SOS, CQD and the History of Maritime Distress Calls To Telegraph Office Main Page Welcome back to the Telegraph Office. This month we are going to diverge a little from talking about wire and wireless artifacts and talk about wireless telegraph distress signals. Mystery, intrigue as well as misinformation surrounds the origin and use of maritime distress calls. The general populace believes that "SOS" signifies "Save Our Ship." Casual students of radio history are aware that "CQD" preceded the use of "SOS." Why were these signals adopted? When were they used? Why did one replace the other? What is one likely to find by digging a little deeper? The practical use of wireless telegraphy was made possible by Guglielmo Marconi in the closing years of the 19th century. Until then, ships at sea out of visual range were very much isolated from shore and other ships. A ship could vanish from the high seas, and no one would know until that vessel failed to make a port connection. Marconi, seeing that wireless would not compete with wire telegraphy for land based communication, concentrated his efforts on ship to shore communications. Ships equipped with wireless were no longer isolated.

The first use of wireless in communicating the need for assistance came in March of 1899. The East Goodwin Lightship, marking the southeastern English coast, was rammed in a fog in the early morning hours by the SS R. F. Matthews. A distress call was transmitted to a shore station at South Foreland and help was dispatched. By 1904 there were many Trans-Atlantic British ships equipped with wireless. The wireless operators came from the ranks of railroad and postal telegraphers. In England a general call on the landline wire was a "CQ." "CQ" preceded time signals and special notices. "CQ" was generally adopted by telegraph and cable stations all over the world. By using "CQ," each station receives a message from a single transmission and an economy of time and labor was realized. Naturally, "CQ" went with the operators to sea and was likewise used for a general call. This sign for "all stations" was adopted soon after wireless came into being by both ships and shore stations. At the first international congress of wireless telegraphy in 1903, the Italians recommended the use of "SSSDDD" to signal an emergency.

"D" had previously been used internationally as the signal for an urgent message. The origin of "S" is not known, but it may have come from the first letter of the word ship, indicating a ship in distress. The sending of "SSSDDD" would signal all other stations to stop sending and leave the channel open for emergency traffic. Though discussed, it was not adopted. Deciding on a distress signal was put on the agenda for the next meeting in 1906. "DDD" would later be adopted for the silent signal, indicating all stations must cease sending. In 1904, the Marconi company filled the gap by suggesting the use of "CQD" for a distress signal. It was established on February 1 of that year by Marconi Company's circular No. 57. Although generally accepted to mean, "Come Quick Danger," that is not the case. It is a general call, "CQ," followed by "D," meaning distress. A strict interpretation would be "All stations, Distress." In the U.S.

Senate hearings following the Titanic disaster, interrogator Senator William Smith asked Harold Bride, the surviving wireless operator, "Is CQD in itself composed of the first letter of three words, or merely a code?" Bride responded, "Merely a code call sir." Marconi also testified, "It [CQD] is a conventional signal which was introduced originally by my company to express a state of danger or peril of a ship that sends it." At the second Berlin Radiotelegraphic Conference of 1906, the subject of a distress signal was again addressed. The distress signal chosen was "SOS." (The American distress signal "NC" for "Call for help without delay" was not adopted, although it remains as the international flag symbol for distress to this day.) Popular accounts portray the adoption of "SOS" as being derived from "SOE," which the Germans had used as a general inquiry call. These accounts suggest there was objection because the final letter of "SOE" was a single dot, hard to copy in adverse conditions. The letter "S" was substituted accounts say, for three dots, three dashes and three dots could not be misinterpreted.

Popular accounts of the origin of "SOS" fail to mention that the Germans had used "SOS" for a distress signal. They adopted the signal "SOS" for distress as well as "SOE" for inquiry on April 1, 1905, a year before the Berlin conference. The Electrician, May 5, 1905 published "German Regulations for the Control of Spark Telegraphy" which stated: "...---..., "Distress" signal (Notzeichen). This is to be repeated by a ship in distress until all other stations have stopped working." Unfortunately, the 1906 Conference proceedings do not give an account of the discussions nor the origin of SOS. The proceedings merely specify what the signal will be. In the Service Regulations Affixed to the International Wireless Telegraph Convention, paragraph 6a, "Signals of Transmission" states:: "Ships in distress shall use the following signal: ...---... repeated at brief intervals." The Marconi Yearbook of Wireless Telegraphy and Telephony , 1918 states, "This signal [SOS] was adopted simply on account of its easy radiation and its unmistakable character.

There is no special signification in the letter themselves, and it is entirely incorrect to put full stops between them [the letters]." All the popular interpretations of "SOS," "Save or Ship," "Save Our Souls," or "Send Out Succour" are simply not valid. Stations hearing this distress call were to immediately cease handling traffic until the emergency was over and were likewise bound to answer the distress signal. Although the use of "SOS" was officially ratified in 1908, the use of "CQD" lingered for several more years, especially in British service where it originated. It is well documented in personal accounts of Harold Bride, second Radio Officer, and in the logs of the SS Carpathia, that the Titanic first used "CQD" to call for help.

When Captain Smith gave the order to radio for help, first radio officer Jack Phillips sent "CQD" six times followed by the Titanic call letters, "MGY." Later, at Brides suggestion, Phillips interspersed his calls with "SOS." In SOS to the Rescue, 1935, author Baarslag notes, "Although adopted intentionally in 1908, it [SOS] had not completely displaced the older "CQD" in the British operators' affections." Marconi in his U.S. Senate testimony on the Titanic disaster said, "I should state that the international signal [SOS] is really less known that the Marconi Co.'s [CQD] signal." (It is interesting to observe that Marconi was waiting in New York to return home to England on the Titanic.) The first use of wireless in the rescue of an American ship was in 1905. Off Nantucket, the operator of Relief Ship No. 58, a light ship, sent "HELP" in International Morse and American Morse. (Trans-Atlantic ships used International Morse and coastal ships used American Morse.

The use of American Morse on seagoing vessels ceased in 1912 although it survived for many years on the Great Lakes.) A Naval Radio Station in Rhode Island answered the "HELP" call. The rescue of 1,500 passengers and crew from the Republic and the Florida by the Baltic in January of 1909, was the defining moment in wireless rescue history. The White Star liner Republic was rammed in a dense fog by the Italian Florida. Wireless operator Jack Binns of the Republic, sent out a "CQD." (The Florida was not wireless equipped.) The Baltic came to the rescue after hunting for the Republic in the fog for many hours. Those concerned with the maritime industry now realized the importance of equipping ships with wireless. The number of ships equipped with wireless grew rapidly after the Republic disaster. For example, at the end of 1909 the Marconi Co. owned and operated 143 wireless stations on the high seas. By the summer of 1911, the number grew to 303 stations. By the end of 1912, there were 580 shipboard wireless installations. The U.S.

Department of Commerce, Bureau of Navigation publication, Important Events in Radio telegraphy, 1916, recorded maritime disasters in which wireless played a part in rescue on the seas and the Great Lakes. From 1899 to 1908, there were nine such events. In 1909 there were 18 rescues and in 1915, 35 rescues. The following quote, though not directly rescue related, demonstrates the extreme importance of shipboard wireless: "November, 1914 -- Great Lakes storms destroyed 19 vessels, none of which were equipped with wireless. All vessels having radio apparatus installed received warning of the coming storm and sought safety." The first recorded use of "CQD" by an American ship was in 1908 by the steamer Santa Rosa off the coast of California. Commander Richard Johnstone records this in his memoir My San Francisco Story of the Waterfront and the Wireless, 1965. The first recorded American use of "SOS" was in August of 1909. Wireless operator T. D.

Haubner of the SS Arapahoe radioed for help when his ship lost its screw near Diamond Shoals, sometimes called the "Graveyard of the Atlantic." The call was heard by the United Wireless station "HA" at Hatteras. A few months later, the SS Arapahoe received an "SOS" distress call from the SS Iroquois. Radio Officer Haubner therefore has the distinction of being involved in the first two incidents of the use of "SOS" in America, the first as the sender and the second as the receiver. Being slow to adopt international wireless standards, the U.S. did not officially adopt "SOS" until 1912. Besides "CQD" and "SOS," "XXX" was used as an urgent signal, being less urgent than "SOS." "XXX" was used when there was concern for the safety of a ship or the safety of person on board or a person sighted from on board. "TTT" was used as a safety signal to precede ice, storm and other navigational warnings including coastal artillery practice. "MEDICO" was used by ships without a doctor seeking medical advice from another ship or shore station.

During W.W.II, the signal "SSSS" was used for "submarine sited". The distress call by radio telephone is the two words "MAY DAY." This corresponds to the French pronunciation for "m'aider", which means "help me." On voice, the "XXX" (urgent) equivalent is the word "PAN." This corresponds to the French pronunciation for "panne", which means "mishap" or "accident." The "TTT" (safety) equivalent is "SECURITY." This corresponds to the French pronunciation for "sécurité", which means "safety." The calling frequency for voice was 2182 kilohertz. During the investigation into the Titanic disaster, Guglielmo Marconi stated that he was experimenting with a device that could be used as an automated alarm for distress signals. Upon hearing a series of signals, an alarm bell would ring. Some European nations put these alarms into service. A sequencing device was connected to the output of the receiver. Upon the reception of four or more dashes of exactly four seconds duration, a device rang an alarm bell in the radio shack, the radio officer's quarters and on the ship's bridge.

The system was employed as a substitute for a second operator. Because the system could miss a call under adverse conditions or ring the bell in error, American radio authorities deemed it unreliable and not a substitute for another on duty operator. Americans later mandated the used of automatic alarms with the Communications Act of 1934. At the third international radiotelegraph conference in 1912, it was agreed that ships would listen for distress signals on a wavelength of 600 meters. This is a frequency of about 500 kilohertz. (The calling and distress frequency for the Great Lakes was 410 kilohertz.) International law required each ship to cease transmitting for three minutes at 15 and 45 minutes past the hour. During this interval they were required to listen for distress calls. At this conference, the recent Titanic disaster was fresh on the minds of the delegates, particularly the British. Consequently, many advances were made concerning the cooperative use of wireless for safety at sea. It is interesting that the use of "CQ" as a general call was displaced by "QST" in 1911. Radio amateurs, or hams as they are more commonly called, continue to use both.

"CQ" is used as "calling any station" and "QST" is used as "calling all stations" Wireless and radio literature of the early and mid 20th century is rich in documenting the use of maritime distress signals. Only the surface of the subject is covered here. Yet, perhaps next time a reference to "SOS" is seen, there will be a little more appreciation of its lineage. Special thanks to Thomas White for providing electronic copies of German Regulations for the Control of Spark Telegraphy, Important Events in Radiotelegraphy and International Wireless Telegraph Convention. Without them, this article would not have been complete. Bibliography Baarslag, Karl. SOS to the Rescue. New York: Oxford University Press, 1935. DeNeuf, Don. SSSDDD? SOE? CQD? SOS?. Telecommunications, Old Timer's Bulletin, Vol. 30. No. 2, Antique Wireless Association, 1989. End of SOS Recalls Early Origins. Dots and Dashes - Official Publication of the Morse Telegraph Club, Inc. Vol. 27. No. 1, 1999.

"German Regulations for the Control of Spark Telegraphy." The Electrician, May, 1905. Hancock, H. E. Wireless at Sea, The First Fifty Years. Chelmsford, England: Marconi International Marine Communications Company, 1950. Important Events in Radiotelegraphy, Department of Commerce, Bureau of Navigation, Radio Service, Washington: G.P.O., 1916. International Wireless Telegraph Convention. Washington: G.P.O., 1907. Johnstone, Richard. My San Francisco Story of the Waterfront and the Wireless. Larkspur, California: Richard Johnstone, 1965. Kuntz, Tom. (editor) The Titanic Disaster Hearings: The Official Transcripts of the 1912 Senate Investigation. Pocket Books, 1998. "Marconi's Latest -- Wireless Distress Signal That Rings a Bell -- Titanic Commission Hears of New Invention." Daily Sketch (British newspaper) 19 June 1912. from The Titanic Disaster - As Reported in the British National Press April - July 1912. compiled by Dave Bryceson.

New York: Norton, 1997 Morgan, Alfred P. Wireless Telegraphy and Telephony. New York: Henley, 1920. Nilson, Arthur R. and Hornung, J. L. Radio Operating Questions and Answers. New York: McGraw-Hill, 1940. Olson, Hank and Orr, Bill. The KFS-Federal-MacKay Story: From CW Arc to Silicon Valley. The AWA Review, Vol. 8, 1993. Schroeder, Peter B. Contact at Sea, A History of Maritime Radio Communications. Ridgewood, N.J.: The Gregg Press, 1967. Strichartz, M. H. Marine Radio Manual. New York: Cornell Maritime Press, 1944 The Year-Book of Wireless Telegraphy & Telephony 1918. London: The Wireless Press, LTD., 1918. Image Collins, Francis A. The Wireless Man His Work and Adventures on Land and Sea (Boy Scout edition).

Grosset & Dunlap, 1912 SOS - encyclopedia article - Citizendium This editable Main Article is under development and not meant to be cited; by editing it you can help to improve it towards a future approved , citable version. These unapproved articles are subject to a disclaimer . [ edit intro ] 1912 drawing of a ship captain watching while a radio operator telegraphs Morse code during an emergency. SOS is the conventional description used for the Morse code international distress signal (· · · — — — · · ·). Under the current version of the Safety of Life at Sea (SOLAS) convention, ships and search and rescue centers no longer monitor the 500 KHz maritime emergency channel; Morse code telegraphy is obsolete in maritime use. [1] The SOS distress signal is actually an unbroken series of three-dots/three-dashes/three-dots, without internal letter spacing. However, because three dots form the letter S in International Morse code, and three dashes stand for the letter O, "SOS" became an easy way to remember the correct sequence.

SOS has often been said to stand for such things as "Save Our Souls", "Save Our Ship", and "Stop Other Signals". However, these phrases are unofficial and came later, and are used as mnemonic devices to help remember the correct telegraphic pattern. This distress signal was first adopted in radio regulations issued by German government, which took effect on April 1, 1905. It became the worldwide standard when it was included in regulations affixed to the second International Radiotelegraphic Convention, which was signed in Berlin, Germany on November 3, 1906, with an effective date of July 1, 1908. Contents History Initial suggestions Radio communication — originally known as " wireless telegraphy " — did not exist prior to the mid-1890s. Before then, seagoing vessels used visual signals, including semaphore flags, signal lights and flares, plus audio signals, such as bells and foghorns, to draw attention and signify when they required assistance. However, the range of these early devices was limited, and the long distances covered by radio communication in all weather conditions promised to revolutionize safety at sea.

Early radio transmitters could not transmit full-audio signals, so stations adopted the dots-and-dashes of Morse code that had been developed for land telegraphy. However, there was no commonly used distress call in landline telegraph practice. Although it was recognized that there was a need for standardized seagoing radio communication, competition between rival radio companies initially limited cooperation. In 1903, the first International Radiotelegraphic Conference met in Berlin, Germany. During this conference, Captain Quintino Bonomo, an Italian representative, brought up the issue of common operating standards, and in part suggested that "ships in distress... should send the signal SSS DDD at intervals of a few minutes". However, procedural issues were not a part of the Conference's mandate, so the Conference did not adopt an official distress signal, although Article IV of its Final Protocol, signed August 13, 1903, did state that "Wireless telegraph stations should, unless practically impossible, give priority to calls for help received from ships at sea." Thus, individual governments and companies were left to independently develop their own standards.

The first radio distress call to be adopted appears to have been "CQD", by the Marconi International Marine Communication Company, for Marconi-operated shipboard stations. It was announced on January 7, 1904 by the company's "Circular 57" that "...on and after the 1st February, 1904, the call to be given by ships in distress or in any way requiring assistance shall be 'C.Q.D.'." ("CQ" was a general call to all stations; amateur or " ham " radio operators still use it today when soliciting a contact with any station that hears the call.) An alternate suggestion appeared in the 1906 edition of "Manual of Wireless Telegraphy for the Use of Naval Electricians" by S. S. Robison, which was used by the United States Navy. A section of this book stated that the symbols used by International Code of Signals for visual signaling would also likely be adopted by the radio service. In this system the visual flag signal "NC" stood for "In distress; want immediate assistance"; Robison suggested that this would also likely be adopted internationally as the distress call for radio operators.

Germany creates SOS (1905) A third independently adopted standard became the genesis for SOS. National radio regulations announced by the German government in March, 1905, effective April 1, 1905, included three new Morse code sequences for specialized use: Notzeichen ("Distress signal"), consisting of three-dots/three-dashes/three-dots (· · · — — — · · · ), "to be repeated by a ship in distress until all other stations have stopped working". Ruhezeichen ("Cease-sending signal"), formed by six consecutive dashes ( — — — — — — ), used by shore stations to inform other local stations to stop transmitting. Suchzeichen ("Quest signal"), composed of three-dots/three dashes/one-dot, (· · · — — — · ), designed for transmitting to shore stations a ship's desire for attention. The Notzeichen signal marked the first appearance of the SOS distress signal. International adoption (1906) A second International Radiotelegraphic Convention, with a broader mandate, met in Berlin in 1906.

This body signed an international agreement on November 3, 1906, with an effective date of July 1, 1908. An extensive collection of Service Regulations was included to supplement the Convention, and in particular Article XVI adopted Germany's Notzeichen distress signal as the international standard, stating: "Ships in distress shall use the following signal: · · · — — — · · · repeated at brief intervals". Usage The first well documented use of the SOS distress call is by the Arapahoe on August 11, 1909, when it suffered a broken shaft in the Atlantic Ocean, near Cape Hatteras, North Carolina. However, an article titled "Notable Achievements of Wireless" in the September, 1910 Modern Electrics suggests that an earlier SOS distress call was transmitted by the Cunard liner Slavonia, on June 10, 1909. There was some resistance among Marconi operators against dropping the use of "CQD", and at the time of the April, 1912 Titanic disaster, that vessel's Marconi operators transmitted both CQD and SOS distress signals.

However, the use of CQD largely disappeared after this point, because of the needs of public safety to have a single international standard. Unlike CQD, which was transmitted as three separate letters, the SOS distress call has always been officially transmitted as a continuous sequence of dots-and-dashes, instead of three individual letters — both the April 1, 1905 German law, and the 1906 Berlin regulations, explicitly defined the Morse code sequence, with no mention of any letter equivalents. However, as noted above, it soon became the practice parse the sequence into three equal parts, and refer to it as "SOS" — an early example is "The International Radio-Telegraphic Convention" in the January 12, 1907 Electrical World, which reported: "Vessels in distress use the special signal, SOS, repeated at short intervals." In International Morse, VTB, IJS and SMB also correctly translate into the · · · — — — · · · distress call sequence, but by tradition only SOS is used. Also, in American Morse code , which was used by U.S.

coastwise vessels throughout much of the early twentieth century, although three dots also stood for the letter "S", three dashes designated the numeral "5", so in some early U.S. references the distress signal was said to be "S5S". SOS has also sometimes been sent visually, composed of three-short/three-long/three-short light flashes, or with the letters "SOS" spelled out, for example, formed from logs laid on a beach, or stamped in the snow. The fact that SOS reads the same way both right-side-up and upside-down makes visual recognition easier. References (in chronological order) Notable Achievements of Wireless , Modern Electrics, September, 1910, page 315. Collins, Francis A., Some Stirring Wireless Rescues , from "The Wireless Man", 1912, pages 104-141. Turnball, G. E., "Distress Signalling" , The Yearbook of Wireless Telegraphy and Telephony, 1913, pages 318-322 (includes text of "Circular 57" announcing the adoption of "CQD").

Baarslag, Karl, SOS to the Rescue, Cadmus Books, Chicago, 1935. Footnotes ↑ The U.S. Coast Guard sent its last Morse transmission, and ceased listening for Morse SOS signals, on March 31, 1995. The Morse key and radio equipment used to send the last message (which referred to the "SOS" signal, and ended with the phrase transmitted by S.F.B. Morse at the first public demonstration of telegraphy, "What hath God wrought") is on display at the Coast Guard's Communications Area Master Station Atlantic (CAMSLANT) in Chesapeake, Viginia.) SOS - Wikipedia, the free encyclopedia SOS SOS in Morse code Problems listening to this file? See media help . SOS is the commonly used description for the international Morse code distress signal (· · · — — — · · ·). This distress signal was first adopted by the German government in radio regulations effective April 1, 1905, and became the worldwide standard under the second International Radiotelegraphic Convention, which was signed on November 3, 1906 and became effective on July 1, 1908.

SOS remained the maritime radio distress signal until 1999, when it was replaced by the Global Maritime Distress Safety System . [1] SOS is still recognized as a visual distress signal. [2] From the beginning, the SOS distress signal has actually consisted of a continuous sequence of three- dits /three- dahs /three-dits, all run together without letter spacing. In International Morse Code , three dits form the letter S, and three dahs make the letter O, so "SOS" became an easy way to remember the correct order of the dits and dahs. In modern terminology, SOS is a Morse " procedural signal " or "prosign", and the formal way to write it is with a bar above the letters, i.e. SOS. In popular usage, SOS became associated with phrases such as "save our ship" or "save our souls". These were a later development, most likely used to help remember the correct letters (a backronym ).

As the SOS signal is a prosign , its respective letters have no inherent meaning per se, it was simply chosen due to it being easy to remember.[ citation needed ] Contents [ edit ] Formalization The use of the SOS signal was first introduced in Germany as part of a set of national radio regulations, effective April 1, 1905. These regulations introduced three new Morse code sequences, including the SOS distress signal. In 1906, at the second International Radiotelegraphic Convention in Berlin, an extensive collection of Service Regulations was developed to supplement the main agreement, which was signed on November 3, 1906, becoming effective on July 1, 1908. Article XVI of the regulations adopted Germany's Notzeichen distress signal as the international standard, reading: "Ships in distress shall use the following signal: · · · — — — · · · repeated at brief intervals". The first ship to transmit an SOS distress call appears to have been the Cunard liner Slavonia on June 10, 1909, according to "Notable Achievements of Wireless" in the September, 1910 Modern Electrics.

However, there was some resistance among the Marconi operators to the adoption of the new signal, and, as late as the April, 1912 sinking of the RMS Titanic , the ship's Marconi operators intermixed CQD and SOS distress calls. However, in the interests of consistency and water safety, the use of CQD appears to have died out after this point. In both the April 1, 1905 German law, and the 1906 International regulations, the distress signal was specified as a continuous Morse code sequence of three-dits/three-dahs/three-dits, with no mention of any alphabetic equivalents. However, in International Morse, three dits comprise the letter S, and three dahs the letter O.

It therefore soon became common to refer to the distress signal as "SOS." An early report on "The International Radio-Telegraphic Convention" in the January 12, 1907 Electrical World stated that "Vessels in distress use the special signal, SOS, repeated at short intervals." (In American Morse code , which was used by many coastal ships in the United States through the first part of the twentieth century, three dahs stood for the numeral "5", so in a few cases the distress signal was informally referred to as "S5S"). In contrast to CQD, which was sent as three separate letters with spaces between each letter, the SOS distress call has always been transmitted as a continuous sequence of dits-and-dahs, and not as individual letters. There was no problem as long as operators were aware that "SOS" was technically just a convenient way for remembering the proper sequence of the distress signal's total of nine dits and dahs. In later years, the number of special Morse symbols increased.

In order to designate the proper sequence of dits-and-dahs for a long special symbol, the standard practice is to list alphabetic characters which contain the same dits-and-dahs in the same order, with a bar atop the character sequence to indicate that there should not be any internal spaces in the transmission. Thus, under the modern notation, the distress signal becomes SOS. (In International Morse, VTB, IJS and SMB, among others, would also correctly translate into the · · · — — — · · · distress call sequence, but traditionally only SOS is used). It has also sometimes been used as a visual distress signal, consisting of three short, three long, three short light flashes such as from a survival mirror, or with "SOS" spelled out in individual letters, for example, stamped in a snowbank or formed out of logs on a beach. The fact that SOS can be read right side up as well as upside down became important for visual recognition if viewed from above. [ edit ] Later developments Additional warning and distress signals followed the introduction of SOS.

On January 20, 1914, the London International Convention on Safety of Life at Sea adopted the Morse code signal TTT ( — — —), three letter T's (—) spaced correctly as three letters so as not to be confused with the letter O (- - -), as the "Safety Signal," used for messages to ships "involving safety of navigation and being of an urgent character." With the development of audio radio transmitters, there was a need for a spoken distress phrase, and " Mayday " was adopted by the 1927 International Radio Convention as the equivalent of SOS. For TTT the equivalent audio signal is " Securité " for navigational safety. During the Second World War , additional codes were employed to include immediate details about attacks by enemy vessels, especially in the Battle of the Atlantic . The signal SSS signalled attacked by submarines, whilst RRR warned of an attack by a surface raider, QQQ warned of an unknown raider (usually an auxiliary cruiser ), and AAA indicated an attack by aircraft. They were usually sent in conjunction with the SOS distress code. All of these codes later switched from three repeats of the letter to four repeats ("RRRR", etc.).

None of these signals were used on their own. Sending SOS as well as other warning signals (TTT, XXX etc.) used similar procedures for effectiveness. These were always followed correctly. Here is an example of an SOS signal; the portions in brackets are an explanation only. SOS SOS SOS de (this is) GBTT GBTT GBTT (call sign of the QE2 repeated 3 times) Queen Elizabeth 2 (name of ship) psn (position) 49.06.30 North, 04.30.20 West. Ship on fire, crew abandoning ship (nature of distress) AR (end of transmission) K (invitation to reply). Ships and coastal stations would normally have required quiet times twice an hour to listen for priority signals. However, many merchant vessels carried only one or two radio operators in which case the SOS may not be heard by operators off duty. Eventually equipment was invented to summon off-duty operators by ringing an alarm in the operators berth. This was triggered by the operator of the ship in distress transmitting twelve long dashes of four seconds duration each. These were sent prior to the SOS hopefully ringing the automatic alarm in ships so equipped.

If possible a short delay was given before transmission of the SOS proper. This was to give those off watch operators time to get to their radio office. [ edit ] Cultural references S.O.S. is the title of a 1975 song by the Swedish pop group ABBA . The Delorean time machine, in the 1985 sci-fi/comedy film Back to the Future , flashed its headlights to this-during the climax; as the engine stalled, low on fuel . The same-named brand of kitchen scouring pads had a popular television commercial in 1994. Kitchen and tablewares alike all clinged and tapped the original jingle in unison, to signal being in need of the product. 2007 saw the famous Kool-Aid beverage mix air its "Singles" flavours. The commercial began with an aerial view of an island, advertising, "S.U.S.: Stirring Up Singles", on the sand below. Inviting those from a helicopter to try the individual packs. [ edit ] Famous SOS calls What is the Meaning of SOS? - BoatSafe.com What is the Meaning of SOS? Harmony asks "Do the letters in the term SOS represent three words?

If so could you let me know what they are?" Thanks to Neal McEwen for allowing us to use information from his article "SOS", "CQD" and the History of Maritime Distress Calls. There is much mystery and misinformation surrounding the origin and use of maritime distress calls. Most of the general populace believes that "SOS" signifies "Save Our Ship." Casual students of radio history are aware that the use of "SOS" was preceded by "CQD." Why were these signals adopted? When were they used? The practical use of wireless telegraphy was made possible by Guglielmo Marconi in the closing years of the 19th century. Until then, ships at sea out of visual range were very much isolated from shore and other ships. The wireless telegraphers used Morse Code to send messages. Morse Code is a way of "tapping" out letters using a series of dots (short signals) and dashes (long signals). Spoken, short signals are referred to as "dih" and long signals are referred to as "dah".

The letter "A" is represented by a dot followed by a dash: By 1904 there were many trans-Atlantic British ships equipped with wireless communications. The wireless operators came from the ranks of railroad and postal telegraphers. In England a general call on the landline wire was a "CQ." "CQ" preceded time signals and special notices. "CQ" was generally adopted by telegraph and cable stations all over the world. By using "CQ," each station receives a message from a single transmission and an economy of time and labor was realized. Naturally, "CQ," went with the operators to sea and was likewise used for a general call. This sign for "all stations" was adopted soon after wireless came into being by both ships and shore stations. In 1904, the Marconi company suggested the use of "CQD" for a distress signal. Although generally accepted to mean, "Come Quick Danger," that is not the case. It is a general call, "CQ," followed by "D," meaning distress.

A strict interpretation would be "All stations, Distress." At the second Berlin Radiotelegraphic Conference 1906, the subject of a danger signal was again addressed. Considerable discussion ensued and finally SOS was adopted. The thinking was that three dots, three dashes and three dots could not be misinterpreted. It was to be sent together as one string. The Marconi Yearbook of Wireless Telegraphy and Telephony , 1918 states, "This signal [SOS] was adopted simply on account of its easy radiation and its unmistakable character. There is no special signification in the letter themselves, and it is entirely incorrect to put full stops between them [the letters]." All the popular interpretations of "SOS," "Save Our Ship," "Save Our Souls," or "Send Out Succour" are simply not valid. Stations hearing this distress call were to immediately cease handling traffic until the emergency was over and were likewise bound to answer the distress signal. Although the use of "SOS" was officially ratified in 1908, the use of "CQD" lingered for several more years, especially in British service where it originated.

It is well documented in personal accounts of Harold Bride, second Radio Officer, and in the logs of the SS Carpathia, that the Titanic first used "CQD" to call for help. When Captain Smith gave the order to radio for help, first radio officer Jack Phillips sent "CQD" six times followed by the Titanic call letters, "MGY." Later, at Brides suggestion, Phillips interspersed his calls with "SOS." In SOS to the Rescue, 1935, author Baarslag notes, "Although adopted intentionally in 1908, it [SOS] had not completely displaced the older 'CQD' in the British operators' affections." (It is interesting to observe that Marconi was waiting in New York to return home to England on the Titanic.) The first recorded American use of "SOS" was in August of 1909. Wireless operator T. D. Haubner of the SS Arapahoe radioed for help when his ship lost its screw near Diamond Shoals, sometimes called the "Graveyard of the Atlantic." The call was heard by the United Wireless station "HA" at Hatteras.

A few months later, the SS Arapahoe received an "SOS" distress call from the SS Iroquois. Radio Officer Haubner therefore has the distinction of being involved in the first two incidents of the use of "SOS" in America, the first as the sender and the second as the receiver. The U.S. did not officially adopt "SOS" until 1912, being slow to adopt international wireless standards. Related Articles: Morse Code - Engineering and Technology History Wiki Morse Code International Morse Code Morse Sounder Morse code is a communications language created by Samuel Morse and Alfred Vail originally to be used with the telegraph. Each letter of the alphabet is made up of combinations of dots and dashes that were originally sent over telegraph wires or by radio waves from one place to another. Morse is the earliest type of digital communications, as the code is made solely from Ones and Zeros (ons and offs). It was the only way to rapidly communicate over very long distances before voice communications and two-way radios were able to do the job better. Morse Code communications can tolerate noise in the communication channel that would otherwise prevent voice (SSB, AM or FM) communications.

Perhaps the most famous "word" in Morse Code is SOS. Contrary to popular belief, SOS does not mean “save our ship,” although it often did just that. Rather, it was chosen as the international Morse code distress signal, because the three dots for S and the three dashes for O (... --- ...) make a clear and distinct signal. An example of the SOS sound: Audio File Play (Morse_SOS.mp3) Before SOS became the standard radio distress signal, there were others. CQ (“seek you”) was a general call to any station. D was internationally recognized in telegraph cable traffic to precede urgent messages, thus CQD (-.-. --.- -..) meant “urgent message to any station.” Telegraph Key At the First Congress of Wireless Telegraphy in 1903, the Italians suggested SSSDDD (... ... ... -.. -.. -..) to combine the distinct three dots of the S with the urgency of the D. German radio operators used SOE (... --- .) but quickly realized that the single dot of the E could get easily lost in the static noise.

For that reason they had already shifted to SOS by the time of its adoption at the International Radio Telegraphic Convention of 1906. The United States did not adopt SOS until after the Titanic disaster in 1912. A handful Nokia engineers used morse code as their standard alert tone when short message service (SMS) messages were received, of course the morse code reads SMS.This was implemented by them circa 1985 (guess). In 1995, the United States Coast Guard ended the use of Morse Code transmissions in its maritime communications service, signaling the end of an era in the history of communications. While morse is nowdays commercially unused, and no longer examined for radio licences, it does have widespread use in Amateur Radio , and oddly the @ symbol is formally allocated as a new international Morse Code character in February 2004. The new sign, known as a "commat," consists of the signals for "A" (dot-dash) and "C" (dash-dot-dash-dot), with no space between them.

In 2008 a WW2 morse code key was dropped into the Indian Ocean on 28 April as part of a remembrance service for the lost crew of HMAS Sydney which was sunk in 1941. Wired Morse Telegraphy The following code definitions were used for telegraphy (not wireless) in the Americas and Europe. There are other morse variants for Japan. Morse Telegraphy, 1920 (pdf) Wireless Morse Telegraphy The wireless telegraphy morse code sequences are derived from the wired telegraphy code and are shown in the sound summary below. Morse used in wireless telegraphy is colloquially known as CW (Continuous Wave). The practical use of morse code involves the use and recognition of many abbreviations, and as can be seen in the 1920's, there are 'short numercial' sequences defined. Other abbreviations used in morse include TU meaning 'thankyou', 73 meaning 'goodbye', PSE meaning 'please', WX meaning 'weather', plus a whole sequence of 3 letter "Q" codes. Examples are QRZ meaning "Identify yourself", QSY meaning "Please change yopur operating frequency'.

Even other abbreviations are used that pertain to subject matter being communicated, eg K can mean "kilo" or "1,000", FNN can mean "599". Learning Morse Code In these modern times, why would anyone want to learn a commercially obsolete ‘language’? Here is some food for thought: Morse code is still used widely in Amateur Radio communications, as Morse code signals can get a message through noise, whereas a voice signal often cannot. It is a novelty... did Klingon’s use Morse code? More seriously, it has allowed quadriplegics to communicate with just the battering of an eyelid... in Morse. It can allow a listener to uncover hidden messages in some music (yes they do exist), and it can be troubling when someone is using a swear word for their phone ring-tone, and you are the only person in the room offended. Oddly, the “F” word is one of the most melodious in Morse. The best way to learn Morse is to listen. A variety of software program can be downloaded onto iPads, Mac and PC’s to facilitate this, and also there are radio beacons run by radio clubs to allow you to practice receiving Morse code off air.

The following are suggestions are for the readers benefit, and not endorsed in any way. Morse Mania software SOS - definition - What is ? What is ? SOS definition : SOS SOS is the International Morse code distress signal (· · · – – – · · ·). This distress signal was first adopted by the German government in radio regulations effective April 1, 1905, and became the worldwide standard under the second International Radiotelegraphic Convention, which was signed on November 3, 1906, and became effective on July 1, 1908. SOS remained the maritime radio distress signal until 1999, when it was replaced by the Global Maritime Distress and Safety System. SOS is still recognized as a visual distress signal. The SOS distress signal is a continuous sequence of three dits, three dahs, and three dits, all run together without letter spacing. In International Morse Code, three dits form the letter S, and three dahs make the letter O, so "SOS" became an easy way to remember the order of the dits and dahs.

In modern terminology, SOS is a Morse "procedural signal" or "prosign", and the formal way to write it is with a bar above the letters: SOS. In popular usage, SOS became associated with such phrases as "Save Our Ship" or "Send Out Succour" or "Save our Soul". SOS is only one of several ways that the combination could have been written; VTB, for example, would produce exactly the same sound, but SOS was chosen to describe this combination. SOS is the only nine-element signal in Morse code, making it more easily recognizable, as no other symbol uses more than eight elements. ==Formalization== The use of the SOS signal was first introduced in Germany as part of a set of national radio regulations, effective April 1, 1905. These regulations introduced three new Morse code sequences, including the SOS distress signal. In 1906, at the second International Radiotelegraphic Convention in Berlin, an extensive collection of Service Regulations was developed to supplement the main agreement, which was signed on November 3, 1906, becoming effective on July 1, 1908.

Article XVI of the regulations adopted Germany's Notzeichen (distress signal) as the international standard, reading: "Ships in distress shall use the following signal: · · · – – – · · · repeated at brief intervals". The first ship to transmit an SOS distress call appears to have been either the Cunard liner on June 10, 1909, according to "Notable Achievements of Wireless" in the September, 1910 Modern Electrics, or the steamer SS Arapahoe on August 11, 1909. The signal of the Arapahoe was received by the United Wireless Telegraph Company station at Hatteras, North Carolina, and forwarded to the steamer company's offices. However, there was some resistance among the Marconi operators to the adoption of the new signal, and, as late as the April 1912 sinking of the , the ship's Marconi operators intermixed CQD and SOS distress calls. However, in the interests of consistency and water safety, the use of CQD appears to have died out thereafter.

In both the April 1, 1905, German law, and the 1906 International regulations, the distress signal was specified as a continuous Morse code sequence of three-dits/three-dahs/three-dits, with no mention of any alphabetic equivalents. However, in International Morse, three dits comprise the letter S, and three dahs the letter O. It therefore soon became common to refer to the distress signal as "SOS". An early report on "The International Radio-Telegraphic Convention" in the January 12, 1907, Electrical World stated that "Vessels in distress use the special signal, SOS, repeated at short intervals." (In American Morse code, which was used by many coastal ships in the United States through the first part of the twentieth century, three dahs stood for the numeral "5", so in a few cases the distress signal was informally referred to as "S5S".) In contrast to CQD, which was sent as three separate letters with spaces between each letter, the SOS distress call has always been transmitted as a continuous sequence of dits and dahs, and not as individual letters.

There was no problem as long as operators were aware that "SOS" was technically just a convenient way for remembering the proper sequence of the distress signal's total of nine dits and dahs. In later years, the number of special Morse symbols increased. In order to designate the proper sequence of dits and dahs for a long special symbol, the standard practice is to list alphabetic characters that contain the same dits and dahs in the same order, with a bar atop the character sequence to indicate that there should not be any internal spaces in the transmission. Thus, under the modern notation, the distress signal becomes SOS. (In International Morse Code, VTB, IJS, VGI, and SMB, among others, would also correctly translate into the · · · – – – · · · distress call sequence, but traditionally only SOS is used.) It has also sometimes been used as a visual distress signal, consisting of three short, three long, and three more short flashes of light, such as from a survival mirror, or with "SOS" spelled out in individual letters (for example, stamped in a snowbank or formed out of logs on a beach).

The fact that SOS can be read right side up as well as upside down (as an ambigram) became important for visual recognition if viewed from above. ==Later developments== Additional warning and distress signals followed the introduction of SOS. On January 20, 1914, the London International Convention on Safety of Life at Sea adopted the Morse code signal TTT ( – – –), three letter Ts (–) spaced correctly as three letters so as not to be confused with the letter O (– – –), as the "Safety Signal", used for messages to ships "involving safety of navigation and being of an urgent character". With the development of audio radio transmitters, there was a need for a spoken distress phrase, and "Mayday" was adopted by the 1927 International Radio Convention as the equivalent of SOS. For TTT, the equivalent audio signal is "Sécurité" for navigational safety. It is interesting to note that "Mayday" actually originated as the French m'aidez ("help me") and that there is a third, lesser distress call (before securité and after Mayday): "panne" (French for "breakdown"), spelled "pan" in English.

French was the international language at the time that these were formalized. During World War II, additional codes were employed to include immediate details about attacks by enemy vessels, especially in the Battle of the Atlantic. The signal SSS signaled attacked by submarines, while RRR warned of an attack by a surface raider, QQQ warned of an unknown raider (usually an auxiliary cruiser), and AAA indicated an attack by aircraft. They were usually sent in conjunction with the SOS distress code. All of these codes later switched from three repeats of the letter to four repeats, e.g., "RRRR". None of these signals were used on their own. Sending SOS as well as other warning signals (TTT, XXX etc.) used similar procedures for effectiveness. These were always followed correctly. Here is an example of an SOS signal; the portions in parentheses are an explanation only. Ships and coastal stations would normally have required quiet times twice an hour to listen for priority signals. However, many merchant vessels carried only one or two radio operators, in which case the SOS may not be heard by operators off duty. Eventually, equipment was invented to summon off-duty operators by ringing an alarm in the operator's berth.

This was triggered by the operator of the ship in distress transmitting twelve long dashes of four seconds duration each. These were sent prior to the SOS in the hope of ringing the automatic alarm in ships so equipped. If possible, a short delay was given before transmission of the SOS proper. This was to give those off-watch operators time to get to their radio room. ==Historical SOS calls== * (which used CQD as well), sank in 1912 *, torpedoed in 1915 *HMHS Britannic, sank in 1916 *, sank in 1956 ==See also== *500 kHz *2182 kHz *Distress signal *Global Maritime Distress and Safety System (GMDSS) *Mayday *Pan-pan *Save Our Shores *Sécurité *Vessel emergency codes ==References== ==Further reading== * *[ Final Protocol, First International Radio Telegraphic Conference], Berlin, 1903. * * * *[ 1906 International Wireless Telegraph Convention], U.S. Government Printing Office.

* *[ "S 5 S" Rivals "C Q D" for Wireless Honors], Popular Mechanics, February, 1910, page 156. *[ Notable Achievements of Wireless], Modern Electrics, September, 1910, page 315. *Collins, Francis A., [ Some Stirring Wireless Rescues], from "The Wireless Man", 1912, pages 104–141. *Turnball, G. E., [ "Distress Signalling"], The Yearbook of Wireless Telegraphy and Telephony, 1913, pages 318–322 (includes text of "Circular 57"). *Dilks, John H. III, "Why SOS?" in OSS, June, 2007, pages 88–89. Category:Emergency communication Category:Encodings Category:Morse code Category:Rescue Category:Survival skills Category:Distress signals Category:Brevity codes de:Morsecode#SOS S.O.S S.O.S For other uses, see SOS (disambiguation) .

sdfhgidl is the commonly used description for the international Morse code distress signal (' · · · — — — · · · ). This distress signal was first adopted by the Germangovernment in radio regulations effective April 1, 1905, and became theworldwide standard under the second International Radiotelegraphic Convention,which was signed on November 3, 1906 and became effective on July 1, 1908.SOS remained the maritime radio distress signal until 1999, when it was replacedby the Global Maritime Distress Safety System [2] From the beginning, the SOS distress signal has actually consisted of acontinuous sequence of three- dits / three- dahs /three-dits, all run together without letter spacing. In International Morse Code , three dits form the letter S, and threedahs make the letter O, so "SOS" became an easy way to remember the correctorder of the dits and dahs. In modern terminology, SOS is a Morse " procedural signal " or "prosign", and the formal way to write it is with a bar above the letters,i.e.

SOS.In popular usage, SOS became associated with phrases such as "Save Our Seamen", "Save our Ship", "Survivors On Shore" or "Save Our Souls". Thesewere a later development, most likely used to help remember the correct letters(something known as a backronym ). Formalization he use of the SOS signal was first introduced in Germany as part of a set of national radio regulations, effective April 1 , 1905 . These regulations introduced three new Morse code sequences, including the SOS distress signal: 1. ("Cease-sending signal"), consisting of six dahs( — — — — — — ), sent by shore stations to tell other local stations tostop transmitting. 2. ("Quest signal"), composed of three-dits/three dahs/one-dit,all run together ( · · · — — — · ), used by ships to get the attention of shorestations. 3.

("Distress signal"), consisting of three-dits/three-dahs/three-dits ( · · · — — — · · · ), also in a continuous sequence, to be repeated by aship in distress until all other stations have stopped.SOS was developed from the general German radio call "SOE", with the 3 dits of a "S" easier to hear in under noisy conditions than the one dit of an "E". Also, theotherwise meaningless string of letters was selected because it is easilyrecognizable and can be sent rapidly. Comparing SOS (di-di-di-dah-dah-dah-di-di-dit) with the older CQD (dah-di-dah-dit dah-dah-di-dah dah-di-dit) ( — · — · / — — · — / — · · ) it is obvious how much simpler the new code was.

Also, it wouldnot be mistaken for CQ, the radio code for "calling anyone" used in casualcircumstances.In 1906, at the second International Radiotelegraphic Convention in Berlin, anextensive collection of Service Regulations was developed to supplement themain agreement, which was signed on November 3 , 1906 , becoming effective on July 1 , 1908 . Article XVI of the regulations adopted Germany's Notzeichen distress signal as the international standard, reading: "Ships in distress shall usethe following signal: · · · — — — · · · repeated at brief intervals". The first ship totransmit an SOS distress call appears to have been the Cunard liner Slavonia on June 10 , 1909 , according to "Notable Achievements of Wireless" in the September, 1910 Modern Electrics . However, there was some resistance amongthe Marconi operators to the adoption of the new signal, and, as late as the April,1912 sinking of the RMS Titanic , the ship's Marconi operators intermixed CQDand SOS distress calls.

However, in the interests of consistency and water safety, the use of CQD appears to have died out after this point.In both the April 1 , 1905 German law, and the 1906 International regulations, the distress signal was specified as a continuous Morse code sequence of three-dits/three-dahs/three-dits, with no mention of any alphabetic equivalents.However, in International Morse, three dits comprise the letter S, and three dahsthe letter O.

It therefore soon became common to refer to the distress signal as"SOS." An early report on "The International Radio-Telegraphic Convention" inthe January 12 , 1907 Electrical World stated that "Vessels in distress use thespecial signal, SOS, repeated at short intervals." (In American Morse code , whichwas used by many coastal ships in the United States through the first part of thetwentieth century, three dahs stood for the numeral "5", so in a few cases thedistress signal was informally referred to as "S5S").In contrast to CQD, which was sent as three separate letters with spacesbetween each letter, the SOS distress call has always been transmitted as acontinuous sequence of dits-and-dahs, and not as individual letters. There wasno problem as long as operators were aware that "SOS" was technically just aconvenient way for remembering the proper sequence of the distress signal'stotal of nine dits and dahs. In later years, the number of special Morse symbolsincreased.

In order to designate the proper sequence of dits-and-dahs for a longspecial symbol, the standard practice is to list alphabetic characters whichcontain the same dits-and-dahs in the same order, with a bar atop the character sequence to indicate that there should not be any internal spaces in thetransmission. Thus, under the modern notation, the distress signal becomesSOS. (In International Morse, VTB, IJS and SMB, among others, would alsocorrectly translate into the · · · — — — · · ·

Question: In Morse code, what was the radio distress signal used before the adoption of SOS in 1908?
Answer: CQD