There are three drawn details: end view, part side elevation, lateral bracing in horizontal plane. The towers are the two end parts of the bridge that hold the central span and the suspended car. The towers are referred to as North and South. The South Tower is nearer to Minnesota Point, the North Tower is on the "mainland." Drawing 167, Sheet M11.
Contributing Institution:
University of Minnesota Duluth, Kathryn A. Martin Library, Northeast Minnesota Historical Collections
Technical details and named parts of the suspended car and its supporting structure for the bridge's builders. Included on the drawing are dimensions, rivet poles, braces, center lines, bolt connections, plates, trusses, knee brace, hanger roll. Drawing 161, Sheet M5.
Contributing Institution:
University of Minnesota Duluth, Kathryn A. Martin Library, Northeast Minnesota Historical Collections
Two detailed drawings of the car, or gondola, which carried vehicles and people across the canal. The drawing shows etched glass, punctured decorative steel plates, electric light fixtures, seats with perforated wood bottoms, maple flooring, glass paneled doors, lattice rail, copper flashing, wire supports, wire ropes, dimensions, floor beams, pine planks, and oak flooring. Drawing 162 Sheet M6.
Contributing Institution:
University of Minnesota Duluth, Kathryn A. Martin Library, Northeast Minnesota Historical Collections
A side elevation of the car, or gondola, which carried vehicles and people across the canal. The drawing shows: decorative circular metal plate with the word Duluth and floral-like details, wooden wall with windows, open lattice feature. Plan of strut is drawn as a detail for the bridge builders. Drawing 163, Sheet M7.
Contributing Institution:
University of Minnesota Duluth, Kathryn A. Martin Library, Northeast Minnesota Historical Collections
Detailed drawing of the suspended car, or gondola, and the vertical structure that holds it. This is the element that moves from one side of the bridge to the other above the canal. This transfer car could hold vehicles and people. Normal speed of the car was 4 miles per hour; it made the trip in about 1 minute. This drawing includes dimensions of individual structural elements such as braces. Drawing 160, Sheet M4. Turner is identified as engineer, 816 Phoenix Building Duluth.
Contributing Institution:
University of Minnesota Duluth, Kathryn A. Martin Library, Northeast Minnesota Historical Collections
The Claude Turner design for the original Aerial Bridge from 1901. Many companies and designers vied for this project. The bridge was built in 1904-1905. This drawing shows the spires and steel structural detail as well as the concrete footings and dimensions. Both towers are shown with an end view. In 1929 the suspended car transfer was eliminated and a lift span was installed.
Contributing Institution:
University of Minnesota Duluth, Kathryn A. Martin Library, Northeast Minnesota Historical Collections
Fifty-second Congress First Session Executive Document Number 80 United States Senate
Date Created:
1892-04-18
Description:
Thirty-one page government document, beginning with a letter form the Secretary of War, in response to Senate resolution of April 12, 1892, relative to the proceedings of the board of officers convened to consider the construction of a bridge in Duluth. This document is discussing placing a bridge over the Duluth ship canal where a bridge has never existed. The document uses the language "Aerial Lift Bridge" which must have been a design under consideration. In fact, the Aerial Ferry Bridge, or Aerial Transporter Bridge was the initial bridge constructed in 1904-1905. It wasn't until 1929 that the first bridge was remodeled with a lift span.
Contributing Institution:
University of Minnesota Duluth, Kathryn A. Martin Library, Northeast Minnesota Historical Collections