Galloping power lines
Galloping transmission or power lines can occur when freezing rain creates icicles and odd-shaped ice on transmission towers and conductors. High winds push on the icicles and conductors and lifts them up, creating a galloping, or jumping, motion.
If you see galloping transmission lines, stay clear. Do not approach the transmission lines or towers. You can be hurt by ice breaking off or power lines breaking loose. Power lines can sway in high winds, but it’s the combination of wind and ice that causes them to gallop more forcefully.
Transmission lines are designed to withstand galloping or jumping. However, if the energized conductor gets close enough to any grounded part such as the steel of the tower, the grounded skywire, or another energized conductor, a short circuit occurs until protection devices such as relays and circuit breakers interrupt the break. This causes lights to flicker.