Covered Bridges of America

The first covered bridge in America was built in 1804 by Theodore Burr of Connecticut. The bridge spanned the Hudson river in New York and was named the Waterford Bridge. It lasted for 105 years. Before covered bridges were built, they used ferries. The ferries could not be used in the winter and could only carry so much. This speed ed up the idea of a permanent structure like a bridge.

The most significant part of the bridge structure is the truss. In 1817, the Burr-arch truss was patented. It took a king post extended it and put an arch with it to strengthen it. That idea was used for a quarter of a century. Then the Warren truss was introduced. It was a w shaped type truss that was easy to put up and less expensive. The only disadvantage of this truss was the tension and squeeze it put on a bridge in the center of it.

The Howe truss used steel rods that would connect the top and bottom chords of a bridge with steel washers and nuts.

Thomas and Caleb Pratt patented a truss which inverted Howe's' idea by making diagonals of iron and the compression of vertical timbers. It had a strong appeal to railroad workers because of its' strength. The Pratt truss was preferred for short spans and the Warren-Howe truss was preferred for longer spans.

Another man that had a lot to do with the early development of covered bridges was Stephen Long. He worked for the government and was instrumental with his engineer designs for the railroad.

Today there are about 1500 covered bridges left in America. They are most common in the New England states, Indian, Ohio, and Pennsylvania. However, they are located all over United States. There are many covered bridge societies that exist for the purpose of maintaining bridges in certain areas of the country. Many covered bridges are considered to be historical landmarks and are protected by the states they exist in.

During the Civil War, many bridges were destroyed to keep troops from advancing to certain areas. The bridges were called "kissing bridges". This is because many a young couples would congregate to them in a form of courtship. They had a special charm that was brought to rural America.

There are three things that have hurt the bridge structures. Floods, fire, and vandalism have done major damage to bridges over the years. In the early 1990's, what is known as the "Hundred year flood", took out many of the smaller bridges in the Midwest. Arson (fire) has also claimed some bridges. On the average, two bridges are lost to fire each year. Today many bridges are being equipped with fire prevention alarms and sprinkling systems.

Vandalism also has taken its' toll on bridges. Many people don't realize that the graffiti of carving in names and initials hurts the structure over time. Some paints that are used also have chemicals that over time can weaken a bridge. The carving allows for insects to build nests and multiply in certain areas of the truss. This can lead to the deterioration of the wood.

Today many covered bridges are used for movies, videos, paintings, pictures, and festivals. They are considered a part of Americana. Some states sponsor a covered bridge festival that lasts an entire weekend. Many are held in the fall when the leaves start turning color.

A question that comes up at many trivia contests is "Why was a bridge covered in the first place?" Many thought it was to keep the bridge safe from being slippery. The true reason was for protection and strength. It cut down on the sun's rays as well as protect from moisture. Also, the lattice on some sides of the bridge added to the strength of it.

Many of the bridges today have strict weight limits on them for protection. They are also checked annually for deficiencies and corrected. However, it has long been the desire to stay within the parameters of the original architects designs. Adding to them or taking away from that design, lowers the quality of the original building.