The Mackinac Bridge

by Alisha Muma

David B. Steinman, a structural architect of the Mackinac bridge. http://www.mackinacbridge.org/history/historical-construction-album

The Mackinac bridge, designed by American structural engineer David B. Steinman, has been part of Michigan history for the past 59 year.  When it was built, it was the longest suspension bridge in the world.  One of the riskiest endeavors that changed Michigan forever is the five-mile long suspension bridge that spans the straits of Mackinac to the upper and lower peninsulas of Michigan. This landmark was completed December 1, 1957, with the purpose of creating year round access for traders and travelers. As exploration of the state’s minerals and timber resources increased, the area between the straits became an important transport route in the 19th century.  In the 20th century, as automobile traffic proliferated, the newly established state highway department that also suggested the need for a Straits bridge.

An American structural engineer named David B. Steinman designed many notable bridges as well as the Mackinac Bridge. Not only was he a phenomenal engineer he was also a published author. He planned on pursuing the design of the Brooklyn Bridge while he was growing up in New York City. His devoted inspiration for his future passion for bridges led him to earn his bachelor’s degree from City College of New York in 1906, his master’s and doctorate degrees from Columbia University in 1909 and 1911. Steinman sought out employment as an assistant engineer for the new central Railroad. In 1957, he received the Franklin institute Louis E medal award. Throughout Steinman’s career, he built bridges in the United States, Thailand, England, Portugal, Italy, Brazil, Haiti, Puerto Rico, Canada, Korea, Iraq, and Pakistan, becoming one of the most significant bridge designers of his time.

November 1st when G Mennen Williams first crossed the Mackinac Bridge. Photo Credit: ©Getty Images

On November 1, 1957, the bridge was ready for traffic.  However, fearing the inclement autumn weather typical at the Straits, officials decided that while the official opening of the bridge would go ahead on that date, a formal dedication ceremony would follow in June of the next year. On the first day of November the weather was exceptionally sunny and decent. G Mennen Williams paid the first $3.25 toll fee (editors note:  about $28 in 2016 dollars) and was the first one to cross the Mackinac Bridge, with his wife Mrs. Williams who was driving the car across because the he forgot his drivers license. On this opening day G Mennen Williams predicted that the bridge would add $1 million annually to the state’s tourist trade, and to pay back the cost of the bridge. Unfortunately, due to the fact that the weather in late June was so cold and wet, a lot of the events had to be shortened or cancelled.

Roadway truss sections are suspended from the North and South Mackinac Bridge towers. Photo Source: http://www.mightymac.org/buildingmackinacbridge3.htm
Mackinac Bridge towers with two Great Lakes Freighters. Photo Source: http://www.mightymac.org/buildingmackinacbridge3.htm

After more than 70 years of different plans for bridging the Straits of Mackinac, the ground breaking for the construction of the Bridge took place in St. Ignace on November 7, and Mackinac City on Nov 8, 1954. The construction of the bridge started with the pillars.  Caissons were constructed and floated into position then sunk to provide the footings for the two immense towers, which would suspend the center span of the bridge. Once the caissons were in place, derricks were added, which raised materials to erect the towers as their built heights continued to rise. The Bridge had to be constructed tall because of the freighters and large ships that travel underneath, and in order to avoid waves, as high as six feet during certain times of the year, from splashing over any road deck. The roadway truss section was assembled in sections and floated in position to be raised into place.

The construction took 48 months, 3,500 workers, 895,000 blue prints and structural drawings, 71,300 tons of structural steel, 931,000 tons of concrete, 42 miles of cable wire, 48,517,000 steel rivets, 1,016,600 steel bolts, and 99,800,000 dollars. There were 350 engineers and another 7,500 men and woman who worked at quarries, shops, mills and other locations.