Frank J. Sprague and Railroad Safety [History]

Once hailed a triumph of mechanical ingenuity and the largest and handsomest depot in the world, Grand Central Station was showing its age by the beginning of the 20th century, despite numerous improvements and renovations. Once at the northern edge of New York City, as the metropolis grew around it, the great rail yard had become an eyesore. The burgeoning steam-driven rail traffic in the tunnels to the north belched smoke, cinders, and steam that were not only increasingly offensive but also deadly.