The New York Railroad Solar Storm (1921)

At 7:04 a.m. on May 15, 1921, the entire signal and switching system of the New York Central Railroad below 125th street was put out of operation. Aurora that appeared simultaneously was declared the cause.

The prelude to what’s known as the New York Central Railroad solar storm began with a major sunspot on the sun, a spot vast enough to be seen with the naked eye through smoked glass. The sunspot was 94,000 miles long and 21,000 miles wide and, by May 14, 1921, was near the center of the sun in a prime location to unleash an earth-directed coronal mass ejection, or CME. At 7:04 a.m. on May 15, the entire signal and switching system of the New York Central Railroad below 125th street was put out of operation, followed by a fire in the control tower at 57th Street and Park Avenue. The event corresponded to a grand auroral display: Auroras were visible in the Eastern United States, with additional reports from as low as Pasadena, Calif. The cause of the outage was later ascribed to a ground current that had invaded the electrical system and railroad officials formally assigned blame for the destruction to the aurora.

One telegraph operator said he was driven away from his telegraph instrument by a flame that enveloped his switchboard and ignited the entire building at a loss of $6,000. Overseas, in Sweden, a telephone station was burned out, and the storm interfered with telephone, telegraph and cable traffic over most of Europe.

If a similar storm occurred today, scientists believe it would have a massive impact on the US high voltage power transmission system.

Resources/References:

• SUNSPOT CREDITED WITH RAIL TIE-UP; New York Central Signal System Put Out of Service by Play of Northern Lights. New York Times, May 16, 1921.
• Behr, Peter. "This Week's Solar Flare Illuminates the Grid's Vulnerability." New York Times, June 9, 2011.