Inside a covered bridge, which spans the Walkill River in Ulster County, New York, 1913.
Covered bridges were built to help protect the wood from the weather. Since local governments were responsible for the upkeep of bridges and roads, these improvements were welcome. Several inventors helped to improve the structures with their truss designs.
Theodore Burr designed a highly successful span bridge that combined a simple timber truss with an arch, which he patented in 1817. His first successful bridge was erected across the Hudson River at Waterford, New York. It was sheathed with pine plank siding and covered by a shingled roof. The truss design shown here was the Town lattice truss, patented in 1820 by architect Ithiel Town. Consisting of a top and bottom cord connected by alternating diagonal timbers, the lattice truss had no vertical members. This made it possible to span wider spaces.
Other improvements to the design and strength of covered bridges were made by Colonel Stephen H. Long in the 1830s and by William Howe in 1840. You can see examples of these bridges all over New York State. The use of metal for the construction of bridges brought a close to the era of the covered bridge.
How does the availability of transportation affect the economic and cultural aspects of a society?
Check for Understanding
Describe the scene in the photograph and evaluate the impact of this technology on local communities.
Create a brochure with a map of New York State showing the locations of covered bridges that are still standing.
Science: Create a bridge out of newspaper that will support the weight of your Social Studies textbook. Research different bridge designs, such as suspension bridges.
English Language Arts: Compare and contrast the different kinds of covered bridges that were built.