Steel is used to build everything from skyscrapers to cars to pots and pans. Because it is used in so many places and in so many things, it is easy to forget how steel can also transform an ordinary building into something remarkably new.
Almost everyone can picture a sports stadium, an airport, or a bridge – we have all either been in, at or on one of them at one point in our lives. A huge football stadium that can close its roof, an airport by the sea that is impervious to corrosion, and a glass-bottomed bridge that allows only the most steel-hearted of pedestrians to look deep into one of the most famous canyons on earth – all made possible through innovations in steel.
Rolling Back the Roof at NRG Stadium
This year’s pro-football championship game between Atlanta and New England will be held at Houston’s NRG Stadium where hardcore Falcons and Patriots fans are rushing to get their hands on some of the few tickets left. Tickets are reselling for an average of $5,101, but if you want a view from the 50 yard-line it is going to set you back USD $11,000 to $12,000.
NRG Stadium, completed in 2002, is famous for being the first-ever NFL stadium with a retractable roof – allowing events to be held in open air or air-conditioned comfort.
Designed to utilize the principles of kinetic architecture, the roof is able to open and close without reducing the overall structural integrity. The roof’s panels are 117m x 152m and supported by two sections of five trusses each that meet at the 50-yard line. These two sections are supported by two supertrusses that run for almost 300m each along the field’s sidelines. Along each supertruss is a wheel rail to guide the roof as it opens and closes, in as little as 10 minutes.
With so many moving parts, the retractable roof represents an amazing feat of engineering. The steel beams, trusses, and motors weigh thousands of pounds, but it is still able to zip open in a few minutes. Come rain or come shine, ticketholders will be able to stay dry until the winner raises the Lombardi Trophy at the big game on Monday.
Stainless Steel at Incheon International Airport
With over 49 million passengers each year, Incheon International Airport is one of the busiest airports in the world, and consistently ranked as one of the best. Internationally praised for its remarkable facilities and services, which include a spa, golf course, movie theater, museum, and ice skating rink; the airport also prides itself on its efficient design.
When the first passenger terminal was built in 2001, they decided to use POSCO’s 446M stainless steel. The 446M steel contains high amounts of chromium (26%) and molybdenum (2%), which gives it superior corrosion resistance – excellent for use in exterior construction near coastal areas, like Incheon.
Seventeen years after the construction of the first terminal, there have been little signs of corrosion. So, as preparations began for a new second terminal, the airport decided to use the same type of stainless steel. Also, a bead blast process will be applied to the steel that will give it a rough texture to lower the reflectivity rate for aircraft pilots during take-offs and landings.
Despite being located on a small island in the Yellow Sea, the stainless steel used at Incheon Airport has been almost completely unaffected by corrosion. Already in its 17th year of operation, the stainless steel exterior will ensure that it lasts much longer.
Seeing Deep into the Canyons at Zhangjiajie, China
The majestic Zhangjiajie Grand Canyon, located in the western part of Hunan Province, is one of the most beautiful sites in China. Made famous in the Western world when James Cameron used it as inspiration for the landscapes in his film Avatar (2009), it is best seen atop the world’s highest and longest bridge.
Sitting 300m over the canyon, the Zhangjiajie glass bridge gives visitors a breathtaking, and terrifying, view of the park. The bridge is supported by 4 support towers and a steel frame with over 120 glass panels set into its walkway. The towers are installed directly into the canyon sandstone and each panel of glass is layered, so that even if one layer cracks, the others will hold.
Those with stomachs of steel can enjoy the bridge while experiencing one of the most beautiful parts of the world. The glass floor may seem fragile, but the steel frame holds it together to create one of the most amazing yet vertigo-inducing views.
If we look around, we will see that steel is everywhere. For something that seems so ordinary, it can also change the way we see buildings, and even change the way we see the world.