Harmon, Ltd. To Construct Blast-Resistant Curtain Wall for New Las Vegas Federal Building and United States Courthouse.

MINNEAPOLIS--(BUSINESS WIRE)--Feb. 2, 1999--A leader in innovative architectural curtain wall solutions, Harmon, Ltd. has been contracted to design, fabricate, and install a blast-resistant curtain wall to help heighten the level of protection for the Las Vegas Federal Building and United States Courthouse. Included in the project requirements, Harmon, Ltd. provided two full-scale mock-up specimens for bomb blast testing. This is the first building in the country using full scale testing to exhibit the performance of a curtain wall design's resistance to blast loads.

"Up until now, blast-resistant exteriors were monolithic, concrete structures with small slit windows that you can't see out of. This is a new application in conventional, custom curtain wall design," says Kevin Cole, engineering manager responsible for all professional engineering at Harmon, Ltd.

Scheduled to start in January 1999, Harmon, Ltd. will complete the curtain wall portion of the project in January 2000. The final, eight story building as a whole is scheduled for completion in May 2000.

"Our experts handle some of the largest and most technologically complex design projects in the world," continues Cole. Establishing a basic design early in the design build process, and working closely with the project team, Harmon's designers helped achieve the delicate balance between aesthetics, cost and performance. "The best aspect of this design is that it heightens security and still looks appealing without adding more than 20 percent in material costs. As the threat of terrorism continues to grow, we expect that more architects, building owners and tenants will want similar protection."

The curtain wall design was labeled "an unqualified success" by independent testing at the White Sands Missile Range, N.M. Even at twice the specified charge, the curtain wall remained intact. The test facility was built to simulate the thermal effects of a nuclear blast on military equipment. Since the end of the Cold War, the facility has refocused on blast testing of full scale, exterior cladding systems. Harmon's test was the second full-scale test held at this facility.

"We're proud that our curtain wall design not only met, but exceeded the security criteria," adds Cole. "The panelized curtain wall system allows for a more integral connection between the vertical and horizontal. Laminated glazing siliconed into the frame offered an inherently more flexible framing system. This way the glazing can better absorb the energy of a blast, resisting a higher pressure."

The 134,000 square foot curtain wall consists of four different framing systems including: 100 11-foot-wide by 22-foot-tall, unitized glass and aluminum frames and 250 11-foot-wide by 22-foot-tall, panned, steel trusses. Within the trusses are 7-by-7 foot punched windows with the balance of the trusses being aluminum panels.

Identical mock-ups were tested at the Construction Research Laboratory, Miami, for air and water infiltration, as well as seismic movement as required by the stringent 1997 Uniform Building Code.

Harmon, Ltd. is the largest custom curtain wall provider in the United States. Based in Bloomington, Minn., the company has regional offices in Chicago, Los Angeles, and Baltimore. Working in partnership with owners, architects, consultants, contractors, and suppliers, Harmon, Ltd. plays a leading role in shaping the urban landscape of Asia, Europe, the United States, and other parts of the world.

Through global integration of functions and resources, Harmon brings an innovative approach and maximum value to the design, engineering, fabrication, and installation of exterior cladding systems for the world's most distinctive buildings. Harmon provides these services as part of the Building Products and Services segment of Apogee Enterprises, Inc., a publicly held, international corporation.

Note: Curtain wall engineer manager Kevin Cole and blast mock-up facility chief directorate Major Richard "Tex" Hall will be speaking at the Technical Advisory Committee on Blast Resistant Glazing Systems meeting in Arlington, Va. on April 23, 1999.

Note: For photos, supporting information or interviews with Harmon, Ltd. curtain wall experts or other members of the Las Vegas Federal Building and United States Courthouse building team, please contact Heather West at [phone] or via e-mail at [e-mail]