Wet TBM Interventions
Olentangy-Scioto Intercepting Sewer Augmentation Relief Sewer (OARS)–
Prime Contractor: Kenny/Obayashi JV
The tunnel project consisted of approximately 23,300 linear feet (7102lm) of 20’ (6m) inside diameter tunnel. With extreme inflows of groundwater, hyperbaric interventions were not possible. Ballard Marine Construction worked with the Joint Venture to adapt the TBM to allow for divers to change cutters on the submerged machine. Ballard’s commercial divers and dive supervisors were critical in getting the machine back to mining.
This operation was the first of its kind in North America. With its vast network of commercial diving offices around the United States, Ballard was able to fully staff the project immediately upon request.