SUBSTATIONS. Hidden behind modest facades throughout New York City were once behemoth machines that moved the subways. For over a century, these 125,000-pound rotary converters operated round the clock, supplying power to the city’s subway trains, elevated lines, and trolleys, but in 1999 the last manually operated substation was decommissioned and its equipment sold for scrap. Today, only vestiges of this early electrical network remain—the shell of a building here, a piece of machinery there.

In 1997, I befriended an official of the Metropolitan Transit Authority’s Power Division and he introduced me to the substations, literally opening doors that had remained closed for decades. For five years, I rushed to photograph, draw, and write their history before they were completely gone. Their story can be found in my 2002 book, New York's Forgotten Substations: The Power Behind the Subway, published by Princeton Architectural Press.