ALPHABETS OR SYSTEMS OF SIGNALS. SIGNAL ALPHABETS.
The following abbreviations, conventional signals, and code calls are authorized in visual signaling: ABBREVIATIONS.
CODE CALLS.
FOOTNOTE: Although the use of but one alphabet is authorized in visual signaling in the U. S. Army, emergencies may arise where it may be imperative to use either the Army and Navy, the Continental Morse, or the American Morse alphabet. Instructions for the use of either alphabet under such conditions are given. EXECUTION OF SIGNAL ALPHABETS.THE ARMY AND NAVY ALPHABET. SIGNALING WITH FLAG OR TORCH, HAND LANTERN, BEAM OF SEARCHLIGHT, AND HELIOGRAPH. There is one position and three motions. The position is with the flag or other appliance held vertically, the signalman facing directly toward the station with which it is desired to communicate, his body erect and feet sufficiently separated to insure stable equilibrium. The first motion ("one" or "1") is to the right of the sender, and will embrace an arc of 90°, starting with the vertical and returning to it, and will be made in a plane at right angles to the line connecting the two stations. The second motion ("two" The beam of searchlight will be ordinarily used exactly as the flag, the first position being a vertical one. To use the torch or hand lantern, a footlight must be used as a point of reference to the motion. The lantern is more conveniently swung out upward to the right of the footlight for "1," to the left for "2," and raised vertically for "3." In using the heliograph, the first position is to turn a steady flash on the receiving station. The signals are made by short and long flashes. Use short flashes for "1," two short flashes in quick succession for "2," and a long, steady flash for "3." The elements for a letter should be slightly longer than in sound signals. Each word, abbreviation, or conventional signal is followed by "3." The full address of a message is considered as one sentence and will be followed by the signal "33." The signal to indicate that "cipher follows" and "cipher ends" is with the flag and torch "XC3," and with other methods, except the International Code, by "XC." It will always precede and follow a cipher message or such part of a plain text message as is enciphered. The following conventional signals are authorized in the use of the army and navy alphabet:
THE MORSE ALPHABETS.TO SIGNAL WITH THE FLAG, TORCH, HAND LANTERN, OR BEAM OF SEARCHLIGHT. The dot is made by a motion to the right of the sender embracing an arc of 90°, starting from the vertical and returning to it, in a plane at right angles to the line connecting the two stations. The dash is made by a similar motion to the left. The space which occurs only between dots is made by prolonging the signal for the last dot for an interval of time equal to the time of an additional dot, the staff of the flag, the beam of the searchlight, etc., being maintained in a horizontal position for the time specified. The signal so made would therefore represent a dot and space. The letter "C" is accordingly made thus: Right, right prolonged, right. The long dash ("L") is distinguished from the short dash ("t") by prolonging the signal to the left for a period of time equal to one dot. The long dash representing "naught" is similarly made by prolonging the signal to the left for a period of time equal to two dots. The "front" signal is made by lowering the flag from the vertical position to the front and immediately returning it to the vertical position. A slight pause is made between each signal. The following conventional signals are authorized, using the Morse alphabets:
TO SIGNAL WITH THE HELIOGRAPH OR FLASH LANTERN.The dot is made by pressing down the key of the shutter and immediately releasing the same. The short dash is made by pressing down the key and holding it down for a period equal to two dots. The long dash ("L") is made by holding down the key for a period equal to three dots while the longer dash (naught) requires the key to be held down for a period equal to four dots. The space is made on the heliograph as in ordinary telegraphy by the absence of any signals for a period equal to the time of one dot. On the heliograph the letter "C" is made as follows: Short flash, short flash, interval, short flash. When the call of a station is acknowledged, both stations will adjust each on the flash of the other. INTERNATIONAL CODE OF SIGNALS.Description.—By means of the International Code of Signals people of different nationalities may communicate with each other, although neither party has knowledge of any language save his own native language. The code is, as its name indicates, international, and every seagoing vessel of every nation is equipped with its flags. The Code of Signals contemplates the use of 26 flags (figs. 14 and 15); one for each letter of the alphabet and a code pennant. Complete instructions relative to the use of this code are contained in a book issued by the Hydrographic Office, Navy Department, and known as the "The International Code of Signals." In using this system the signals are displayed by hoisting combinations of two, three, or four flags. All possible combinations represent words, expressions, or phrases, which may be found in the "International Code of Signals," referred to above. Two-arm semaphore.—This system is frequently used by the United States Navy, the following instructions covering the use of the system: 1. To communicate with a station: Face the station and wave the flags over the head to attract attention, making at frequent intervals the call letter of the station. When the station called is ready to receive the message, it answers by displaying its own call letter until the sender makes the 2. To call a ship: Hoist International Code letter J and make code letter of ship; then proceed as in article 1. 3. To make a general semaphore signal: Hoist cornet; all ships answer by answering pennant; then make signal. 4. At the end of the message extend the arms horizontally and wave the flags until the receiver answers in the same manner, showing that the message is understood. Should the receiver miss a word, he signifies the fact by waving the flag over his head. The sender will then cease signaling and wave his flags similarly to show that he understands. The receiver then makes "repeat last word," or whatever he wishes to say. Should the sender make a mistake, he will make the "error" signal until answered by the receiver with the same signal. He then proceeds with the message. THE ARDOIS SYSTEM.In using this system in connection with the Army and Navy Code, the red lamp indicates "1" and the white lamp "2." Four lamps are placed on a vertical staff and electrically illuminated to indicate the numerals of the Myer Code, which represents the letters of the alphabet. For instance, white-white, or "22," represents the letter "A," and white-red-red-white, or "2112," represents the letter "B," etc. In this system the lights indicating the letters of the alphabet are read from the top downward. When the lamps are placed horizontally, they are read from the sender's right to his left, and consequently from the receiver's left to his right. When the letters of the alphabet are to be used to indicate the meaning set opposite them in the following tabulation, the upper light of the display is pulsated. This is effected by means of a special pulsating key. Special signification is not given "I" and "T," they being represented by a single lamp. Before numerals are made, the distinctive signal for "numerals" "X" is shown and the upper light is pulsated, which serves still further to distinguish them from letters. The resumption of letters after using numerals will be indicated by the upper light being no The acknowledgment of the correct receipt of a message will be indicated by the letter "R." If the message has not been fully received, or if it is not understood, indication thereof will be made by signaling the letter "G." The end of a word is indicated by 2212. COSTON SIGNALS.Letters of the army and navy alphabet may be represented at night by Coston lights, port fires, or other colored pyrotechnical lights by displaying the "red" for one and the "white" for two. In using the Morse alphabet the "red" represents the dot and the "white" the dash. Coston signals and other similar lights are best suited for preconcerted signals. VERY'S NIGHT SIGNALS.The navy signal book is used, to which the following explanation refers: The letter R stands for red and the letter G for green, and each letter designates a separate star or cartridge. Bracketed stars are a pair of different colors, discharged together from two pistols. The system is based on the Army and Navy Code, red representing "1" and green "2." 1—RRRR. 2—GGGG. 3—RRRG. 4—GGGR. 5—RRGG. 6—GGRR. 7—RGGG. 8—GRRR. 9—RGGR. 10—GRRRG.
ROCKET SIGNALING.In general, rockets and shells are best used in displaying preconcerted signals. Sequence rockets may also be used to display different colored lights in sequence to represent letters or numerals of the army and navy alphabet. The method of attaching the sections in the base of the sequence rocket is described in Chapter III. In using sequence rockets in this manner, the element "1" of the army and navy alphabet is represented by a red star, while a white star represents the element "2." To send the letter "A" a rocket showing two white stars is sent up. If "B" is to be sent, a rocket showing white-red-red-white is discharged. Each star In the preparation of codes for signals with rockets or bombs there should always be arranged a "preparatory signal" which means "Are you ready?" etc., and an "answering signal," which means "Repeat your last signal," etc., a signal "annul," which means "Disregard last signal," and a signal to signify the correct receipt of the complete message, or "Signal seen and understood." semiphore A-L Semiphore M-X Semiphore: Y, Z and special signals
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