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Directional boring machine. Directional boring, also referred to as horizontal directional drilling (HDD), is a minimal impact trenchless method of installing underground utilities such as pipe, conduit, or cables in a relatively shallow arc or radius along a prescribed underground path using a surface-launched drilling rig. Directional boring ...
Trenchless construction includes such construction methods as tunneling, microtunneling (MTM), horizontal directional drilling (HDD) also known as directional boring, pipe ramming (PR), pipe jacking (PJ), moling, horizontal auger boring (HAB) and other methods for the installation of pipelines and cables below the ground with minimal excavation.
However, depending on the depth of the underground cable; greater EMF may be experienced on the surface. [4] The electric current in the cable conductor produces a magnetic field, but the closer grouping of underground power cables reduces the resultant external magnetic field, and further magnetic shielding may be provided.
A horizontal boring machine has its work spindle parallel to the ground and work table. Typically there are three linear axes in which the tool head and part move. Convention dictates that the main axis that drives the part towards the work spindle is the Z axis, with a cross-traversing X axis and a vertically traversing Y axis.
A sea plough is a cable-laying plough for submarine operation. A pipe-and-cable-laying plough or moleplough [1] is a method to bury cables or pipes. The machinery is a form of a subsoiler with a single blade. It is used to lay buried services of virtually any description, for drainage, water, electricity, telecommunications, gas supply etc..
In a horizontal or vertical cable rail, the cables, once tensioned must be rigid enough to prevent a 4-inch sphere passing through it. Factors influencing this rigidity are: the tension of the cable, intermediate posts (or cable spacers) spacing, the diameter of the cable, top rail cap material and the cable to cable spacing. [7]
A sailboat's mast is supported by shrouds (side-to-side) and stays (fore-and-aft) – nautical equivalents of guy wires.. A guy-wire, guy-line, guy-rope, down guy, or stay, also called simply a guy, is a tensioned cable designed to add stability to a freestanding structure.
In North American practice, for residential and light commercial buildings fed with a single-phase split 120/240 service, an overhead cable from a transformer on a power pole is run to the service entrance point. The cable is a three conductor twisted "triplex" cable with a bare neutral and two insulated conductors, with no overall cable jacket ...