1, high-altitude tight line hair and high-altitude marking tight line method

The high-altitude tight line method is mainly used in the tight line construction of distribution lines with small cross-sectional area and small tight line tension. It has the advantages of simple construction method, small operation site and few construction machines. However, most of the processes must be completed at high altitude, increasing the workload of high-altitude operations. When tightening the line, the remaining line should be tightened first, usually with manpower or traction equipment to operate directly on the ground. When the overhead line in front is separated from the ground, the wire tightener can be set at a certain distance (estimated wire tightening length) in front of the tension operating lever tower, the wire tightener can be pulled by the traction equipment, and the wire can be tightened by the pulley at the wire hanging place. When the overhead line is tightened close to the required sag value, slow down the traction speed. When the sag observer in front notifies that the required sag value has been reached, stop towing immediately. When the overhead line stops jumping and the sag does not change, mark the line hanging point hole on the operating lever tower. After marking, the construction personnel on the tower will install the lead and ground wire with strain clamp at high altitude, and hang the lead and ground wire on the tower. This method of operation because the overhead line does not need to be panasonic landing, so called a tight line method. If the guide and ground wire are loosened to the ground after high-altitude marking, the ground operator shall install the strain clamp according to the mark, assemble the insulator string at the same time, tighten the wire again and hang the wire. This method is called secondary lifting and tightening method. The advantage is to reduce the amount of high-altitude work. It is suitable for wire cross-section and tight line tension line, especially the crimping tension clamp, high-altitude construction is quite inconvenient, so most of the use of this method.

 2、Ground marking tight line method

It is referred to as the ground marking method, which is to hang the overhead line on the tight line operating rod tower close to the ground for sag observation. As the overhead line is close to the ground for easy control, it can avoid the situation that the line is too far loose after high-altitude marking under complex terrain conditions, resulting in difficult cutting line crimping, and is simpler and safer than the high-altitude marking method. Although the use of this method to calculate the workload, but since the electronic computer into use, the calculation of the working conditions have been improved, so the use of this method is also more and more.

3,low sag tight line method

When the distance is not too long, the construction method of low sag tight line can often be adopted to avoid repeated adjustments in order to obtain the required sag value. The use of low arc hanging tight line, wire tension is small, can simplify the tight line operation process, speed up the speed of tight line. The method is to tighten the overhead line with relaxation tension, and measure the sag of the overhead line at this time, which is larger than the required standard sag. When installing the strain clamp, subtract a section of line length, so that after the line is hung, the sag of the overhead line meets the design requirement.

 4、Multi-gear Tightening Method

It is a method that treats the tightening of several consecutive tension segments as one tension segment. When tightening the line, a comprehensive representative distance of all connecting tight line stops can be selected for sag observation, and the representative distance of the last tension section close to the fixed end of the tight line can also be selected for sag observation. In this way, the sag is observed according to a selected representative span to determine the line length of each tension section, which will cause the line length in each tension section to be inconsistent with the design requirements. Therefore, when measuring the installation length of the line length in each tension section, it is necessary to adjust the line length error caused by the difference between the representative span of each tension section and the selected representative span.

 5、Assembly tight line method

It omits the original operation steps such as marking the tight line on the tower and sag observation when tightening the line, and only needs to hang the line. This is the way to improve construction efficiency and labor saving. However, before stringing, the gear distance must be accurately measured according to the calculation of the actual length of the required guide and ground wire and the measuring scale of the guide and ground wire.

 6、Tension line tightening

It uses the method of tightening the line on the tower. Only individual line segments are divided into tension segments and tightened in tension towers. The tension tower tightening line is much more complicated than the straight tower tightening line, so it is only used when the straight tower cannot tighten the line.