TILT at 360 Chicago in Chicago. Courtesy 360 Chicago.



Sitting on the 94th floor of the John Hancock Center, 360 CHICAGO provides visitors a panoramic view of Lake Michigan and four Midwestern states. To enhance their experience, the owner hired Thornton Tomasetti to design Tilt, an operable steel and glass structure on the south side of the building that allows patrons to hover 1,000 feet over the city.

Tilt’s mechanism is a two-part system composed of a stationary base structure and a movable viewing platform constructed of standard and custom built-up steel sections. The stationary base is supported and directly connected to the existing steel structure. The 26-foot-wide platform rotates on one axis and is supported at three locations by the fixed structure. Three overhead hydraulic actuators extend to rotate the platform 30 degrees beyond the face of the building.

The viewing window is composed of several layers of reinforced, fully tempered glass panels. A similar system of layered reinforced glass forms a partial roof to prevent weather and debris from entering and exiting the space. Patrons stand in one of eight individual partitions along the length of the platform. Handrails on each side and a waist band provide additional support.

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