This is a two part video that introduces the different types of bridges. The bridge types will be introduced in historical order from simple (beam and arch) in the first video to more complex (truss and suspension) in the second video. This will show how bridges evolved as our designs and available materials expanded. The design of each bridge will be shown schematically along with the load distribution. The advantages and limitations of each type will be described. Video of actual bridges around Boston of the different types will be shown with the load distributions overlaid on freeze frames. Other iconic bridges will also be shown as still images with load distributions. Technical concepts covered will be tension, compression, bending, span, force balances, material selection and beam/cable design. License: Creative Commons BY-NC-SA More information at http://k12videos.mit.edu/terms-conditions