Wartime beginnings

In February 1942, the United States government announced plans to spend an estimated $8 million to build a state-of-the-art icebreaker incorporating successful design ideas found on a fleet of privately owned rail ferries in service at the Straits of Mackinac that were capable of operating in heavy ice. Such a vessel was essential because a longer shipping season was needed to help vessels move vital raw materials on the Great Lakes during World War II. At the start of the conflict, all available cutters had been called to wartime duty leaving the Great Lakes with no available icebreakers.

Construction continued at Toledo Shipbuilding Co. for more than two years. Delays lead to stiff penalties for the shipyard, so severe the company went bankrupt. The project was completed by the American Shipbuilding Co., and the vessel was side-launched on March 4, 1944.

Her name was originally to have been Manitowoc, but that was changed before the Mackinaw entered service when it was discovered another government vessel already carried that name.

With fitout complete, she was commissioned on Dec. 20, 1944 at a final cost of $10 million, an enormous amount for the day. One of four “heavy” class icebreakers built for wartime service (the others were Northwind, Southwind and Westwind), the Mackinaw was the only one assigned to the Great Lakes.

Mackinaw's 2005 replacement icebreaker of the same name cost 80 million dollars, the same amount as the original if the 1944 construction price was figured in 2005 dollars.

Click here to view a PDF detailing the Mackinaw's historic engineering.

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