Brilliant_ The Evolution of Artificial Light - Jane Brox [97]
Because the relay did not work, there was an overload on the line. This caused relays on other lines feeding through the plant to operate circuit breakers and the total of 1.6 million kilowatts going through the Beck station suddenly reversed course—as electricity will do when it is unable to flow in the direction it is supposed to.
Much of all this vast quantity of electric current raced back across upper New York State, tripping safety equipment from Rochester to Boston and points beyond. At this point the second phase in the breakdown occurred. Consolidated Edison in New York City, and other power companies to the south that had been receiving power from the area knocked out of service by the power surge, were hit by a reverse flow in their own lines. Their power rushed, somewhat as air will rush to fill a vacuum, into the upstate New York—New England—Ontario region. The generators in New York City and elsewhere, inadequate to fill the huge power vacuum, automatically shut themselves off.
Twenty-eight of the forty-two power plants in the region shut down, and the darkness sped south and east within the span of just over twenty minutes. At 5:17 Rochester and Binghamton, New York, shut down. Then eastern Massachusetts, the Hudson Valley, New York City, and Long Island lost power. All of Connecticut shut down at 5:30. Parts of Vermont and southwestern New Hampshire—the last to go—went dark at 5:38. The plant on Staten Island maintained power because it was able to break free of its network connection before failure. This good fortune was as bewildering as the bad:
In the New York State system ... the 345,000 volt lines ... are so designed so that a region hit by a local power failure can immediately have a surge of energy sent to it from ... another power source.... To be capable of this instantaneous action, the system must be able to accept a wide range of power loads. Hence the main trunk, the electric superhighway bisecting the state, is not equipped with circuit-breakers sensitive to slight changes in load. The decision to cut a local system out of the grid is a human one and the actual cut-off must be done manually at a local control center.
But on Staten Island, for some reason, a circuit breaker tripped unexpectedly, automatically severing it from the rest of the grid. The manager of system operations there could only say, "I don't know why it opened."
Northern New Jersey, Pennsylvania, and Maryland had systems that carried lesser voltage, and their circuit breakers were set to trip automatically, which severed them from the grid in time. The state of Maine's power system was only weakly connected to the rest of New England's and so was able to cut itself off from the failure and subsequently lend power to parts of New Hampshire. The lights in these areas formed a fringe of illumination around a vast darkness: almost everyone across 80,000 square miles of the northeastern United States and part of Ontario—30 million people—had lost their electricity.
At the time of the breakdown, there was no apparent reason for the outage—no storm, no high winds or lightning, no trees touching high-tension wires—and the cause would not be known for days. In each power plant, engineers and technicians were left to wonder whether something in their own system had triggered the shutdown, while people in the countryside—accustomed to occasional local outages even in good weather—naturally thought that maybe a car had hit a pole somewhere down the road. In the cities, there were vague notions of sabotage: "'The Chinese,' a housewife on New York's East Side thought when she saw New York fade from her window, and then was a little