Located on Lake Michigan at the mouth of the Chicago River, The Chicago Harbor Lock serves at the gateway to one of the nation's busiest commercial and recreational waterways, and is one of the only lock systems to rely on gravity rather than pumps to shift water levels. With the entire system—constructed in 1938—aging and in need of replacement, the US Army Corps of Engineers, which owns and operates the Chicago Harbor Locks, commissioned CTE AECOM to design a new control house as the first phase of a complete renovation of the locks. The primary issue was the need for a control operations facility with an unobstructed view of the harbor and locks. Secondary was the need for office space and maintenance and storage facilities.

The new, $5.5 million control operation facility opened in October 2007. CTE AECOM's design was driven by the size of the site, which is only 40' wide, and inipired by the nautical environment. The Chicago Harbor Lock is a historic site but the structures within it have no consistency of architecture, so the architect was not required to design a structure that would blend with the existing buildings. The control operation facility occupies the entire second floor and glass tower, which were designed to provide a 270-degree view of the harbor. The tower is tilted and the desks are glass so the engineers can look down through them to the lock below. Schaefges Brothers Inc. of Wheeling, IL served as the general contractor for the project.

Shaffner Heaney Associates of South Bend, IN engineered and fabricated 9,000 square feet of Reynobond® Zinc Composite Material, 4 mm, FR Core, skin thickness of 0.7 mm, and skin alloy of RHEINZINK® Titanium Zinc with a pre-weathered finish, for the southern and eastern elevations of the lower building and on all elevations and soffit of the tower. "It was a complex installation," said Craig Heaney of Shaffner Heaney. "We were faced with the difficult challenge of mimicking the complex geometry of a ship. Enhancing the complexity was that the only wall structure provided was a concrete shear wall. All of the panels and glass walls are supported on hundreds of unique framing members much like ribs on a ship." BBC of Bensonville, IL attached the panels to the shear wall to create the geometry of the "ship's" bow, sides and stern.

Reynobond® ZCM panels were also used on interior column enclosures and Reynobond® Brushed Aluminum Composite Material was also used to fabricate interior window stools.

Representatives from Alcoa Architectural Products and Shaffner Heaney were involved early in the project, working with the architect regarding the material specifications and design. CTE AECOM ultimately specified Reynobond® ZCM for the project for several aesthetic and practical reasons. "Zinc is one of the most environmentally friendly materials available," said Melita Ristovska of CTE AECOM. "It also becomes more beautiful as it ages. In this case, I believe the patina will develop a bluish color reflecting the natural environment of the locks, and that as it ages and the patina deepens it will meld beautifully with the historic structures on the site." Reynobond® ZCM gives the façade a flat, contemporary look that will stay smooth. Ristovska said that the durability and longevity provided by the Reynobond® ZCM material made the client more comfortable with using zinc.

Photos 1-4 by Bill Gnech/The Apple Group. Photo 5 courtesy of Shaffner Heaney.