Tower parts pre-fab

These tower were fabricated horizontally, on the ground, at the yards of American Bridge Div. Of U.S. Steel, at Ambridge, Pennsylvania, Electronic reproduction of photograph.  The Mackinac Bridge 1954 - 1958. Mackinac Bridge Authority
Abstract/Description: These tower were fabricated horizontally, on the ground, at the yards of American Bridge Div. Of U.S. Steel, at Ambridge, Pennsylvania
Subject(s): Bridges--Design and construction
St. Ignace (Mich.)
Mackinaw City (Mich.)
Mackinac Bridge (Mich.)
Date Created: 1955 (approximate)