2025 Volume 87 Issue 5 Pages 289-308
Counterweights (CW) are widely used devices for preventing heavy snow accretion on single conductors in transmission lines. However, CW may lead to galloping. To address this issue, the loose counterweight (LCW) was developed as a countermeasure designed to mitigate both heavy snow accretion and galloping. A conductor equipped with LCW initially has the same torsional stiffness as one without any countermeasure device. However, once the conductor reaches a specific torsional angle—referred to as the “loose angle”—the LCW increases its resistance to twisting, making it as twist-resistant as a conductor with CW. This study examined the effectiveness of LCW through field observations in a natural environment and compared its performance to that of CW. Observations from two snow accretion and galloping events indicated that LCW with a loose angle of up to 60° provided the same level of snow accretion suppression as CW. This was because the process of snow accretion was similar between conductors equipped with LCW and CW. However, because LCW temporarily reduces torsional stiffness, it increases the snow accretion area on the conductor surface, which in turn prevents the natural shedding of accumulated snow. As a result, the risk of galloping increases, leading to more severe galloping in conductors with LCW compared to those with CW. LCW is effective in suppressing heavy snow accretion but does not provide sufficient galloping suppression ．Further research and development are necessary to optimize LCW for both purposes simultaneously.
