The U.S. Navy’s use of shipboard radiotelephone (RT)—also known as “voice radio”—for tactical communications began in 1916, when the first RT message was sent from ship to ship. During World War I, primitive voice radios were used for limited tactical purposes in convoys and among hunter-killer groups. Progress was sporadic between the world wars, but the Navy was often at the forefront of radio development.
As the electromagnetic spectrum became better understood, the correlation between radio frequency and range of communications emerged as a tactical characteristic; the lower the frequency, the longer the range. Radios operating in the part of the spectrum identified as the “high-frequency range” (3–30 megahertz, or MHz) could be relied on for long-distance communications, but the extended range meant an enemy was more likely to intercept those transmissions and, using radio direction finding (RDF) equipment, could locate the transmitting ships. Raising the frequency to the VHF (very-high frequency at 30–300 MHz) and UHF (ultra-high frequency at 300–3,000 MHz) reduced the effective range to just beyond the visible horizon, permitting ships to communicate by radio with less risk of detection.
Radiotelephony came of age in World War II with the development of the now legendary “talk-between-ships” (TBS) system, a relatively low-powered crystal-controlled system. The Navy used eight different models of TBS during the war for maneuvering, target (and friendly) identification, weapons employment, and other functions. By operating in the VHF part of the electromagnetic spectrum, these radios essentially kept the range to “line-of-sight” distances, approximately 25 miles.
After World War II, TBS was replaced by more sophisticated systems that allowed primary tactical (PRITAC) and secondary tactical (SECTAC) circuits to become standard on bridges and in combat information centers. Operating in the VHF and UHF ranges again ensured that signals did not extend much beyond line-of-sight, thereby reducing the chance of enemy detection.
Because of the precision necessary in tactical operations, strict voice communications procedures were established early on and continue to this day. Standardized formats and specific “prowords” (such as “OVER,” “OUT,” “ROGER,” and “WILCO”) were developed to ensure brevity and to minimize misunderstanding.
Over the years, movies and television have made frequent use of RT procedures to add authenticity and color, but all too often with notable inaccuracy. The hallmark of an entertainment production that has not done its homework is the ubiquitous use of the phrase “OVER AND OUT.” Joining these two prowords makes no sense to the trained ear. In radiotelephony, “OVER” is a shorthand way of saying “This is the end of my transmission to you and a response is necessary.” “OUT” means “This is the end of my transmission to you and no answer is required or expected.” In short, “OUT” is roughly equivalent to “goodbye” on a telephone. So, when actors on big and small screens say “over and out,” they are, in essence, saying, “I am finished talking and now it is your turn. Goodbye.”
Similar violations of RT procedure involve the prowords “ROGER” (I have received your last transmission satisfactorily) and “WILCO” (“I have received your signal, understand it, and will comply”). The redundancy of using these two prowords together is obvious. Sailors using voice radio communications must learn many additional prowords such as “SAY AGAIN,” “I AUTHENTICATE,” and “RADIO CHECK.”
Call signs are another important component of radiotelephony. Providing standardization, brevity, and (to some extent) security, they are used to identify individual units, groups, and commanders. Originally, call signs were assigned aliases with random meanings. For example, the USS Independence (CV-62) was assigned the call sign “Guntrain” and Commander, Destroyer Squadron 8, was once “Pistol Flash.” Not all call signs were so martial sounding, including some such as “Party Girl” or “Slide Rule.”
After years of use, any pretense of security was lost to repetition (the Soviets came to know our call signs as well as we did), so names were replaced by changing call signs using random alphanumeric combinations. These lacked the color that the names provided but were much more secure because they changed every 24 hours. Of course, this was an added burden for watchstanders, who must daily use all new call signs.
The advent of encrypted voice radio obviated the security concerns, but it costs considerably more, and its sophisticated technology adds additional maintenance requirements and reduces its reliability. And it remains vulnerable to signal detection by enemies.
Just as signal flags can be used to execute tactical maneuvers (see “The Flag Bag,” June, p. 6), so can radiotelephony. When the officer in tactical command of a group of ships wants to issue tactical orders, he or she can use either the “delayed executive method” or the “immediate executive method.” The former is preferable because it allows time for units to make sure they understand the signal and are properly prepared to carry it out. The latter is necessary when time is of the essence.
For more than a century, tactical radiotelephony has played an important role in naval communications and is likely to remain for many years to come.