Wireless Communications: Past, Present, and Future


IV.TRANSOCEANIC COMMUNICATION



Download 134.12 Kb.
Page3/6
Date02.02.2017
Size134.12 Kb.
#16038
1   2   3   4   5   6

IV.TRANSOCEANIC COMMUNICATION



1. Transmitting Radio Signal across the Ocean
Marconi’s first aim in perfecting communication without wires had been to break the isolation of the sea. The first life-saving possibilities of wireless were realized in 1899 when a wireless message was received from the East Goodwin lightship – which had been equipped with Marconi wireless apparatus. It had been rammed in dense fog by a steamship R.F. Matthews. A request was made for the assistance of a lifeboat.

By the end of April 1900, the company had changed its name to Marconi's Wireless Telegraph Company and been granted its famous 'Four Sevens' patent, covering a syntonic tuning device that solved the problem of mutual interference (jamming) of wireless signals. To exploit the opportunities now opening in shipping, a subsidiary, The Marconi International Marine Communication Company, was formed to undertake all maritime work.

Marconi's next project led him to become the first person to bridge the Atlantic by wireless. It was a huge gamble in both scientific and financial terms and the experiment eventually cost some £50,000, a vast sum in those days. The company was living off its capital and many respected scientists believed that the curvature of the earth would prevent the wireless waves, traveling in straight lines, from spanning the Atlantic. Marconi, with his experience of such waves already reaching destinations beyond the horizon, believed an Atlantic crossing to be possible, and he persuaded his board of directors to agree to the experiment. Lucrative contracts with the Admiralty, Lloyds and various shipping companies helped to keep the company financially viable while building work for the necessary stations was carried out.

Marconi chose sites at Poldhu in Cornwall, Cape Cod in Massachusetts (USA), and later, Glace Bay in Canada. In September 1901, the 200 feet aerial masts erected at Poldhu were blown down in a storm. Despite this setback Marconi decided to continue, and a temporary aerial was erected. He agreed to replace the system of masts with a permanent structure of four wooden towers. It was also decided that, initially, transmission should be attempted to the nearest landfall on the American continent, namely in Newfoundland, rather than to Cape Cod where, in November, the masts were also blown down in a storm.


Marconi sailed to Newfoundland in November 1901, with two assistants and his equipment. The colonial government of Newfoundland offered him assistance and he was loaned premises at Signal Hill in St. John's in which to set up his apparatus. On 11 December the first attempt at transmission from Poldhu took place. A weak signal was received but the wind was so strong that the balloon holding the aerial aloft was lost. On 12 December, after losing one kite, a second was launched with the aerial attached and the signal from Poldhu was heard unmistakably by both Marconi and Kemp, his assistant. "The chief question," recalled Marconi, "was whether wireless waves would be stopped by the curvature of the Earth. All along I had been convinced that this was not so. The first and final answer came at 12:30 when I heard ... dot ... dot ... dot." It was Poldhu's letter 'S' in Morse code.

The British press was skeptical, as were many scientists. But in North America the Canadian government hailed Marconi as a benefactor and offered him land plus £16,000 towards building a wireless station there. In New York he was honored by the American Institute of Electrical Engineers, and by Alexander Graham Bell and Thomas Edison personally. Shares in cable companies dipped sharply; but Marconi returned to England with his case unproven.


2. Bidirectional Communication
In February 1902, however, Marconi sailed once more for the USA on board the SS Philadelphia, which had been fitted with aerials attached to the ship's masts. As the ship steamed westwards signals were sent from Poldhu and came through clearly on the Morse tape inker. The captain attested that readable messages were received up to 1,551 miles at sea. Reception of the Morse code for the letter 'S' was maintained on the filings coherer up to 2,099 miles. All this was achieved using aerial masts of 150 feet, as against the kite - supported aerial at St John's of 500 feet.

At last skeptics were silenced. By the end of 1902 Marconi had established a permanent station at Glace Bay in Nova Scotia, Canada, as well as at Cape Cod in the USA. Messages were sent in December from the Governor General of Canada and Marconi to King Edward VII, also from Marconi to the King of Italy. In January 1903, the first wireless message to be transmitted directly from the USA to England was sent from the President to King Edward VII.

By 1903, the Company had built a number of stations on shore and many merchant ships had been fitted with its wireless sets, which had to be rented from the company and were operated by Marconi personnel, who were allowed to communicate with operators using apparatus from rival companies during emergencies only. As a result of the growing maritime business the Company began to make a profit.

The company was also making enemies, especially the Germans, who called the first international conference to stop what they saw as a ruthless drive for monopoly. Through constant innovation, however, the company retained its edge. For instance, the first thermionic valve was patented in 1904. Its inventor was Professor Ambrose Fleming, the company's scientific adviser.

In January 1909, over 1,700 people were rescued at sea when the S.S. Republic was in collision with an Italian steamer, the Florida in thick fog off the US East Coast. For two days in freezing condition Jack Binns, the Marconi radio operator aboard the Republic, send out a total of two hundred messages to help guide rescuing ships to his stricken vessel’s position. Thanks to his messages all but those passengers killed by the initial impact were rescued. Binns received a special medal for his services and Marconi himself presented him with a gold watch. He then shared the Nobel Prize for Physics with one of the founders of his company's rival, the Telefunken Company of Germany.

In July 1910, Marconi enjoyed success again when the wireless was sensationally applied for the first time to apprehend a dangerous criminal. On the westward bound SS Montrose, the captain asked his Marconi operator to send a brief message to England: "Have strong suspicions that Crippen London cellar murderer and accomplice are among saloon passengers. Accomplice dressed as boy. Voice manner and build undoubtedly a girl." A detective from Scotland Yard boarded a faster ship and arrested him before the SS Montrose docked in Montreal.

Soon it was mandatory for every large ship to be equipped with wireless and have at least one operator, but even this could not prevent accidents happening. On the night of 14 April 1912, on her maiden voyage to New York, the liner, SS Titanic, deemed unsinkable, struck an iceberg and sank, with the loss of some 1,500 lives. Among them was one of the two Marconi wireless operators, whose distress signals nevertheless brought rescue to over 700 survivors. "Those who have been saved," said the British Postmaster-General, "have been saved through one man, Mr. Marconi ... and his wonderful invention." But for his luck, Marconi and his wife would have been on board. Marconi changed his passage to an earlier sailing on the SS Lusitania, and Marconi's wife also cancelled her journey when, at the last minute, one of children became unwell.

In July 1912, however, his luck changed; when in the wake of negotiations with the government to implement the Company's plan for an Imperial Wireless Scheme, the city was swept with rumors that ministers, privy to the information, had been speculating in Marconi shares. Subsequently the rumors were found to have no substance, but what became known as the Marconi Scandal left its scars, emotional and physical, and while recuperating in Italy, Marconi lost an eye in a head-on car crash.

Marconi was in England at the outbreak of the First World War in August 1914. When Italy chose neutrality he was classified in Britain as an alien but the government permitted him to leave after first requisitioning his company's sites.

Company personnel played a significant part in every aspect and theatre of conflict from training army signalers to developing air-to-ground and air-to-air telegraphy and equipping 600 planes of the Royal Flying Corps; from building shore stations for the Royal Navy to setting up a direction - finding (DF) chain for locating enemy Zeppelins and submarines; from providing a lifeline for merchant ships to tracking the German fleet before the Battle of Jutland.

As a non-combatant, Marconi was elevated to the Senate in Rome. He then sailed for the USA on the SS Lusitania to fight a legal battle in his commercial war-by-proxy with Telefunken. On her return journey without him, the ship was torpedoed - reportedly through a mistaken German plot to take him prisoner! As a combatant, once Italy had declared for the Allies, Marconi served in the army and navy before being seconded to the diplomatic corps, in which he represented Italy after the war at the Paris Peace Conference.

In 1919, Marconi bought a 700-ton steam yacht originally built for an Austrian grand duchess. This he renamed Elettra and equipped it as his floating laboratory. On the Elettra he could work in solitude, spend holidays with his children and entertain 'high society' friends - royal and titled grandees, tycoons and Hollywood film stars.

Throughout the 1920s, major countries including the U.S., France and Great Britain developed networks of high-powered radio stations. The American Telegraph and Telephone Company became much more active, as did Marconi's Wireless Telegraph Company of Canada. 

At this stage in its development, the true potential of radio telephony – the transmission of words and music – was slowly becoming clear, and an entire industry evolved based on the recreational value of radio. Wireless technology factories, abandoned after the war, were re-opened to begin mass production of radio receivers for the general population. 

Radio sets became common on aircraft, ships and tanks. Radio telephony was also adapted for use in crime detection by police forces in Britain and the States.




Download 134.12 Kb.

Share with your friends:
1   2   3   4   5   6




The database is protected by copyright ©ininet.org 2024
send message

    Main page