Direct-buried cable
Encyclopedia
Cable
A cable is two or more wires running side by side and bonded, twisted or braided together to form a single assembly. In mechanics cables, otherwise known as wire ropes, are used for lifting, hauling and towing or conveying force through tension. In electrical engineering cables are used to carry...
which is especially designed to be buried under the ground without any kind of extra covering, sheathing, or piping to protect it.
Description
Most direct-buried cable is built to specific tolerances to heatHeat
In physics and thermodynamics, heat is energy transferred from one body, region, or thermodynamic system to another due to thermal contact or thermal radiation when the systems are at different temperatures. It is often described as one of the fundamental processes of energy transfer between...
, moisture
Moisture
Humidity is the amount of moisture the air can hold before it rains. Moisture refers to the presence of a liquid, especially water, often in trace amounts...
, conductivity, and soil acidity. Unlike standard telecommunications and power cables, which have only a thin layer of insulation and a waterproof outer cover, DBC consists of multiple layers of heavy metallic-banded sheathing, reinforced by heavy rubber covers, shock absorbing gel, wrapped thread-fortified waterproof tape, and stiffened by a heavy metal core.
Benefits
Most cable of this kind is coaxialCoaxial cable
Coaxial cable, or coax, has an inner conductor surrounded by a flexible, tubular insulating layer, surrounded by a tubular conducting shield. The term coaxial comes from the inner conductor and the outer shield sharing the same geometric axis...
or bundled fiber-optic
Optical fiber
An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...
in nature. Direct-buried cable is cheaper and easier to lay than other kinds of cable that require protection from the earth. However, DBC is also easily cut during digging or other excavations. As a result, most direct-buried cable is found on side roads, not main thoroughfares.
DBC is preferable in some areas since it is more resistant to being the focus of lightning
Lightning
Lightning is an atmospheric electrostatic discharge accompanied by thunder, which typically occurs during thunderstorms, and sometimes during volcanic eruptions or dust storms...
discharges.