Cable Design and Manufacture for the Transatlantic Submarine Cable System

General features of (he cable structure adopted for the transatlantic cable project 1 are illustrated in Fig. 1. The cable consists of two basic parts: (1) the coaxial, or the electrical transmission path, and (2) the armor or outer protection and strength members. The coaxial is made up of three parts: (1) the central conductor, (2) the insulation, and (3) the outer or return conductor. The central conductor is composed of a copper center wire surrounded by three helically applied copper tapes. The insulation is a polyethylene compound which is extruded tightly over the central conductor. The insulated central conductor is called the cable core. The outer or return conductor is composed of six copper tapes applied helically over the insulation. The protection and strength components shown in Fig. 1 for the type D deep water cable are provided by a teredo tape of thin copper applied over the outer coaxial conductor, a fabric tape binding, a layer of jute rove for armor bedding, the textile covered armor wires and finally, two layers of jute yarn flooded with an asphaltum-tar compound. This cable is characterized by the extra tensile strength of its armor wires and by the extra precautions taken to minimize corrosion of these wires. * Bell Telephone Laboratories. 189 190 THE BELL SYSTEM TECHNICAL JOURNAL, JANUARY 1 9 5 7 At the shallow water shore ends, the armor types are characterized by the use of mild steel wires which are increased in diameter in steps as the landing is approached.