Span, stagger, wire height, tension, wave propagation velocity, bending rigidity, vibration endurance, wear... when it comes to overhead or catenary lines, there are lots of things to worry about, not to mention the services and added value that overhead lines bring to your customers such as high-speed transport, power for running portable computers or air conditioning.
Your maintenance program needs an accurate and reliable system, one that won't have you sending out your maintenance staff for every anomaly revealed in measurement.