Ask Geoffrey: 4/30

A Visit to the Hancock’s Crown of Lights

Geoffrey Baer visits the John Hancock’s Crown of Lights to find out how the Hancock Building makes its seasonal lighting wardrobe changes in this week’s edition of Ask Geoffrey. 

How long does it take to change the lights at the top of the John Hancock Building? It seems to take a several days. What is involved in changing the lights from one color to another? 
Trish Holland, West Loop

This is a great question! One of the Hancock Building’s most recognizable features is what’s called the Crown of Lights at its very top. A Chicago Tribune article from 1970, the year John Hancock was completed, noted that the lights were intended to “enhance the night time appearance of the 1107-foot high tower and to provide a point of identification for aircraft.”

As for recent years, the lights have been used to celebrate holidays, seasons, support charities and of course, wear the colors of Chicago sports teams. 

Bill Casey, Chief Engineer at the Hancock brought us up to see his crew change the Hancock Building’s wardrobe for spring. Because it’s April, they’re switching to blue to support Autism Awareness month.

The Crown of Lights comprises 552 eight-foot-tall fluorescent light tubes adorning the inside of the windows all the way around the 99th floor. The tubes are paired in cabinets that open from the inside. 

The coloring process is fairly straightforward – engineers climb to a 99th floor catwalk, remove the light tubes, slip them inside colored plastic sleeves, and replace them. But to replace all 552 tubes takes some time – about 40 hours for two building engineers.

The plan for the future is to replace the tubes with LED fixtures that can be controlled remotely via computer, but for now, it’s handled the analog way.