Salas O’Brien Receives Top Honors for Cold-Formed Steel Design

The cold-formed steel (CFS) design of the Park Union Bridge in Colorado Springs, Colorado receives first place in the Non-Building Applications category at the Cold-Formed Steel Engineers Institute’s Annual Design Excellence award ceremony

Salas O’Brien is excited to announce that its Denver-based structural engineering team along with the rest of the project team (listed below) have been recognized by the Cold-Formed Steel Engineers Institute (CFSEI) with the first place Design Excellence Award in Non-Building Applications for the CFS design of the Park Union Bridge in Colorado Springs, Colorado.

The award ceremony was part of CFSEI’s annual expo and conference in New Orleans, Louisiana. CFSEI is a national organization comprised of structural engineers and other design professionals, and its annual Design Excellence Awards program recognizes outstanding achievement in creative design, technical innovation, and overall project excellence in the use of cold-formed steel, according to the CSFEI website.

Called “the bridge of the future”, the Park Union Bridge is in southwest downtown Colorado Springs, Colorado. The 250-foot-long $20M pedestrian bridge connects the U.S. Olympic and Paralympic Museum with America the Beautiful Park.

Architect of Record Diller Scofidio + Renfro Partner-in-Charge and Lead Designer Benjamin Gilmartin noted, “The bridge is an exercise in fitness - both in terms of material and geometry. The hybrid steel structure system functions as an arch and a truss, elegantly preserving views from Downtown to the majestic mountain ranges of Pike’s Peak.”

The Salas O’Brien project team, led by Senior Principal Russ Leffler, PE, P.ENG, MLSE and Vice President Ryan Nelson, PE, was tasked with designing the CFS framing that supported the canted wall panels wrapping the inside of the twisting oculus. The CFS framing gradually curved and varied in height on each end, above and below the oculus.

The primary challenge presented by the CFS design was the three-dimensional and rotational movement of the steel structure as it induced thermal, wind, seismic, and live loads. Each element required an allowable tolerance of movement so that the panels could achieve their smooth, flawless appearance. It took careful coordination with the structural engineer of record Arup North America, LTD, panel manufacturer MG McGrath Inc., and CFS contractor Spacecon Specialty Contractors to secure the final design.

Project Team:
Owner: City of Colorado Springs
Architect of Record: Diller Scofidio + Renfro
Engineer of Record for Structural Work: Arup North America, LTD
Cold-Formed Steel Specialty Engineer: Salas O'Brien
Cold-Formed Steel Specialty Contractor: Spacecon Specialty Contractors

More information, including all the 2023 CFSEI Design Excellence award winners, can be found at CSFEI’s website at

Photos Courtesy of Colorado Springs Government Infrastructure Announcement.