CHEMIN HAMEL/ SHERBROOKE/ QUEBEC CITY, QUEBEC, CANADA-
A rare gem of a historic bridge is no more, and police suspect faul play. The Pont Davy was a wooden deck truss bridge, whose design resembles a truss bridge built almost two centuries ago but it was 70 years old when it met its demise. The bridge was a two-span Town Lattice deck truss bridge, with a total length of 200 meters. Built in 1951, the bridge carried a local road until its abandonment a couple decades ago. It was first discovered by pontists 10 years ago and the bridge has become a popular tourist attraction. Its red Town lattice trusswork is one of the youngest that was built, and its natural surroundings made it a popular stop for hikers and photographers alike. Work had been progressing on finding out its history prior to its destruction.
Police and criminal investigators are looking into the cause of the fire, which occurred at the bridge on 23 September, causing the entire structure to collapse. No one was injured in the disaster. Since then, authorities have suspected arson and are looking for person(s) responsible for the fire. Information and leads should be reported to the local authorities immediately.
More information and photos of the bridge can be found via link here:
The Pont Davy was one of over a dozen covered bridges that are remaining in Quebec. A tour guide on the bridges can be found here:
It’s also in the Tour Guide page of the Chronicles. The Chronicles will keep you posted on the latest on the arson at the bridge.
A few months ago, the Chronicles did a special on the Thacher truss bridges, designed and patented by Edwin Thacher and first used in 1884 in the state of Iowa. To refresh the reader’s memory, the Thacher truss is a combination of Warren, Kellogg and Pratt truss with an A-frame in the center panel of each truss span. While the Wrought Iron Bridge was reported to have built these trusses, using the exact design prescribed by Thacher, the King Bridge Company built the hybrid version of the design that resembled a Warren truss bridge with a center panel that is half the length of the outer panels. If you count in the Phillips Mill Crossing in Rockford, the pony truss variant located west of Milford and the three hybrid Thachers in Emmet County, Hamlin County (South Dakota) and near Hastings, Minnesota, a total of ten Thachers were reported to have been built.
With this mystery bridge, as seen in the picture, let’s make it eleven Thachers.
Fellow pontist Luke Harden came across this picture of a Cedar River crossing in Waverly. According to the information, the bridge (which is in the background behind the wagon bridge) served the Chicago and Great Western Railroad and featured at least three spans of the Thacher truss. The bridge was about 400-500 feet long, looking at the picture more closely, with each truss span being about 120 feet long. The bridge served traffic until a train derailment brought down the entire structure in 1914.
This means that the structure was in place for no longer than 30 years. Even more curious is the fact that the trusses were built using a combination of wood and steel, making the railroad bridge look rather unusual for the materials used for bridge construction. While bridge builders used iron and wood for construction in the 1860s and 1870s, it is even rarer to see a wooden truss bridge built using steel truss support, although one is reported to exist in Allamakee County in the Red Bridge (abandoned for over four decades).
While the bridge no longer exists- a replacement was built but only existed for another 30 years before the railroad abandoned the line and removed the bridge- piers from the structure can be seen from Adams Parkway Bridge, located next to it in the northeast end of the city. Yet more information about the bridge is needed. For instance: when exactly was the bridge built? What were the exact dimensions? Who built this bridge? And lastly what was the cause of the mishap. Any information on the bridge can be submitted using various channels including the comment section of the Chronicles.
Furthermore, information is needed for the Adams Parkway Bridge, for the two-span truss bridge existed before its replacement in 1968, yet its markings is similar to a bridge built by the Clinton Bridge Company at the turn of the century, including the portal bracings. Both bridges will be included in the Iowa Truss Bridge book, which is being compiled by the author even as this article is being posted. Any information would be much appreciated.
With this latest discovery, it leads to the question of how many other Thacher truss bridges were built in Iowa, let alone in other parts of the US. We’ll find out more as other pontists and people finding old photos will bring bridges like this one to the attention of the readers and other interested people alike.
Here’s a quiz for you: How many of you had either a set of Lincoln Logs, Tinker Toys, or something similar to that, when you were a child growing up? And if so, what kinds of things did you build with your set? I remember when I was growing up, I used to build human beings with my set of Tinker Toys and covered bridges and telephone poles with Lincoln Logs. But like many engineers and bridge enthusiasts, I was different from those who were supposed to build log cabins and other skeletal structures, as was directed on the package. Yet if we go back 100 years, many engineers and bridge designers referred to the Erector Set to get their imagination going. It was a set of steel beams with nuts and bolts, which allowed them to spend hours perfecting their ideal building- or bridge.
Perhaps the person who built this bridge in California used the combination of the three to design and patent this truss bridge. The Dinkey Creek Bridge is a jewel that was found by one fellow pontist two years ago while hiking through the Sierra Nevada National Forest. Built in 1938 by the Civilian Conservation Corps, this bridge spans the creek which snakes its way through the forest from neighboring Fresno, in Fresno County. It is one of the most unique examples of bridges that were built during the era, where President Franklin Roosevelt encouraged bridge designers and builders- most of them out of work because of the Great Depression- to build something that will attract tourists and last forever. And for this bridge, it is something that is worth seeing. It was the first bridge to be built using Redwood trees and the first to use steel, split-ring timber-connecting devices, which enabled the bridge to handle heavy traffic, which was rare in this area when it served traffic. Yet the truss design can be confusing, for when looking at the pictures provided by Craig Philpott, it appears to be a Parker Truss because of its polygonal shape, even though the State of California considers it a bowstring arch bridge. While there are some examples of bowstring arches that have a polygonal-like shape, 90% of all bowstring arch bridges were built with the top chord creating an arch, like a bow and arrow, as seen with the Turkey River Bridge in Winneshiek County, Iowa (now extant). In addition, it is unknown who designed this unique bridge, let alone oversaw the construction of the bridge, even though a couple workers have been honored recently for their work.
This leads us to two questions about the Dinkey Bridge, our Mystery Bridge:
1. Is this bridge a bowstring arch bridge or a Parker truss bridge? Please ignore the fact that the bridge is a through truss.
2. While the CCC was responsible for the construction of the bridge, who designed the bridge and utilized the steel connectors? And who oversaw the whole process.
Have a look at the pictures and let the author know, using all the channels available. The bridge is listed on the National Register of Historic Places and is now a pedestrian bridge serving a local inn. It’s one of the bridges in the Sierra Nevada Mountains that is a must-see when passing through.
Special thanks to Craig Philpott for allowing the author to use the photos.
There is sometimes a misconception as to determining the meaning of a wooden covered bridge. Many people have a tendency of considering bridges, like the one above to be a covered bridge. Yet the definition of a covered bridge is different. A covered bridge is a truss bridge that is covered by siding and most of the time, a gabled roof. There are many examples of covered bridges that exist in the US and Europe, including the Marysville Covered Bridge, located at a park near Knoxville, Iowa.
But going back to this mystery bridge, the bridge made of wood is considered plainly a wooden truss bridge, whose wooden beams are connected with nuts and bolts but are neither pin-connected, welded nor riveted. There were numerous wooden truss bridges that were built during the second half of the 1800s and fewer that were built between 1900 and 1960. There are only a handful of these bridges that exist in the US for wood has the shortest lifespan of any bridges made of other materials, and is one with the highest maintenance- it needs to be varnished and painted regularly to ensure that they last just as long as bridges made of iron and/or steel.
The mystery bridge featured here is located in eastern California, spanning the Middle Yuba River between the Milton Reservoir and dam and the Jackson Reservoir, just 500 feet west of Heness Pass Road. The bridge features three spans of a double-intersecting Warren pony truss (shaped in a Howe lattice design) made of wood. Judging by its appearance in the pictures presented below, the wooden truss bridge features both riveted connections (on the top chords) and bolted connections, where intersecting beams are connected with bolts and nuts that were drilled into the wood. The bridge was discovered by Aimee Stubbs while on a camping/ motorcycle trip in 2011 only to revisit the bridge again this past summer.
The bridge appears to have seen better days as it partially collapsed some time ago (although it not pinpointed as to when it happened), and only one of the truss spans is still standing. Since it served a dirt road located not far from the county road, the bridge and road seemed to have been abandoned, with nature taking its course on both. To reach the bridge via dirt road would require walking to the structure, which is challenging given the landscape where the bridge is located. According to Stubbs, the Middle Yuba River is infamous for its recurring floods, causing damage and erosion to the bridge and the road. Yet there is no information on the bridge’s history that was found with the exception of the fact that the river separates both Sierra and Nevada Counties, two counties that were created in 1851-2 after seceding from Yuba County.
Ms. Stubbs has been researching this bridge since finding it for the first time and needs your help. With three spans, this bridge is one of the rarest in the country, if not the world. Yet its recent demise due to its collapse makes it even more important to find information on the structure so that people are aware of its existence (or at least its partial existence). If you have any information pertaining to the bridge, please contact her using the following information below. The Bridgehunter’s Chronicles will keep you posted as soon as information comes to light on this unique structure. If you know of another bridge that is similar to the one shown here and still exists today, please contact Jason D. Smith using the contact details below as well. That information will be added as well.
The Bridgehunter connects the past with the future through research and preservation of historic bridges in the present.