April 5, 1919 SCIENTIFIC AMERICAN 335· Hunting Submarines with a Sound Detector American Invention That Played an Important Role in the War Against the V-Boat By Brewster S. Beach FTER nearly two years of the closest censorship, the cable to the operator who was located in the ship's hold. abroad, the American submarine detectors were uni­ A United States Navy Department has given approval A third adaptation of the listening principle was an versally adopted by all the Allied navies. to the publication of certain data relating to the develop­ instrument which protruded through the hull and was a It was found to be much superior in many ways to ment in the United States during the war, of submarine stationary part of the vessel's equipment. A somewhat any of previous development, and came to be considered detecting devices, which were used to signal advantage similar device was constructed for use on submarines, but one of the most effective offensive weapons ever used by this country and the Allies in prosecuting and bringing all of them were used to advantage. Phonograph records against the submarine. It is only necessary to recount to a successful conclusion the campaign against the of various sounds heard by the observer were made and a few pertinent points to illustrate the practicability of German U-boat. catalogued, preserving a complete record of the accom­ the device. The apparatus may be termed the composite work of plishment of the detector. These records were used in Under ideal conditions with extraneous noises reduced the General Electric Company, Submarine Signal Com- training students to distinguish between submarine to a minimum or entirely eliminated, the device was and surface craft. effective at a range of from 15 to 25 miles. Under average circumstances, the device was good for a range Fitting Aircraft with Sound of between 3 and 8 miles. Trained operators could Detectors clearly and invariably distinguish between the sounds While demonstrating the made by approaching surface craft and underwater device to the British Admir­ vessels (submarines). Within five miles the engine alty, our American engineers characteristics of different vessels was clearly marked were asked to study the even to the point of identifying by name certain (unseen) question of fitting submarine vessels after they had been observed previously for more detection units to airplanes, than one time. (This test was substantiated by a series balloons and dirigibles. of night time experiments at the entrance to Boston After some experimenta­ harbor in September and October 1917.) It was found tion, followed by more prac­ practical to tell when a submarine changed from her oil tical tests and conferences engines to electrical drive which was necessary every with the Lancashire Group time the vessel submerged. The direction of sound could usu­ ally be computed within a very few tJZi:4- c5ta rt,-,,<!:I--">:"'-'-- •• degrees of its actual location and a good judgment of the distance could generally be made. This was proved to the satisfaction of all concerned following a number of practical tests off Cape Cod, Mass., in the late summer of 1917, in waters adjacent to Boston and in Long Island Sound. --/l!toclrby; .s.C.3? While in fairness to all of the sound 01/ one'cglihdricc/ ob/l!! ct· �_IttrdMrr!,H1OYements detecting devices developed during �rroi;/c oFter Chisattoclr the war period, it must be s!tid that the American device was in., rior in I certain respects when it came ",0 the Using a trailer to remove the receiver application of these devices cL.1der ; from the noises of the ship's , ..D actual battle conditions, but in heavy own engines II/toe;" .s.c.."� sea and weather they stood up re- pany, Western Electric Company, the National Research Council, assisted and advised by .many eminent scientists, engineers and research men, chief among whom were Drs. W. R. Whitney, Irving Langmuir and W. D. Coolidge, Prof. R. A. Milikan, Prof. Max Mason, etc. Realizing that the prompt solution ; of the submarine problem was the key . ;; to a successful termination of hostilities, .Finish -SuiHno�/n. 'Te"�r�� "ro,"I,.� .?5Revo/ver .:!hot�heard Secretary Daniels, immediately upon our entr.ance into the conflict, appointed �..r/7dex = a special board to devise ways and 0 = Lhtening means to overcome it. • =f)epthCl1orge At the suggestion of Dr. Whitney, a ---a.(JosePo&horChasers group of scientists was formed at Na- ---=Cour.se orSv.bn7orine hant, Mass., under Dr. Irving Lang- '----------------- ---_____: muir, where the results of extensive Chart of an actual pursuit of a U-boat which ended research activity were put to practical in the destruction of the submarine tests under actual conditions as nearly as possible approaching those in European waters. of scientists at Harwich, apparatus Another group under Prof. Milikan, head of the was developed which met these needs Physics Department of the University of Chicago, was and many aircraft were equipped organized at New London, Conn., where the work of with sound detectors which rendered both bodies was later coordinated. it possible for them to follow the Out of the efforts of these two groups and the work course of the enemy after they had carried on in Schenectady,assisted by Allied commissions seen her submerge, a valuable faculty of scientific men, there grew the American Submarine which such craft did not possess until Detector-a development of the old principles of sound the introduction of the American wave transmission in water in an altogether new and detector. startling manner. Permission has not yet been ob­ The apparatus, finally perfected and put to immediate tained to enter into a detailed de­ use, was first designed to hang overboard from naval scription of the devices invented craft amidship below the water line and it depended for during this period. The Gonrn­ Using the listening device in an American submarine its direction getting qualities on the peculiar and here­ ment, having spent large sums of tofore little understood faculty of the human ear to money on the apparatus, desires the intricacies of its markably well. This factor was of especial value during detect the direction of sound by the shifting of that sound manufacture still kept secret, while other matters involv­ operations in the English Channel and the North Sea from one ear to the other. ing several American concerns, makes discretion the which has been termed the roughest body of water fo . ; Owing to the interference of sounds made by the better part of valor in attempting to tell the inner secrets its size in the world. listening ship's own motors, it was found more practical of its development. The addition of these listening devices to submarines to stop the engines when about to take observations and However, when the devices had proved themselves added the heretofore lacking sense of hearing to all the this added greatly to the effectiverange of the instrument. eminently sati�factory after exhaustive experimentation underwater craft and made them at once a much more To overcome this obstacle, another device was devel­ here, the Navy Department organized a special Service effective weapon of offense. An Allied submarine on oped which could be trailed off the stern a hundred or so Party under Capt. R. H. Leigh of the Bureau of Steam one occasion chased a German U-boat for four hours, feet away where the engine noises of the ship were out of Engineering to demonstrate the detectors to the British while both craft were submerged, without once losing range and the sound was then brought in by electric Admiralty. Shortly after the arrival of this party (Continued on page 353) © 1919 SCIENTIFIC AMERICAN, INC April 5, 1919 SCIENTIFIC AMERICAN, 353 worm; but it has been done. In one district of the �eychelles lslands, for instance, every one of the 740 houses now has an approved latrine, thoug;h only Sf'ven were so equipped when the work began. '] he suggestion that this statement refer� to European residents can easily be dis­ posed of by citing the fact that for the entire archipelago the white population i� but 600. And what has been done in Sevchelles has been done-in small areas, - to be sure, but none the less effcctively for (j)/je $i20 those areas-in the West Indies, in �iam, r/ in Costa Rica and Nicaragua, in our own ,./1(Jooa S/Jop southern st.ates. Perhaps in the last may have confidencein the named locality the problems of the workers you were as acute as anywhere, because here goods of a men's wear shop that there was to be combatted not alone recommends the Boston Garter. popular ignorance and indifference, but You may be sure that the policy a.ctual hostility against interference with of the dealer is to give the cus­ th() liberty of the individual. Yet in 66 tomer full value for his money. he I the communities in the South where 1 of 300 Boston Garter is first in quality and this sort of work was conducted within a �� first in service. Ask for it. certain period, not a home was left without an approved latrine; the percentage of 3!; c�nta and upward in lead­ $4� $4':!!! $5'� $6'� $r� & $8'� ine .tor�. from coaat to coaat. I houses so equipped before the campaign IF you have been paying $10.00 to $12.00 for fine GE:ORGE: FROST CO" MAKERS. BOSTON , was, for these communities, 76. lL shoes, a trial will convince you that for style, much for prevention. In addition, it ;)0 comfort and service W.L.Douglas and .