Covered Bridge Facts and Legends The most controversial Covered Bridge fact is the abundant claims of "longest." As an example, the longest covered bridge ever built was constructed in Pennsylvania between Lancaster County and York County. This bridge was over a mile in length and was completed in 1814.

An interesting "Bluegrass" note to our covered bridge facts: the longest wooden covered bridge in the world once stood near the town of Butler, 7.5 miles north of Falmouth in Pendleton County, Kentucky. The Butler Station Bridge over Licking River consisted of three spans of 152 feet each, for a total length of 456 feet. The bridge was built in 1870 and 1871 at a total cost of $18,450. Severely damaged by winds and floodwaters in 1937, it was torn down in September of that year.
 

The current longest-standing single-span covered bridge in the US is the Bridgeport Bridge of California, built around 1862, at 233 feet in length.

The longest existing American Covered Bridge is the Smolen-Gulf Bridge built-in 2008 in Ashtabula County, Ohio at 613 feet, but has a long time to go to meet historical bridge requirements. 

Another "longest" claim in covered bridge facts is the longest existing covered bridge in the World is the Hartland Bridge built in Hartland, New Brunswick, Canada at 1282 feet in length. The bridge was built in 1901 but was not covered until 1922.

Windsor-Cornish Covered Bridge that spans the Connecticut River between Windsor, Vermont, and Cornish, New Hampshire is the longest two-span covered bridge in the world, at 465 feet, and the longest wooden bridge in the United States. (All these “longest” claims depend on how they are determining length.)

In America, the first covered bridge was built in Connecticut in 1804 by Theodore Burr. Named the Waterford Bridge, which spanned the Hudson River in New York and lasted for 105 years.

Unchallenged in covered bridge facts is the earliest documented covered bridge in the US was the 550 foot Permanent Bridge constructed over the Schuylkill River in Philadelphia by Timothy Palmer in 1805.

The oldest documented American-covered bridge still standing is the Hyde Hall Bridge in Glimmerglass State Park near Cooperstown, New York, built-in 1825.

One of the most interesting covered bridge facts is that the history of covered bridges can be traced as far back as 780 B.C. in ancient Babylon.

The USA at one time had over 14,000 covered bridges crossing its rivers and streams.

Pennsylvania has the most standing covered bridges with 213. Ohio is second with 148.

Parke County, Indiana is the US County with the most covered bridges standing, with 31.

According to covered bridge facts, most of America's covered bridges were built between 1825 and 1875.

Currently, about 95 percent of the nation’s covered bridges are not a part of the federal highway system because they do not meet its standards.

American-covered bridges range in length from less than 100 feet to several hundred feet, and, like snowflakes, no two are alike.

American-covered bridges use about 18 different types of patented trusses.

 

Covered Bridge Legends

Covered bridges were attractive to robbers, who would hide in the rafters, and then drop down on their victims while going through the bridge.

In 1862, the price for crossing the Virginia City Turnpike Company's 14-mile section of roadway, including passage over the Bridgeport Covered Bridge, was $.25 for foot travelers, $.50 for horsemen, and $6 -- the maximum toll -- for a team of eight animals.

The earliest winters with covered bridges brought another challenge. In the latter part of the nineteenth century and the early twentieth century, workers would be paid to shovel snow onto bridge floors to enable winter horse and sleigh traffic. If the rest of the roads in the area were snow-covered, travelers would have utilized a horse-drawn sleigh in lieu of the traditional carriage to get around. Without snow covering the floorboards of the bridges, crossing them in a sleigh would otherwise have been extremely difficult.

The bridges of Madison County are the No. 1 make-out spot in Iowa, according to the website: roadtrippers.com.

The loss of Kentucky's covered bridges began during the Civil War when many were burned by troops on both sides of the conflict to keep the enemy from crossing the river.

A fourteenth surviving Kentucky-covered bridge truly is "covered" - by water. At the bottom of Herrington Lake near the Boyle-Garrard county line is the King's Mill Covered Bridge. When the lake was built in 1925, the old mill and bridge were left in place and were covered by the waters of the lake as they backed up behind the man-made dam. Due to the fact that the bridge has been completely immersed in freshwater, it is likely that this 175-foot span remains intact.

Stowe Hollow Bridge in Vermont, also known as "Emily's Bridge", was built in 1844. The locals call it Emily's Bridge because it is Emily, they believe, who haunts it.  In 1849, Emily wanted to marry a man her family did not approve of.  Though forbidden to marry, the couple decided to elope and meet one night, on Stowe Hollow Bridge. Emily waited for hours for her lover to join her.  Broken-hearted, Emily hung herself from one of the rafters.  Now, her angry, desperate ghost haunts the bridge, waiting for her fiancé to return to her.  Many locals refuse to cross this bridge at night because they believe it is Emily who shakes their cars, and sometimes, may even slash visitors with invisible claws.  Tales of horses, people, and cars being slashed by these invisible claws have run rampant for 150 years.  Others have heard a woman weeping.

Sach's Covered Bridge in Adam's County, Pennsylvania, was built in 1854 and supposedly haunted by three Confederate soldiers. They deserted their posts and when captured, were hung from the rafters inside Sach's Bridge.  Folks who have taken pictures of the inside of this covered bridge get strange orbs on the film.  When inside the covered bridge, many people even report feeling cold spots.

The Concord Covered Bridge in Smyrna, Georgia, is a one-lane bridge, built in 1872. Supposedly, if you park on the bridge, turn off your lights, and place a Snicker's bar on the roof, you will hear ghostly pattering and then the Snicker's bar will be gone.  The ghostly pattering is of children who drowned in the creek below. 

Some people believe a woman haunts the Van Sant Covered Bridge in New Hope, Pennsylvania. Others believe it is a highwayman who was murdered here. The woman, supposedly, threw her baby off of the bridge and it drowned in Pidcock Creek.  As the legend goes, many years ago a young woman got pregnant out of wedlock.  Her family wanted nothing to do with her and her child. Upset, she crept out in the middle of the night with her baby in her arms and headed to the nearby bridge. Once there, she flung her baby into the water and then hung herself from the bridge’s rafters.

This particular legend refers to the Van Sant Bridge in southeastern Pennsylvania, but different iterations of it are associated with several different so-called “Crybaby Bridges” across the United States. Whatever the particular details might be, the core elements of the myth remain the same: a child (or multiple children) met an untimely death at the bridge; the bridge is therefore now haunted, and the haunting manifests in the form of ghostly cries of the departed children that can still be heard to this day. In the case of the Van Sant Bridge, the story goes that if you park your car in the middle of the bridge you can hear not only the wail of the poor forlorn babe but also the toes of the hanging woman scraping your car roof. Apart from the unwed mother of the crybaby legend, the Van Sant Bridge is also reputed to have been a hanging place for horse thieves.

Jericho Covered Bridge in Joppa, Maryland, was built in the early 1800s. During the Civil War, several lynchings were reported to have occurred on this bridge.  If you drive your car onto this bridge late at night and look in your rearview mirror, you are supposed to be able to see the image of a dead person swinging from the rafters.

Glasgow, Kentucky. A covered bridge exists here where, legend says, is haunted by the sounds of an axe hitting a chopping block.  What's being chopped?  A head, of course.  In the 1800s, a slave kidnapped the daughter of his wealthy master and took her back to the covered bridge.  He cut off her head with an axe.  People say if you drive onto the bridge and roll down the car windows, you can hear the sound of the axe hitting the chopping block.

The Colville Road Covered Bridge in Paris, Kentucky, is haunted by a girl killed in a car wreck with her boyfriend. Returning from the prom, they prepared to stop at the bridge and instead careened into the water below.  If you sit in your car in the middle of the bridge, headlights might come up behind you, but when you look you see the car has fallen into the water.

The Stonelick Covered Bridge in Milford, Ohio, built in 1878, is home to urban legend. It is said that you can summon the apparition of a hanging man while on the bridge. To do this, you stop on the bridge, near its only window, and shut off your engine. Then, flash your headlights 3 times. According to the legend, at this point, you will see the apparition of a man hanging by his neck in the trees by looking out the window. Your car will then not start again until the apparition disappears.

And finally, The Eunice Williams Covered Bridge marks the site where the life of a young mother was abruptly cut short, just hours after the Deerfield Massacre. Nowadays, legend holds that Mrs. Williams never left the place where she died. It was still dark on the morning of February 29, 1704, when 300 warriors from the French Army and their allies from the Abenaki and Mohawk tribes crept into Deerfield. The French and British were fighting Queen Anne’s War for control of the continent. The little New England town barely knew what had hit it before houses were plundered and burned, livestock was killed, 56 residents were murdered and 112 were captured. Those 112 would spend the next few months hiking to Canada. 

Among the 112 captured were the Reverend John Williams, five of his seven children, and his wife, Eunice, who was in no shape to make the trek to Canada; she had given birth just a day before. Her baby did not survive the attack. Unable to make the journey, Eunice collapsed and was struck down by a tomahawk not far from her husband and surviving children. 


Some say that Mrs. Williams haunts the river by the bridge in remembrance of the violent death she faced: struck down by a tomahawk in icy waters while her family watched, just hours after her newborn was torn from her arms and killed. Others say that she appears to passersby’s whom she mistakes for her family. After all these years, perhaps she still waits for them to come back for her.

 

To understand Covered Bridge Facts and Legends better, visit:

• • Bridgehunter - - - www.bridgehunter.com
  • Covered Bridges - A Close-up Look  - - -  Alan Giagnocavo and HABS
  • Bucks County Covered Bridge Society  - - -  www.buckscountycbs.org
    
    

 

Covered Bridge Restoration

The art of covered bridge restoration and repairing covered bridges properly is the primary means of keeping bridges in service and preserving the craft that went into building them for future generations to appreciate. The investment requires decision-makers and contractors to understand the importance of its original construction and engineering. The consideration to repair using original surviving bridge components is an important cornerstone of the National Historic Covered Bridge Preservation Program.

 

   Covered bridges were usually constructed of timbers native to the area; the range included spruce, poplar, oak, walnut, chestnut, red cedar, and white pine. Shingles often were used for the roofs, although some builders used galvanized metal or tin.  In covered bridge restoration, preserving the authenticity of each bridge requires locating the same type of timber that was originally used during their construction.  That in itself can be very costly as several of these tree species have nearly vanished due to disease and urban development. Refurbishment projects often call for maximum use of original parts and that replacement parts be as close to authentic timber as possible. Some modern covered bridges, however, have glue-laminated timber, the type of wood commonly used for soaring church arches. The pieces have consistent quality throughout and can be cut into specific shapes unique to a particular bridge’s construction.

   Most of the bridges that remain and continue to carry both vehicular and pedestrian traffic have undergone some covered bridge restoration and preservation work over the bridges' lifetime. Repairs have included strengthening to increase load capacity, replacement of deteriorated members, roofs, and sidings, and addition of arson prevention alarm systems in some.  In a number of cases, the bridges have been re-engineered keeping only the external appearance the same.

   The preference when restoring covered bridges is to keep them open for today’s vehicular traffic even though they were not designed as such. Many times this is done by keeping the external appearance but reengineering the structure. In order to truly restore a historic covered bridge, however, not only the external appearance but the engineering aspects and material integrity should be preserved, while any proposed strengthening method is complementing the original architecture. Since these structures are listed, or eligible to be listed, with the National Register of Historic Places, any strengthening methods recommended need to be in line with the Secretary of Interior’s Guidelines for the preservation of historic structures.

   Covered bridge restoration may include replacing deteriorated materials, roofs, siding, or decking to strengthen the loading capacity and sustain bridge function. More intense restoration to re-engineer the truss design is sometimes required to maintain structural integrity as well as the external appearance.

   Regardless of which type of wood is used, or the size of the restoration, covered bridge restoration is not cheap, nor is it quick. Restorations may range from weeks for smaller projects, to years for complete rehabilitation, which no doubt becomes a burden for local traffic.  Funding can be quite difficult as well. Some bridge refurbishment funds are available through ISTEA, a federal program that provides for the enhancement of historical transportation projects.

   In addition, many states have their own funding mechanisms. For example, the Pennsylvania Historical and Museum Commission give bridge preservation grants and also has set up an approval process for refurbishment projects. If not for that, inferior workmanship or people who aren’t concerned about using original materials or engineering practices would be a major concern.

   In Oregon, the state lottery allocates some of its revenues to covered bridge restoration and preservation efforts. Another state, Kentucky, provides matching funds for ISTEA-allocated projects. While refurbishment is mostly viewed as a public good, this does not always translate into dollars. The general public is very interested in having covered bridges restored and refurbished, but finding the funds for a major restoration can become quite a challenge.

   While some people may believe that today’s covered bridges are antique and delicate, therefore should be looked at and admired, rather than used. This is not actually true. It might seem that a covered bridge restricted to light-duty use would be in better shape than one that still bears the weight of automobiles, but that is not always correct. Better maintenance generally is given to bridges that must bear the weight of vehicles.

   Much like a muscle, covered bridges have a “use it or lose it” character to them. Interestingly, covered bridges are in much better condition when they are used. With wooden bridges, the compression, tension, and flexing that come from being used keep the wood from becoming stiff and brittle; a used covered bridge stays supple and safe.

   Understandably, there are plenty of fans of covered bridges. Thus, even when cities and towns are not on board with preserving them, covered bridge lovers sometimes band together to do it themselves, appealing to other fans of covered bridges to help them keep the bridges strong and standing. A list of some of the Covered Bridge Societies and Organizations can be found on this site, along with their contact information.

 

To read more about covered bridge restoration, you can visit:

• America's Covered Bridges  - - -  by Terry E. Miller and Ronald G. Knapp
• Historic American Covered Bridges  - - -  by American Society of Civil Engineers Brian McKee
  
  

 

Patented Covered Bridge Truss Designs  A patented covered bridge truss is a structure that consists of members organized into connected triangles so that the overall assembly behaves as a single object. Patented Truss designs are most commonly used in bridges, roofs, and towers.

   A patented covered bridge truss is made up of a triangle or a web of triangles joined together to enable the even distribution of weight and the handling of changing tension and compression without bending or shearing. The triangle is geometrically stable when compared to a four-sided (or more) shape which requires that the corner joints are fixed to prevent shearing from excessive stress from use.

   

   A patented covered bridge truss is a structure that consists of members organized into connected triangles so that the overall assembly behaves as a single object. Patented Truss designs are most commonly used in bridges, roofs, and towers.

   A patented covered bridge truss is made up of a triangle or a web of triangles joined together to enable the even distribution of weight and the handling of changing tension and compression without bending or shearing. The triangle is geometrically stable when compared to a four-sided (or more) shape which requires that the corner joints are fixed to prevent shearing from excessive stress from use.

   Covered bridge trusses consist of triangular units constructed with straight members. The ends of these members are connected at joints, known as nodes. They are able to carry significant loads, transferring them to supporting structures such as load-bearing beams, walls, or the ground.

   In general, patented covered bridge trusses are used to achieve long spans, minimize the weight of a structure, and support heavy loads. Trusses are typically made up of three basic elements: a top chord which is usually in compression a bottom chord which is usually in tension, and bracing between the top and bottom chords.  The top and bottom chords of the truss provide resistance to compression and tension and so resistance to overall bending, whilst the bracing resists shear forces.

   The efficiency of trusses means that they require less material to support loads compared with solid beams. Generally, the overall efficiency of a truss is optimized by using less material in the chords and more in the bracing elements.

   Early covered bridge trusses were designed without an understanding of the engineering dynamics at work.  It wasn’t until 1847, that American engineer, Squire Whipple, published the first correct analysis of the way a load is carried through the truss, which enabled him to design stronger bridges with fewer materials.

   American-covered bridges use about 18 different types of patented covered bridge trusses. Each consists of vertical members, called posts, and diagonal members. The vertical and diagonal members hold together the upper and lower chords, which serve as horizontal beams. These trusses, ranging in complexity from simple triangles and lattices to X-shapes, absorb the stress of vehicle weight and transfer it to the abutments. This construction technique made it possible for wooden pieces to span a distance much greater than the length of any single piece of lumber.

 

   
The king post truss is used for simple roof trusses and short-span-covered bridges. It is the simplest form of truss in that it is constructed of the fewest truss members (individual lengths of wood or metal). The truss consists of two diagonal members that meet at the apex of the truss, one horizontal beam that serves to tie the bottom end of the diagonals together, and the king post which connects the apex to the horizontal beam below. A bridge would require two king post trusses with the driving surface between them. A roof usually uses many side-by-side trusses depending on the size of the structure. The oldest surviving roof truss in the world is a king post truss in Saint Catherine's Monastery, Egypt, built between 548 and 565.

A multiple king post truss is a truss that can be thought of as a cross between a king post truss and a queen post truss. Installing this type of truss is an easy way to stretch the span capability of a truss. It allowed the construction of bridges about twice the length of a Kingpost-covered bridge truss design. 

 

The Queen Post truss design forms an elongated, topless triangle with support posts at each end.  Although it is still a simple design, the Queen Post patented truss permits greater covered bridge lengths than the King Post truss. The longest Queen post bridge was 100 feet using a single truss system. There are 40 of this type of bridge still remaining across the state of Pennsylvania.

 

   Early North American bridge builders actively pursued patents for their designs in an attempt to gain more bridge construction contracts. A few of the very first covered bridge patents involved general bridge construction, but by 1797, there were several that involved specific schemes for timber arches. Among others, Timothy Palmer received a patent and began construction of his Permanent Bridge only a few years after this, his initial patent.

   Lewis Wernwag was born in Germany in 1769 and obtained a covered bridge truss patent in 1812, which was used in another remarkable bridge crossing the Schuylkill River at Philadelphia’s Upper Ferry. The huge 340 ft. trussed arch span was quickly termed the "Colossus" and represented a major triumph in bridge construction, with its attractive and apparently efficient use of timber, supplemented with iron rod bracing members. Wernwag owned a metal works company and relied more on early forms of metal connections and components rather than on traditional timber joinery only. He received a second patent in 1829 for improvements in his structure. Regrettably, his “Colossus” bridge was lost to fire in 1838.

  

Theodore Burr obtained the first of his many covered bridge truss patents in 1804. His second patent was issued in 1817. Burr's trademark design dates from this patent. He extended curved lower ribs that had reached only bottom chords, up along the trusses, all the way to the top chord. This superposition of arch and truss forms seems to have been influenced by earlier bridges built in Switzerland.

  The resulting structure has been described as a combination of conventional trusses (parallel chords with compression diagonals) and supplemental arches. One of Burr's early examples of this bridge form, and probably the basis for his 1817 patent, was his Union Bridge crossing of the Hudson River between Lansingburgh and Waterford, NY, circa 1804. This was a significant structure; 244 m (800 ft) long, with four spans. The structure was rebuilt after being in service for some time, including a roof and siding. This heavily braced and counterbraced structure exemplified what today is called a Burr Arch.

Ithiel Town (1784-1844) of New Haven, CT, was a prominent architect known for designing many types of buildings. He also planned many bridges, initially experimenting with various truss arch combinations before he landed on his patented covered bridge lattice-style design. Town wanted to devise a structure that would require fewer carpentry skills than was required by the intricate joinery details of some of the early bridges. Using only planks joined with round wooden pegs, he began developing a lattice style of truss construction and obtained his first patent in 1820.

   He was nearly as good a promoter as an inventor, and the lattice truss design became very popular, although it has been criticized for its apparent waste of material. It could be “built by the mile and cut off by the yard,” was his sales pitch. This truss layout proved to be very adaptable. It could include heavier members for longer spans, and could even be doubled up to include two layers of web members and three layers of chords for heavy loads, such as those generated by the railroads. A few of his bridges were built with such heavy members that they became identified as a timber lattice, as compared with the more common plank lattice. The most famous of the surviving timber lattices is found in the Windsor, VT-Cornish, NH, covered bridge over the Connecticut River, which remains one of the longest two-span covered bridges in the United States.

 

   

Stephen Long (1784-1864) had a varied background and career. He gained his experience as a timber bridge builder while serving in the U.S. Army. Long was commissioned to locate, plan, and build the Baltimore and Ohio Railroad. 

 

   He chose to use a standardized covered bridge truss for all his spans, with timber counterbraces in all the panels. With the addition of timber wedges at the bearing joints between the posts and diagonals, he found that he had better control over the trusses' as-built geometry. He obtained his first bridge patent in 1830 and established himself as another wooden truss patentee when he invented the Long truss design. It was the first wooden truss in America where a few mathematical calculations were entered. His truss design was a panel truss that needed no arches. When viewed from the side, the Long truss resembled a series of Boxed X’s. This truss design vied with Town’s lattice design truss for favor among the land railroad networks, toll bridge companies, and town highway planners for about ten years. After 1840 though, both Town’s and Long’s patented covered bridge trusses were almost totally eclipsed by the introduction of the Howe truss design.

William Howe (1803-1852) made a major contribution to the evolution of timber-covered bridges by being the first to use metal components as primary members within an otherwise timber truss. He used parallel timber chords, with timber diagonals and counters in the panels, but he used round iron rods for the vertical tension members. The threaded rod ends allowed easy adjustment of the structure, to keep it tight both during and after erection. Many modifications were made over the years to Howe's original design to address various desired details, but his truss was quickly adopted to withstand the heavy loads on railroads. The popularity of the Howe truss continues today. It is often selected when constructing new covered bridges. Howe's modification was a major reason for the short life and reduced popularity of Stephen Long's covered bridge truss-which was essentially the same but without the iron rod verticals.  Howe’s truss design resembled Long’s truss design so much that Colonel Long claimed patent infringement for years, and he never got any satisfaction on his claim from the patent office.

   
Thomas Willis (T. W.) Pratt and his father Caleb were well-known engineers/architects in New England in the middle of the 19th Century. T. W. attended college in Troy, NY at the Rensselaer Institute, later Rensselaer Polytechnic Institute. He did not graduate, which was not uncommon in those days, as only about a third of those who matriculated graduated. He returned to Massachusetts to work on the Boston and Worcester RR and the Providence & Worcester RR in the mid-1840s. Pratt no doubt had seen Howe’s Springfield Bridge, patented in 1840, across the Connecticut River and was aware it was adopted by many railroads replacing the Long and Towne Trusses. The span of the Howe Truss was limited, as the diagonal compression members were susceptible to buckling as their length increased with an increase in span.

   Pratt basically took the Long patented covered bridge truss and replaced the wooden diagonal members with two iron rods with threads and nuts, while keeping wooden verticals in compression, on both ends to make necessary adjustments to obtain the required camber and pre-stress. Since longer spans were possible with the long members in tension, the bridge appeared to correct some of the problems with the Howe Truss. T.W., along with his father, obtained a patent, #3,523, on April 4, 1844, for a TRUSS FRAME OF BRIDGES (Truss Bridge). Not many bridges in wood and iron were built to this Patent.

 

Developed in 1846 by Horace Childs, the Childs patented covered bridge truss was used exclusively after 1883 by Ohio bridge builder Everett Sherman. The truss simply added diagonal iron rods to a multiple kingpost design. E.S. Sherman, a bridge builder from Vermont, won the contract to build 14 Childs Truss bridges and one Kingpost Truss bridge in Preble County between 1886 and 1896. He moved to Eaton right after the storm in 1886 and won the contract due to the fact that the bridges he built were so sturdy, economical, and quickly erected. The following bridges are still standing today in different parts of Preble County, Ohio.

 

Robert W. Smith was born in 1833 in Miami County, He worked as an apprentice for several years before going out on his own. His very first invention, though never patented, was a self-supporting roof truss for large barns. Smith was living in Tippecanoe City, Ohio, in 1867 when he was granted a patent for a wooden truss bridge. Later that year, he formed the Smith Bridge Company and moved to Toledo. He built five bridges in Ohio and Indiana in 1867, 22 in 1868, and 75 in 1869. Also in 1869, a second patent was granted to Smith on an improved covered bridge truss. However, in his bridges, Smith never exactly followed his patented designs but constantly made changes to improve strength and design. The Smith Bridge Company maintained a yard in Toledo where all timbers were cut and first fitted together for each bridge. They would then be disassembled and shipped by rail or boat to the bridge site for reassembly by either a company carpenter, a Smith Company agent, or a local crew of carpenters. So in a sense, Smith was the Henry Ford of the covered bridge business.

   A typical Smith truss rarely had vertical posts. The timbers between the two chords were braces set at an angle. Smith truss bridges were four distinct types: Type 1 was the original patent with two posts and crossed timbers in the center panel; Type 2 had open V-timbers; Type 3 was a reinforced truss with two diagonal timbers; Type 4 was the strongest as it had further reinforcements of both double and single sets of diagonals.

   Prior to 1977, there remained many original documents concerning Smith and his proposed bridges. Two handwritten bids gave the cost of proposed bridges. For a superstructure with the Smith Patent truss, the following costs were quoted: an 80-foot span, $11.50 per linear foot, plus $250 extra for siding and roof; a 100-foot span, $14 per linear foot, covering extra; a 120-foot span complete with siding and roof at $19.50 per linear foot; and a 150-foot span complete at $21.50 per linear foot. He eventually received contracts for two Howe truss bridges in Carroll County, Ohio: the Lancaster and Adams Mill. Both are still standing.

   The Smith Bridge Company built 21 bridges in Indiana. Regardless of whether a bridge was built by Smith or an agent, Smith always guaranteed the structure. Bridges with Smith-constructed trusses were built in Indiana, Ohio, Pennsylvania, and Oregon. Some 20 years after its inception in the early 1990s, the Smith Bridge Company was taken over by the Toledo Bridge Company. Smith then became interested and involved in real estate until his death in 1998.

   

   Peter Paddleford (1785-1859) was a bridge builder from Littleton, New Hampshire. He was a user of the Long truss. He created his own truss by modifying the Long truss, and stiffening it with a system of interlocking counterbraces. His work was challenged by the holders of the Long Truss patents because of its similarities.

   The Paddleford patented truss resembles the Long truss in that the vertical posts are lapped, or notched, into the upper and lower chords; the braces set into notches in the vertical posts. Both designs use counterbraces for a special purpose. In the Paddleford truss, channels are cut into the inner chord planks and into the faces of the braces and vertical posts where the counterbraces cross. The posts, braces, and chords are locked together into one unit by the counterbraces. An inside arch is often added.

   They both use a parallel chord system with vertical posts, and they both use braces and counterbraces. But the designers each had something different in mind. Long designed his truss to implement his pre-stressing idea while Paddleford tried to make the braces work both in compression and tension by having the braces lap overall of the frame members. He tried to use wood like people later used iron rods. It's hard to make a tension joint with wood unless you have a lot of distance to do it in. It is a complicated joinery.

   Paddleford did it with the counterbraces by running them through the series of tight-fitting channels across members that are under loading stresses. The stresses tend to re-align the truss members, causing them to lock onto the counterbraces. While the Paddleford covered bridge truss design was never patented because of court challenges threatened by the owners of the Long Truss patent, it was widely used, especially in New Hampshire where many exist today. It was also popular in Orleans and Caledonia counties where Vermont's last two Paddleford bridges stand.
  

In 1839, Haupt patented a covered bridge construction technique called the Haupt Truss. Two of his Haupt truss bridges, both built in 1854, still stand in Altoona and Ardmore, Pennsylvania. The brace configuration in Haupt’s truss implementation distributes, at least for the first several truss panels, compression forces more directly to the abutments. This is a key feature of the Haupt patented covered bridge. In 1840, Haupt was appointed a professor of mathematics and engineering at Pennsylvania College. He drew the attention of J. Edgar Thomson who became chief engineer of the Pennsylvania Railroad. Haupt returned to the railroad business in 1847, accepting a position as a construction engineer on the Pennsylvania Railroad, and then becoming its general superintendent from 1849 to 1851. Haupt and Thomson designed the Horseshoe Curve (now a National Historic Landmark) which enabled the Pennsylvania Railroad to cross the Allegheny Mountains and reach Pittsburgh, Pennsylvania.

  From 1851 until 1853, Haupt was the chief engineer of the Southern Railroad of Mississippi, then became the Pennsylvania Railroad's chief engineer until 1856; in the latter position, he completed the Mountain Division with the Allegheny Tunnel, opening the line through to Pittsburgh. He was the chief engineer on the five-mile (8 km) Hoosac Tunnel project through the Berkshires in Western Massachusetts from 1856 to 1861.

 
The Warren patented covered bridge truss was awarded in 1848 to James Warren and Willoughby Theobald Monzani, and consists of longitudinal members joined only by angled cross-members, forming alternately inverted equilateral triangle-shaped spaces along its length, ensuring that no individual strut, beam, or tie is subject to bending or torsional straining forces, but only to tension or compression. Loads on the diagonals alternate between compression and tension (approaching the center), with no vertical elements, while elements near the center must support both tension and compression in response to live loads. This configuration combines strength with the economy of materials and can therefore be relatively light. The girders being of equal length, it is ideal for use in prefabricated modular bridges. It is an improvement over the Neville truss which uses a spacing configuration of isosceles triangles. A Warren truss or equilateral truss is a type of engineering truss employing a weight-saving design based on equilateral triangles.

   Bridge historians and early textbooks generally call a truss with alternating compression and tension diagonals a Warren; however, sometimes it is called an equilateral truss since all panel lengths and diagonals are of equal length creating a series of equilateral triangles. When the panel lengths are shorter than the equal-length diagonals, it is sometimes called an isosceles or isometric truss. James Warren and Willoughby Monzani's patent of 1848 in England was based on similar trusses that were built in France by Alfred H. Neville and a patent that was granted in England to William Nash in 1839 on a similar design. Warren and Monzani were well-known English engineers, and their design was for a truss that could be used as a deck or a through truss.

   
A Brown patent covered bridge truss is noted for its economical use of materials and is named after the inventor, Josiah Brown Jr., of Buffalo, New York, who patented it on July 7, 1857, as US patent 17,722. The Brown truss is a box truss that is a through truss (as contrasted with a deck truss) and consists of diagonal cross-compression members connected to horizontal top and bottom stringers. There may be vertical or almost vertical tension members (which the patent application diagram does not show) but there are no vertical members in compression. In practice, when used in a covered bridge, the most common application, the truss is protected with outside sheathing.

  The floor and roof are also trusses, but are horizontal and serve to give the truss rigidity. The bottoms of the diagonals tend to protrude below the sheathing. This type of truss is particularly suited for timber structures that use iron rods as tension members. The Brown truss is noted for the economy of materials as it can be built with very little metal. The Brown truss enjoyed a brief period of favor in the 1860s and is known to have been used in four covered bridges in Michigan.

   
Reuben L. Partridge (September 10, 1823 – July 17, 1900) was an American pioneer and engineer in Union County, Ohio, known locally as "The Bridge Builder." Partridge received a patent for a design that was remarkably close to the Smith's truss. Designed and patented in 1872, after local bridge designs proved ineffective against road traffic and heavy rains. It became the standard for covered bridges built in central Ohio in the late 1800s and early 1900s. Due to the design of local bridges at the time, they would sometimes crumple under the sudden stress of heavy rains. Partridge saw this and worked to design a new truss and brace system to support additional stresses including vehicle traffic. In 1855, he built the first self-supporting bridge in Union County, Ohio. On June 11, 1872, he received a patent for a new U-shaped truss bridge design, the "Partridge Truss" (Patent #127,791). As of 1882, Partridge was responsible for having built 90% of the bridges in Union County, and by 1883 had built over 125 bridges. In 1886, he moved to Columbus and worked as the Vice President of the Columbus Bridge Company for the next 10 years. While most of the bridges he built were wooden covered bridges of the "Partridge truss" design, he did design and build some iron bridges while with Columbus Bridge Company.

   Partridge moved back to Marysville in 1896. He died 4 years later, on July 17, 1900, from complications, after breaking his leg falling through a bridge he was supervising the removal of in Taylor Township north of Marysville. Over the course of his life, Partridge built over 200 bridges across Union County and central Ohio. He was also an active member of the first militia formed in Union County, a Marysville city council member, township clerk, township trustee, and avid supporter of the local veterans of the Mexican War and Civil War. He is buried at the Oakdale Cemetery in Marysville.
  
A Post truss is a hybrid between a Warren truss and a double-intersection Pratt truss. Invented in 1863 by Simeon S. Post, it is occasionally referred to as a Post patent truss although he never received a patent for it. (Iron rods indicated by dashed lines). The Ponakin Bridge and the Bell Ford Bridge are two examples of this truss and were one of the major bridge forms used in developing the national railroad network, including major crossings such as that of the Union Pacific Railroad over the Missouri River (the Bell’s Ford Bridge in Jackson County, Indiana, collapsed in 2006).
 
McCallum, 1867 patent. Posts are flared slightly. One example is the Powerscourt Bridge in Québec. The Powerscourt Covered Bridge was designated a national historic site of Canada in 1984 because it is the only known example of a McCallum inflexible arched truss bridge still in existence; it is one of the oldest covered bridges that exists in Canada.

The heritage value of Powerscourt Covered Bridge lies in its age and in its use of rigid (or inflexible) arch-truss construction technology. This technology, more commonly used for railway construction, was invented by New York bridge builder Daniel McCallum in 1851. Also known locally as Percy Bridge, it was built in 1861 to carry traffic on the First Concession Road over the Châteauguay River.

Key elements of the bridge include the linear footprint, the rectangular massing, and the curved roofline. The use of vertical wooden board and batten weatherboard siding are key to the McCallum rigid arched truss, as is an opening between the roof and side covering.
 
No Name Truss (neither a Haupt nor a modified Burr), two examples: Sayres Bridge in Orange County, Vermont, and Bath Village Bridge in Grafton County, New Hampshire.

To learn more about patented covered bridge trusses, visit:

• Covered Bridges of Yesteryear  - - -  www.lostbridges.org
• The Architecture and Building of Bridges - - - by Alan Benau Jr.
• Parke County, Indiana  - - -  www.coveredbridges.com
  
  

Covered Bridge Societies and Organizations

Covered Bridge Societies began forming when the high cost of covered bridge maintenance made counties replace them with lower-maintenance modernized bridges. Besides the growing presence of Covered Bridge Societies, various organizations and covered bridge advocates became involved in saving this glorious part of history as well. Some of these Covered Bridge Societies, Associations, and Covered Bridge publications are listed below.

 

Covered Bridge Societies and Associations:

Indiana Covered Bridge Society  - - -  www.indianacoveredbridges.org

National Society for Preservation of Covered Bridges  - - -  www.coveredbridgesociety.org

New York State Covered Bridge Society  - - -  www.nycoveredbridges.org

Ohio Historic Bridge Association  - - -  www.oldohiobridges.com/ohba.htm

Oregon Covered Bridge Society - - -  www.covered-bridges.org/about.htm

Theodore Burr Covered Bridge Society of Pa.  - - -  www.tbcbspa.com

Bucks County Covered Bridge Society  - - -  www.buckscountycbs.org

Vermont Covered Bridge Society  - - -  www.vermontbridges.org

 

Informative Covered Bridge Sites:

Dale J. Travis Covered Bridges  - - -  www.dalejtravis.com/bridge/cbridges.htm

Covered Bridges of Yesteryear  - - -  www.lostbridges.org

Covered Bridges of Maine  - - -  www.maine.gov/mdot/historicbridges/coveredbridges

Parke County, Indiana  - - -  www.coveredbridges.com

Maryland Covered Bridges  - - -  www.mdcoveredbridges.com/index.html

New Hampshire Covered Bridges  - - - www.nh.gov/nhdhr/bridges/index.html

Pennsylvania Covered Bridges  - - -  www.pacoveredbridges.com

Covered Bridge Info  - - -  www.glcp.uvm.edu/landscape_new/learn/

Bridgehunter - - - www.bridgehunter.com

 

International Covered Bridge Sites:

Swiss Timber Bridges  - - -  www.swiss-timber-bridges.ch

Chinese Covered Bridges  - - - www.intrans.iastate.edu/app/uploads/sites/12/2019/03/LIU_AncientChineseTimberArchBridges.pdf

Chinese Covered Bridge History & Facts  - - -  www.built-heritage.springeropen.com/articles/10.1186/

 

Covered Bridge Publications: 

America's Covered Bridges  - - -  by Terry E. Miller and Ronald G. Knapp

Historic American Covered Bridges  - - -  by American Society of Civil Engineers Brian McKee

Chasing Covered Bridges and How to Find Them  - - -  By Paul Parrott

Oregon Covered Bridges  - - -  by Marshall Powell

Covered Bridges - A Close-up Look  - - -  Alan Giagnocavo and HABS

China's Covered Bridges: Architecture over Water - - - by Ronald G. Knapp and Terry W. Miller

Covered Bridges of Alabama  - - -  by Will Elrick and Kelly Kazek

Pennsylvania's Covered Bridges  - - -  By Fred J. Moll

Indiana's Covered Bridges  - - -  by Robert Reed

New Hampshire Covered Bridges - - -  by Harold Stiver

Vermont Covered Bridges: a Traveler's Guide  - - -  by Eric Riback

World Guide to Covered Bridges

The Architecture and Building of Bridges - - - by Alan Benau Jr.

 

If your organization or publication is not included in these lists, please contact us.