The SOS distress signal has been the recognised international call for help for more than 100 years, and although communications technology is very different now to the days of Morse Code, the term is still widely used today.
SOS built on the the work of the British Marconi International Marine Communication Company and the German company Telefunken. It was established as an International Distress Signal on October 3, 1906, and was introduced on July 1, 1908.
To celebrate this landmark, we take a look at some of the interesting SOS facts from across the last 112 years of international rescues:
SOS does not stand for anything
Contrary to popular belief, SOS does not stand for ‘save our souls’ or ‘save our ship’. Nor does it mean ‘send out succour’. SOS actually stands for nothing at all.
SOS was selected purely because it could be very easily transmitted in Morse code during distress · · · – – – · · · (dot-dot-dot, dash-dash-dash, dot-dot-dot). Only later did the likes of ‘save our souls’ emerge.
The SOS signal was first used in 1909
SOS was formally introduced on July 1, 1908 and almost a year later it was used by the Cunard liner SS Slavonia on July 10, 1909 during a shipwreck off the Azores, Portugal.
All on board were rescued, and some of the cargo – which included 400 bags of coffee, 1,000 ingots of copper and 200 casks of oil – were salvaged from the wreckage before it was completely abandoned.
SOS took a while to be adopted
Even though the SOS distress signal was made official in 1908, it took some time to be widely adopted. So much so that in 1912, the radio operator aboard the striken Titanic used the old CQD distress signal first before he joked that they may as well do the new SOS distress signal too as they may never get a chance to try it again.
SOS was almost SOE
At the conference in Berlin to establish a universal distress, signal countries clubbed together to pitch their ideas. The UK used CQD, the Italians used SSSDDD, while the Germans had SOE.
However, the final E represented one dot, and many agreed it could be easily missed. And so, the E was replaced with an S.
SOS signals could be sent with extra emergency codes, especially in World War II, when ships could be under attack.
For example, SSS signalled attack by submarine, AAA an attack by enemy aircraft. In peacetime, XXX is used to signal for urgent help, while TTT is the 'safety signal' used for messages that concern safety to navigation.
SOS was replaced in 1999
Countries began decommissioning Morse equipment on board ships from 1992, and in 1999 a new satellite-based system for sending distress signals at sea was fully introduced, known as the Global Maritime Distress and Safety System.