Main features of the powerful and sensitive equipment that keeps the vessel in constant touch with other ships and with the shore
THE OPERATOR’S DESK is generally placed against a bulkhead, to which most of his instruments are fixed. His telephones are shown connected to terminals on the receiver fastened to this bulkhead. The two transmitting keys -
AT twenty minutes to six on a dark January morning in the North Atlantic, the look-
The collision occurred on January 23, 1909, in latitude 40° 17’ N, longitude 70° W. The Republic, bound for Madeira, had left New York the day before, and during the night had run into a belt of fog. The vessel was proceeding slowly about twenty-
Only six lives were lost when the vessels crashed together, but about 2,000 people were placed in imminent danger, for both ships were seriously damaged. The Florida, groping her way back and guided by fog signals, first took on board all the passengers. The doomed Republic sank, but not before her wireless had summoned the Baltic and other vessels. They reached the scene in time, transferred passengers and crews, and landed all those involved in the collision without further loss of life.
A wireless station is concealed in the dummy forward funnel of the Cunard White Star Liner Georgic. This ship is one of the largest motor vessels in the world, with a gross tonnage of 27,759. The lead-
The quality of the seamanship displayed on that occasion, the swift transfer in boats, the rescue of the Republic’s captain and crew when the vessel sank -
The modern liner’s radio apparatus is, of course, entirely different from those early wireless installations. It is at once more powerful and more sensitive -
In some of the larger ships a passenger may speak from any of the ship’s telephones in the public rooms, or from his private cabin. Connexion is made between the wireless room and the selected telephone through the liner’s switchboard; thus the call between ship and shore can be made as conveniently as from one house to another in the same town.
There are also several other valuable applications of wireless technique that assist the seafarer. The Merchant Shipping Act now provides that all passenger-
Lifeboat sets are another part of the large liner’s wireless equipment. In the event of the boat becoming separated from others its miniature wireless set is able to serve the small community in much the same way as the main installation serves the ship herself.
Electric waves are used also for depth-
ONE OF THE WIRELESS CABINS in a modern liner, showing on the left the 2-
Wireless apparatus in a ship includes the loudspeaker-
These subsidiary applications of wireless are, however, of minor importance compared with the main transmitter and receiver, on which the ship depends for reliable communications. The passenger liner -
The ship’s wireless receiver and transmitter must therefore be of special type, widely different from the corresponding apparatus used ashore. A typical valve receiver, for example, will be able to cover all the wavelengths from 15 to 20,000 metres. Its tuning must necessarily be far more intricate than that of the ordinary broadcast receiver, which cannot be tuned below 200 nor above 2,000 metres.
TELEPHONING TO THE SHORE FROM MID-
In addition to covering an extraordinarily wide band of wavelengths, the liner’s wireless receiver must be capable of picking up not only telephony (speech and music) as commonly heard ashore, but also the other forms of marine wireless communication in general use -
The valves are supplied with high-
Most of the space in the wireless room is devoted to transmitting apparatus, because this is necessarily much larger than the receiver, and is in dual form -
The transmitter can be adjusted to work on any wavelength between 583 metres and 820 metres, and the change from one wavelength to another can be made in a few seconds. Three valves are employed: two for rectifying the alternating current supply, and the third for generating the high-
Measuring instruments are incorporated in the transmitter, to enable the high-
Supplementing the main transmitter is the emergency apparatus. This derives its power from a motor alternator, driven from a 24-
An installation of this kind, typical of thousands now in operation all over the world, is a powerful factor in the safety of life at sea. The evolution of the ship’s wireless set, from crude apparatus such as that in the Republic to the wonderful instruments in the liner of to-
[From part 5, published 10 March 1936]
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