Marine Consumers Energy

THE TEST OF TIME

Durocher-VanAntwerp Inc. (Durocher Marine) laid the first subaqueous power cables across the Straits of Mackinac in 1956.  Four 46 kV subaqueous power cables were laid on the lake bottom between St. Ignace, MI and Mackinaw City, MI.  The operational life of this subaqueous power cable circuit was estimated at 50 years. However, due to increased demand the cables were abandoned in place in the 1980s. In the spring of 2018, a ship’s anchor struck the power cables severing and moving the abandoned cables onto other utilities.

INSIDE THE PROJECT

Durocher Marine mobilized a tug and barge for cable removal to the site.  The barge carried several roll-off containers to contain the removed cables.  A mini excavator with a demolition shear was used to cut cables into manageable dumpster sized lengths.  A dive team was also required to clear entangled cables in water depths to 270 ft, A Remotely Operated Vehicle (ROV) was also used to monitor removal operations in real time.

A linear cable engine was used to recover cable from the lake bottom to the barge deck.  The mini excavator would handle the cable as it was discharged from the linear cable engine cutting it into lengths as it passed over the roll off containers.  Cable removal operations recovered 82,000’ of cable during the campaign.  Several trips between our Cheboygan, MI yard and the Straits of Mackinac were required to resupply the barge deck with empty roll off containers.  All scrap cable was taken to an approved salvage facility for recycling of the copper, lead, steel and disposal of waste materials.  

WHY IT MATTERS

The Straits of Mackinac is a high visibility area with a 3,500 ft wide cable and pipeline easement, which has under daily public inspection. The owner was concerned about potential environmental impacts if the out-of-service cables remained on the Lake Bottom.  Removing the cables was proactive and eliminated this concern.

BEYOND THE PROJECT

The owner has removed the entire system from their permitted easement in Lake Michigan.  This reduces their future risk and creates usable space for future utilities.

PROJECT DETAILS:
  • Project Name:
    Consumers Energy