Signalling distress

Today is the centenary of the most famous distress signal in history. On 14 April 1912, during a moonless night in the middle of the Atlantic, the Titanic hit an iceberg. Soon afterwards Captain Smith ordered the First Radio Officer, Jack Phillips, to radio for help.

These were the pioneering days of wireless communication. Wireless telegraphy had only just started to be used on ships through the work of Guglielmo Marconi (who was waiting in New York to join the Titanic on the return journey). Telegraphers used morse code to send messages by tapping out letters using a series of dots (short signals) and dashes (long signals).

CQD the first distress signal

When Phillips first sent the Titanic’s distress signal he tapped out: CQD CQD CQD CQD CQD CQD. British wireless operators used CQ as a general broadcast to all stations, and since 1904, CQD as a distress signal. The letters meant calling all stations (CQ) we are in distress (D) and did not represent a message such as Come quick danger.


After little response to the CQD message, Harold Bride, the Second Radio Officer suggested they also use SOS SOS SOS. SOS had been adopted in 1908 as the international distress signal (after much debate) because the three dots, three dashes and three dots were unmistakable and could not be misinterpreted. There is a popular but incorrect belief that SOS means Save Our Ship, Save Our Souls, or Send Out Succour.

The distress signals of the Titanic were recognised but the ships that responded were not close enough to get there before she sank.


More than a decade later, with the development of voice transmission, a new international distress message was required. The Mayday callsign originated in 1923 when Frederick Mockford, a senior radio officer at Croydon Airport in London, was asked to think of a distress call easily understood by pilots and ground operators. Because most of the airport traffic at that time was between Croydon and Le Bourget Airport in Paris, he proposed the word Mayday from the French m’aider, a shortening of venez m’aider meaning come help me.


The distress signal pan-pan is used for an urgent situation of a lower order than a Mayday (or SOS) such as a mechanical breakdown or a medical problem. It comes from the French, panne, meaning a breakdown. Similarly to other distress signals there are constructed meanings for the word: Possible Assistance Needed or Pay Attention Now.

These distress signals, CQD, SOS, Mayday and pan-pan, have all been derived from words or codes. The constructions of phrases around them are examples of “backronyms”, reverse or backward acronyms, phrases constructed around words rather than acronyms that are words constructed from phrases.

Today (14 April 2012) we will remember the lost souls of those passengers who, despite the signals of their radio operators, were not rescued from the waters of the freezing Atlantic a century ago.