Contractor Strabag AG took a unique approach to construction for the Niagara power project when they elected to use a Main Beam TBM to excavate the 14.4 m diameter tunnel. Strabag had previous experience with Robbins HP-TBM™ technology from the Second Manapouri Tailrace Project in New Zealand. For Niagara, Strabag again elected to go with a Robbins HP-TBM™, this one being the world’s largest hard rock TBM. The machine was the first ever to be fitted with back-loading 20″ cutters, and was assembled onsite in Robbins’ first instance of Onsite First Time Assembly (OFTA).