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DuPont Monster Bridge: “The most exciting seat in sports”

Safety glass with SentryGlas® high strength interlayer Photo ©DuPont

Race fans seated 10 meters above the track at Dover International Speedway are protected by a combination of steel cable net and safety glass made with SentryGlas®.

“The ability to watch the faces of drivers coming at you at 170 mph, three-abreast, is exhilarating. You can almost feel your heart pumping as fast as the bridge is vibrating!” Mike Katerman, president and CEO of Magee Rieter Automotive Systems.

Weekend NASCAR races June 4-6 and September 24-26, 2004, saw the debut of the DuPont Monster Bridge at Dover International Speedway in Delaware, USA. The Monster Bridge is suspended just 10 meters above the NASCAR racetrack.

Talking about what he called “the most exciting seat in sports”, the executive vice president of Dover Motorsports Inc. Jerry Miraglia, said: “Many sports put fans on the sideline close to the action but no other seat in sports allows them to stare into competitors’ eyes as they roar towards them and pass beneath their feet.”

“It’s like you’re hovering over the 50-yard line of a football game,” commented Brian France, the chairman and CEO of NASCAR. “It’s truly unique.” Mike Katerman, the president and CEO of Magee Rieter Automotive systems, another of the fans on the bridge on 4th June agreed: “It’s like a rainbow of colors coming right at you. The ability to watch the faces of drivers coming at you at 170 mph, three, abreast, is exhilarating. You can almost feel your heart pumping as fast as the bridge is vibrating!”

But mostly, Katerman said, the bridge gives fans a view and experience that they can’t get anywhere else. The bridge offers all the creature comforts of a luxury suite – noise reduction among the foremost of these - along with an unprecedented view of the racing action.

Maximum views – minimum obstruction
Craig Williams, project architect with Becker Morgan Group said: “Our client asked us to design VIP seating with maximum views and minimum obstructions – both for those in the bridge and those in the stands. The four side walls of the DuPont Monster Box are made of laminated glass, meeting this specification.

“Yet with a huge glass box positioned just 10 m above the track, safety was clearly a foremost concern. It’s an untested environment to seat people in front of oncoming traffic speeding at up to 160 mph. Large car parts are prevented from reaching the glass by a wire mesh in front of the bridge. However, lug nuts and other smaller debris can be thrown at high speed from the racetrack directly onto the façade. This is a significant concern when you realize that the best seats in the DuPont Monster Bridge are situated just 2 ½ feet away actual glass façade. The laminated glass solution suggested by DuPont and Cardinal Glass solved these concerns and is backed up by substantial research data.

Cool, comfortable and quiet
“A second concern was heat: most big races take place in the summer where temperatures are on average around 100 degrees F. We were pleased that new laminated glass technologies make the Monster Bridge wonderfully cool even on the hottest day because of the IR blocking interlayer in the laminated glass.

“Third, we wanted to cut out noise and vibration for the comfort of Monster Bridge spectators. If you knock on the glass walls, they don’t vibrate. The structure feels solid not fragile, as solid as a standard wall system. You feel safe inside it. We have not yet measured the decibel reduction as the project is so new but I can tell you, having been there, that you can have normal conversations with you neighbours whereas out in the stands that’s very difficult.

Corporate logos
“Lastly, the corporate sponsors wanted their logos to appear in the Monster Box. DuPont™ SentryGlas® Expressions™ solved this challenge very well because it allowed us to print the logos – and the Dover International Speedway ‘Monster Mile’ mascot - while blocking glare and maintaining transparency

Future developments
“In the future we would like to be able to design in a clear floor, while complying at the same time with fire standards in the case of an accident below, on the racetrack. Today, to comply with fire standards we had to include a 6-inch layer of concrete over the steel decking.

“Major missile impact is the glass challenge of the future. If the wire mesh can be eliminated, I can see ‘Monster Bridges’ appearing world wide – in Olympic track events, for example, where the view could be vastly improved and where there is less danger than from car racing. It’s also easier to build a narrower bridge; human or horse racing takes up less bridge width than car racing.”

DuPont™ SentryGlas® “essential for the project”
Director of Cardinal Glass, Mike Wothe, said: “DuPont™ SentryGlas® was essential for the successful realization of this project. Its qualities are greater than PVB in many respects including longevity, small missile protection and impact resistance. The applications for DuPont’s structural interlayer started in the hurricane market but have spread to anti-ballistic applications. The product is especially interesting with a low-E coating and anti-spall protection applied via the inboard lite for added occupant safety.

“The glass panes are 1.8 x 2.2 m and are fairly heavy at 1.8kg. There were 200 panes in the construction. The laminated glass construction was relatively conventional - each insulated glass construction is 28 mm thick. We selected an IG laminated glass construction because when you temper the glass the optics become distorted.”

Testing lab shoots lug nuts at 200 mph at the glass
Chris Anderson of DuPont Glass Laminating Solutions said: “The major technical challenge was to develop a system capable of stopping lug nuts (small bolts from NASCAR tires that tend to fly off at high speed during races) hitting the glass at 170 mph or faster. Computer modelling and ballistic testing protocols were developed specifically to address this design challenge. Physical testing and high-speed ballistic event filming were performed at H.P. White labs in Maryland. The test apparatus was set up to propel actual NASCAR-specified lug nuts at speeds of over 200 mph, impacting on a variety of laminated glass constructions. The selected laminated glass made with DuPont™ SentryGlas® structural interlayer prevented lug nut penetration.”

“A completely visceral experience”
Construction of the bridge started in November 2003 and was completed by June 2004. Jerry Miraglia concluded: “Dover Motorsports is always looking for ways to improve its facilities, and the DuPont Monster Bridge at Dover International Speedway is truly revolutionary. There is only one group of people closer to the action – and they are the drivers behind the wheels. No other professional sport puts fans so close to the action. We’re very proud that, thanks to a panoply of excellent DuPont products for the construction industry, Dover International Speedway is the only facility in the world to provide this opportunity to watch a race from a truly unique perspective.”

“The goal of the DuPont Monster Bridge is to provide fans with a completely visceral experience. A seat in the DuPont Monster Bridge allows you to see – and feel – the NASCAR action only 10 meters below your feet. No other seat in sports puts you on top of the action. Only 43 seats are better – and those are the seats of the drivers on the track. Thanks to DuPont products and technologies, the conditions inside the Monster Bridge are more comfortable, however!”

GLASS FACTS

Total area:
Approx. 2500 sq ft of safety glass fills the vertical surfaces of the 110-ft-long, by 13-ft-deep, by 10-ft high enclosed bridge structure.

Glass type:
Insulated Glass (IG) units, 1 and 5/16 in. thick
Front-facing panels (those facing the race traffic):
Outer laminate: 3/16 in. annealed glass, 120 mils DuPont™ SentryGlas® structural interlayer, 3/16 in. annealed glass (Cardinal LoE2-170 climate control coated)] Air gap: 3/8 in. Inner laminate: 3/16 in. annealed glass, 45 mil printed DuPont™ SentryGlas® Expressions™ decorative interlayer, 3/16 in. annealed glass

Rear- and side-facing panels:
Outer laminate: 3/16 in. annealed glass, 90 mils DuPont™ SentryGlas® structural interlayer, 3/16 in. annealed glass (Cardinal LoE2-170 climate control coated)] Air gap: 7/16 in. Inner laminate: 3/16 in. annealed glass, 45 mil printed DuPont™ SentryGlas® Expressions™ decorative interlayer, 3/16 in. annealed glass.

Special testing performed
The major challenge in designing glass for the DuPont Monster Bridge was developing a system capable of stopping lug nuts at speeds of 170 mph. Computer modeling and testing protocols were developed specifically to address this requirement. Physical testing and high-speed ballistic event filming were performed at H.P. White labs in Maryland. NASCAR-sanctioned lug nuts were propelled into a variety of laminated glass constructions at speeds over 200 mph. Laminated glass made with DuPont™ SentryGlas® structural interlayer prevented lug nut penetration.