Wood is one of the most abundant resources on the planet. It is strong, durable and capable of holding heavy loads. It should be no surprise that wood was used as one of the world’s first materials to make bridges. Some of those bridges are engineering marvels and many others are tourist attractions like the covered bridge.
Covered bridges exist in Asia, Europe and North America. At the height of their popularity 12,000 were in existence in the United States alone. Today about 1,600 are still standing around the world with around 1,500 in the US in 30 states. Pennsylvania claims the most with around 220.
The first covered bridges were built in Europe placing horizontal beams on top of piles driven into the water. This limited the length of a span but was much cheaper and easier to build than a stone bridge. The timber-truss was developed and allowed for much longer spans. German covered bridges began using panel bracing to strengthen their bridges. At their height covered bridges could stretch for more than a mile as the Wrightsville-Columbia Bridge on the Susquehanna River in Pennsylvania did before it was burned to prevent Confederate soldiers from crossing into Lancaster County in 1863. It is even claimed that the burning of this bridge set in motion the events that culminated at Gettysburg a few days later. Today the world’s longest covered bridge is in Hartland, New Brunswick crossing the St. John River and is 1,282 feet long.
Covered bridges were ideal for many reasons. While cheap to build, an uncovered wooden bridge had a lifespan of about 10-15 years. Placing the cover on the bridge expanded that lifespan exponentially and with white oak available in abundance these bridges were not only cheap but extremely strong. The bridge provided shelter for anyone using it and also kept thirsty animals from seeking water while walking across it. Those same animals would also not be scared while crossing a river during a thunderstorm as their view of the water would be blocked thereby reducing stampedes. These bridges also gained the nickname “kissing bridges” as it was a popular (and romantic) spot for a gentleman to court a lady and to use the darkness to get in a quick smooch. Eventually with cheaper metal becoming available and the need for wider bridges to accommodate modern vehicular traffic the covered bridge fell out of favor.
The oldest covered bridge in the world is the Qiancheng bridge near Tangkou in the Fujian Province in China and is over 1,000 years old (though it has been rebuilt several times). Several other bridges in the area like the Yangmeizhou bridge are also Chinese cultural icons and on UNESCO’s National List of Intangible Cultural Heritage. Considering the tools used to build these bridges and the environmental challenges overcome these are engineering marvels. The covered bridge originated in China during the Han dynasty (206 BC to 25 AD) and Italian explorer Marco Polo brought the covered bridge to Europe around 1287. The oldest surviving covered bridge in Europe is the Chapel Bridge or Kapellbrücke in Lucerne, Switzerland. This bridge, which also features a water tower is one of Switzerland’s primary tourist attractions.
The first covered bridge built in the US crossed the Schuylkill River in Philadelphia at what is now the 30th Street Bridge. The bridge no longer stands and many modern commuters are certainly thankful for that. The oldest still-standing bridge is a matter of some controversy. Three bridges all have pre-1830 construction dates: the Hyde Hall Bridge in Oswego County, NY (acknowledged as the oldest by the National Society for the Preservation of Covered Bridges), the Haverhill-Bath Bridge in Woodsville, NH and the Roberts Bridge in Preble, OH.
Today many covered bridges are protected as historic sites and a few even allow vehicular traffic on them. But the bridges do need to be replaced from time to time and it has opened up a market for recycled wood from covered bridges to make furniture. It has also spawned a black market for covered bridge wood forcing some bridges to have alarms and sensors installed on them to prevent theft of the wood and for willing locals to patrol the area to deter thieves. Fortunately instances of this are rare and the most pressing danger to modern covered bridges come from truck drivers.