This Mystery Bridge is in connection with last week’s photo of the week. It is a unique find and one that will come up fast when approaching the city of Mittweida, located 15 kilometers north-northeast of Chemnitz. The city of 15,000 inhabitants is home to the college of applied sciences and has a unique historic setting, which straddles the valley of the River Zschopau and its tributaries.
This bridge is located at the junction of Burgstädter Strasse and Stadtring, which heads north towards the college. It’s a three span railroad viaduct that features a combination Pratt and Wichert Truss designs supported on steel, A-shaped piers. The total length is approximately 100 meters. The Wichert truss was designed by E.M. Wichert in Pittsburgh in 1930 and is characterized by its deck arch design with a diamond-shaped panel above each pier. The curved lower chord gives the bridge the form of an arch, but it does not rely on arch action to carry the load, according to sources. Wichert trusses were experimented with numerous deck-truss-arch bridges in and around Pittsburgh, and many of them still exist today. The most common Wichert truss bridge is the Homestead Grays Bridge near Pittsburgh. The 3,100-foot long bridge was built in 1936 and was last rehabilitated in 2006. Other Wichert truss spans can be found in Maryland and West Virginia.
Yet the viaduct in Mittweida had the characteristics of the Wichert truss design in it, which leads to the question of how Wichert developed and patented the truss design. Was it based on his observations of the previous designs, directly or indirectly? There is little known information written about Wichert, except the fact that his family name is predominantly German, meaning he may have emigrated from Germany to the US during one point in his life to start his career in Civil Engineering, just like the bridge builders before him, such as Albert Fink, Gustav Lindenthal, John Roebling, and Fritz Leonhardt. Finding out more about Wichert would open the doors to find out about his life and career. It would also help answer the question of the origin of his patented truss span.
As far as the bridge itself is concerned, the structure was built between 1906 and 1907 as part of the project to build a railroad line connecting Mittweida and Dreiwerden, located 12 km to the southeast. The line was built to allow trains to carry goods to the paper factory in Dreiwerden. The northern branch connecting Mittweida and Ringenthal was built at the same time to transport raw materials to the power plant. That line was dismantled after 1974. As for the southern branch where this viaduct is located, train service continued until its abandonment in 1997. The line has since been partially dismantled, but the bridge still stands today. It is unknown who built the bridge during that time, but the line was built under the auspisces of the Saxony Railroad Company (Sächsische Eisenbahngesellschaft GmbH) and financed by the Kingdom of Saxony during that time.
To summarize the points on this mystery bridge:
- The bridge was built between 1906 and 1907, serving the Mittweida-Dreiwerden southern branch, connecting the main train station with the paper factory.
- The bridge features one of the earliest of the Wichert truss designs even though it was patented in 1930.
- Little is known about E.M. Wichert, the inventor of the truss design, except that he may have been one of the German-immigrants that started his career in the States as a bridge builder and engineer.
Now it’s your turn to provide some information about this bridge and the inventor of the Wichert truss. If you have some useful information for either the bridge or the engineer, feel free to contact the Chronicles, using the channels available. The information will be updated as it comes in. A biography of E.M. Wichert will be included in the Chronicles under the category Bridge Builders Directory. Wishing you happy hunting and many thanks for your help.
Till we meet again. 🙂
