32 



DISCOVERY 



Directional Wireless 



By Lieut. -Col. C. G. Crawley, R.M.A., 

 M.I.E.EJ 



As a nile, at small wireless staticns, such as these fcr 

 communication with ships and those in the ships 

 themselves, no attempt is made to obtain any directive 

 effects, that is to say, the waves from the sending 

 station are radiated in all directions, and at the receiv- 

 ing station waves can be received equally well from 

 all directions. 



For the ordinary purposes of communication between 

 ships, and between ships and shore stations, it is indeed 

 essential that all-round signalling should be the normal 



4 _ 6 



Long'itude 



Fig. I.— BRITISH AND GER-M.\N DIRECTIOXAIv WIRELESS 

 STATIONS. 



arrangenient, so that a distress signal from a ship will 

 be heard by all ships and stations within range, irrespec- 

 tive of direction ; but it may often happen, especially 

 in the case of ships and aircraft, that an indication of 

 the direction from which signals are being received will 

 be of great value. This fact was grasped very early 

 in the war by the Air Forces on both sides, and 

 directional apparatus for navigational purposes was 

 rapidly developed, and extensively used, in military 

 aircraft. For ships, on the other hand, the develop- 

 ment ran on another line, that of locating enemy ships, 



which were using wireless, by means of direction- 

 finding shore stations, and stations used for this 

 purpose by both sides round the North Sea are shown 

 in Fig. I. These stations, at any rate those on our 

 side, did excellent work in obtaining timely infonna- 

 tion on many occasions of the movements of enemy 

 craft, both ships (including submarines) and aircraft. 

 The most famous occasion was that leading up to the 

 Battle of Jutland. This was well told at a meeting of 

 the Institution of Electrical Engineers by Admiral of 

 the Fleet Sir Henry Jackson in the following words : 

 " We have heard much about the use of direction- 

 finding for minor tactical movements of all arms, but 

 this is a case of a major strategical operation which 

 brought about the historical meeting of the British 

 and German Fleets at the Battle of Jutland on May 

 31, 1916. I was First Sea Lord at the time, and so 

 was responsible for the disposition of the Grand Fleet. 

 I may incidentally mention that, in spite of other 

 statements of which I have heard, its Commander-in- 

 Chief (Lord Jellicoe) and I lived, so to speak, with 

 the object of bringing oft such a meeting. Our wireless 

 direction-finding stations, under Captain Round, kept 

 careful and very intelligent watch on the positions of 

 German ships using wireless, and on May 30, 19 16, 

 heard an unusual amount of wireless signals from one 

 of the enemy ships which they located at Wilhelms- 

 haven. This was reported to me ; the time was a 

 critical and anxious one in the war, and I had also 

 some reasons for expecting that the German Fleet 

 might put out to sea during the week. Our Fleet was 

 ready at short notice and had arranged, unless other- 

 wise prevented, to put to sea on the following day for 

 a sweep of the North Sea. But if the German Fleet 

 got to sea first, the chance of a meeting in waters not 

 unfavourable to us was remote ; our object was to try 

 to get to sea before or shortly after the Germans, and 

 hitherto we had not succeeded in doing so. Later on 

 in the afternoon, it was reported to me that the German 

 ship conducting the wireless had changed her position 

 a few miles to the northward. Evidently she and her 

 consorts had left the basins at Wilhelmshaven and had 

 taken up a position in the Jade River ready to put to 

 sea. This movement decided me to send our Grand 

 Fleet to sea, and move towards the German Bight 

 at once and try to meet the German Fleet and bring 

 it to action. This they did with their usual prompti- 

 tude, and the result was the famous Battle of Jutland, 

 and it was indirectly brought about by the careful and 

 accurate work of Captain Round and his staff, for 

 which I hope they will now accept my belated thanks 

 and appreciation. Their work is not ended. Direc- 

 tion-finding has come to stay for more general use in 

 peace. Errors are being eliminated, and there should 

 be a great future before it, especially on the lines 



