Before the installation of optical cable, the design of optical cable line must be estimated. Optical cable generally replaces a ground wire in the overhead line and is erected at the ground wire position on one side of the tower. It has dual functions of lightning protection and communication. Cable reels are produced with fixed length, and each reel can only be used in the specified section.



What preparations shall be made before construction: generally, the stretching field for laying OPGW cable fittings shall be along the line direction, and the angle between the OPGW outgoing line and the ground shall not be greater than 30 °. It is better to arrange the stretcher at 15 ° - 20 ° (generally, the distance from the tension tower is more than 1.5 times the height of the tension tower, and should not be less than 130m), and the bending radius of OPGW outgoing line should be greater than 0. 5m. According to the site topography, the tension machine can be installed on the tower with anchor tower tension clamp outside the tension section in the following two ways: 1. It is arranged in the tensioning section, and the anchor tower tensioning clamp is installed on the ground, i.e. at the outlet of the tensioner. Hoisting and testing of optical cable (1) the optical cable must be placed horizontally in the process of storage and transportation. It is strictly prohibited to place vertically to avoid crushing and damaging the optical fiber. (2) When hoisting the optical cable, first insert the shaft pole into the shaft hole of the cable bridge, and then fix the optical cable on the shaft pole for hoisting, so as to avoid damaging the cable bridge due to rope extrusion. (3) Optical time domain reflectometer is used to measure optical fiber attenuation, optical fiber length, optical fiber on-off, etc. when all parameters meet the requirements and no optical fiber is disconnected, cable laying can be carried out. After a section of optical cable is laid out and before optical fiber fusion, the parameters of this section of optical cable shall be retested in advance. After passing the test, the OPGW optical cable hardware fusion and junction box can be installed.




The suspension block of the scrapped repayment block shall be checked one by one before suspension to see whether it can rotate flexibly and whether the glue is in good condition. In general, one pulley is hung for each tangent tower and tangent small angle tower; for tangent tower with large downforce and envelope angle greater than 60 °, two pulleys are hung. For tension angle tower, when the angle is greater than 30 °, hang double pulley; when the angle is less than 30 °, hang single pulley. Construction measures for crossing power line the main measures for live crossing are to prevent optical cable (conductor) from falling on the power line due to carelessness or other reasons, install crossing frame and nylon net at the crossing place, assign personnel to supervise during the crossing process, and cooperate with the construction commander to find out problems in time and take measures for breaking. The connection method of wire rope sleeve is to use 3T lead screw (double hook tensioner) to tighten the ground wire at both sides of the tension tower near the outlet of the ground wire tension clamp, and take out the ground wire tension clamp at both sides from the lifting point. Connect the tension clamps on both sides of the ground wire with 15.5m long wire rope sleeve and 3T bend joint. At the same time, loosen the lead screw on both sides to make the bearing capacity of the wire rope sleeve gradually bear the force in the pulley groove of the paying off pulley, make the connecting pipe press into a straight line, and use the air blasting pressure method to connect the ground wires on both sides. At the same time, loosen the temporary anchors in the air on both sides, so that the crimped steel strand is stressed and falls into the pulley groove of the paying off pulley.