Following is the first section of my article on how the big blackouts of 1965 and 1977 came about (photo credit, The Guardian).
It was the first time I wrote about a system so complex that no single person could stay on top of it. That realization laid the foundation for Inviting Disaster later.
The rest of the feature can be accessed at the Invention & Technology issue archive.
Learning from the Big Blackouts
Two nights of darkness, in 1965 and 1977, showed how fragile the nation’s power system could be
James R. Chiles
Fall 1985 | Volume 1, Issue 2
Normally night spreads from east to west with the rotation of the earth, but the evening of November 9, 1965, was different. Darkness also spread from north to south. Southern Ontario went dark first, much of New York State a few seconds later, then most of New England, and finally New York City. By 5:28 P.M., thirty million people were stumbling toward any light available. Subways stopped and furnaces chilled, and America briefly lost one-fifth of its electricity. What was the cause? Maybe a generator failure, maybe sabotage—for several awkward days no one knew.
America’s electric-power network is so vast that solar flares affect it and so convoluted that the start-up of one generator affects others thousands of miles away. It is perhaps our most complex technology. But the 1965 blackout—and others that have followed—taught that complexity does not equal sophistication.
In the twenty years since that catastrophe, power companies have been working with mixed success to prevent more outages. Transmission lines have greater capacity now, control centers are more computerized and hold tighter reins over power flows, utilities cooperate and share more information, generating stations have emergency power to restart generators thrown off the grid by electrical jolts, and operating procedures have been revamped. Still, major outages happen every year, benighting thousands and occasionally, as in New York in 1977, millions of people, but many in the industry are confident that another 1965-scale blackout is unlikely.
Smaller blackouts can be costly too, though, and some observers fear that the stability of the network is threatened by certain utilities’ financial problems and by economic pressure to move electricity long distances from power-rich areas to utilities dependent on oil-fired power plants. In parts of the country, such long-distance purchases of economy power are pushing transmission lines to the limits of safety by straining their capacity.
In 1965 the utility industry was about eighty years old. America’s first central power station had started supplying a small district of Manhattan in 1882. The idea didn’t catch on for several years because building owners could provide for themselves more cheaply by buying generators and putting them in basements. But the price of central service dropped by 1886, and the new electric streetcars were increasing daytime demand dramatically. The same advantages of reliability and savings that then led isolated users to join in a central system also persuaded utilities to link with one another once high-voltage alternating-current equipment was available.
Regional grids started forming: the Pacific states, the Southwest, the Southeast, and the Upper Midwest. The first big interconnection in New England came about in 1913 because the utility at Turners Falls, Massachusetts, had a surplus of cheap hydroelectric power to sell. Interconnections multiplied rapidly across the Northeast during World War I, when defense plants needed power in amounts that isolated utilities could not supply. In 1959 Ontario Hydro joined the Northeast Interconnection, which then changed its name to Canada-United States Eastern Interconnection and acquired the acronym CANUSE.
November 9, 1965, was—until the blackout—an ordinary day. From New York City on the southern end of CANUSE to Ontario in the north, the weather was clear and cool. As the sun dropped, lights went on. Power stations all over the Eastern Interconnected System—CANUSE and the other big systems it was connected to—opened water and fuel valves to meet the need.
One of these was the Sir Adam Beck No. 2 hydroelectric plant, set on the Canadian cliffs near Niagara Falls. Most of its output was going west and north to Toronto, across Lake Ontario. The Beck plant was working a bit harder than usual because the Lakeview power station near Toronto was having problems with its machinery. The load on Beck’s transmission lines reached the point at which an obscure relay, installed in 1951 and last adjusted in 1963, ordered a circuit breaker to disconnect one line. This started a chain of events that no one could have predicted exactly, because alternating current finds its own pathways through the multitude of combinations possible in a large power network, which is itself changing every minute. At 5:16 and eleven seconds, the system began to move with frightening speed.
When the Beck relay ordered the first westbound transmission line cut off, 375 million watts of power crowded onto the four other westbound lines. In less than three seconds they tripped out in turn, and at least 1.5 billion watts rushed into America across two other lines strung over the Niagara River. The surge of electricity tried to reenter Canada at the Massena, New York, interconnection, but that interconnection overloaded, and the surplus power turned south, down the backbone of the CANUSE transmission system.
Relays interpreted the power surge as a short circuit and started signaling circuit breakers to separate the system into islands. Shuddering under the impact of all these circuit breakers and the wildly fluctuating current, generators slowly fell out of the sixty-cycle-per-second, threephase lockstep that the alternating-current networks demanded. One island, which took in southeast New York State, New York City, and much of New England, was suddenly short of generation capacity, with a severe deficit in the northern end pulling great pulses of power from the south. The deficit grew as the electrical chaos forced generators off the network.