Nice Dog on Instagram: "These lines typically operate at 115 kV, 230 kV, 345 kV, 500 kV, and even up to 765 kV, allowing large amounts of power to travel efficiently with minimal energy loss.. Suspended hundreds of feet above ground on steel towers, they cross rivers, valleys, highways, and flight paths places where visibility becomes essential.. That’s where aviation warning balls, also called marker balls, come in.. These large, hollow spheres usually 36 or 48 inches in diameter are mounted di