Radio communications in the Colton yard

This paper describes five different radio systems which are used in the Southern Pacific´s large railroad freight classification yard located in Colton, California. Each of these systems is discussed in turn, with emphasis on how that system is tailored to satisfy a specific communications requirement in the operation of the Colton Yard. It is intended that a discussion of the various radio applications in this yard will illustrate the types of communications which are necessary for operation of any large classification yard.