Hoosac Tunnel electrified: an early high-voltage ac overhead catenary railroad

The tunneling of the Hoosac mountain range in the northwestern corner of Massachusetts in the 19th century was a monumental project that established a railroad connection between Boston and New York state. Steam locomotives were originally used the tunnel. However, in the early 20th century, it became possible to electrify the tunnel so as to eliminate the severe smoke problems associated with steam locomotive operation. This paper describes the construction of this tunnel and its electrification