One of the joys of running this site is getting the chance to meet interesting people. When researching the supposed Nazi sabotage of Grand Central’s sub basement known as M42, I encountered a video on YouTube showing one Robert Lobenstein—identified as the retired General Superintendent of Power Operations at New York City Transit—starting up an old rotary converter. I had seen rotary converters before, the very ones in Grand Central’s M42, in fact. Yet I had never seen one in operation, and the video fascinated me. It was clear that the modern static frequency converters I had encountered on filming...