The Howe Truss

howe bridge 2

The bridges in the Scio area are each constructed with variations of the Howe truss. Click on the images to see them larger.

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This design could be constructed from local materials with a minimum of tools. Wood was readily available in the Scio area and these bridges were constructed as late as 1966. Only steel cables or rods were required to complete a very strong, rigid structure capable of carrying great weights over wide spaces without intermediate supports.

William Howe of Massachusetts patented the Howe truss design in 1840. It is really an elaboration on the multiple kingpost design where by two heavy metal rods are substituted for the vertical timbers.

There are also variations on this pattern that add a second diagonal timber to the original single diagonal of the multiple kingpost and/or another diagonal timber running in the opposite direction between the vertical rods.

Some accounts indicate that the Howe design provided a bridge that was stronger than an all-wood structure; as a result, it became the forerunner of iron bridges. Because of its inherent great strength, the Howe truss was and is still used commonly in the construction of railroad bridges.

To the locator map to the five bridges