[wrab]

Chicago Tribune
Cityscapes
Blair Kamin
August 20, 2009

What's 'that thing' atop the Aon Center? Three guesses: A) an antenna; B) a Homeland Security device; C) one of Mayor Daley's cameras

Never as architecturally distinguished as the former Sears Tower and the John Hancock Center, the Aon Center at least presented a vision of clean vertical lines, rising with aloof calm beside Grant Park.

But now, as sharp-eyed skyline watchers have noticed, a nasty little carbuncle has appeared on the roof of the 1,136-foot tower. About 85 feet tall, it resembles a cylinder stuck atop a flagpole. And people are wondering what it is.

"Do you know what it is used for?" e-mailed Tribune reader Matt Bergstrom of Chicago. "It does look strange up there and kind of ruins the boxy shape I'd resigned myself to."

Added reader Rich Johnson from Oak Park: "Do you know what that thing is that was added onto the Aon Building? Is it an antenna, a weather reading device, a Homeland Security device, or another camera courtesy of Mayor Daley? Whatever it is, it doesn't look good."

It's a communications antenna. Erected in July, the antenna has three transmitters, one of which is leased to Chicago radio station WDRV, according to Brooke Houghton, a spokeswoman for Jones Lang LaSalle, the tower's property manager.


"It brings additional revenue to the building," Houghton said. "We don't think it takes away from the iconic stature of the building or the aesthetics of the skyline."

She dismissed the idea that the Aon Center's owners installed the antenna to make up for the departure of major tenant and Kirkland & Ellis, a Chicago-based law firm, to a new riverfront skyscraper at 300 N. LaSalle St. The Aon Center is 92 percent leased, Houghton said, and recently signed tenants including Microsoft.

Whatever one thinks of the antenna, it apparently has taken one distinction away from the Aon Center. The Emporis building database (emporis.com) describes Aon as "the tallest building in the world without any major antennae, spires, or finials at the top."

Perhaps a rewrite is in order.


http://featuresblogs.chicagotribune....09/08/aon.html