The dramatic rescue of over 700 survivors from the Titanic disaster in April 1912 was made possible thanks to new wireless telegraphy equipment.
More than 1500 of the 2224 passengers and crew on board were lost, but four days after the sinking, the Cunard liner Carpathia steamed into New York carrying over 700 survivors.
What were the technological advances that made this possible, and how did the new equipment work on ships miles out at sea?
Who was behind the wireless telegraph?
The Irish-Italian wireless pioneer Guglielmo Marconi had been the first to see the advantages—and the commercial possibilities—of equipping ships with wireless telegraph equipment. The technology was based on discoveries made by physicists in the latter half of the 19th century.
In December 1864, James Clerk Maxwell proposed a theory of electromagnetic radiation in a lecture to the Royal Society of London. More than 20 years later, in 1887, Heinrich Hertz in Germany confirmed Maxwell’s theories.
Oliver Lodge was the first to publicly demonstrate the transmission and detection of electromagnetic radiation, at London’s Royal Institution in 1894. But his equipment did not convey comprehensible messages.
Marconi first heard of wireless telegraphy when he attended lectures by Augusto Righi in Italy in 1895. He was fascinated.
An entrepreneur of great technical skill, he set out to exploit the discovery of radio waves by developing a working system of wireless transmission. He formed the Wireless Telegraph and Signal Co. Ltd in 1897, the first commercial development of this new technology in the world.
How did wireless work on ships?
The new mode of transmission had to compete with existing cable networks. Marconi sold his earliest systems to lighthouses and ships, which could not access the cable network and yet had most need of rapid communication.
By the time of Titanic’s maiden voyage in 1912, most passenger ships operating in the north Atlantic had a Marconi installation staffed by Marconi Company operators.
Communication between ship and shore was by Morse code, as it was for conventional telegraphy. The equipment only transmitted messages for about 300 miles in daylight, although that figure doubled or tripled after dark thanks to the refraction of long-wave radiation in the ionosphere.
What did wireless telegraphy mean for the Titanic?
At this time, wireless operators worked for the Marconi company and as well as communicating with other ships, they also relayed passenger messages—the new technology was something of a fashionable novelty, and first-class passengers would have enjoyed being able to send messages ashore.
Titanic was fitted out with some of the best wireless equipment available. But there was not yet an established practice of keeping a clear channel for emergency communications.
This early wireless telegraphy wasn't like calling a telephone, with the ability to speak to one person directly—instead, the channels were open to everyone at the same time.
Since Titanic's wireless operators were transmitting over the same frequency as other ships, and the channels were jammed with passenger communications, several ice warnings from other vessels were either missed or ignored.
If this wasn't enough, on most ships there was only a single wireless operator, who worked a long shift and then closed down for the night.
But as Titanic collided with an iceberg in calm seas on the night of 14 April 1912, Harold Cottam, operator on nearby Cunard liner Carpathia, was still awake.
He was in a position to receive the first distress signal from Titanic, sent by senior wireless operator Jack Phillips. When Carpathia received the distress call, it immediately turned and steamed the 60 miles towards Titanic’s given position, a journey of almost four hours.
Was Titanic the first to use the SOS distress signal?
The International Radiotelegraphic Convention, signed in 1906, had agreed on SOS—three dots, three dashes, three dots in Morse code—as the international distress signal. The Convention had come into force in 1908, but 'CQD', the Marconi Company's distress signal, was still widely used at the time of Titanic's voyage, including by Jack Phillips.
For two hours on Titanic, Phillips and assistant operator Harold Bride continued to send out a stream of distress signals and messages that were picked up by other vessels. Not knowing that Carpathia was already on the way, at some point Bride turned to Phillips and said,
Send SOS. It’s the new call, and it may be your last chance to send it.
As dawn broke Carpathia arrived at the grid reference transmitted by Phillips. Two hours earlier Titanic had foundered and sunk.
Shocked passengers were adrift in lifeboats, while numerous others, killed by the icy water, floated in their life jackets. There had not been enough lifeboats for all the people on board, and those that were launched had not been filled.
Carpathia’s crew rescued all the survivors they could find, retrieved 300 bodies from the water, and set course for New York.
Without the wireless telegraph, there would likely have been no survivors at all.
Those who have been saved, have been saved through one man, Mr Marconi... and his marvellous invention.
Herbert Samuel, Postmaster General (April 1912)
What was the impact for radio communication?
Hard lessons were learned from the disaster.
Soon afterwards, the International Radiographic Conference in London passed new regulations for wireless communication on board ship.
Perhaps the most important of these were that first-class passenger ships had to set a permanent 24-hour radio watch, use the same wavelength to transmit signals and maintain radio silence at regular intervals to listen for distress calls.
Marconi was already established as a celebrity, synonymous with the wireless itself, but the rescue of passengers from Titanic conferred heroic status on him and his invention. The story garnered publicity for wireless technology that cemented the commercial success of his company.