Naperville Millennium Carillon — Naperville, Ill.

Development Team
DESIGN: Charles Vincent George Design Group Inc., Naperville, Ill.
CONSTRUCTION MANAGER: Schramm Construction, Geneva, Ill.
MEP ENGINEER: W-T Engineering, Schaumburg, Ill.
CIVIL ENGINEER: Roake & Associates, Naperville, Ill.
STRUCTURAL ENGINEER: McCluskey Engineering Corp., Naperville, Ill.

The residents of Naperville, Ill., wanted to present the city with a gift that would reflect the past while evoking the future, so a carillon was selected.

The design team faced the challenge of supporting 72 brass bells, an instrument-playing cabin and an observation deck 162 ft. above ground.

Frame Has Three Structural Elements

The structural frame is made up of three elements.

An onlooker notices that there is no true skeleton to which the skin of the building is attached. The structural steel frame, the eight compression rings and the post-tensioned precast panels are tied to each other in alternating connection sequences.

As a result, a "tri-union" of structural elements supports the building.

The bells are mounted in a fixed, stationary position to a steel beam in the belfry because the clappers strike them. The beams are joined together to create a frame that supports the bells, playing cabin, belfry stairs and observation deck above the bells.

The facility sits on two large girders below the tower midpoint, which transfers loads to the perimeter walls. The precast walls then carry the weight of the tower into concrete foundations, which rest on bedrock.

The precast concrete walls, the structural steel frame, the steel compression rings and the bell structure were integrated so that portions of the tower would be fully accessible to all persons. In addition, the belfry and observation decks were designed to be accessible by stairs.

Another challenge was funding the project. Millions of dollars were raised through presentations and the creation of detailed CAD models.

The jury commented, "As a commercial building, this is a very interesting, very nicely done building. Three structural systems are coming together in a very impressive way."

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