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Wednesday, July 5, 2017

The Big Mac

     The Mackinac Bridge (pronounced MAK-in-aw), generally known as “the Big Mac”, is a suspension bridge spanning the Straits of Mackinac to connect the Upper and Lower Peninsulas of Michigan. Opened in 1957, the 26,372-foot (4.995 miles) bridge is the world's 19th-longest main span and the longest suspension bridge in the Western Hemisphere. 
     The weather can get so terrifying and the lanes are so narrow that the bridge authority offers to help drive overwhelmed motorists across. Despite its scary reputation, the Mackinac Bridge is actually one of the safest bridges in the country and offers incredible views. The Big Mac ranks as one of the scariest bridges in the U.S. Others are: 

Seven Mile Bridge in the Florida Keys. It's just 65 feet above the Gulf of Mexico. The bridge might spark concern not just to drivers who fear bridges, but also those who have a fear of water. 
The Chesapeake Bay Bridge in Maryland reaches nearly 200 feet high and measures 4.3-miles long from end to end. Some motorists find driving across the bridge out of the question and so there's a service offering to drive people across the bridge. 
Deception Pass Bridge,Washington State's two-lane, 1,486-foot-long bridge, was built in 1932 and is 180 feet high above water. When the fog and mist mix on the driver’s windshield it creates tough driving conditions and poor visibility. It's hair-raising size and weather can be a danger for pedestrians as well. The pedestrian lane of the bridge is very narrow and as cars drive by and water rushes from below, pedestrians can find it frightening. 
Cape William Moore Bridge, located outside Anchorage, Alaska looks ordinary, but it's over an active earthquake fault. Designers says is designed to withstand quakes though.
Golden Gate Bridge in San Francisco, California stretches three miles long and is a mile wide. It was declared as one of the “Wonders of the Modern World” by the American Society of Civil Engineers. It has become has become synonymous with suicide due to the number of people who have plunged to their deaths from the bridge. It's scary for drivers because they feel the wind whipping across the bridge. It was built to withstand 100 mile-per-hour winds and even earthquakes. 
Lake Pontchartrain Causeway in Louisiana is the longest bridge over water in the world. The four-lane bridge stretches for 25 miles across Lake Pontchartrain and is just 25 feet above water. 
Verrazano-Narrows Bridge in New York City is the longest suspension bridge in the world. The double-decker bridge spans just over two-and-a-half miles and rests 228 feet above water. It opened in 1964 and connects Brooklyn to Staten Island. Due to the intimidating size of the bridge, it is paralyzing to some drivers who want to go across. 
Royal Gorge Bridge in Colorado is the country’s highest suspension bridge. It rests 90 stories between two tall cliffs over the Arkansas River. It features a 100-foot-tall pendulum swing known as the Royal Rush Skycoaster and even a zip line. The bridge is constantly under threat from wildfire. In June 2013, the bridge had to be evacuated after it was damaged by flames. It reopened in January 2014. 
Gold Brooke Bridge, a quaint Vermont bridge, is also known as Emily’s Bridge and is said to be haunted. According to legend, a girl named Emily killed herself on the bridge in the 1920s. Visitors to the spot still claim they hear footsteps and see apparitions. 

     As for the Big Mac, which is part of Interstate 75 and connects the city of St. Ignace on the north end with the village of Mackinaw City on the south, an 1884 newspaper article pointed out that an experiment to provide all-year service across the Straits by boat had failed, and a bridge or tunnel would be required. The big question was the enormous cost. 
     During the ensuing years there were a few far fetched ideas about the connection of Michigan’s two peninsulas. In 1920 the state highway commissioner suggested a floating tunnel. One engineer came suggested a series of bridges and causeways. In 1923 the Legislature ordered the State Highway Department to establish a ferry service at the Straits. Within five years traffic on this facility became so heavy that the Governor ordered a study of bridge feasibility. The report was favorable and its cost was estimated at 30 million dollars. Some efforts were made to get the project underway were taken but it was eventually dropped. 
     Early in 1934 the question of a bridge was revived. Although limited funds didn't allow for a full preliminary study, the conclusion was that it was feasible to construct a bridge directly across the Straits at an estimated cost of not more than $32.4 million. Between 1934 and 1936 two attempts to obtain loans and grants from the Federal government were refused despite endorsement by the Army Corps of Engineers and President Roosevelt favoring the bridge. 
     From 1936 to 1940 the route was selected, borings were made, traffic, geologic and ice and water current studies were completed. A causeway jutting 4,200 feet into the Straits from St. Ignace south was constructed. Preliminary plans for a double suspension span were drawn and the possibility of a bridge became very real. World War Two intervened and in 1947, the State Legislature abolished the Bridge Authority. 
     By 1950 new legislation was enacted, but it limited the newly created Authority to only determining the feasibility of constructing a bridge. In January of 1951 the Authority submitted a favorable preliminary report, stating that a bridge could be built for $86 million. This time there was a shortage of materials because of the Korean War and legislation to finance and build the bridge was delayed until early in 1952. Bonds to finance constructions were offered in March of 1953. There weren't enough takers though because of a weak economy. To help take up the slack, the Legislature passed an act whereby the operating and maintenance cost of the structure would be paid for out of gasoline and license plate taxes and by the end of 1953 the market recovered and bonds were bought by investors all over the country. 
     Today's bridge was designed by engineer David B. Steinman and was opened to traffic on November 1, 1957 according to schedule, despite the many hazards of marine construction over the turbulent Straits of Mackinac. 
     The last of the Mackinac Bridge bonds were retired July 1, 1986. Fare revenues are now used to operate and maintain the Bridge and repay the State of Michigan for monies advanced to the Authority since the facility opened to traffic in 1957. 

Fun Facts: 
# Fifth longest suspension in the world, and longest in the Western Hemisphere. 
# The total length of the bridge is 26,372 feet. 
# The main suspended span between the two towers is 3,800 feet long. 
# 31 expansion joints allow the center of the bridge deck to move as much as 35 feet to accommodate high winds and temperature changes. Normal movement is much less and unnoticeable to drivers. 
# Total Weight of Bridge is 1,024,500 tons. 
# The height of the main towers is 552 feet. 
# The bridge took 48 months to complete with over 3,500 workers and $99.8 million. 
# Total number of steel bolts used in the bridge: 1,016,600 
# Total number of engineers employed: 350 
# The main bridge cables are made from 42,000 miles of wire.

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