OCR Text |
Show WAR DEVELOPS RADIO TRIUMPH 'Method Discovered of Communicating Communi-cating With Submerged TSubmarines. YOUTHS ARE LUCKY FINDERS Revelations 'Come .When Researchers Are at Work on Something Else Single "Turn loop Brings Amazing Results. Washington,. C. In a general way it is known that during the wnr a method was found to communicate with a -submerged submarine from shore or sea. How this is done and how it came to 'be discovered that it could be done not until now has been made public. Like a good many other revslations.it came when the researchers research-ers were at work on another problem. The scientists of the radio section of the bureau -of standards stumbled on its secret and the lucky ones to suspect sus-pect it were two young assistants not long out of high school. Their experiments experi-ments and the development of what is known as the "loop aerial" for submarine subma-rine radio communication by the bureau bu-reau resulted in a device so simple and perfect, and producing such wonderful won-derful results, that the navy has adopted it and Is equipping all its undersea un-dersea craft with this style of loop. In the fall of 1017 a series of experiments experi-ments was undertaken by the bureau to develop an apparatus for the detection detec-tion of enemy submersibles. J. A. Wil-loughby Wil-loughby and P. D. Lowell were engaged en-gaged in the work. They had a notion that a closed or rubber encased coil of wire offered the best chances for success. They made one and threw It one night into a tank of fresh water on the grounds of the bureau near Chevy Chase, Md a suburb of Washington. Wash-ington. To their delight they received a signal from the big radio station at Arlington. The- next night they submerged sub-merged the coil in the tidal basin of the Potomac near t lie new navy building. build-ing. Again the signal came with no difference in strength whether the loop or coil was suspended in air or sunk in the river. Discovery Significant. The significance of this discovery struck both young men. Here was a wey possibly to detect the presence of snemy submarines, but surely to talk -A-lth our own, which was equally im-oortant, im-oortant, had been thought impossible. Vhls was in November. j In December improvements in the ; nbmerged coil brought the reception f signals from Lyons, France; Paris -nd San Diego, Cal. By March last tear excellent signals were received m a single turn coil 150 feet long hy dxty feet high having a wave length if 100 meters by 15,000 meters. In April Mr. Willoughby discussed witli Lieutenant Commander H. P. St. Clair of the radio division of the navy, the use of loops on submarines for both transmission and reception under waler. Both he and Mr. Lowell were sent to Xew London to work under Commander McDowell in charge of the base, to install the apparatus for a try-out try-out on submarine D-l. It is a simple contrivance, the metal frame of the submarine itself being a part of it, this being used as a "ground" just as the earth is used In hand telegraphy. The circuit is thus made complete. As finally perfected the loop consists of two Insulated wires grounded at the extreme ends of the hull carried over suitable supports to the conning tower and thence through "radio-lead-ins" down into the boat to the receiving and sending apparatus. A single turn loop was used on the D-l. With its top submerged three feet signals were received from a submarine chaser three-quarters of a mile away. Boat Used as "Ground." A new type of loop was tried on the. TJ. S. S. G-3, In which the lead-in wires were brought in from the upper side of the loop instead of the lower and tiie entire loop was Insulated from the hull. Better, but not satisfactory. suits were obtained. Up to this tlmt the frame of the boat had not been used as a "ground." The lower side of the loop was re-moved re-moved and the ends of the wire fastened fas-tened to the bow and stern. The top of the loop was submerge eight feet; signals from N'aiien. Germany, were clearly heard. Very sharp indications of direction were obtained when under water or on top of it. And soon other stations were heard, including Carnarvon, Carnar-von, England ; Kome, Italy, and various vari-ous merchant vessels. Later experiments experi-ments showed that communications can be carried on at sea under all conditions con-ditions more efficiently with the closed loop aerial than with the ordinary antenna now in general use. When a submarine equipped with the perfected apparatus Is submerged any North American or European station sta-tion can be received as distinctly as when it Is on the surface. The maximum maxi-mum depth of submergence at which signals can be heard Is determined by the wave length. Signals can be transmitted from the loop to a distance of ten or twelve miles when the submarine is completely com-pletely submerged, the maximum distance dis-tance being obtained when the top of the loop is practically at the surface. The distance decreases to two or three miles when the loop is eight or nine feet beloa' the surface. |