Cable bent pier for Mackinac Bridge (14 of 15)

Pier 21, the north cable-bent piers, consists of a pair of circular foundations 50 feet in diameter founded on bedrock, 65 feet below the surface.  Each concrete cylinder was topped with a pedestal 16 feet in diameter.  The sheet piling used for the cofferdam was cut off eight feet bellow the waters surface.  The underwater portion is clearly visible through the clear waters of the straights and are ready for the above portion of the pier., Electronic reproduction of photograph.  The Mackinac Bridge 1954 - 1958. Mackinac Bridge Authority
Abstract/Description: Pier 21, the north cable-bent piers, consists of a pair of circular foundations 50 feet in diameter founded on bedrock, 65 feet below the surface. Each concrete cylinder was topped with a pedestal 16 feet in diameter. The sheet piling used for the cofferdam was cut off eight feet bellow the waters surface. The underwater portion is clearly visible through the clear waters of the straights and are ready for the above portion of the pier.
Subject(s): Bridges--Design and construction
St. Ignace (Mich.)
Mackinaw City (Mich.)
Mackinac Bridge (Mich.)
Date Created: 1955 (approximate)