Council on Tall Buildings and Urban Habitat
John Hancock Center Tour

October 21st, 2009
Report written by Jeff Herzer, CTBUH Special Media Correspondent

. A nuts-and-bolts-only description of the John Hancock Center  is too sterile a treatment for a creation that embodies the identity and spirit of Chicago.  Besides, “Big John” and I have known each other for more than 40 years now, back before either one of us had reached full height.

I’ve taken out-of-town and out-of-country guests to the Hancock Observatory more times than I can count, generally early in the evening and right after dinner at one of the local pizza establishments. Like any working city dweller, the elegant side of the Hancock comes out at dusk. As we walk to the building up North Michigan Avenue, we are introduced to a big, brawny tough guy in a tuxedo with a white bow-tie of light. He treats to an evening that is more above the town than “on” it, with spectacular nighttime views of downtown and beyond.

From the Chestnut Street lobby on the first floor, we went down one level to the Concourse, home to much of the building’s 170,000-plus square feet of retail space.  From North Michigan Avenue, the concourse is accessed through a sunken plaza that  served as a skating rink when the building opened.  Today, it is lined with plants and fountains and called the “Garden Plaza”.

The John Hancock Center viewed from Chicago Avenue

We were told the Concourse, one level down from the sidewalk-level first floor, is also the lowest level in the building.  The John Hancock Center stands barely 400 meters from the shore of Lake Michigan.  You can imagine the pressure the weight of the building exerts on the water table underneath. Brian Keaty told a story from the early days of the building, when construction on the building’s loading dock required creating a break in the concrete floor. 

Construction workers accidentally punched through the protective membrane below the floor, resulting in a gusher of water that reached the ceiling.  The breach was finally repaired with concrete pours.

Floors 4 thru 12 are devoted to parking, with 710 parking spaces accessed via a spiral-ramp “parking drum” on the building’s east side.  This was not a tour stop, but I did park in the building while staying at my hotel across the street (price a competitive US$37.50 for 12-24 hours). Parking is abundant and the garage interior offers no clue of where you are except for sections of the external X-braces visible on the outer walls.  The value of a covered, climate-controlled car park in the building was especially apparent with the cold, rainy weather that persisted the entire week. 

The first floor lobby off the Chestnut Street entrance View of the bridge connecting the parking drum to the first parking level (fourth floor)

The next tour stop took us to levels 42/43, a double floor devoted to mechanical systems.  Mechanical floors are also located on 16/17 and 98/99.   A prominent feature on these floors are water pumping stations for the building’s air conditioning system.   As water circulates through the building, it carries away internal heat.  Warm water is pumped from the mechanical levels to six cooling towers on 98/99. Chilled water circulates back down. Six round  ducts with fans for each chiller can be seen in aerial photos of the roof. 

All of the pumps, pipes and heavy equipment we saw were hoisted by crane and installed during the building’s construction in the 1960s.  These systems are reaching the end of their service life and when replacements are installed, everything that is torn out or brought in must go through the building’s freight elevators, the same ones we all squeezed onto for the ride upstairs.

Part of the building’s water circulation system for climate control on level 42/43 Conference delegates with the Hancock’s chief engineer, Brian Keaty of Golub & Co. LLC

Again, the sights you see on this kind of tour are interesting not only for what they are  but where they are.  The fleeting glimpses of “where” can be enticing or just plain hair-raising. There are no windows on the mechanical floors but I did see my favorite sign of the tour on a door along one wall on 42: “WARNING – Risk of fall. Free air drop to ground on other side of door.”  This was an access door for window washers and Brian Keaty obliged our curiosity.  The view outside was as advertised.  I would have gladly peeked over the edge if there had been a rail front of me.  My business casual dress and desire not to hold up the tour kept me from crawling across the floor to stick my head and my camera out over the precipice.  We do know that, given the Hancock’s sloping façade, a “free air drop” would be interrupted by a rug burn or two against the face of the building before that last bounce to infinity.

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Brian Keaty, the Hancock’s chief engineer opens a ingress/egress door for window washer crews
The other side of the door: Water Tower Place across the street.

A similar door on another level, seen from the outside

The 44th floor is known for its legendary swimming pool (as of this writing, still the world’s highest above-ground pool) and its amenities for residents of the condominiums on floors 45-92.  The Skylobby on the eastern side is a grand entrance to this section of the building, with a beautiful view of Lake Michigan framed by the diagonals of the building’s “X” braces.  I had seen this space before only in magazine photos and documentary interviews.

Down the hall on the north side of the building is the “Potash Bros. Gourmet 44”, a 5200-square foot full-service grocery store that exclusively serves condo residents upstairs and office workers on floors below.   Prices here are not bad, considering the convenience the store offers.  The wine section, meat and produce looked especially good. So did the views outdoors from the rows canned goods and breakfast cereals.  This was a prime location to view the Palmolive Building, just across the street and to the north.  

A quintessential Hancock environ, the skylobby on the 44th floor

Potash Bros. on the 44th floor. A nicely stocked grocery store with a very nice view

The Signature Room restaurant occupies floors 95 and 96, the highest floors open to the public and the highest I had ever been in the building. For many years, I had wanted to get behind the iconic crown of lights around the top. This area, seldom seen by visitors, was the next stop.  The crown of lights consists of 552 eight-foot tall fluorescent light tubes that shine out from behind the glass of the 99th floor.  The light tubes are contained in pairs inside cabinets that open from the back like locker doors.  The rear walls of the cabinets are white to reflect and diffuse the light.   The color of the crown is periodically changed for various seasons and occasions.  Workers remove each of the fluorescent lights, slide them into colored plastic tubes and replace them in their fixtures. It takes a crew of two roughly 40 hours apiece to complete a changeover.  The fluorescent tubes will some day be replaced by LED fixtures that can be controlled from a computer in the building manager’s office.  

Close-up view of the Hancock’s signature “crown of lights” around the perimeter of the 99th floor

Brian Keaty, the Hancock’s chief engineer, holds a blue plastic sleeve used to color the building’s crown of lights

The final stop was the Hancock Observatory on the 94th floor, where we could take in the sights at our leisure.  I told the story of bringing my grandmother here shortly after the building opened in 1970 and how she stood with her back against an interior wall and refused to budge.  (This was a woman born in 1905 who emigrated for Italy and had witnessed the first moon landing only the year before. I could imagine what she would say about my looking up her birth date on the Internet in about ten seconds.)

It seems every supertall observatory nowadays has some unique feature to bring viewers closer to the outside: transparent glass floors or ledges are favorites in Toronto, Shanghai and across town at the nearby Willis (formerly Sears) Tower.  The Hancock’s variation on this theme is the “Skywalk”, an enclosed area with a concrete sidewalk floor, where windows have been replaced with screens.  This allows visitors to hear the sounds of the city and feel the wind and weather 94 floors up.   Other recent improvements including the addition of coffee/snack shops and table spaces along the windows have turned the Hancock Observatory into a place that encourages visitors to linger, look and enjoy.

Tour attendees and their hosts at the 94th floor John Hancock Observatory

As the CTBUH representative on this tour, it was my privilege to welcome our international visitors to Chicago and to my favorite building.  Though other buildings have grown up around it or surpassed it over four decades, “Big John” remains the most beloved building on the skyline, a perfect embodiment of Carl Sandburg’s image of a “City of the Big Shoulders”, but a city with a heart.

Attendees: Georges Binder, Buildings & Data sa; JiYoung Choi, Illinois Institute of Technology; Thomas Finnegan, First Communications; Guy Geva, Waxman Govrin Engineering; Jonathan Groswasser, Y. A. Yashar Architects Ltd.; Stephen Kennedy, SPS Floors; Jong-Ho Kim, Chang & Minwoo Structural Consultants; Taee Jin Kim, Chang & Minwoo Structural Consultants; Elias Layoun, Seguibat S.A.; Sang Yun Lee, Illinois Institute of Technology; Thomas Leslie, Iowa State University; Yvonne Martin, Otis Elevator Company; Anthony McGuire, McGuire Engineers; Yoav Michael, Y. A. Yashar Architects Ltd.; Annett Mickel, Hafen City Universitat Hamburg; Steve Mikkelsen, Lerch Bates Inc.; Shay Miller, Shay Miller Ltd.; Jongpil Park, Illinois Institute of Technology; Giles Pendleton, SPS Floors; Anuj Puri, Santiago Calatrava New York/Festina Lente LLP; Annett Snider, Medill News Service; Won Il Sunu, Dong Yang Structural Engineers Co. Ltd.; Guy Turner, SPS Floors; Thomas von Borstel, Hamburg University of Technology; Paul Wisniewski, Dow Corning Corporation; Dan Woosley, Evan Terry Associates, PC; Congzhen Xiao, China Academy of Building Research; Stephan Zech, Hafen City Universitat Hamburg.

Picture Gallery
Click an image below to enlarge.
. . . .
Overall view

First Floor Lobby of the Chestnut Street entrance Parking drum

Parking ramp meets building at fourth floor
Parking level

Water system on floor 42/43

Mechanical level 42/43

Mechanical level 42/43

Sign on 42nd Floor

Opening window washing crew access door
View out winow washing access door Similar door viewed from exterior
44th floor skylobby

44th floor skylobby

44th floor grocery store
44th floor grocery store

Palmolive Building viewed from 44th floor
Exterior view of "crown of lights"

Interior view of crown from 98th floor

Accessing light cabinet on 99th floor

Plastic sleeve used to color the "crown of lights"
94th floor observatory

94th floor observatory

94th floor open air observation area Tour attendees in the 94th floor observatory