In electrical engineering and telecommunications submarine cable is a cable specially constructed and placed on the bottom of the sea, a lake or a river (underwater cable), used to transport information on a section or dorsaledella transport network data or electricity in the network electrical transmission across the Atlantic. There are therefore two categories of submarine cables: those for the telecommunications and those for the transport of energy.
The main problems related to submarine cables as well as electrical in nature (attenuation and signal distortion) are mechanical in nature. The cables must in fact be protected by ship anchors, from the nets of fishermen, but also by marine animals that can bite or puncture the insulation. For this reason, the terminal part of the lines near the coasts has a greater armor, typically it consists of one or more layers of robust steel net. The portion intended to lie on the seabed has minor section, but still a degree of armor steel.
Another problem to be taken into account at the design stage of the cables of great depth, is represented by the water pressure, which rises by about 10 MPa (100 atmospheres) every kilometer. The insulating material is in fact compressed by these enormous pressures, causing the decrease of the section of the cable and the alteration of the impedance of the line.
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