OPALCO’s Submarine Cable

The barge on Griffin Bay preparing to lay the new cable – SJ Update photo

OPALCO is making good progress on laying the new submarine cable “George” across Griffin Bay from Lopez to SJ Island.

It’s been a project long in the making and the end is now nearly in sight. It all began in 2011 during routine maintenance when divers discovered significant damage to the 1977 cable. Over the next several years a lot of planning, design and permitting took place including bathometric scans to create 3D mapping of the sea floor to identify the best crossing location for the new cable, to protect it from rocks, tidal action, etc.

This is the San Juan Island end of the crossing near Pear Point Road – SJ Update photo

In 2015, OPALCO signed a contract with the Japanese company Sumitomo USA for the manufacture of the new cable. It is a one-piece, continuous length of cable, 13,596 feet in length (2.6 miles) and includes 3 phases of electrical conductor and 144 strands of fiber optic cable. It should meet our needs for the next 50+ years. It weighs 33 pounds per foot of length. Add that up and it’s a total of 400 metric tons for the entire thing.

Fiber is now an integral part of OPALCO’s automated electrical distribution system, and equipment on either end of the cable uses the fiber to monitor and protect the cable itself. “We depend on fiber throughout our 20-island system to monitor power quality, identify faults and open and close circuits to reroute power during outages,” said Joel Mietzner, System Engineer. He credits the foresight of OPALCO’s leadership and engineering teams for their decision to go with fiber optics back in 1999 and notes that this crossing is one of the last places in the entire system where fiber isn’t installed.

Before laying the new cable, it was necessary to remove the old 1977 cable first and that project was just completed a little over a week ago. The cable was pulled up onto a barge and cut into sections and it will be returned to Sumitomo for recycling.

With that cable out of the way, laying of the new cable begins this week between Pear Point Road on San Juan and Otis Perkins Park on Lopez. Once this is complete, land connections will be made at either end, and then testing and final regulatory approvals will be obtained and the cable will be energized in 2018.

See more information on OPALCO’s website, including the entire timeline of this project at this link (PDF)

And just for fun, check out this video of the first cable to the San Juans, laid by Bonneville Power Administration back in 1951:

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