Antennas on Chicago skyscrapers...

[SearsTower1973]

Hello everyone. This is my first post here, so I apologize if it belongs elsewhere...

1. As you probably already know, the big TV antennas were added to the Sears Tower in 1982. Prior to that point, the building was topped with two stubby, little antennas. Were these original antennas actually part of the design, or was the original design without them?

2. My father seems to recall that the John Hancock Center was also originally built with stubby antennas. However, I have never found a picture of it in that state. Are his recollections accurate?

3. Why are the John Hancock antennas no longer striped? When did they start going with solid white?

[harryc]

A shot of the John Hancock under construction is in the background of part of this movie, the base for an antenna is under way.

Chicago 10 - 2007

http://www.imdb.com/title/tt0905979/?ref_=fn_tt_tt_30

[SearsTower1973]

Thank you for the tip, I'll have to check that one out.

[ChiSoxRox]

Not sure if they were in the design from the start, but the stubby antennae were part of construction.

[DrNest]

Awesome old photographs. I love seeing both Sears and Aon under construction. Amazing to see how much they tower over what was there at the time.

[jsr]

Sears Tower Says It's Tallest --just Because
May 04, 1996|By Blair Kamin, Tribune Architecture Critic.

The proclamation of a council is very important in some minds," Wagener said, "but common sense would suggest that 1,518 feet is taller than 1,483 feet."

There is no disagreement about the 1,483 feet. That's the height of the Petronas Towers. But the real question is whether the Sears Tower should be measured at the 1,518 feet that the Buck Co. is now touting or the 1,450 feet previously claimed.

When the Petronas Towers were under construction, the Buck Co. and Sears' designers, Skidmore, Owings & Merrill of Chicago, began insisting that the base of Sears' broadcast antennas should count. That would have brought the tower's height to a still-tallest 1,518 feet.

[jsr]

John Hancock Center nearing completion showing the antenna mounts.
From my personal archives. Original image source unknown.


An original model of the John Hancock Center. Note the stubby mounts. This would be a "later" model because the structural cross bracing shown is in the final design configuration.
From my personal archives. Original image source unknown.

I believe the JHC and Sears Tower both had structural tubes integrated into their original design. These later served as the mounting bases for the antennas. Large antennas were planned from the start. It's the point SOM tried to argue in defending the Sears Tower's tallest title from the Petronas Towers in the article I posted above. The antennas can be dismantled and removed, but the mounting tubes cannot. They are a permanent part of the upper structure. Obviously The Council on Tall Buildings didn't buy it.


Sear Tower after completion showing some communication equipment affixed to the tubes.
From my personal archives. Original image source unknown.