"On This Day" In Engineering History

On this day in engineering history, the first Blue Water Bridge was opened to traffic between Port Huron, Michigan and Port Edward, Ontario. The international crossing spans the St. Clair River at the southern end of Lake Huron, and is jointly owned by the United States and Canada. Today, the 6,535-ft. long cantilever truss is one of two bridges which connect U.S. Interstates 69 and 94 with Canada's Highway 402. Now one of the busiest transportation arteries in North America, the original Blue Water Bridge carries three lanes of west-bound traffic from Ontario and the Eastern seaboard to the American Midwest and points beyond. A newer bridge that opened in 1997 carries three lanes of eastbound traffic, and is part of a large complex of toll booths and inspection stations.

The Politics of Planning

Planning the first Blue Water Bridge posed numerous political and financial hurdles. During the 1920s, a group of Port Huron investors floated plans for a bridge that would enable their city to attract business and better compete with Detroit, a bustling industrial hub whose Ambassador Bridge linked the Motor City to Windsor, Ontario. At first, proponents of the St. Clair River Project planned to connect the downtown business districts of Sarnia, Canada with Port Huron, Michigan. When plans for a bridge that would span Sarnia Bay proved too expensive, however, a local businessman named Maynard D. Smith suggested a shorter structure that would link the small Canadian community of Port Edward to Fort Gratiot, a Michigan village which Port Huron had annexed in 1893. Although downtown business owners sought to stall Smith's efforts, American and Canadian officials agreed to support the proposed crossing.

Building the Blue Water Bridge

In 1928, Maynard D. Smith hired a Pennsylvania-based company named Modjeski and Masters to what would become the Blue Water Bridge. Ralph Modjeski, a Polish-born engineer who would become known as "America's greatest bridge builder", served as lead engineer for the project. In developing a design, Modjeski faced obstacles posed by the U.S. Army Corps of Engineers, which sought to ensure that the St. Clair River remain navigable for military and commercial vessels. Bridge construction could not interfere with navigation, bridge builders could not use floating platforms, and the completed span was required to clear the water by 150 ft. Originally, Modjeski proposed a mammoth suspension-style bridge with tall towers and massive cable anchorages; however, because of the 150-ft. vertical clearance requirement for shipping, he opted instead for a cantilevered through-truss design.

Resources:

http://en.wikipedia.org/wiki/Blue_Water_Bridge

http://www.michigan.gov/mdot/0,1607,7-151-9618_11070-22062--,00.html

http://www.michigan.gov/documents/constrhistory_16062_7.pdf

http://en.wikipedia.org/wiki/Ralph_Modjeski