RISING UP TO THE CHALLENGE
ATLANTA’S NEW MERCEDES-BENZ STADIUM
By Laura Relyea
The Atlanta skyline is about to change. Though the ever-progressing Mercedes-Benz stadium may not scrape the sky the way the city’s most iconic buildings do — such as the Westin Hotel or the Bank of America Building, which loom over the downtown district of the city — but the vibrant, bright, and intrepid design of the forthcoming stadium is sure to have a striking effect on the makeup of the city’s horizon regardless.
Poised a mere 84 feet from the Georgia Dome that it is primed to replace — the Mercedes Benz stadium makes a strong statement for the future of Atlanta and its long-term investment in professional sports. The aspirational arena will surpass its predecessor in size by 300,000 feet — covering 1.9 square million feet upon completion, and soaring 305 feet –approximately 30 stories — into the skyline.
Everything about the project exudes ambition, from the construction timeline to its groundbreaking approach to sustainability and green efforts. It is expected, upon its 2017 completion, to host an SEC Championship, the Chick Fil-A Bowl, the BOA Classic and NCAA Men’s Final Four — convocations that are anticipated to bring in $130 million for the city of Atlanta itself. In addition to that, it is hoped that the new stadium will attract the attention of the NFL enough to score the city a Super Bowl, and the attention of MLS enough to house a FIFA World Cup, events that would bring in an estimated $225 million in commerce to the city.
DESIGN THAT TAKES WING
Atlanta’s landscape is in a constant state of flux, seemingly under a semi-permanent state of construction and long-term improvements since the 1996 Olympics graced the city — the stadium stands to be a literal and figurative testament to the ever-evolving city which it will call home. With an exterior and roofing system chiefly constructed of glass and retractable panels, the architects of 360 Architecture (recently acquired by HOK) who came up with the initial designs of the stadium managed to create a predominately indoor stadium with a completely outdoor feel.
Aesthetically, the stadium’s design is intended to emulate the shape of a falcon’s wing. “To be quite frank — there aren’t a lot of attractive retractable roof facilities out there — that’s just my opinion — but I thought, in order to make it truly iconic, it had to be completely integrated,” said Bill Johnson, 360 Architecture’s lead architect on the initial design of the stadium. The facility’s soaring trusses and capitalization of natural light is sure to do so. The Northeastern corner will feature a 30 story floor-to-ceiling window facing the city, allowing patrons to connect with the landscape and skyline as never before.
The idea to utilize natural light was an inspiration brought about by a pre-existing icon — the Roman Pantheon, which allows light to shine in from a singular hole in the center of its roof. “We decided to pursue the oculus theme for a lot of reasons. It had a lot to do with the operations and the good buzz and feelings that people had about it,” Johnson said. The team set to create a retractable roof that was truly integrated with the structure of the building itself. Johnson added, “We thought, what if we create the experience of a spotlight on the field, right on the logo on the 50 yard line, and then let it grow?”
THE SKY’S THE LIMIT
What grew from the team’s original vision to the shape of an incredibly ambitious design that opens and closes similarly to an 8-blade camera lens aperture, imagined in collaboration with Engineer Buro Happold, the convertible kinetic roof will be predominantly constructed of translucent Ethylene Tetrafluoroethylenean (ETFE), and will be capable of opening and closing completely in a mere 8 minutes.
Since being developed by DuPont 40 years ago as an ‘inert coating for aerospace,’ EFTE has gone on to be used in a myriad of modern applications in a variety of fields, varying from agriculture to solar cell coating. The material made its debut in construction in the early 1980’s with the Eden Project in Cornwall. Since then it’s been incorporated into designs at the Allianz Arena for the 2006 World Cup and the infamous “water cube” at the 2008 Beijing Olympics.
The substance is produced from a raw plastic granulate that is then extruded into sheets, commonly referred to as “foil” or “film.” Incredibly durable, flexible, and lightweight, EFTE films are unbelievably elastic — with up to a 600% breaking point, and with a tensile strength of elasticity of 21–23 n/mm^2 and with a breaking point of 52 n/mm^2. EFTE is resistant to dust and dirt, recyclable, and UV transparent –meaning it doesn’t discolor over time.
When applied in single layers EFTE can be reinforced with wire cables, lightweight steel or aluminum. In heavier applications, as with the Falcons Stadium, the substance can be used in double or triple layers, using a pneumatic system that maintains air between the multiple layers of film, which are attached to aluminum extrusions and supported by lightweight structures. This creates inflated cushions that are filled with low-pressure air, ideal for thermal insulation and capable of creating great weather-resistant structural stability, capable of sustaining both wind and snow.
THE HALO BOARD
Directly beneath the 8 roof petals will perch the stadium’s second-most ambitious feature — the “Halo Board.” In an attempt to reinvent the scoreboard, a design was a made for a 360-degree video board that will prove to be the largest in the NFL and the world to date. The board will stand 58’ tall and 11 hundred feet in diameter, capable of providing each and every patron with a unique camera view and with experience-enhancing digital content. Even more astounding, the board will hang from the circumference of the roof opening, viewable regardless of whether or not the roof is opened or closed.
TIME AND SPACE CONSTRAINTS
With such great ambition comes a great amount of responsibility — to the city of Atlanta, Mercedes-Benz, the Falcons, and Atlanta United respectively. Building such a massive structure in the center of a city already struggling with urban sprawl certainly comes with its own host of challenges.
Construction in such close quarters to the city’s pre-existing Georgia Dome is certainly its own task.
The project features multiple Liebherr LR1400/2, LR1600/2 and two Liebherr LR11000 cranes with heavy-lift attachments, all for the purpose of handling some very large trusses specific to the roof design. Due to space constraints, the herculean cranes are currently working from within the stadium itself, accommodating challenging angles and large loads with progressive add-ons to help the project keep up to schedule. All of the Liebherr cranes on the jobsite, from the towering LR11000’s (so large it had to be transported in segments by trucks and then assembled on-site) to the smaller LR1400/2 utilize EVOLUTION TK17 Plus special wire ropes produced by Teufelberger Seil, Austria. All of the construction underway may be viewed from the stadium’s live-streaming webcam. The stadium is currently on course to be opened in time for the 2017 football season.
ROOM FOR GROWTH
With such a myriad of events to host within the stadium itself, some of the most thorough features of the stadium are its flexible capacity. Through the use of a mechanized curtaining system the stadium can increase and decrease its size — capable of holding up to 83,000 guests, as would be necessary for an NCAA Final Four. The curtaining system is also capable of masking the immense stadium to be more intimate for smaller functions, such as concerts and soccer matches. It’s for this reason that Atlanta United’s FC General Manager Jim Smith feels that the new coliseum is ideal for the MLS team. “The design had soccer in mind from the very beginning,” he says. In these instances, the mechanized curtaining system will cover the stadiums mid and upper bowls, fluctuating the capacity for approximately 29,000 — the anticipated attendance for an average soccer match. Covering just the upper bowls restricts the seating to 75,000, making it an ideal capacity for a potential Super Bowl or World Cup.
A STADIUM TO MAKE A CITY PROUD
The mindfulness of the stadium experience carried through to every portion of the stadium itself — with a consistent focus on sustainability and reduced energy consumption. Currently, the stadium is seeking LEED (Leadership in Energy & Environmental Design) certification at the highest level from the U.S. Green Buildings Council.
As a zero-waste facility, the arena has kept a focus on recycling and composting waste materials whenever possible. Solar Panels will be installed throughout the campus of the stadium, and in partial building re-use to make vast improvements to energy efficiency, as well as to provide energy for a parking structure that will include charging stations for electric vehicles.
In addition to energy-focused efforts, the design of the stadium was highly-conscious of water-use; rainwater collection and reuse have been incorporated throughout the stadium’s design, along with measures to promote reduced water consumption within the facility. These efforts have led to the stadium to additionally seek LEED water-related credits — a first for any major sports facility.
It seems that throughout the design, concept, and execution of such an endlessly ambitious project as the Mercedes-Benz stadium, the bar is certainly being raised across the board. “One of the things that [Falcons’ Owner] Arthur Blank challenged us with in the beginning was that we really create an icon, a new symbol, another symbol for the city of Atlanta. The bar was set a little bit higher,” said Bill Johnson. There seems to be little doubt that the stadium will rise up to Blank’s expectations — maybe even surpass them.
