Cable bent pier cofferdam

The cofferdams used for the cable bent piers, built at St Ignace, were 75 feet high and 50 feet in diameter.  They were sunk to bedrock (65 feet for pier No. 21, the north cable bent pier) sheet piling was added and excavation was done within., Electronic reproduction of photograph.  The Mackinac Bridge 1954 - 1958. Mackinac Bridge Authority
Abstract/Description: The cofferdams used for the cable bent piers, built at St Ignace, were 75 feet high and 50 feet in diameter. They were sunk to bedrock (65 feet for pier No. 21, the north cable bent pier) sheet piling was added and excavation was done within.
Subject(s): Bridges--Design and construction
St. Ignace (Mich.)
Mackinaw City (Mich.)
Mackinac Bridge (Mich.)
Date Created: 1954 (approximate)