Repairing Submarine Fiber Cable Breaks

Repairing Submarine Fiber Cable Breaks

Repairing Submarine Fiber Cable Breaks – ANCHORAGE, Alaska (KTUU) — GCI is investigating a subsea fiber optic cable break discovered earlier this week in Cook Inlet, near Kenai, the company said in a press release Friday.

Customers may have noticed a minor disruption on Tuesday as the network traffic was quickly routed to an alternate subsea fiber path, GCI wrote.

“GCI operates in some of the most challenging terrain on earth and we prepare for situations like this,” said GCI Senior Engineer Bruce Rein.

When the break initially occurred, GCI says it’s network systems rerouted wireless and internet traffic, quickly restoring initial service interruptions. Until repairs are completed, GCI will continue to route traffic over the alternate network path, the company wrote.

GCI said it delivers connectivity through a network composed of multiple rings that ensure service can be rerouted. This week’s subsea fiber break occurred at a point along the red strand on the map.

As a precaution, GCI says it spends nearly $2 million per year on a deep-sea fiber repair vessel based in British Columbia. The Cook Inlet break appears to be in waters approximately 7 meters deep.

GCI said Cook Inlet’s extreme tides and ice coverage, currently estimated between 70-80 percent near the area of the break, add an additional level of complexity and risk to repair efforts.

“In order to successfully splice a piece of subsea fiber optic cable, the ship needs to be able to stay completely stationary for roughly 24 hours, which is extremely difficult with such a large amount of ice coverage and currents that can unpredictably move the ice pack,” said Rein.


“Though precautions can be taken to deflect floating ice away from the vessel, it can still present a risk to the ship and our crews. Because the safety of the crew is our highest priority, repair efforts may need to wait until ice conditions improve. We continue to consult with experts to determine when repair operations can begin.”

GCI said both the exact repair timeline and cause of the break are currently unknown. Breaks in subsea fiber are rare but can be caused by encounters with manmade equipment like bottom trawling fishing gear and ship anchors or natural causes like subsea turbidity currents, sea ice or seismic activity according to the company.