of two 3/8-inch lites with a .06-inch polyvinyl butyral interlayer. They rise about five feet from the glass floor, allowing visitors an unobstructed view out over the railing, Watson says.

“It’s like there’s not a barrier, as in an aquarium,” Watson says. “It feels a lot more sensory. You can feel the wind in your face.”

The 2-inch thick structural glass floor consists of five layers of glass alternating with four layers of the SentryGlas Plus interlayer from DuPont Building Innovations of Wilmington, Del. The bottom four layers are 3/8-inch glass, with a 5/16-inch lite on top.

Valerie Block, senior marketing specialist for DuPont says engineers specified the ionoplast interlayer because of strength, edge performance, ability to withstand weather elements and its ultra-clear appearance.

The bridge can support 71 million pounds, and was designed to sustain winds in excess of 100 miles per hour and an 8.0 magnitude earthquake within 50 miles, according to the Grand Canyon Skywalk Web site.

“The engineering of the Skywalk presented challenges, determining appropriate loads, then confirming through analysis that the Skywalk would provide adequate performance,” Block says.

Above the top 5/16-inch lite is a 5/16-inch sacrificial lite that protects the structural layers. Eckelt Glas in Austria, a Saint-Gobain subsidiary, supplied the sacrificial lites that are 110 inches wide with 27-inch frits along the edges.

“Unless you’re a base jumper or astronaut, you’ve never been that high,” Watson says. “The frit gives element of traction where most people walk; where they feel as if they’re walking on something, not just air. They can also hold on to handrails on the sides.”

The frit also provides slip resistance and cover up the steel beams that support the walkway, Watson says.

While visitors are required to wear shoe covers to protect the glass, scratches are inevitable, Watson says. So, the sacrificial lites will be replaced as needed.

Crews will clean the surface periodically through the day to ensure the most unobstructed views, he says.

Giroux Glass of Las Vegas installed the glass. Saint-Gobain performed all the design and engineering the structural glass, balustrades and handrails. Saint-Gobain subsidiaries Kinon and Döring, both of Germany, fabricated the structural glass floor and balustrades, respectively.

-By Katy Devlin, e-Newsletter Editor, e-glass weekly