Abstract :
This paper describes the Long Island Rail Road\´s selection, purchase, and installation of substation 12 M, the first outdoor silicon rectifier for electric traction use in the United States. Because of the great interest at this time in rail rapid transit in the United States as well as many other countries around the world, concrete information on actual installations of this "new breed" of high-efficiency low-maintenance cost rectifier in all-outdoor housing should be of interest to many people. This information includes 1) a brief history of silicon rectifier use in electric traction systems, 2) a description of the Long Island Rail Road\´s electrification equipment and some typical rush-hour train loadings, 3) details of site work and field assembly for a 3000-kW outdoor silicon rectifier, 4) description of rectifier and switchgear equipment, 5) performance and maintenance experience after approximately one year\´s operation, 6) some general cost figures for a 3000-kW silicon recitifier station installed on Long Island, and 7) conclusions on the specific advantages of silicon rectifiers of the outdoor type for traction use.