Sault Ste. Marie International Bridge Strengthening

摘要

1. 1887 - Four railroads formed the St. Mary's Falls Bridge Company and built 10 through truss spans and one swing span 2. 1899 - Canadian Swing span construction 3. 1910 - Double leaf bascule span construction, one through truss span was removed 4. 1959 - Vertical lift span replaces US swing span.