• Matt Blaze@federate.socialOP
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    13 days ago

    NYC’s IRT subway, opened in 1904, is powered by a 600 volt DC third rail running alongside the tracks. Power is fed to the system via a number of substations throughout the city, where high voltage AC is converted to the lower voltage DC used by trains.

    Until recently, this was done with electromechanical rotary converters (essentially a combination AC motor and DC generator). They have been supplanted by solid state rectifiers, but a few of the original rotary converters remain operational.

    • Michael Richardson@todon.nl
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      13 days ago

      @mattblaze@federate.social presumeably the electromechanical converters are immune to EMP. Are the solid-state rectifiers? Are there control systems that monitor them that might be vulnerable? Just thinking aloud for reasons to keep the older converters.