Method for fabricating a submarine cable having a core in the form of a tube made of tow metals and containing optical fibers

摘要

It is an object of the invention to provide an optical fiber cable (10) having hermetically-sealed optical fibers (25) and excellent strength characteristics without utilizing a costly welded steel tube. It is a further object of the invention to provide an optical fiber cable (10) that is capable of efficient and fast manufacture. These and other objects are satisfied, in accordance with the invention, by an optical fiber cable (10) employing a novel cable core (20), the cable core (20) fabricated by a method comprising the steps of: a) forming an inner, longitudinally extending, substantially-closed C-section tube (15) having a longitudinally extending seam and an interior cavity; b) introducing at least one information-carrying component (25) into the interior cavity of the inner, longitudinally extending, substantially-closed C-section tube (15); c) forming an outer, longitudinally extending tube (18) concentrically around the inner, longitudinally extending, substantially closed C-section tube (15) in a substantially close-fitting manner; and, d) sealing the outer, longitudinally extending tube (18) to hermetically seal the at least one information-carrying component (25) in the interior cavity. Advantageously, the C-section tube (15) assists in protecting the optical fibers (25) against crush, impact and pressure, and may also enhance the tensile strength of the optical fiber cable (10). The use of the C-section tube (15) also allows the optical fibers (25) to be efficiently introduced into the interior cavity of the C-section tube (15) during cable production. And, as the C-section tube (15) provides the desired strength characteristics of the cable core (20), the outer tube (18) may be advantageously optimized to hermetically seal the optical fibers (25) in the cable core (20). Thus, the outer tube (18) may be designed, for example, according to its sealing characteristics and manufacturability without significant regard for mechanical characteristics such as strength.