Submarine Assessment Results in Cost Savings for Town
The Stevens Street Culvert is located on a 300-foot long causeway that connects two adjacent ponds. The structure was built in 1956 and consists of two individual 4-foot diameter pipes that are submerged 12-feet underwater. The visible above-grade portions of the headwall and roadway were in poor condition, leading the Town to believe that full replacement of the culverts would be needed and the Town should begin budgeting accordingly.
Tighe & Bond was engaged to perform a condition assessment and provide a recommendations report for the structure. In order to cost-effectively evaluate the pipes underwater, Tighe & Bond procured a Remotely Operated Vehicle (ROV) to navigate through both pipes and obtain video footage. The ROV (a.k.a. the submarine) was equipped with high powered lights and a 4k UHD video camera, and was operated remotely from the roadway level using a tablet.
The underwater investigation resulted in recommendations that avoided full pipe replacement that would have required significant de-watering with large environmental impacts. Instead, it was determined that only the upper portions of the headwalls required improvements, resulting in a solution that saves the community approximately $500,000 in unnecessary replacement costs. The remainder of the project design and construction phases are projected to be completed in the upcoming years.
The project team received an award for Excellence in Innovation/Research from the Young Professionals in Transportation (YPT) Boston Chapter in 2018.
Tighe & Bond’s innovative approach for investigating the submerged structure was not only helpful for the Town of North Andover, but paved the way to use this technology for other engineering applications.
Tighe & Bond performed a conditions assessment and formulated recommendations for the proposed replacement of the Stevens Street Culvert. The analysis determined that a full replacement was unnecessary, instead recommending improvements to only the upper portions of the headwalls.