Chicago and 150 North Riverside

I first read about 150 North Riverside Chicago a couple years ago in Civil Engineering, the magazine for American Society of Civil Engineers (ASCE). As an Ironworker by trade, I am always interested in unique structures that magnify engineering achievements. It’s why I enjoy walking through large cities: I get to take in some of the most amazing architecture and engineering feats.

I was recently in Chicago so I couldn’t pass up the opportunity to explore the city and see this unique building. Plus, I’m not a professional photographer but I do like to take pictures – to use for interest here as well as try and capture some of the best angles for recollection. Armed with my I phone (the quality of cell phone cameras has increased exponentially) and time to peruse the city, away we went.

Downtown on the Riverfront

The Chicago River meanders through downtown with skyscrapers all along it

Chicago is interesting to me for numerous reasons – but the one I found especially intriguing is how it has the Chicago river meandering through downtown. It provides a nice feature to work with, increases the chances for river walks and parks, and, of course, there are numerous bridges.

I’ve been to New York a few times, Boston, Philadelphia, Charlotte, Atlanta – numerous cities that have sprawling skyscrapers, mass transportation, and lots to see. Chicago, at least to me, is different. First, it’s in the Mid-West – an area I frequent regularly but I have never really had the chance to explore. Second, as stated above, it’s charming how the Chicago river flows through portions of downtown. Third, they have some unique architectural interests to see. The bean. The numerous parks scattered throughout the city as opposed to New York’s Central Park. The elevated mass transit system. The view of Lake Michigan.

Not surprised at the crowds; the bean is a major tourist destination in Chicago

Like I said, Chicago is unique.

The Windy City

Another branch of the Chicago river chock full of architecture

This city lives up to it’s name: It. Was. Windy. Not that I mind it; it’s just an observation at the onset. What’s more, I was surprised at the level of greenery in Chicago. While it may be an unfair comparison, I felt like Chicago was much cleaner than New York. Plus, there seemed to be a concerted effort to provide parks, river walks, and outdoor scenery to enhance the lifestyle. This was a welcome site as far as I’m concerned.

A Blend of the Old and New

The elevated transportation system bridges between a modern skyscraper and an old brick building

More charming was the interesting blend of the old and the new – and it was just about everywhere you looked. You would see a smaller, older brick building flanked by skyscrapers. Old riveted bridges crossed over while modern walkways meandered the river. Elevated mass transit laid out along roads with cars underneath. Chicago was, to me anyway, a very interesting city littered with the old and the new. It’s always nice to see this as opposed to the destruction of the old at the expense of the new. Kudos all around.

The effort to have greenery wherever mixed well with the old & new theme

150 North Riverside

Chicago has intentionality when it comes to river walks and greenery

The main reason I wanted to actually walk through the city, though, was to visit 150 North Riverside and marvel up close. This building represents a willingness to overcome obstacles and create something not only architecturally pleasing but extremely functional.

The lot, while a total size of 2 acres, is greatly reduced when you take into consideration city easement, Chicago’s riverwalk requirements, and the active rail line beside it. Designers were left with a workable lot size that was 39 feet wide. Given that most buildings are larger at the bottom and reduce their size at the top, the lot was seen as unbuildable for almost eight decades.

Architects always seeking to push boundaries – and relying on modern engineering – created an interesting opportunity to design a marvel. And design a marvel they did.

Getting a chance to see this marvel was the main reason for a visit to the city

While I could only take pictures of the finished product, there are scores of pictures online of the building process and one of the most notable difficulties was the active rail line beside the building. Chicago may not be the known as the city that never sleeps but the rail line could not be slowed at all, which presented a challenge: How to build on a site next to an active rail line.

ENR has a great article about the constraints, including the active rail line – and Amtrak’s easement rights. The solution – which was ingenious to me – was to build a park over the active tracks, essentially encapsulating those active tracks in a tunnel of sorts. Above where the rail lines are is now a nice park, full of greenery. In effect, they isolated the rail lines, constructed a park full of shrubs, trees, and pathways – and downstairs next to the rail lines (separated by a 4 foot thick concrete wall) have what can be called an “amenity platform” – with a conference center, restaurant, and fitness center.

Hard to imagine that under this (you can see the lobby in the background) is an active rail line

Color me impressed.

How They Did It

You can see how the building extends out over what’s known underneath as the amenities platform

The building is what is known as “core supported;” The core of the building is at the heart of it all. The whole foot print has caisons supporting it – and they sunk them into the bedrock 5 feet deep. Going to bedrock makes sense – we don’t want a repeat of the Millennium Tower in San Francisco. (Millennium Tower is leaning) The concrete core meets the footprint constraints and floors 8 to 52 have full leases. The glass lobby, which terminates above the rail lines now covered, is rather large and luxurious.

The transition from the core to the full width of the building is due to the massive W36 x 925 that taper out. I couldn’t see them but the pictures online are rather impressive. The glass work, including the lobby, are made all the more impressive when you consider that beneath them are an active rail line that is now enclosed.

Noteworthy also is how they deal with wind loads. Normal buildings have a ratio of 12:1 – that is, the building’s height related to it’s width at the bottom. 150 North Riverside has a ratio of 20:1 and that presents challenges with wind loads. One of the more unique solutions to this problem was to use tanks filled with water at the top; some 200,000 gallons of water that create a tuned damper. What happens is that when the wind blows against the building (and it does), and the building sways (and it will), the water in those tanks due to gravity wants to stay in one place – and it pushes against the wind, helping to stabilize the building. The inertia the water brings is important since the footprint is much smaller than conventional skyscrapers. This design feature also has another purpose: it is also water reserves for fire protection if needed.

An Engineering Marvel

150 North Riverside really is something to marvel at

This building is impressive, from it’s concrete core, to it’s tapered feature. To conceive a building that is 39 feet wide at the bottom to a max width of 120 feet, encapsulating an active rail line, and create a park above it is nothing short of an engineering marvel. What’s more, and this is something I look forward to seeing worked out, is the number of unique buildings that will be designed going forward – built on previous skill, engineering, and function. There are other buildings with somewhat similar features – notably is the Rainier Tower in Seattle – and I believe there will be more to come. It’s one thing to design buildings for architectural interest – it’s another thing altogether if it’s done due to lot constraints. Those lot constraints should provide us with some great engineering and designs in the coming years.

It’s projects like this that make me glad to be an Ironworker – to see the meld of great architecture, engineering, and skilled talent to make it all come together.

Here’s to a bright AEC future!