www.sefindia.org

[Dr. N. Subramanian]

The Oklahoma City Skydance Bridge

In 2008, the mayor of Oklahoma City, Oklahoma, USA announced an open competition to design a pedestrian bridge in the city's downtown. The design had to accomplish three goals: span a recently relocated highway, connect the north and south halves of a major city park, and serve as an Oklahoma City icon for citizens and visitors. After a design competition that included 16 firms, Oklahoma City chose the submission by Architect MKEC Engineering and Butzer Design Partnership, led by Hans Butzer.

Butzer is well-known as the designer of the Oklahoma City National Memorial. Design consortium S-X-L (Spatial Experiments Lab) overcame a number of internationally renowned design firms with its winning design.

Skydance Bridge is a 119 m long, 9 m wide pedestrian bridge and spans Interstate 40 near Robinson Avenue south of downtown. Wings rise above the bridge, reaching as high as 56m in the air, and a 66-inch high ornamental metal railing spans the length of bridge. It opened to foot traffic April 23,2012.

The bridge’s soaring architecture was inspired by Oklahoma’s state bird, the scissor-tailed flycatcher. The bridge was designed to evoke Oklahoma's sweeping prairie winds. The bridge's unique hybrid architecture consists of a soaring, vertically cantilevered tri-cord truss (split into sections known as the "wings," "legs," "hub," and "tail") and a simple span truss bridge. The construction of the wings was influenced by the flycatcher's lightweight bone structure, in which an outer "skin" is stretched around a hollow core. These wings also serve as the housing for more than 600 angled steel "feathers," which help give the structure its distinctive textured silhouette. The bridge is located on Harvey Avenue between SW 7th and SW 10th.

The bridge has HSS members. The bridge is made of stainless steel panels that shimmer in the sun, and uplighting at night emits a skyward glow. The wings, made from a translucent material, appear to glow from within. This unique form is lit nightly with a dynamic, color-changing LED lighting solution from Philips Color Kinetics. 33 ColorReach Powercore floodlights and 16 ColorBlast Powercore wash lights were installed on custom steel mounting plates and evenly distributed throughout the structure's wings, legs, hub, and tail to illuminate the feathers with intense, saturated color. The lighting installation is controlled by a single iPlayer 3 digital controller, allowing city officials the flexibility to change color schemes and lighting effects with the push of a button.

Two key design objectives of the installation were to promote local industry and use sustainable solutions whenever possible. All installation and raw materials requirements were met by local steel fabricators, lighting contractors, and lighting suppliers, helping to support in-state jobs and reduce transportation costs. Durable construction materials containing a high percentage of recycled content — such as steel and glulam wood decking — were used to minimize the project's environmental impact and maximize its longevity.

The project's focus on durability, sustainability, and aesthetic elegance made the decision to choose a Philips Color Kinetics lighting solution easy, said co-designers Hans Butzer and Stan Carroll of S-X-L. "We discovered quickly that the Philips Color Kinetics series offered the best range of fixture types to help the design team achieve its vision," Butzer and Carroll said.

A truly green solution, the lighting system is predicted to have an energy cost of less than $2,000 annually.

Construction of the Skydance Pedestrian Bridge began in August 2011, just as the I-40 construction entered final stages. The estimated $6.6 million construction cost was funded by both city and federal money, about $3.5 million coming from the Oklahoma State Department of Transportation's federal funding and the rest from the city of Oklahoma City.
A national nonprofit group named Oklahoma City's SkyDance Bridge one of the nation's 50 best public art projects.SkyDance was chosen from more than 393 works from 147 cities.

Photo Credits: Ralph Cole

Sources:
http://www.colorkinetics.com/showcase/installs/Skydance-Bridge/
http://butzerarchitects.com/skydance-bridge/yylrgqjes89e6zq8ow4asp1xijo4s7