CHICAGO – The Museum of Science and Industry (MSI) recently opened its Science Storms exhibit to teach visitors about natural phenomena like tornadoes and avalanches. PRG worked with MSI officials and the museum's general contractor, Norcon, Inc. For the tornado and avalanche features, PRG and Norcon worked with MSI senior project manager Christopher Wilson to engineer, fabricate and install the designs of environmental artist Ned Kahn and architect Jack Pascarosa, AIA, of New York-based Evidence Design.
The tornado display is 60 feet high, 27 feet in diameter and weighs 75,000 pounds – the largest effect in the hall. It creates a 40-foot vortex of air and vapor that rises continuously from the floor and is able to be controlled by guests through a series of dampers that shape the air column. From the balcony level, guests can activate lasers to cut through and reveal the airflow patterns of the illuminated vortex.
PRG constructed the interactive tornado to meet building codes and artistic stipulations. One of the biggest challenges for PRG was the sheer size of the structure. "We couldn't fully test it anywhere except at MSI because it was so big and so complicated," noted Wilson. "PRG had to get it fabricated and installed as early as possible so if there were any problems we would have time to correct them. They had to think carefully about how they were going to get the pieces into the building."
PRG also engineered and fabricated the avalanche disk, in which guests trigger a 20-foot avalanche to reveal how granular materials behave and better understand how avalanches form. The avalanche takes place when the giant disk is set at a 23° angle to horizontal. When rotated by guests, they see how granular materials can act like a liquid as well as a solid, a key concept to understanding how avalanches behave.
"PRG's approach to the avalanche was a game changer for us," said Wilson. "We were considering building the avalanche disk as a single piece. The concept of building it in small pieces, bringing it into the hall and assembling it, and then pouring a special urethane compound to make the final disk surface was all PRG's idea, and it was brilliant. It saved us a lot of time, a lot of money and it also allowed us to do a full test in their shop."
While the avalanche disk may not be as imposing as the tornado, at 16,500 pounds, it is no lightweight, and at MSI, building loads were an important consideration.
"It is an old building," Wilson noted, "and PRG had to-and did-take very seriously how they were imposing physical loads on the building." PRG could not exceed a maximum load of 250 pounds per square foot (PSF) for floor loading. Since the avalanche has dynamic motion, they needed to subtract for the live load, meaning PRG really only had 150 PSF.
Both the tornado and the avalanche displays were fabricated at PRG's facility in New Windsor, N.Y.
For more information, please visit www.prg.com.
