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U-M divers retrieve 8,900-year-old piece of wood from Lake Huron
Annarbor.com (12/12)
University of Michigan researchers announced they have found a 5 1/2 foot long, pole-shaped piece of wood that is 8,900 years old in Lake Huron.
RIVERKEEPERS: Tending the waterways
Niagara Gazette (2/6)
The goal of the Buffalo Niagara Riverkeeper is two-fold: protecting the water quantity and the quality, as well as connecting people to the waterfront.
Internationally renowned ‘Ocean Doctor’ to speak in Grand Rapids
MLive.com (2/3)
Known as the “Ocean Doctor,” David Guggenheim will speak in Grand Rapids, Mich., about the many similarities between the threats to the oceans and to our Great Lakes.
SUNY Fredonia to lead Great Lakes pollution study
Wall Street Journal (2/3)
Plastic pollution in the Great Lakes will be the focus of a study this summer. Led by the State University of New York at Fredonia, researchers will try to quantify the amount of plastic polluting the fresh water Great Lakes.
SSC students taking part in marine science bowl
Arenac County Independent (1/31)
Teams of Michigan high school students will be heading to Ann Arbor this weekend to take part in the annual Great Lakes Bowl, a quiz event that focuses on questions about marine and freshwater systems and biology.
No aquarium for Windsor
CBC News (1/31)
Aquariums in Cleveland, Toledo, and Chicago prove to be too much competition for Windsor.
What's going on in your neighborhood this month? Meet other people and learn together at recreational and educational events! Our new dynamic calendar is updated daily with current educational events.
2 | The construction period: 1954-57
Because the bridge was in a remote area, financing the project was slow and difficult. The total cost of the project was upwards of $100 million (originally estimated at $70 million).
Construction began in 1954 and during the 42 months that followed hundreds of men worked on the various phases of the bridge construction.
The first step was to sink the large, double-walled cylinders that form the bases of the two main tower piers. These cylinders are called caissons (cay-säns). The caissons had to be sunk down into the bedrock on the lake floor, a great challenge for the divers involved.
When the foundation pillers were finished, the iron workers were brought in to string the massive cabling network! More than 500 workers were housed in St. Ignace, Mich., during this construction period.
A "catwalk" made of cyclone fence enabled the workers to navigate between the bridge towers, high above the lake below.
When finished, the cables were close to 25 inches in diameter. Each cable consists of 340 wires banded into a single strand; 37 strands are then assembled into a single cable. To complete the job and add extra strength, a covering is spun around each finished cable. More than 42,000 miles of wire were used in the two main bridge cables!
The last step was to construct the road surface. The inner lane on the middle span of the bridge includes an open grid riding surface. This was installed to allow wind forces to move through the bridge.
Images: Erecting the north tower and adding trusses and cables, courtesy "Picture Story of the Mackinac Bridge," 1978 Voyager Press; the Mighty Mac close to completion in 1956, courtesy Albert Ballert.
