ITU Home Page International Telecommunication Union Franšais Espa˝ol 
  Print Version 
ITU Home Page
Home : ITU News magazine

Sending out an SOS

How a famous disaster spurred agreement on international rules

Willy St÷wer



Titanic sank in 1912 with the loss of nearly 1600 lives  

As reported in the April issue of ITU News, this year marks the centenary of the International Radiotelegraph Conference held in Berlin in 1906, where 29 countries signed a convention on wireless communication for ships at sea. Its annex laid down the first international rules for wireless telegraphy — today known as the Radio Regulations — which became a cornerstone of ITU’s work. Very soon after its invention, this technology had been adopted as a way for ships in distress to summon help. It was necessary to set a standard for communication that everyone, from whatever nationality, would be able to understand, especially in an emergency.

ITU 770405/Marconi Corporation
  Guglielmo Marconi is seated at a radio transmitter on board a ship. He had booked a passage on Titanic’s return journey to Europe, which was never to be made

Morse code

As in the telegraphy that was sent across land, Morse code was the method used by ships’ wireless operators for conveying information. But what distress signal would be universally understood? Before the 1906 agreement, various countries and organizations each decided their own signals for shipping. One of the most widely adopted was the “CQD” of the Marconi International Marine Communication Company. The first two letters (CQ) were already used in landline telegraphy for announcing a general call to all stations, and the “D” was added to stand for “distress.” This gives part of the answer to the question posed on last month’s Pioneers’ Page: who signalled “CQD…MGY, ….CQD…MGY” and when? It was sent on 15 April 1912 by a ship in distress, which the second group of letters (MGY) specifically identified as “Titanic.”

The tragic maiden voyage of the British liner Titanic is a well-known story. On the night of 14-15 April, the ship struck an iceberg off the coast of Canada and sank with the loss of nearly 1600 lives. Could more people have been saved if radio communications had been better managed? Almost certainly, the answer is: yes.

A night of confusion

Six years after the agreement at the Radiotelegraph Conference, not everyone had adopted its rules. More than one emergency signal was still in use. The sinking of the Titanic also highlighted the lack of 24-hour radio communication on ships, and that even when messages were heard, in some cases operators were unwilling to respond.

It was a common practice only to communicate by radio during daylight hours. “Californian,” the closest ship to the sinking Titanic, did not hear her distress call because radio operators were not on duty overnight. The rockets fired by Titanic also confused the Californian’s crew, perhaps because ships owned by different companies had many differing patterns of lights for communicating at night. Commercial rivalry also played a part. Wireless operators were the employees of the companies that supplied ships’ radio equipment, and these firms fought hard to capture market share. This meant that operators working for one firm might not respond to radio signals coming from an operator working for a rival. It seems this is what happened to some of the signals passed between Titanic (using a Marconi system) and other ships.

Another difficulty could have been that Marconi operators were still being instructed to use “CQD” to signal distress, and this was transmitted for much of the time by Titanic’s wireless operator John Phillips (who was to die in the sea). Eventually, as suggested by assistant operator Harold Bride, he interspersed this with the new signal, “SOS.”

Shocked into action

The “SOS” signal originated in national radio regulations issued in Germany in 1905, and was adopted internationally by the Berlin conference in 1906. The conference decided that “ships in distress shall use the following signal: . . . _ _ _ . . . repeated at brief intervals.” It is a continuous group of Morse dots and dashes, rather than separate letters, and was chosen because the pattern is simple and unmistakable. However, because it can be read as “SOS” in Morse code, this became the usual mnemonic for the signal.

The sinking of the Titanic spurred maritime authorities to improve emergency procedures. Just a few months after the tragedy, the 1912 International Radiotelegraph Conference, held in London, agreed on a wavelength of 600 metres (about 500 kilohertz) for ships’ radio distress signals. Also, every ship was instructed to maintain a three-minute radio silence at 15 and 45 minutes past each hour, when operators should listen for distress calls. In 1914, the International Convention for the Safety of Life at Sea (SOLAS) was signed, requiring (among other safety measures) all ships carrying more than 50 passengers to have a radio on board.

Janet Burgess



The final SOS

Because it is such a memorable code, “SOS” has been adopted into general use whenever people want to impart the idea of emergency. Flood victims, for example, have written it on the rooves of their homes to signal rescue helicopters, and the well-known letters can even be seen quite frequently on banners in protest marches for various causes. The use of “SOS” as an official distress signal, though, ended on 1 January 1998, replaced by modern satellite communication systems and the use of voice messages, rather than Morse code. But on the very night before the regulations were to change, a ship in distress used the old signal.

The MV Oak was carrying timber from Canada to the British port of Liverpool when it lost engine power and its cargo shifted dangerously in a storm. On 31 December 1997, it reportedly signalled “SOS…SOS. This is Oak. Position 53 16 N, 24 59 W. Stop engine. We need assistance.” The British Coast Guard responded immediately, even though they at first thought the message might have been a joke: it was New Year’s Eve and not having heard a Morse code “SOS” for many years, they had suddenly received one on the last day of its official use. Fortunately, the crew of MV Oak proved to be safe in lifeboats, having sent the final “SOS” in the 90 years of the signal’s history.

Question for next month

One hundred and fifty years ago this July, a scientist was born in the Balkans at the stroke of midnight during a thunderstorm. He ended his career working on a “death ray.” Who was he?

The answer will appear in the next issue of ITU News.



Top - Feedback - Contact Us - Copyright ę ITU 2014 All Rights Reserved
Contact for this page : Corporate Communication Unit
Generated : 2014-07-26