Retransmission of Telegrams

a part of the series of operations involved in processing a telegram. Retransmission is done at an intermediate telegraph office and includes (1) receiving the telegram from a terminal office or another intermediate office, (2) sorting to determine transmission route, based on destination, (3) conveying the telegram from the receiving telegraph apparatus to the transmitting one, and (4) transmitting the telegram to another intermediate office or to a terminal office for delivery to the recipient. Retransmission of telegrams is an economic necessity, since it would be wasteful to maintain constant connections between each terminal telegraph office and all other offices of a telegraph network. A telegram may be retransmitted from one to six times, depending on the geographic locations of sender and recipient.

Until the 1950’s, retransmission was done manually. In the early 1950’s, reperforators and transmitters made automation possible. The receiving telegraph apparatus uses a reperforator to record the telegram on a perforated tape. A section of the tape is subsequently conveyed to the transmitting telegraph apparatus, with the telegram then transmitted automatically. The sorting operation was also automated, allowing special devices to decode the heading of the telegram and send the telegram to the appropriate transmitting apparatus. Later the mechanical transport of telegram forms or perforated tapes was replaced by electronic transmission of telegraph signals. Thus the duties of a telegrapher in an intermediate telegraph office are now confined to supervising the flow of telegrams and controlling the operation of reperforators and transmitters.

Since the early 1970’s, computers have been used for automated retransmission of telegrams in the USSR, the USA, Switzerland, the Federal Republic of Germany, and elsewhere. A computer in a telegraph office is programmed to read and decode the heading of the received telegram, select the most efficient routing, and either transmit the telegram or place it in line for later transmission. The computer also records and checks the flow of telegrams.