Overhead wire markers are safety instruments applied to the overhead power lines marking transmission lines and ropeways along the flight path during the day.Aerial marker balls for Power linesMarking of Army airfield-heliport operational and maintenance facilities - 7-9 Markers page 7-6 Markers are often installed on overhead lines near airfields, or at river crossings where there is a possibility of seaplanes using the river. Some markers contain conductor marking lights or strobe lights to improve visibility at night or in fog.
See also Balisor
Notes and references