Replacing vintage subsea cable to scenic Michigan Island

by P Ebersold, Kerite Company

 

Published in Electricity+Control, October 2014 (pages 16 – 17)

Enquiries: Email powercable@kerite.com or visit www.kerite.com

 

Download the full article on Replacing vintage subsea cable to scenic Michigan Island in PDF format.

 

Cloverland Electric Cooperative needed to replace the ageing subsea cable that serves Drummond Island in Michigan’s Upper Peninsula. They approached utility consultant GRP Engineering, Inc to plan and design the subsea cable project. Kerite Corporation provided the new cable, which was shipped out using a special truck designed for extra-heavy loads. Running subsea cable from the Michigan mainland out to Drummond Island under the tight timeline dictated by permit conditions went smoothly. The two subsea cables, one subsea cable serving mainly residential dwellings - the other subsea cable serving the quarry, were installed in 1975 and 1989 respectively, and had reached the end of their useful life.

When the quarry was operating at full capacity, there was insufficient capacity between the subsea cables in the event of a failure, causing the quarry to partially shut down. While the load at the quarry is not anticipated to grow, Cloverland determined that the resort load is likely to increase as older smaller cabins are turned into larger ones, and modern amenities like air conditioning are added. Cloverland decided to install a new subsea cable that could handle the entire island. The plan was to maintain two circuits. The first would be replaced in 2014, while the sister subsea cable is budgeted for completion in 2017.

 

Take note

  • The Ethylene-Propylene-Rubber (EPR) insulation formula enables its subsea cables to operate in direct contact with water.
  • The subsea cable is covered with individually jacketed steel armour wires for mechanical protection and ease of installation pulling.
  • The subsea cable was shown to be good for 340 A.