How the Louisiana Superdome Saved Lives

In August 2005, the Louisiana Superdome became a shelter of last resort as Hurricane Katrina set sights on New Orleans. Although 30 years old and built in a floodplain, the structure stood firm and saved the lives of thousands of people. How strong is the Louisiana Superdome?

Building the Superdome

The Superdome, also known as Mercedes-Benz Superdome, is a public/private New Orleans, Louisiana (NOLA), project designed by New Orleans native Nathaniel "Buster" Curtis (1917–1997) of Curtis & Davis Architects. The contractors were Huber, Hunt & Nichols. A domed structure is not a new idea—the concrete dome of the Pantheon in Rome has provided shelter for the gods since the second century. The 1975 Louisiana Superdome was not even the first large-domed sports arena to be built in the U.S.; the 1965 Houston Astrodome in Texas provided nearly a decade's worth of experience for the NOLA architects. The design mistakes of the Astrodome would not be repeated. The new NOLA dome would not include skylight glare to impede the vision of the players below it. The Superdome would not even try to grow grass inside.

Many sports stadia have playing fields below ground level, which allows the building's height to be modest on the outside. A good example is the 2010 Meadowlands Stadium in New Jersey, whose exterior facade disguises the lower location of the field below ground level. This type of stadium design would not work in the flood-prone Mississippi River Delta. Because of a high water table, the 1975 Louisiana Superdome in New Orleans was built on a platform atop a three-story underground parking garage.

Thousands of concrete pilings hold the steel frame exterior, with an additional "tension ring" to hold the weight of the enormous domed roof. The diamond-shaped steel framework of the dome was placed onto the ring support all in one piece. Architect Nathaniel Curtis explained in 2002:

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"This ring, capable of withstanding the massive thrusts of the dome structure, is made of 1-1/2-inch-thick steel and prefabricated in 24 sections that were welded together 469 feet in the air. Because the strength of the welds is critical to the strength of the tension ring, they were performed by a specially trained and qualified welder in the semicontrolled atmosphere of a tent house which was moved around the rim of the building from one weld to another. Each individual weld was x-rayed to ensure the perfection of the vital joints. On 12 June 1973, the entire roof, weighing 5,000 tons, was jacked down onto the tension ring in one of the most delicate and critical operations of the whole construction process."

The Superdome Roof

The Superdome roof is nearly 10 acres in area. It has been described as the world's largest domed structure (measuring the interior floor area). Fixed dome construction fell from popularity in the 1990s, and several other domed stadiums have closed. The 1975 Superdome has survived its engineering. "The Superdome's roof system consists of 18-gauge sheet-steel panels laid down over the structural steel," writes architect Curtis. "On top of this is polyurethane foam one inch thick, and finally, a sprayed-on layer of Hypalon plastic."

Hypalon was a state-of-the-art weatherproofing rubber material by Dupont. Cranes and helicopters helped place the steel panels in place, and it took another 162 days to spray on the Hypalon coating.

The Louisiana Superdome was designed to resist wind gusts up to 200 miles per hour. However, in August 2005, Hurricane Katrina's 145 mph winds blew away two metal sections of the Superdome roof while more than 10,000 people sought shelter inside. Although many hurricane victims were frightened, the architecture remained structurally sound in part because of a 75-ton media center hanging from the roof's interior. This gondola of televisions is designed to act as a counterweight, and it kept the entire roof in place during the storm. The roof did not collapse or blow away.

Although people got wet and the roof needed repair, the Superdome remained structurally sound. Many victims of the hurricane were transported to Reliant Park in Houston, Texas, for temporary shelter in the Astrodome.

The Superdome Reborn

Soon after the hurricane survivors left the shelter of the Louisiana Superdome, the roof damage was assessed and repaired. Thousands of tons of debris were removed and several upgrades were made. Ten thousand pieces of metal decking were examined or installed, coated with inches of polyurethane foam and then several layers of urethane coating. In 13 short months, the Louisiana Superdome reopened to remain one of the most advanced sports facilities in the nation. The Superdome roof has become an icon of the city of New Orleans, and, like any structure, is the source of continual care and maintenance.

Sources

• Karen Kingsley, "Curtis and Davis Architects," knowlouisiana.org Encyclopedia of Louisiana, edited by David Johnson, Louisiana Endowment for the Humanities, March 11, 2011, http://www.knowlouisiana.org/entry/curtis-and-davis-architects. [accessed March 15, 2018]
• Nathaniel Curtis, FAIA, "My Life In Modern Architecture," The University of New Orleans, New Orleans, Louisiana, 2002, pp. 40, 43, http://www.curtis.uno.edu/curtis/html/frameset.html [accessed May 1, 2016]
• National Register of Historic Places Registration Form (OMB No. 1024-0018) prepared by Phil Boggan, State Historic Preservation Officer, December 7, 2015, https://www.nps.gov/nr/feature/places/pdfs/15001004.pdf
• Super Bowl Press Kit February 3, 2013, www.superdome.com/uploads/SUPERDOMEMEDIAKIT_12113_SB.pdf [accessed January 27, 2013]
• Mercedes-Benz Superdome Renovations, http://www.aecom.com/projects/mercedes-benz-superdome-renovations/ [accessed March 15, 2018]
• Kim Bistromowitz and Jon Henson, "Superdome, Super Roof,"Roofing Contractor, February 9, 2015, https://www.roofingcontractor.com/articles/90791-superdome-super-roof-iconic-mercedes-benz-superdome-in-new-orleans-sports-its-brightest-look-yet
• Additional photo credits: Meadowlands interior LI-Aerial/Getty Images; Meadowlands exterior Gabriel Argudo Jr, gargudojr on flickr.com, Creative Commons 2.0 Generic (CC BY 2.0)