Grosse Ile Bridge
Structural Consulting Services
Grosse Ile, Michigan

Built in 1914, the Grosse Ile Bridge is one of only two bridges connecting the island of Grosse Ile with southeastern Michigan. The bridge consists of four 180 foot long fixed bridge sections and a 305 foot center section. The center section rotates 90 degrees, allowing ocean going vessels passage through the shipping channel. Ruby+Associates has provided structural engineering services for the bridge for the past two decades.

Challenges / Solutions:

In 1992, a freighter struck the bridge, destroying one of the fixed bridge sections. Ruby prepared construction documents for the replacement span, which was built using modern methods and materials while replicating the look of the original structure. In 1994, Ruby designed the award winning swing span mechanism replacement. The new mechanism replaced the aged original mechanism using present day technology. The project was designed to allow continual use of the bridge by vehicular traffic while the replacement took place. Recently, Ruby designed the replacement of the existing timber and asphalt bridge deck with a new steel bridge deck and concrete road surface. These and many other Ruby designed improvement projects will allow the bridge to serve the residents of Grosse Ile for many years to come.