A Submarine Telephone Cable with Submerged Repeaters

APRIL of year there was installed between Key West, INand Havana, lastthe aconventionaltelephone cable systemsubmarineFlorida, Cuba, submarine involving a radical departure from art of long distance teleph- ony. This departure consisted of the inclusion within the armor of the submarine cable of electron tube repeaters which are designed to pass through the cable laying machinery and sink to the ocean bottom like a length of cable, and which, over an extended period of perhaps twenty years, should not require servicing for the purpose of changing electron tubes or defective circuit elements. The repeater has the appearance of a bulge in the cable about three inches in diameter and tapering off in both directions to the cable diameter of a little over an inch. The total length of the bulge including the taper at each end is about 35 feet. The bulge is flexible enough so that it can conform to the curvature of the brake drum and of the various sheaves in the laying gear on the cable ship. A repeater, with stub cables, is shown in Fig. 1. The new cable system, comprising cables Nos. 5 and 6 of the CubanAmerican Telephone and Telegraph Company, represents another step in the development of telephonic communication between the United States and Cuba, which has presented many interesting problems. Natural conditions make it difficult, if not impossible, to employ some of the usual methods of communication. One such condition is the absence of high ground in Florida that would permit the use of economic radio systems.