SUBMARINE SIGNALLING.

Manawatu Herald, Volume XXXVII, Issue 1418, 1 July 1915, Page 4

SUBMARINE SIGNALLING.

Considerable progress in submarine signalling continues to be made in America, where opinion as to the future of this means of communication is not less sanguine than in Germany. For some years past Mr Millet’s apparatus has been in successful operation. An even more confident belief in submarine signalling is based upon experiments carried out with the apparatus developed by Mr H. Christian Berger. According to Commander F. H. Sawyer, of the United States Navy, his device consists of a steel wire or script set in longitudinal vibration by means of a fiictiou wheel running in contact with it. A clear musical note is thus obtained, enabling Morse, signals to be transmitted much more clearly than by the employment of a bell. It has been ascertained that the length of wire can be selected so as to obtain the note which the microphone can most readily pick up. Commenting upon this new development, Engineering records that an apparatus made in 1912 consisted of a flat steel strip i-i6in by connected at each end to the hull of the vessel. It was set in vibration by a felt-covered friction wheel driven by a horse power motor, A magnetic clutch on the motor shaft enabled the friction wheel to be started or stopped at will, so that Morse signals could he sent. With this apparatus on cu the United States Navy submarine Ei, in December, 1912, messages were received over a distance of y.S nautical miles wilh.tbe submarine submerged. A later set, with three ribbons 1 iin wide by i-i6in thick, installed on the United States ship Arkanas, enabled distinct signals to be received over 10 nautical miles. “In all these cases the vibrating wire or ribbons were merely attached to the ship’s sides, and it is possible that it special diaphragms had been built into the hulls better results would have been secured.”