If you pass along a quiet New England road in fall and come upon what appears to be someone's misplaced home, you're tempted to recall the romantic version of the origin of covered bridges... They, of course, were built for discretely kissing your favorite girl while on a long buggy ride home from church.
One resists the more practical reason nineteenth-century artisans walled-up the sides and placed a roof over the way across the river. The purpose is lost on us because we have huge, steel structural I-beams and have developed the technology to plow the snow from our roads and bridges using 5-ton trucks pushing massive steel blades. In 1830, wheeled-conveyances were stored away in winter and replaced by sleighs and lone beasts. The road agents of the day used large barrel-like vehicles to roll the snow flat and hard. This caused a problem for the bridges, of course, because they were built of wooden timbers and couldn't support the weight of a long winter's snow.
Karl Johnson of Groton, Mass., a photographer and producer of Covered Bridge calendars, wrote:
"Covered bridges were not invented in New England, but had been used on a limited basis in Central Europe for several hundred years. The ingenuity of five New Englanders, however, launched a whole new era in bridge construction.
"In the late 1700's, America was growing. Rivers were a major obstacle to communication and land transportation. Bridges were needed for commerce, but deep water and spring floods made low, piling-supported bridges impractical.
"About this time, Timothy Palmer of Newburyport and Theodore Burr of Torringford, Conn. adapted European designs and became the first successful builders of large wooden truss bridges in America. Both these men were self-taught craftsmen who built many covered bridges all over the northeast. Old growth forests provided an abundant supply of large timbers.
"Once the viability of large wooden bridges was proven, towns, toll-bridge companies and railroads began building them. By the early 1800's, contractors were competing for a boom in bridge building.
"Ithiel Town of New Haven, Conn., Stephen Long of Hopkinton, NH and William Howe of Spencer, Mass. came up with new truss designs that were easier to build than Palmer's or Burr's designs. All three patented and then franchised their designs to builders who used them all across America.
"Even with proven designs, bridge building was as much art as science. Builders were ingenious, skilled craftsmen with little formal education. They drew on their training from master craftsmen and their own experience. They knew the characteristics of the materials they worked with.-not only how to cut and shape the timbers, but what the load bearing strength was. If there is such a thing as folk engineering, this was it.
"For me, the most fascinating aspect of New England covered bridges is the superb craftsmanship. Because a wooden truss bridge's strength comes from being under constant compression. Every timber and joint in the frame must fit precisely to evenly distribute the load. A typical 100-foot lattice type bridge could have almost a thousand hand-cut, hand-pegged joints.
"That wooden covered bridges built over a hundred and fifty years ago are still in service is a testimonial to their design and the craftsmanship with which they were built. With good supervision and maintenance many of these should last for years to come."
The picture at left above is the Cresson Bridge in Swanzey Center (Courtesy of Arthur Bouffard). At right above is an 1880's view of the Thompson Bridge (Courtesy of the Historical Society of Cheshire County), which crosses the Ashuelot River in the village of West Swanzey. Both bridges were recently repaired to stand modern traffic.