In 2020, operating under a multi-year contract for projects related to UDOT’s Lake Powell ferry system, Advanced Marine responded to a request from the State to survey the large floating ferry mooring structure, located near the Halls Crossing Marina. According to UDOT staff familiar with the ferry, the mooring structure appeared to be floating unevenly, with portions under water. The work scope included restoring the buoyancy of the structure and installing a new boat landing to provide a safe ingress/egress point for the ferry crew.
The floating structure, referred to as a “lee”, is a secure offshore mooring for the steel-hulled 150 ft. M/V Charles Hall that provides ferry service along Utah state highway 276, between Bullfrog and Halls Crossing. The lee is comprised of two sections, joined in the middle. It is constructed of large diameter steel pipe, with a timber superstructure. Each section measures about 100 ft. long by 30 ft. wide, and weighs approximately 110 tons.
The survey showed the lee sections were joined together using two heavy-duty cable winches, commonly used in commercial marinas. The cables passed from each winch through thick steel pad-eyes welded to the lee ends. It appeared a strong side load, likely from ferry docking maneuvers, had torn the pad-eyes and opened holes in the steel pipe. The resulting water intrusion flooded the end chambers and disrupted the overall buoyancy.
Advanced Marine submitted a design for a robust steel two-part hinged connection to replace the old cable and winch system, and a new improved ferry crew landing. On approval from the State, Advanced Marine mobilized crew and equipment from our Carson City, NV facility.
Working with UDOT and Aramark marina crews, the lee sections were separated and pulled up the Halls Crossing concrete ferry loading ramp. Advanced Marine welders cropped the damaged steel sections, de-watered the pipe chambers and welded repair plates over the holes to restore buoyancy. Once the lee ends were cleaned and prepped, the welders installed the new hinge connectors. The Advanced Marine crew installed new steel supports, timber stringers and a synthetic wood deck with fender piles for a boat landing. The design included steps and an opening in the timber walers to match a crew gate Advanced Marine had recently installed in the ferry bulwarks.
