The Mackinac Bridge - Background Reading
The Mackinac Bridge
By David J. Olson
The story of the Mackinac Bridge is more than just cars and concrete or men and machines. It is a tale with heroes and villains filled with suspense, drama, and disappointment. It is also a magnificent achievement. With its official opening on November 1, 1957, by Governor G. Mennen Williams, one era was ended and another begun. As one prosaic representative noted, "The North and South of the state have long been engaged; they now have a wedding ring!"
This marriage was long awaited. For, though scenic, the water which geographically separates the Upper and Lower Peninsulas has also caused economic, political, and cultural divisions as well. Thus, because of necessity, interest soon developed for bridging the Straits. As early as 1884, proponents of construction like the editor of the Grand Traverse Herald plumped for such a structure. Even so noteworthy a person as Commodore Cornelius Vanderbilt called for action. Standing before a board of directors meeting at the Grand Hotel, he summed up his feelings, declaring that "what we need is a bridge across the Straits."
Though needed, the bridge was not built in the nineteenth century. Still, interest was not extinguished. It lingered, waiting to be rekindled. And, rekindled it was. Buoyed by automobile production in the 1920s, advocates again pushed for a Straits bridge. It was foolish, they argued, that such modern means of transportation like the automobile depended on outdated ferry service.
Several ideas were put forward. One, promoted by Horatio "Good Roads" Earle, Michigan's first state highway commissioner, called for a floating tunnel. Another, urged by Charles Evan Fowler, called for a series of causeways and bridges beginning at a point near Cheboygan, across to Bois Blanc Island to Round Island, over the west tip of Mackinac Island, and then across the channel to St. Ignace.
Highly imaginative and somewhat far-fetched, ideas like these were based on the prevailing assumption that the direct course from Mackinaw City to St. Ignace was unsuited for bridge construction. The direct route, as engineers and skeptics alike believed, was impossible to build a bridge over. Current theory maintained that the area rock could not support the structure's weight, and even if it could, the elements would destroy anything that could be erected.
In the face of these arguments, proponents of a bridge stood defenseless. Though the State Highway Department funded and published a report in 1928 stating that a bridge directly across the Straits would cost $30,000,000, no further action was taken.
Thus the 1920s faded into the 1930s with little progress toward a Straits bridge. The passing of time brought with it renewed hope, however. For in the 1930s the Great Depression occurred, and with it came the possibility of federal public works funds. Enamored with the possibility of federal aid, the Michigan Legislature created a Mackinac Straits Bridge Authority in 1934. Organized to investigate the possibility of building a bridge, to issue bonds, to build a bridge, and to operate it, they presented two plans to federal authorities. Both failed. The first plan, a revision of the Fowler island hopping scheme, was presented to the Public Works Administration in 1935. It was rejected. The second, covering a direct route, was sent to the Works Progress Administration in September of 1936. It, too, was rejected.
Disappointed but undaunted, the Bridge Authority pushed forward. They contracted with the long-span bridge engineering firm of Modjeski and Masters in 1937. This contract called for the Authority to furnish relevant data for a route from Mackinaw City to St. Ignace, and for the engineering firm to provide a construction report based on that information. Once soundings and borings were taken, traffic data were obtained, and geological studies were done, the information was turned over to Modjeski and Masters.
The report which resulted from this study did not disappoint bridge advocates. Instead, it judged that construction was possible, probably at a cost of around $24,340,000. In addition, it also called for the building of a causeway from St. Ignace 4,200 feet south into shallow water.
To help implement the plan, the Highway Department, acting for the Bridge Authority, contracted for a causeway, which was completed in 1941. With this done, it seemed as if the bridge might be built. But, just when construction seemed possible, World War II broke out, putting an end to work. Worse yet, with enthusiasm fading, the Legislature abolished the Bridge Authority in 1947. Soon afterward funds were appropriated to construct an ice-breaker ferry capable of carrying 150 vehicles. It was expected that this measure would take care of the foreseeable demand for Straits crossing service.
Though all seemed lost, proponents of a Straits of Mackinac Bridge did not give up. Instead they formed an InterPeninsula Communication Council to drum up public opinion in support of the bridge and to resurrect the Bridge Authority. Eventually they were successful, for in 1950, the Authority was re-formed with former United States Senator Prentiss M. Brown at its head.
Born and raised in St. Ignace, Prentiss M. Brown had long recognized the political, cultural, and economic difficulties spawned by the inadequate transportation across the Straits. He had fought for the bridge during his Washington tenure, personally appealing to President Franklin D. Roosevelt. So when the opportunity presented itself, Brown was the natural choice to be chairman of the newly reconstituted Bridge Authority in 1950. It proved to be a wise choice.
In the beginning, the mandate given the Mackinac Bridge Authority was thin. Possessed with only the power to study the feasibility of construction, they had no authority to finance or construct. Despite these limitations, the Bridge Authority remained undaunted. To answer the age old question of whether a bridge could withstand the area's natural elements they called upon three leading experts on wide-span bridges. By January of 1951, the experts had delivered a report which said that not only could a bridge be built but that it could be placed along the direct north/south route, utilizing the 1941 causeway.
Armed with these favorable reports, the Bridge Authority returned to the legislature asking for the power to finance and construct a bridge across the Straits. Though convinced of their proposal's value, the Authority did not win quick approval. The legislative battle lasted for several months during early 1952, with antagonists lining up on either side of the issue. Those who opposed the bridge cited several reasons. For one, they maintained, this structure was too costly and could not possibly be justified for such a sparsely populated area. For another, they mentioned reputable engineers who doubted that a bridge could be built.
Of course, proponents of the Straits of Mackinac Bridge argued their case too. The idea that such a structure could not be built was bunk, they declared. After all, had not all current studies pointed to the fact that neither existing rock nor climate conditions would hinder the project. Furthermore, the bridge would be a shot in the arm for the Upper Peninsula, ending traffic tie-ups and bringing more tourists and hunters providing for an economic resurgence.
Eventually bridge proponents prevailed. With one more than a two-thirds majority, Public Act 214 sped through the legislature. Signed into law by the Governor on April 30, 1952, this Act had immediate effect, authorizing the Mackinac Bridge Authority to bond, build and operate a toll bridge.
If getting legislative approval was difficult, securing funds to build the Mackinac Bridge was even worse. Because of constitutional and legislative restrictions, the Bridge Authority had to sell the bonds on the open market. This proved painful because the bond market was generally poor during 1953 and 1954. So bad was the market that bond sales had to be postponed twice.
On the third try, the Bridge Authority was successful but barely. In a revised plan, introduced in December of 1953, bonds were sold in two series. One, the so-called first lien bonds, would be issued in the amount of $79,800,000 with a four percent interest rate. Another, called second lien bonds, was to have an interest rate of five percent. As required by law, these offers had to be subject not only to public sale but to approval of the State Administrative Board. It was there in mid-December that trouble began--a difficulty so ill-timed that the project almost failed.
At the meeting with the Administrative Board and the Bridge Authority on December 15, 1953, one Board member opposed the financing methods. He maintained that the financing was too expensive and that the whole question should be brought before the voters. Fortunately, before a vote could be taken, this meeting was postponed.
Yet the postponement of this meeting did end the trouble. On December 16, Senator Haskell Nichols of Jackson filed a petition with the State Supreme Court asking it to prevent the Administrative Board from approving the sale. Before any action could be taken, members of the Bridge Authority saw court officials, asking them not to block the bonds. The argument was that a complete court hearing could be held between December 17, 1953 (the date of sale of the bonds) and February 17, 1954 (the date of the delivery of the bonds). This was done. Subsequently on January 22, 1954, the court upheld the right to sell the bonds.
Thus, with the legal impediments removed, bids for Mackinac Bridge Authority bonds were accepted on December 17, 1953, in the office of Governor G. Mennen Williams. Immediately after this meeting, the Bridge Authority approved the sale. And, not long after, the State Administrative Board convened and voiced their approval too.
At long last, the hoped for bridge could be built. Following ceremonial groundbreaking which took place on May 7 and May 8, respectively at St. Ignace and Mackinaw City, work began.
The first construction challenge awaiting them was to establish precise locations for each of the thirty-four bridge support foundations. This was done by establishing eight land and six sea-based surveying stations. From these positions, the surveyor utilized triangulation techniques to plot the exact position for each bridge section.
While this work was being done, the largest armada in the history of marine construction equipment was assembled at the Straits in 1954. Others had begun assembling caissons and superstructures as far off as Indiana, Pennsylvania and Ohio.
The actual building of the bridge was exacting and challenging. One of the most serious challenges went to the builders of the foundations--Merritt-Chapman & Scott Corporation. Piers 17 and 22, the huge anchorages for the cables, and piers 19 and 20, the support for the 46-story towers, were difficult. For the tower piers, huge caissons were filled gradually with rock and cement and lowered carefully to bedrock with precise calculation. Between the anchorage piers and the cable tower piers with two cables went piers 18 and 2 1. These two required huge foundations.
Though work was painstaking, it proceeded well, and the foundations were finished in 1955. Then, structural steel was put into place by the American Bridge Division of United States Steel Corporation. On July 2, 1955, the first piece was put in. Slowly the shape of the giant towers appeared across the Straits as creeper cranes pulled up each section and then moved within themselves. Riveters followed, making the work permanent.
The next phase, putting the support cable in, required the placing of a catwalk across the span. For, unlike other structural parts, the cable had to be assembled on-site. Quite literally, it had to be "spun" one strand at a time, since its 12,500 ton weight could not be lifted.
Looking back on the project, Dr. David B. Steinman, designer of the Mackinac Bridge, viewed it as the crowning achievement of his career. It was to him both a remarkable engineering feat and a work of art. Indeed, he was careful to make sure to preserve the grace and setting of the structure. He insisted that the 552 foot towers be painted ivory and that the span itself be green, so that its natural lines would be as graceful as a harp.
What, beyond beauty, has the bridge accomplished? For one, it has proven its critics wrong. Not only has it been an engineering success, but its ever increasing traffic has provided a growing business traffic for the Upper Peninsula. It has reduced the crossing time, including waiting time, from an average of one-and-a-half hours in winter or two-and-a-half hours in summer, to just ten minutes. Because of its capacity of 6,000 cars per hour (compared with the 462 cars per hour capacity of the state ferry service), the bridge has eliminated lines of cars which had stretched as long as seventeen miles on U.S. 27 and seven miles on U.S. 131, which could produce a waiting period of up to 19 hours. Most important of all, the bridge has joined the Upper Peninsula and Lower Peninsula, eliminating a geographical barrier, and has proved the wisdom of those who guided it through its financing, designing, and building.
|Length of Main Span||3,800 Ft.|
|Length of Suspension Bridge (Including Anchorages)||8,614 Ft.|
|Total Length of Steel Superstructure||17,918 Ft.|
|Length of North Approach (Including Mole)||7,791 Ft.|
|Length of South Approach||735 Ft.|
|Total Length of Bridge and Approaches||26,444 Ft.|
|Height of Main Towers Above Water||552 Ft.|
|Depth of Tower Piers Below Water||206 Ft.|
|Number of Main Cables||2|
|Diameter of Main Cables||24.5 Inches|
|Number of Wires in Each Cable||12,580|
|Diameter of each Wire||0.196 Inches|
|Total Length of Cable Wire||41,000 Miles|
|Weight of Cable, Wire and Fittings||12,500 Tons|
|Total Estimated Weight of Superstructure||66,500 Tons|
- Brown, Prentiss M. The Mackinac Bridge Story. Detroit, MI: Wayne State University Press, 1956.
- "Mackinac Bridge" in Civil Engineering, May 1956.
- Ratigan, William. The Long Crossing. Grand Rapids, MI: William B. Eerdmans, 1959.
- Ratigan, WIlliam. Straits of Mackinac. Grand Rapids, MI: William B. Eerdmans, 1957.
- Rubin, Lawrence A. Mighty Mac; The Official Picture History of the Mackinac Bridge. Detroit, MI: Wayne State University Press, 1958.
- Steinman, David B. Miracle Bridge at Mackinac. Grand Rapids, MI: William B. Eerdmans, 1957.
The Michigan Department of State first published "The Mackinac Bridge" as a Great Lakes Informant (Series 2, Number 2). © 1998 Michigan Historical Center.
For more information and pictures of the Mackinac Bridge, visit:
- The Upper Peninsula Gallery
- The official web site of the Mackinac Bridge (Mackinac Bridge Authority, Michigan Department of Transportation)