Steel Castings Realizing Architectural Expression inside Chicago O’Hare’s Satellite Concourse 1

Published:

September 10, 2026

Edited:

September 10, 2026

Project Details:

Location: Chicago, IL, United States
Sector: Aviation
Status: In Construction
CAST CONNEX Products Used: Custom Castings, Custom Architectural Tapers (ART), and Universal Pin Connectors (UPC)

Construction progresses on the new Satellite Concourse 1 (Concourse D) at Chicago O’Hare International Airport (ORD), the first major facility being delivered as part of the City of Chicago’s ORDNext expansion program. Designed by SOM in collaboration with Ross Barney Architects, Juan Gabriel Moreno Architects (JGMA), and Arup, the approximately 580,000-square-foot concourse will introduce 19 new gates and serve a key part in the largest terminal expansion in O’Hare’s history.

A highlight feature inside Concourse D is the series of architecturally exposed structural steel (AESS) tree columns that support the expansive long-span roof. Inspired by O’Hare’s origins as Orchard Field, the branching structural system creates open, light-filled spaces while reducing the number of interior columns throughout the concourse. The resulting structure enhances passenger circulation, improves sightlines, and establishes a memorable architectural experience that connects structural performance with architectural expression.

CAST CONNEX is contributing to the realization of this vision through the design and manufacture of custom cast steel tree nodes for the signature AESS tree columns. These custom castings enable the complex branching geometries envisioned by the design team while delivering the refined appearance expected of a premier architectural steel structure. They also enhance both structural and construction performance. The optimized three-dimensional cast steel form resolves complex force paths, reducing stress concentrations while providing exceptional strength and stiffness. At the same time, custom castings consolidate numerous fabricated components into single engineered elements, improving fit-up, simplifying fabrication, and reducing the visual complexity often associated with traditional welded assemblies. The result is improved constructability, and a higher level of AESS quality.

The tree columns distinct aesthetics and performance will also be realized with the use of custom Architectural Tapers (ART) and CAST CONNEX's standardized Universal Pin Connectors (UPC). The tapers provide sleek and minimalistic details at the top of the branches while resolving the roof loads, while the UPCs offer simple and clean tectonic expression of a pin-type connection for horizontal HSS struts that connect to several tree node locations.

Through close collaboration with the project team, CAST CONNEX is helping deliver the seamless geometry, architectural beauty, and high-performance detailing required for one of the most significant airport infrastructure projects currently under construction in North America. By leveraging steel castings in highly visible AESS applications, the project benefits from smooth, elegant transitions between structural members that would be difficult or impractical to achieve using conventional fabricated assemblies.

As the project continues its transition into vertical construction, the tree column assemblies begin to demonstrate how custom castings can unite architectural ambition with structural efficiency.

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