Mackinaw City in Cheboygan County, Michigan — The American Midwest (Great Lakes)
Building Mighty Mac
The Mackinac Bridge is constructed of three segments – at each end is a post-supported truss bridge and in the center is a suspension bridge segment. This bridge was the longest suspension bridge in the world for decades after its construction. Today most of the longest are in China.
Mighty Mac is an engineering masterpiece designed to withstand crushing ice and winds up to 120 mph. It is also a construction triumph, built for $99.8 million between 1954 and 1957 – on time and within budget. The 4.5 million vehicles which safely cross the bridge each year pay tribute to its dedicated builders, the crews that overcame the harsh winters, and the winds of the Straits.
How the suspension part of the bridge works
Truss bridges, supported by posts, are far cheaper to build than suspension bridges. But the water in the Straits of Mackinac gets quite deep, up to 300 feet, and it was impractical to put posts that deep.
The engineers put an anchor block, or main supporting post, (shown in red below) at each edge of the deep water. Cables, propped up by two towers, were stretched between these two blocks across the chasm. The roadbed dangles from the cables. All of the weight of the roadbed, vehicles, and cables is supported by the pull of the cables on the anchor blocks (the
The bridge designers determined the required height of the towers, how tall the towers should be, by calculating the bridge span and the desired height of the roadbed above the water. The roadbed is 149 feet minimum above the water to allow for the passage of freighters and tall ships.
Location. 45° 47.232′ N, 84° 43.664′ W. Marker is in Mackinaw City, Michigan, in Cheboygan County. Marker can be reached from North Huron Street. Touch for map. Marker is located in Cheyboygan Park, on the shore of Lake Huron, along the Mackinaw City Historical Pathway, looking north toward the bridge. Marker is in this post office area: Cheboygan MI 49721, United States of America.
Other nearby markers. At least 8 other markers are within walking distance of this marker. Graveyard of the Deep (here, next to this marker); Old Mackinac Point Lighthouse (about 500 feet away, measured in a direct line); Mackinac Bridge (approx. ¼ mile away); Michigan's First Jewish Settler (approx. ¼ mile away); Island-Hopping the Straits (approx. 0.3 miles away); Fort Michilimackinac (approx. 0.3 miles away); The Dixie Highway (approx. 0.4 miles away); Historic Mackinaw City (approx. 0.4 miles away). Touch for a list and map of all markers in Mackinaw City.
More about this marker.
Related markers. Click here for a list of markers that are related to this marker.
Also see . . .
1. Building the Mackinac Bridge.
After more than 70 years of dreams, with many different plans for bridging the Straits of Mackinac, ground breaking to build the Mackinac Bridge took place in St. Ignace on May 7, 1954 and Mackinaw City on May 8. The photos on this page are from slides taken by my father, Lester Stokes, who lived less than a block from the foot of the Mackinac Bridge in Mackinaw City, and worked on the State Dock which served the automobile ferries until November 1, 1957, when the Mackinac Bridge opened and ferry service was discontinued. (Submitted on August 17, 2017, by Cosmos Mariner of Cape Canaveral, Florida.)
2. History of the Bridge.
The dedication of the Brooklyn Bridge in 1883 gave Mackinac Bridge backers encouragement. A St. Ignace store owner in 1884 reprinted an artist’s conception of the famous New York structure in his advertising and captioned it “Proposed bridge across the Straits of Mackinac.” (Submitted on August 17, 2017, by Cosmos Mariner of Cape Canaveral, Florida.)
The Mackinac Bridge is five miles long and crosses the Straits of Mackinac, connecting the upper and lower peninsulas of Michigan. It is the longest suspension bridge in North America. The building of (Submitted on August 17, 2017, by Cosmos Mariner of Cape Canaveral, Florida.)
Categories. • Bridges & Viaducts • Man-Made Features • Roads & Vehicles •
Credits. This page was last revised on August 18, 2017. This page originally submitted on August 17, 2017, by Cosmos Mariner of Cape Canaveral, Florida. This page has been viewed 40 times since then and 9 times this year. Photos: 1, 2, 3, 4, 5. submitted on August 17, 2017, by Cosmos Mariner of Cape Canaveral, Florida. • Bill Pfingsten was the editor who published this page.