Helping GLWA Deliver Infrastructure Renewal
A mentality for thinking outside the box has been a key driver for the solutions oriented Great Lakes Water Authority (GLWA) project team. When presented with a challenge to provide raw water tunnel repair, an in-the-wet solution was developed, mitigating interruptions to the water supply. It was determined the 10-foot to 14-footdiameter tunnels could be repaired by injecting the cracks with polyurethane grout at one tunnel and with a stainless steel liner plate at the other locations. Ballard, in collaboration with Kelley Engineered Equipment, designed and built a one of- a-kind patent pending underwater transport system to assemble and transport the liner plate ring sections along the bottom of the tunnel, moving them into place in up to two full ring sections totaling nine linear feet of fully assembled liner plate, rather than one individual ring section at a time. “The transporter is the crown jewel for the project as it sums up our commitment to meeting project challenges through innovative solutions,” said Tony Raphael, Project Manager for Ballard.
Ballard’s Underwater Ring Transporter (BURT) was completed at the end of September 2021 and proceeded to undergo considerable testing at Oregon State University’s O.H. Hinsda–le Wave Research Laboratory in October 2021. With a punchlist of lessons learned, BURT returned to Kelley Engineered Equipment’s shop for several design, production, and safety enhancements. Completed in February 2022, BURT arrived on site in Detroit and the team began early assembly and initial testing sequences. Dive crews also ran surface testing to familiarize themselves with all the functions and systems needed to successfully operate BURT in the submerged tunnel environment. On March 16th, BURT was successfully submerged to begin the first tunnel liner installations of the project. After BURT erects all the tunnel rings in the repaired sections, the tunnel annulus is grouted and the tunnel is structurally repaired from within without taking the tunnel out of service or dewatering it.
The project is estimated to be completed in the beginning of 2025 with the result of repairing the raw water tunnel using flexible segmental lining, followed by annular grouting, to ensure GLWA can dewater the tunnel if needed for future inspections. “BURT is going to revolutionize the large diameter tunnel and pipeline rehabilitation market, providing owners with sustainable in-the-wet solutions without interruptions for their assets,” shares Shawn Drobny, P.E., Ballard’s Lead Engineer for the project. “We have an amazing team contributing to the success of BURT – collaboration efforts have been second to none.”