In Franklin Township, Work on Hess Mill Road Bridge Likely to Begin in October08/27/2020 12:10PM ● By Steven Hoffman
Work on the Hess Mill Road Bridge replacement project is now scheduled to begin in October.
The replacement of the bridge in Franklin Township will not only provide an important infrastructure upgrade for local residents, there will also be a significant environmental benefit—the new bridge’s span of 32 feet will eliminate the current stream flow restrictions that result from the existing bridge’s span of 25 feet.
Franklin Township officials proactively took steps in recent months to prepare for the project, with the goal of completing the work in 2020 rather than waiting until next year.
During the construction work, through-traffic on Hess Mill Road will be detoured. All local residents on Hess Mill Road will have full access to their properties for the entire duration of construction. Additionally, all local residents on Hess Mill Road will have full electric service for the duration of the project. The electric power outages that will be necessary will be local to the bridge area and will only be required for short periods during heavy-lift crane operations.
According to Franklin Township supervisor John Auerbach, the township engaged the Chester County Conservation District (CCCD) to evaluate the environmental impact of the project. After a thorough inspection both upstream and downstream, the CCCD determined that the 25-foot span of the existing bridge was restrictive to the flow of the stream. As a result of the environmental improvements that are a part of this project, the CCCD provided a grant of approximately $271,000 to complete the work. The township will then fund about $134,000 of the work. The total project is estimated to cost approximately $405,000.
Originally, the township was going to replace the bridge in 2019, relying entirely on township funds for the work. Then, in June of 2020, Franklin Township was able to secure the grant funding from the CCCD, which enabled the township to avoid an infrastructure capital loan.
The bridge could be closed for six or seven weeks while the construction work is completed.
A tentative schedule for the work includes an Oct. 8 start—that’s the approximate date that the Hess Mill Road Bridge will be closed and the dismantling of the bridge will begin.
The prefabricated bridge is expected to be received around Nov. 9 so that the installation work can begin. The work on the bridge accessories and the finish of the roadway will be completed next. The target date for completion of the entire project and for the reopening of the new Hess Mill Road Bridge is Dec. 1.
The existing Hess Mill Road Bridge is a wooden structure that was constructed in 1974. The bridge is located approximately 600 feet west of South Guernsey Road. Most motorists are unaware of the bridge as the bridge surface is asphalt paving over wood that matches the roadway. Bridge profiles on either side are not visible from the road. The wooden guard rail is the only bridge feature visible to passing motorists.
The bridge has been inspected annually by consulting engineers commissioned and paid for by PennDOT. Since 2011, the bridge has been rated in poor condition and the bridge is classified as being structurally deficient. The primary supporting structure is wood consisting of a series of beams fastened together to form a mat. These beams are in poor condition.
In preparation for the project, the township conducted several traffic count studies using video equipment. In addition to the traffic data collected, the videos indicated that many overweight trucks are using the bridge. The bridge has reached the end of its service life.
The replacement bridge will be a prefabricated, reenforced concrete arch bridge. It will be delivered to the site in several large pieces and erected by a heavy-lift crane. This construction technique significantly shortens the service outage for Hess Mill Road.
The replacement bridge will not have a posted weight limit—it is capable of carrying all registered vehicles.
In 2012, New London Township replaced the West Avondale Road Bridge with a structure that is very similar in configuration to the proposed Hess Mill Road bridge.
The bridge construction schedule is subject to change and residents should monitor the Franklin Township website for updates. The township is working diligently to improve the schedule to move the project completion date earlier than Dec. 1 to avoid any potential issues caused by winter weather.