Abstract :
THE communication system that is used in the operation of railroads has developed very rapidly in the last few years. The most recent addition is what is known as train communication, which is a system of communication for operating purposes between railway vehicles and between such vehicles and fixed points. To illustrate, train communication equipment may be used for two-way telephone or code communication between the two ends of a train, between trains and stations, between trains and towers, between two parts of a train that are separated for work or otherwise, between two different trains whether they are on the same or on adjacent tracks, and between the conductor and locomotives in a receiving or in a classification yard. Following are illustrations of the uses to which such equipment may be put:
