PORTLAND, OREGON- Mail order truss bridge- truss bridges with welded connections that are assembled at the company but taken to its final destination for installment as a pedestrian crossing- seems to be the norm nowadays. While they are easy to build and cost effective, they lack the aesthetic taste that should be characteristic for its surroundings.
Built in 1893, the bridge was a product of the Bullen Bridge Company of Pueblo, Colorado and was erected under the direction of Charles Loweth. It was deemed as the oldest historic bridge that served its original function in the state of Oregon, as it carried the Bull Water Pipeline Conduits 2 and 4, two of the important conduits that provide water to a quarter of the state’s population. For over 80 years, this Pennsylvania petit through truss bridge with Howe portal bracing (with ornamental features) and pinned connections ran parallel to the Lusted Road Bridge, another Pennsylvania Petit through truss bridge that carries vehicular traffic.
Since 2010 the Portland Waterworks has been in storage waiting for reuse somewhere else as a pedestrian bridge. After the two conduits were laid underground, running underneath the Sandy River, the bridge was rendered obsolete and was later dismantled, leaving the Lusted Road Bridge as the only historic bridge left to be seen as part of the Dodge Park complex.
The Portland Waterworks Bureau (PWB) and the Oregon State Historic Preservation Office (SHPO) are working together to give the bridge away to a known party that is willing to use it for recreational use. As the bridge is eligible for listing on the National Register of Historic Places, the bridge must not be destroyed or used for anything other than as a pedestrian crossing, even if the length of the bridge is 300 feet, very unusual for a Pennsylvania truss bridge built small enough to be used as a pedestrian or bike bridge. The deck width is 14 feet. The PWB and SHPO has a handbook guide with information about the bridge, how it is assembled and its historic significance, just to name a few items. They can be found on the PWB website by clicking here. Any party interested in the bridge will receive the structure in parts (as seen in the picture), making it easier to haul, plus some information on how to reassemble the truss bridge at its new location. Yet additional help in terms of funding for the relocation of the bridge as well as expertise from the historic bridge and preservation communities are available upon request.
If you are interested in purchasing the Portland Waterworks Bridge for reuse as a recreational bridge, please contact Kevin Larson of the Engineering Services Group. The contact information can be found on the same website by clicking here. The Bridgehunter’s Chronicles will keep you up to date as to when and where the Portland Waterworks Bridge will find its new home. It is possible that it could find a new home inside Oregon- a plus for many preservationists living in the state as well as those interested in seeing it reused again. Yet as has been seen in many cases, the Waterworks Bridge may end up out of state, like in Colorado, where a party in interested in bringing in bridges for recreational use. More on that in the Chronicles as the information comes in.
Spanning the Arkansas River near Canon City, the Royal Gorge Suspension Bridge still represents one of the best kept secrets as far as its historic significance is concerned. Built in 1929 with the main span of 880 feet and a total length of 1280 feet, its height over the Arkansas River has yet to be broken in the US- 965 feet to be exact. It had held the world record until the Millau Viaduct in France opened in 2004 and is still the fourth highest bridge in the world. It was listed on the National Register of Historic Places in 1983 and has been a place where stunts took place, whether it was bungee jumping or flying over and under the bridge, even though some of the stunts were fatal. A park was built surrounding the bridge where tourists can enjoy not only the bridge but its splendid view.
Now the bridge and the surrounding faciulities are facing a pains-taking task of rebuilding after a brush fire swept through the region yesterday, destroying at least three buildings at the park and causing damage to the decking of the unique suspension bridge. The fire was caused by lighting combined with dry conditions and has spread to include 3800 acres, marching its way toward Canon City. Thousands of people have already been vacuated and work has now focused on containment of the fire. Links to the fire can be found at the end of this article. According to officials, the suspension bridge is still in tact, which may be a blessing, given the rehabilitation done on the bridge in 1983, which featured new suspension cables and reinforcing the decking. There is hope that the suspension bridge itself, if it survives the fire, will be repaired and reopened to pedestrian traffic in a short time. Yet the park and the buildings on both ends will need to be rebuilt as damage to both areas are substantial. The Chronicles will keep you posted on the latest on the Royal Gorge Bridge and the fire that seems to be out of control at the time of this posting. Thoughts and prayers go out to those affected by the fire.
And now the answer to the question of naming the bridge type. As you will recall, in a posting from last Thursday, there was a post card of a bridge that spanned the Wapsipinicon River near Independence in Buchanan County, located in the northeastern part of Iowa. While some people may have found the answer through James Baughn’s website, there are some who are not familiar with that, nor the picture, as it was posted most recently and readers have not yet had a look at the picture until now.
I can tell you that I had written about this bridge type a few years ago as part of an essay for a history class at the university here in Germany, and there are some examples of this bridge type that still exist today, even though there are two different types of this truss type that three bridge builders had used during their days.
The answer: The Thacher Truss. In 1881, Edwin Thacher (1840-1920), an engineering graduate of Renesselaer Polytechnic Institute, invented and patented this unusual truss type. It is a mixture of four truss types: the Warren, Pratt, Whipple and Kellogg. While the Kellogg is a Pratt truss design featuring a subdivided panel supporting the original diagonal beams that connect the vertical beams, the Thacher features two sets of diagonal beams starting at each end of the truss bridge at the upper chord- one creates a panel similar to the Pratt truss, while the other crosses two or three panels before meeting the center panel, which forms an elusive A-frame. The bridge at Independence was the very first bridge that was built using this truss design. It was built in 1881 and was in service for over 40 years. Yet after having the design patented in 1885, Thacher went on to build numerous bridges of this type, most of which were built between 1885 and 1910. He later invented other bridge designs, some of which will be mentioned here later on.
While it was unknown how many of these types were actually built between 1881 and 1920, sources have indicated that Iowa may have been the breeding ground for experimenting with this truss type. Apart from the railroad bridge at Independence, the very first structure that was built using the Thacher, as many as four Thacher truss bridges were reported to have been built in the state. Among them include the longest single span truss bridge ever built in the state, the Philips Mill Bridge, spanning the Winnebago River outside Rockford, in Floyd County. Built in 1891, this 250 foot long bridge, dubbed as one of the most unusual truss bridges built in the country, was the successor to a two-span bowstring through arch bridge and served traffic until it was replaced in 1958. Other Thacher truss bridges built included one over the Shell Rock River north of Northwood (in Worth County), the Ellsworth Ranch Bridge over the Des Moines River in Emmet County and the Okoboji Bridge over the Little Sioux River in Dickinson County. Of which only the Ellsworth Ranch and Okoboji Bridges still exist today.
On a national scale, if one counts the two remaining Iowa bridges, there are five bridges of this kind left, which include the Costilla Bridge in Colorado, Linville Creek Bridge in Virginia, and the Yellow Bank Creek Bridge in Minnesota. Two additional bridges, the Parshallburg Bridge (2009) and the Big Sioux River bridge in Hamlin County (2009) have long since disappeared due to flooding/ice jams and structural instability, respectively. While the majority of the bridges mentioned here were constructed by the Wrought Iron Bridge Company in Canton, Ohio, the King Bridge Company in Cleveland constructed the Ellsworth Ranch, Yellow Bank and Hamlin County bridges, using a different hybrid of Thacher truss that was modified during James King’s reign as president of the bridge company (1892-1922). The Clinton Bridge and Iron Company in Clinton, Iowa built the only Thacher pony truss bridge in the Okoboji Bridge, the bridge that is featured in the next article. While the Ellsworth Ranch Bridge remains closed to traffic and seems to be abandoned, the Yellow Bank Bridge was relocated to Hastings, Minnesota in 2007 to serve as a replica of the Hastings Spiral Bridge at the Little Log Cabin Historic Village.
And that is the answer to the pop quiz, even though for some experts in the field, the answer was obvious. Yet perhaps the next bridge type quiz may be even more challenging than the first one. As for the ones who didn’t know, this one should get you acquainted to the questions that are yet to come that will require some research. So let’s go to the next question, shall we?
Author’s Note: If you know of other Thacher Truss Bridges that existed in Iowa or any part of the US and would like to bring it to his attention (and that of the readers), you know where to reach him: firstname.lastname@example.org or via facebook under The Bridgehunter’s Chronicles. He’ll be happy to add it in any future columns, and for his project on Iowa’s Truss Bridges, it will make an excellent addition.