Design drawing, including plan and elevation of Twin Cities standard streetcar as rebuilt during the 1920s with front exit door by Twin City Rapid Transit.
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
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
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
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
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
This is a general elevation drawing, plus end view of both towers. The suspended car transfer is in the center of the bridge drawing over the canal. Dimensions are included for the distance from the water to the bottom of the bridge span (135 feet) and the footings. The drawing shows small stone and gravel fill near and around the concrete footings at the base of each tower. The finials are shown in detail. Lake Avenue is shown from one tower to the other. Drawing H-5421A, U.S. Patent February 1903.
Contributing Institution:
University of Minnesota Duluth, Kathryn A. Martin Library, Northeast Minnesota Historical Collections
Detailed drawing of four parts of the Aerial Bridge. The end view is a drawing of a tower; part side elevation is of half of the Aerial Bridge with the suspended car transfer. The third drawing is called Section A-A and depicts a tower without the cross structures drawn in. The last drawing is called Section B-B, which is a top down view of one of the towers resting on its footings. All of these drawings have dimensions. The part side elevation includes a very small drawing of the side of the gondola car. The end view includes the phrase "car approaches built by city." The finials are shown on three of the four drawings. Drawing H5421, Sheet 2.
Contributing Institution:
University of Minnesota Duluth, Kathryn A. Martin Library, Northeast Minnesota Historical Collections
This drawing identifies wind forces and their effects on the physical structure. Notes are included on this drawing for example: "Stresses in lower sections of tension diagonals equal or smaller than top sections, but same riveting to be used in detail." The drawing includes a key for live load, dead load, impact, wind at 150 pounds per linear foot, wind stress due to traveler, equivalent to live load. The drawing shows top and bottom laterals. Total weight of the carrier and car is given as 240,000 pounds. The scale is given as 20 feet equaling one inch. Drawing H5421, Sheet 3.
Contributing Institution:
University of Minnesota Duluth, Kathryn A. Martin Library, Northeast Minnesota Historical Collections