Parke County Covered Bridge Festival

The 61st Annual Parke County Covered Bridge Festival features 31 historic covered bridges held yearly in October.
This is the largest festival in Indiana and attracts hundreds of thousands of people from all over. These covered bridges are engineering marvels and are based on the Burr Arch Design.
The Burr Arch Truss design is a combination of an arch and a multiple kingpost truss design. It was invented in 1804 by Theodore Burr and was patented on April 3, 1817. This is the primary design used in covered bridges. The term "covered bridge" refers to the structure with a roof and siding which creates a complete enclosure. The enclosure helps to protect the wooden structural members from the weather. Uncovered wooden bridges typically have a lifespan of only 10 to 15 years because of the effects of rain and sun.
The Burr Arch Truss design combines the strengths of the truss bridge and arch bridge to allow for greater bridge spans. Prior to the Burr Arch Truss design, bridges were built with horizontal beams laid on top of piles driven into the riverbed below which limited the maximum length of each bridge span to the maximum length of each beam.
Theodore Burr, a cousin of vice president Aaron Burr, build nearly every bridge that crossed the Susquehanna River from Binghamton, New York, to Maryland and was the most distinguished architect of bridges in the country. Burr was an inventor from Connecticut and his first "sizable bridge" was built around 1804 and crossed New York's Hudson River at Waterford, New York. The bridge was razed by fire in 1909 and used the "Burr arch truss" which rested on abutments on either end. Burr was awarded US Patent No. 2769 on April 4, 1817 for his arch and truss bridge design. Burr died in 1822.