Marina City Towers

Dominating Chicago’s Skyline

Iconic in form, Marina City’s twin 62-story, corncob-shaped towers have dominated Chicago’s skyline since the early 1960s. These towers, along with three other structures that have over time housed offices, a theater, a hotel, and commercial space, embody the vision of famed architect Bertrand Goldberg for a self-contained development where people could live, work, and socialize. By the end of 1964, Marina City boasted a grocery store, pharmacy, florist, travel agency, restaurants, bars, and other amenities. The development even had a “teleview teller,” which allowed customers to interact with the bank clerk via closed-circuit television, a service innovation that was years ahead of its time. As a firm known for cutting-edge and high-quality design, Severud Associates was retained in 1959 to provide structural engineering services for the towers and theater.

Bandel’s Design

Hannskarl Bandel and his staff of engineers at Severud Associates designed the structural systems for the towers, which were recognized as the tallest residential buildings and tallest reinforced concrete structures in the world when they opened, and they engineered the theater, located on a relatively small portion of the site, as well. The design team turned Goldberg’s vision for the towers into a reality by engineering each with a circular core of concrete shear walls that houses vertical circulation and mechanical systems and resists the entire lateral load on the building. Making a bold decision, engineers and the construction team chose slipform construction to erect each tower’s core in a continuous operation. The core was completed well in advance of the floors.
 
Sixteen reinforced concrete beams on each floor radiate out from the core by nearly 40 feet and extend to 16 exterior columns. Semi-circular balconies were placed between and beyond each pair of adjacent perimeter columns, giving the buildings their unique look. The use—and reuse—of fiberglass forms for beam soffits and column corbels, along with a precise construction schedule, allowed each floor to be completed in a 48-hour cycle. At the foundation level, the towers are supported on three concentric rings of piles, one inner ring for the core and two outer rings for the perimeter columns. An impressive spiral parking garage, made more famous in a car chase scene from the Steve McQueen movie, The Hunter, occupies the first 16 stories of both towers.

Meeting the Challenge

Although much smaller, the structure for the theater at Marina City also posed some interesting engineering challenges. To produce the saddle-shaped roof—a form that would have been difficult to construct in concrete—steel arches were interlaced with steel beams on a triangular grid to create a steel shell; Severud engineers would later use this system for Princeton University’s Jadwin Gymnasium. The steel framing was then sprayed with concrete and clad in lead sheathing for sound isolation. The theater opened on September 25, 1970, with the films The Hawaiians, Hello, Dolly!, and M*A*S*H.

 
In the decades since the landmarked Marina City complex was constructed, Severud Associates has provided structural engineering services for other notable mixed-use developments including TSX Broadway, NYU’s John A. Paulson Center, and 20 Times Square, all in Manhattan