Stroll Power Outage: Why Did National Grid's Underground Electric Cable Fail?

The power outage that struck downtown Nantucket during the island's 50th Christmas Stroll event last Saturday resulted in significant losses for restaurants and businesses on what is typically one of the most profitable weekends of the year. But what caused the blackout and why did it take 27 hours to restore power?

National Grid, the multinational utility company that owns and operates the island's electrical infrastructure, blamed the outage on two sections of underground electric cable that failed.

"We are working to identify the reasons behind the cable failure and an investigation is currently underway," spokesman Bob Kievra told the Current. He declined to comment further.

Sources with knowledge of what happened on Nantucket indicate that at least 500 feet of underground cable along South Water Street from the Sunken Ship store to The Dreamland theater became compromised and needed to be replaced. Once it was removed and the new cable was installed, the crews still needed additional time for splices and connections. 

That work required National Grid to send specialized equipment and additional manpower from the mainland, and those crews arrived late Saturday night and early Sunday morning.

All of those factors combined for a protracted outage at possibly the worst time for downtown businesses.

The underground electric cables that failed on Saturday had a date on them of 1989, which would make them 35 years old, but it's unclear when they were installed. Regardless, that would still put them under the 40 to 50-year life expectancy for underground electric cables. That part of the downtown area, however, is prone to coastal flooding, and the cables could have been affected by repeated exposure to saltwater.

One person who worked on the repair job told the Current it was "just a regular cable fault unfortunately. Just happened to be in one of the worst parts of downtown."

National Grid executives are expected to be in attendance at Wednesday night's Select Board meeting at the request of town officials, but it's unclear whether they will provide an update on the results of their investigation into the power outage.

"It just happens," one utility worker told the Current. "We haven't been able to figure out as to why. It seems to happen when there's more of a load on the cable. At least for other areas of the island."

But one thing has become clear in the ensuing days since the blackout: National Grid does not intend to pay any claims brought against it by island businesses that suffered losses during the outage.

In a letter to the owners of the Nantucket Surf Club on South Water Street, a National Grid representative stated that their claim had been denied. The utility company cited the terms and conditions for its provision of electric service with the Massachusetts Department of Public Utilities under which it "is not obligated to honor any claim for economic loss (loss of profits or revenue, business interruption, spoilage of goods, cost of temporary equipment, etc.)..."

While many or most of the downtown businesses do have private insurance policies for business interruption, it appears those will not provide any relief either. Two island restaurants affected by the outage told the Current this week that their policy only kicks in after 72 hours of business interruption, meaning the 27-hour power outage over the weekend would not be covered.