Mackinac Bridge, Michigan, USA
Created | Updated Sep 4, 2012
Michigan has a state motto:
'Si quaeris peninsulam amoenam circumspice,' (which translates as: If you are looking for a beautiful peninsula, look around you.)Actually it is two peninsulas not one, each hundreds of miles long, each taking its shape from the lakes beside it. Separating the two peninsulas is a strait of water known as the Straits of Mackinac (pronounced Mackinaw1). If this article were written by a resident of the upper peninsula they might tell you that residents of the other peninsula are called trolls because they live below (ie south of) the Mackinac bridge.
Since November 1957 the Mackinac Bridge has been an integral part of the US Interstate Highway System linking the two peninsulas of Michigan. Prior to that time all travel between the Upper and Lower Peninsulas was by boat or air.
How Big Is It?
| Total Length with approaches | 28,195ft (8.594 km) |
| Length of bridge | 17,918 ft (5.461 km) |
| Length between anchorages | 8,614 ft (2.625 km) |
| Length of main span | 3,800 ft (1.158 km) |
| Height above water | 552 ft (168.25 m) |
| Width | 54 ft (16.45m) |
A Marvel of Engineering
This is the 12th longest suspension bridge in the world and the 8,614 ft (2.625 km) distance between anchorages is greater than any other bridge in North America. It was designed during the 1950s.
The 54 foot wide roadbed is divided into four lanes. Two carry northbound vehicles and two carry southbound vehicles. The Mackinac is a toll bridge, with a per-axle charge applied at toll booths that sit on each approach to the bridge. A scenic rest area is also located just north of the bridge on the highway. In one month alone over 500,000 vehicles cross this span. The bridge has design elements to maintain its integrity during high winds. To avoid some vehicle being blown off into the straits, which actually happened once, the Mackinac Bridge Authority will occasionally put special rules in place. They may even decide to stop all vehicles at the toll booth until the wind subsides. In later years a bridge-cam was installed.
A Boon to Shipping
Shipwreck has always been a real danger in the Straits of Mackinac. The tall white towers have the latest in navigational aids.
According to one source2 35 ships missed the channel and were stranded, 14 sank after colliding, eight foundered in storms, seven went down as a result of ice damage and six were left abandoned after heavy storm damage. Most of these were before 1900. For example, in June 1878 the schooner Pestigo accidentally rammed another schooner, the St Andrew, and both sank. In early spring 1894 a 218-foot freighter loaded with grain (The WH Barnum) misjudged the ice in the straits and had to have the crew removed by the tug boat Crusader. Damaged beyond repair, the freighter went down in eleven fathoms of water.
All ships travelling between Lake Michigan and the other Great Lakes must go under this bridge. In the shipping channel the main span is 135 ft(41m) to 155 ft(47m) above the water giving plenty of clearance for even tall ships. A lighthouse on the shore was decommissioned in 1957 because with the towers of the bridge there standing almost three times as tall as the lighthouse the state decided that this light was no longer needed.
History
When New York City built the Brooklyn Bridge certain visionaries in Michigan wanted the same thing for the straits of Mackinac. For various reasons this project was put off, decade after decade until the 1930s. Then, according to an MDOT3 website:
In the extra session of 1934 the State Legislature created the Mackinac Straits Bridge Authority of Michigan and empowered it to investigate the feasibility of such construction and to finance the work by issuance of revenue bonds.The Second World War and the Korean War threatened to derail the project, but Michigan's 41st Governor G Mennin Williams got behind it and the state hired the engineering firm headed by David B Steinman to draw up the plans. With nearly US $100 million4 in bonds sold and State government assurances that maintenance costs would be covered, the building began in 1954. It took three more years to do the work. Finally in November 1957 the bridge opened to traffic.
Annual Labor Day Walk
There is a saying in Michigan that Labor Day5 is the last weekend of summer. Anyone who wants to travel 236 miles (380km)6 north to the Mackinaw Bridge is invited each year to join the Governor in walking the five miles across the bridge. This structure was designed without sidewalks and pedestrians are confined to walking on the roadbed during the few rare occasions when they are allowed on the bridge. During the event vehicles are restricted to the western side of the span and the eastern lanes are available for the Governor and anyone else who wants to participate in the Mackinac Bridge Walk. In 2009 approximately 50,000 people walked the five-mile route from the St Ignace Welcome Center outside St Ignace to Mackinaw City. The walk is from north to south. To get to the starting point thousands of people line up for a school bus ride in Mackinaw City. In 2009 the bus ride took almost as long as the walk because of traffic problems in the northbound lanes.
