Tower caisson for the Mackinac Bridge (22 of 45)

Construction of the first section of a tower caisson.  Note the wedge shaped cutting edge.  These sections were fabricated in Gary, Indiana and shipped to Rockport (Alpena), MI by barge where they were assembled by Wiltse Brothers Shipyard. This edge will cut through the overburden on the lake bottom.  As the additional sections are added and filled with aggregate the caisson will be driven (by it's weight) to bedrock., Electronic reproduction of photograph.  The Mackinac Bridge 1954 - 1958. Mackinac Bridge Authority
Abstract/Description: Construction of the first section of a tower caisson. Note the wedge shaped cutting edge. These sections were fabricated in Gary, Indiana and shipped to Rockport (Alpena), MI by barge where they were assembled by Wiltse Brothers Shipyard. This edge will cut through the overburden on the lake bottom. As the additional sections are added and filled with aggregate the caisson will be driven (by it's weight) to bedrock.
Subject(s): Bridges--Design and construction
St. Ignace (Mich.)
Mackinaw City (Mich.)
Mackinac Bridge (Mich.)
Date Created: 1954 (approximate)