Glass observation decks at Willis Tower

Skydeck, Willis Tower – Chicago, United States

SERAPID LinearBeam actuators provide safe and reliable push-pull motion allowing the Skydeck Chicago glass observation boxes to be retracted into the building when needed.

Ask any visitor to Chicago what their favourite city attraction is and you are sure to hear the cry ‘Chicago Skydeck’. As the eighth tallest building in the world and the tallest in the Western Hemisphere at 110 stories or 1,450 feet high, it stands majestically across the Chicago skyline.

The reason visitors flock to the Willis building is undoubtably for its unique attraction ‘The Ledge’. Seemingly suspended mid air from the side of the 103rd floor, The Ledge is a series of observational decks or balconies made totally of glass which allow visitors to experience the sense of floating in the sky. The ultimate visitor experience, spectators can view up to 50 miles and four states with nothing but reinforced glass and 1,353 feet between them and the ground.

Of course, creating such a thrill-seeking attraction takes tall buildings architecture to a new level. There can be no room for error and 100% reliability and robust building dynamics is essential. To achieve this, architects Skidmore, Owings & Merrill and main contractor, MTH Industries sought out SERAPID’s technology knowing it was the very best in the world for such a project.

Five SERAPID LinearBeam actuators were ceiling mounted and discretely built into the system, so that each glass balcony could bear 5 tonnes of weight. Precise precisioning allows these explosion proof structures to retract 1.2 metres using a push-pull system into the building, for maintenance or when weather demands, leaving the glass building envelope flush with the building walls. 

Skyscrapers have always held an immense attraction but now thanks to SERAPID’s robust and reliable technology, demonstrating kinetic architecture at its very best, the 1.7 million visitors that flock to the Chicago Skydeck a year can experience a height thrill like never before.

Willis Tower Observation Deck - the "Skydeck" or the "Ledge"
Architects: Skidmore, Owings & Merrill
Main Contractor: MTH Industries