In the field of power engineering, preformed tension clamps play a role similar to that of bridge anchors. They are a key technology to ensure that conductors and ground wires are permanently and reliably fixed at the end or corner towers. The average grip strength of this type of wire clamp usually exceeds 95% of the rated breaking force of the wire. It can withstand a continuous tension of up to 50 kilonewtons and has a design life that is in line with the wire itself, reaching over 40 years. For example, in a UHVDC transmission project in China, the preformed dead end grip was successfully used to fix the conductors on ± 800-kilovolt towers, effectively coping with the huge mechanical stress caused by the line span exceeding 1,000 meters, and reducing the risk of material fatigue caused by wind vibration by 70%.
From the perspective of engineering design, the innovation of preformed dead end grip lies in its preformed helical structure. This structure can evenly distribute the grip stress and control the pressure on the wire within the optimal range of 120 megapascals, thereby avoiding wire strand damage caused by local stress concentration. According to the requirements of the international standard IEC 61284, for a preformed tensile wire clamp used for 240 square millimeters of conductors, the slip after installation must be less than 3 millimeters. However, the actual performance of high-quality products often keeps the error within 1 millimeter, with an accuracy improvement of 66%. In 2022, a rare ice storm in the Midwestern United States caused the ice thickness on the lines to reach 30 millimeters. Monitoring data indicated that none of the line sections using this type of clamp experienced sliding failure, while the failure rate of traditional compression type clamps reached 5%, demonstrating its outstanding performance under extreme loads.
Installation efficiency and full life cycle cost are at the core of power project decision-making. A skilled line worker installs a preformed dead end grip in an average of only 10 minutes, saving approximately 50% of the installation time compared to traditional hydraulic compression type line clamps. This enables a 15% reduction in labor costs for large-scale projects. An economic analysis of a large-scale power grid expansion project in Southeast Asia shows that the full adoption of the preform solution along the 500-kilometer line not only shortened the installation period by 20 days, but also reduced the maintenance frequency caused by hardware issues from the estimated 10 times to 2 times within the 20-year operation period, saving more than 800,000 US dollars in maintenance budget. The return on investment is very significant.
At the level of risk prevention and control and system reliability, preformed dead end grip is a key link to ensure the resilience of the power grid. Its high-strength aluminum alloy material ensures excellent anti-corrosion performance. In a C5 grade highly corrosive environment, the annual corrosion rate is less than 0.01 millimeters, which is far superior to that of ordinary steel materials. Historical cases show that after Hurricane Katrina in 2005, preformed tension clamps were widely used in the power grid reconstruction in the New Orleans area, enabling the reconstructed lines to withstand multiple storms in the following ten years and reducing the failure rate by 90% compared to the old lines. This reliability and security make it an indispensable standard component in the construction of modern smart grids, providing a solid foundation for the safe transmission of global energy.
