July 13, 1977 – The New York City Blackout of 1977

On the day in engineering history, the Big Apple suffered an electrical blackout that shook the nation's largest city to its core. The outage began with a series of lightning strikes that crippled some transmission lines and overloaded others. By nightfall, human error and systemic failure darkened a city that had endured a region-wide blackout just 12 years before. But the New York City Blackout of 1977 was different. This "night of terror", Time magazine later wrote, "unleashed a night of looting that ended in 4,000 arrests and $350 million in damages."

On the evening of July 13, 1977, a lightning strike at the Buchanan South substation interrupted the flow of electricity from Indian Point Energy Center (IPEC), a three-unit nuclear power plant 24 miles north of New York City on the Hudson River. Subsequent lightning strikes knocked out two 345-kV transmission lines and overloaded two others. Consolidated Edison, a regulated utility that provides power to New York City, then lost two lines from another substation before manually reducing the load from a generator at an East River facility.

At 9:14 PM EDT, some 30 minutes after the first lightning strike, New York Power Pool (NYPP) operators asked Con Edison to shed load. The utility's operators initiated first a 5% and then an 8% system-wide voltage reduction. But this lengthy, sequential procedure wasn't what the NYPP, a legacy of the Northeast Blackout of 1965, had in mind. Within minutes, a thermal overload tripped the last major interconnect with upstate New York. In turn, this overloaded several 138-kV links to Long Island and tripped a massive 230,000-V interconnection with New Jersey.

As Con Edison struggled to meet demand, the world's first million-kilowatt unit began shutting down. Big Allis, as the Ravenswood No. 3 electric power generator was known, could meet only a fraction of the Big Apple's energy demands. By 9:36 PM, just one hour after the first Buchanan South lighting strike, the entire Con Edison power system had shut down. It was the middle of summer and the height of a heat wave. "Air conditioners, elevators, subways, lights, water pumps – all the electric sinews of a great modern city – stopped," Time magazine later reported.

Con Edison restored power on July 14, 1977, but the damage to its reputation – and to New York City's – would last longer than one hot summer night. "Con Ed's performance is, at the very best, gross negligence", scolded Mayor Abraham Beame, "and at the worst, far more serious." Beame was hardly alone in his anger. Looting, vandalism, violence, and arson resulted in damages to 1616 stores, 1037 fires, nearly 4000 arrests, and $350 million worth of damages.

Resources:

http://www.time.com/time/magazine/article/0,9171,919089,00.html

http://www.csmonitor.com/2005/0719/p14s03-bogn.html

http://blackout.gmu.edu/events/tl1965.html

http://en.wikipedia.org/wiki/Big_Allis