Marine radio was first installed on ships around the turn of the 20th century. In those early days, radio was used primarily for transmission and reception of passenger telegrams. Radio watch-keeping hours were not standardized, and there was no regulatory requirement for carriage of radio by ships. Indeed, there was a general lack of regulation of the radio spectrum. Amateur stations often interfered with commercial stations and vice-versa. All that changed one clear and cold April night in 1912…
(The most modern passenger liner of the time, RMS Titanic, sank on her maiden voyage after a collision with an iceberg.)
1500 people perished in the disaster. Fortunately, 700 people were saved, thanks mainly to the efforts of the Titanic’s two radio officers, who managed to summon help from nearby vessels. However, the vessel closest to the disaster could not be summoned, as her Radio Officer had just gone off watch after 12 hours on duty. The vessel managed to establish communications with other searching vessels after the Titanic had sunk. But by then, it was too late – one thousand five hundred people, including the cream of American and European society, had frozen to death in the North Atlantic. The Titanic disaster brought about a number of fundamental changes to marine radio:
- Carriage requirements and radio watch-keeping hours were standardized;
- Message priorities were standardized
- Distress frequencies were standardized;
- Radio silence periods were introduced
During the 1920’s, 30’s and 40’s, marine radio advanced with the technology of the day – radiotelephone operation was introduced, and most importantly, High Frequency (HF) came into widespread use, thereby allowing communications over ever-increasing distances. Of course, marine radio played a vital role in WW2 – the war provided a great
boost to radio technology in general. Amongst other things, WW2 introduced direct bridge to bridge communications, through the use of what was to become the marine VHF radio band – known during the war years as “talk between ships” (TBS)
After the war, Marine Radio incorporated the latest achievements in electronics – solid state equipment and Marine Radar became commonplace. However by the late 1970’s, despite tremendous general advances in communications, Morse Code still ruled the marine radio waves.
After some 80 odd years of development, marine distress alerting still relied on a human being sitting in front of a receiver. Ship’s Radio Officers sent a distress message using Morse Code in the hope that another ship or shore station would hear the call and respond.
Since the time of the Titanic, Marine Radio has helped to save tens of thousands of lives, and become the key element in Marine Search and Rescue (SAR).
Before the Global Maritime Distress and Safety System came into force, marine radio equipment was required to provide operation over a minimum specified range of 150 nautical miles. This was based on the assumptions that ships usually travelled well-used routes and that there were sufficient ships at sea and shore stations dispersed about the world to receive distress calls. However, if a ship was outside of the normal shipping lanes or was rapidly overwhelmed by the forces of nature, her distress alert may go unheard…. many ships have gone to the bottom without any distress signal being sent.
The International Maritime Organization (IMO) pondered the shortcomings of the existing marine distress systems in the mid to late 1970’s.
The 1979 IMO Assembly decided that a new global distress and safety system should be established in conjunction with a coordinated SAR infrastructure to improve safety of life at sea. And so was born the Global Maritime Distress and Safety System (GMDSS)