High-Tech Glass at the Grand Canyon
The new Grand Canyon Skywalk, the U-shaped glass bridge suspended 4,000 feet above the Colorado River, gives visitors incomparable views of the western edge of the Grand Canyon that had not been available prior to its construction. The engineering marvel was made possible by its durable and ultra-clear glass, designed and produced by Saint-Gobain, the French-based glass manufacturer.

The company manufactured the low-iron Diamant glass for the floor of the Skywalk at its Cologne, Germany, plant. It was processed into laminated glass at three of its European subsidiaries. The deck, approximately 10 feet wide and 70 feet deep, is made of laminated tempered glass more than 2-inches thick. The 46 pieces were shipped directly to the western edge of the canyon. Each piece of glass is held in place by connectors specifically designed by Saint-Gobain for the bridge. The floor glass includes structural interlayers of DuPont SentryGlas Plus.

According to Roger Watson of Saint-Gobain Glass Exprover, the business which oversees architectural glass export to nations throughout the globe, the Diamant glass in the Skywalk contains a significantly lower amount of iron oxide than regular glass, which is designed to make it more clear than regular glass.

The glass deck is supported by outer and inner steel beams anchored into solid stone in the wall of the Grand Canyon. The Skywalk is said to support approximately 100 pounds per square foot and can withstand an 8.0 magnitude earthquake and 100 mph winds.

The structure was not built without controversy. Some members of the Hualapai Indian tribe, which owns the land, think it violates the sacredness of the location. 

Teamwork in Texas
When Fidelity chose to move its regional campus to Westlake, Texas, the company wanted to build something unique to fit into the surrounding community. HKS Inc. of Dallas was given the challenge. Along with glazing contractor Haley-Greer Inc., architectural products supplier Accura Systems Inc. became part of a successful team effort on the project. The fixed window and curtainwall system selected for the structure were customized and the windows were factory-glazed and assembled to achieve project requirements. The 2 ½ x 8 ½-inch deep window units were installed as punched openings, unitized strip windows, and two-story units to fill a 19 x 25-foot clear opening. Accura also provided a factory assembled 6 x 16 ½-inch super mullion between units. A specially-designed structural intermediate stiffener was utilized as an anchor track at the head and sill of the super mullion. 

This feature allowed the glazing contractor to align the vertical feature on the continuous ball anchor at the sill. The fixed window units were also designed and manufactured with an integrated bolt track on the face of the vertical extrusions to easily apply a 6 inch x 1 foot-7 ½-inch continuous sunshade unit in the field. 

During the course of the project, Accura officials report they were proactive in making many of the changes required by tolerance differences that became problematic due to a variety of surrounding conditions. One of the most challenging aspects of the project occurred when the company began modeling the 2 ½ x 10 1/8-inch Accq-wall system for the cafeteria area. This same glazing system was also utilized at the bridge and main entrance that tied the three buildings together. The bridge area was located beyond the main entrance and just outside the cafeteria. The cafeteria was a geometrical vision that included the bridge curtainwall with bisecting clerestory openings projecting out above the cafeteria to four angulated curtainwalls that overlooked the lake area. These angulated curtainwalls were also designed such that the super mullion and sunshade units could be easily installed. Just below the bridge wall was the exposed structural support of the clerestory openings. 

Bank on It
Although First Citizens Bank wanted a modern office building for its new headquarters in Columbia, S.C., the site was immediately adjacent to the Capitol building and, consequently, had to convey a sense “as if it had always been there.” 

The client sought a rich structure exhibiting extensively varying planes in column expressions and cornices. The nine-story structure by Duda/Paine Architects LLP includes 18,000 square feet of glass and 65,000 square feet of Golden Beach limestone from Portugal.

Baker Metal Products Inc., which designed and manufactured the curtainwall, became involved with the design in the early stages of development and was able to offer alternative designs that overcame some of the more difficult details. Working with Holder, Brockett-Davis-Drake, Inc., the curtainwall subcontractor, and the architect, Baker developed a unitized curtainwall design that simplified the edge of slab details and supported the extended faces of stone on aluminum trusses. Each assembled truss weighed about 3,000 pounds and was set on the jobsite with a tower crane. 

Architects' Guide to Glass & Metal
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