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More File-Folder Bridges
A Simple FFB Project  

The bridge-building project included in the book Designing and Building File-Folder Bridges is realistic but relatively complex. We have received many requests for a simpler project that can be completed in less time--but which retains the direct applications of math and science found in the original book.

So here it is! The PowerPoint presentation below will lead you through the design and construction of a simple A-truss structure, based on a well-known 19th century railroad bridge. Like the more complex project in Designing and Building File-Folder Bridges, this project requires the application of geometry, algebra, and some basic trigonometry. Thus it is intended primarily for high school students.


Load-testing the A-Truss.
It carries 5 kilograms!
Designing and Building File-Folder Bridges: The Waddell A-Truss [3,800 KB].  This zipped PowerPoint presentation includes an introduction to truss bridges, basic concepts of structural engineering, structural analysis using the Method of Joints, and step-by-step procedures for designing and building a model of the Waddell A-Truss using manila file folders.
Full-Scale Layout Drawing for the A-Truss:
  - Elevation View and Plan View Drawings in Adobe Acrobat (.pdf) format
  - Elevation and Plan View Drawings in Autocad (.dwg) format

To view this presentation, you need to have Microsoft PowerPoint 2002 (or later) installed on your computer. You will probably be able to open the file with earlier versions of PowerPoint, but many of the "builds" and slide transitions will not work correctly.

You may copy and distribute this presentation without restriction.

 

 

The Waddell A-Truss
Built in 1898, this innovative structure was designed by J.A.L. Waddell as an economical short-span bridge capable of carrying very heavy loads. Located near Trimble, MO, it carried a single track of the Quincy, Omaha and Kansas City Railway for many years. In 1989, it was moved to a public park in Parkville, MO.
You can design and build this simplified model of the Waddell A-Truss by following the step-by-step procedure provided in the PowerPoint presentation at left.