A downed powerline closed the Seward Highway in both directions near Girdwood for more than four hours Tuesday morning.
A chain reaction linked to corrosion snapped a wooden power pole a few hundred yards from the road and caused the wire to fall, Chugach Electric Association spokesman Phil Steyer said.
“Corrosion apparently weakened a pair of anchor rods supporting guy wires, causing the rods to break,” Steyer said in an email Tuesday. “The loss of the guy wires caused the wooden pole holding the wire to break, allowing the conductor to sag near the ground.”
The first report of the downed lines came at 4:02 a.m. after a pickup drove across them at Mile 91, about a mile north of Girdwood, said Alaska State Troopers spokeswoman Beth Ipsen.
The driver wasn’t injured but the pickup sustained minor damage, Ipsen said.
Also, a semi got its mirror tangled in the line at about 4:45 a.m., she said. The semi and driver had to remain in place until a crew from Chugach Electric freed the truck at approximately 7:45 a.m. The truck then turned around and headed back to Anchorage.
Troopers arrived at the scene at 5 a.m., shortly after the Girdwood Fire Department, Ipsen said. The fire department closed the northbound lanes at the Tesoro station, she said, while southbound traffic backed up north of the downed line.
Steyer said the loss of the 115-kilovolt line around 4 a.m. temporarily cut power to about 2,000 customers. Dispatchers were able to restore power in about 15 minutes, he said.
Chugach and contractor crews were expected to install a replacement pole and new anchors by Wednesday.
The transmission line was de-energized between Indian and Girdwood, but no customers are out of power, Steyer said. Chugach was feeding power to Indian from the north and serving customers up to and including Girdwood from generation resources on the Kenai Peninsula. The line was expected to be re-energized on Thursday.