The Virginian EL-C, later known as the New Haven EF-4 and E33, was an electric locomotive built for the Virginian Railway by General Electric in August 1955. They were the first successful production locomotives to use Ignitron (mercury arc) rectifier technology. Although they proved to be a successful design, no more EL-Cs were built, due to the small number of railroads that had electrification and the advent of improved electric locomotive technology. They were among the last mainline electric freight locomotives in the United States.