Determination of damping effectiveness of impact damper on ADSS cable

All dielectric self-supporting (ADSS) fiber optic cables vibrate at severe vibration levels due to their low self-damping characteristics. To reduce these vibration levels and prevent damage to the ADSS cable and possible loss of critical optical signals, dampers are a required component of an effective aerial fiber optic system. One of the most common dampers for ADSS cables is the impact-type damper. One drawback with the impact damper is that it is extremely difficult to evaluate the effectiveness of the damper in the laboratory. This paper discusses how the damper functions and laboratory methods developed to determine the effectiveness of this type of damper. The analysis technique used for laboratory evaluation of the impact damper includes damper energy dissipation measurements, following the IEEE 664 Standard. These laboratory evaluations are then compared to results from field vibration studies conducted on ADSS cables. For the field vibration studies, actual measurements are taken using specialized vibration recorders to determine how severe the vibration is in the field. These readings are taken both with and without dampers installed to provide a means for evaluating the effectiveness of the damper in reducing field vibration levels. A good correlation was found between damper performance in the laboratory and the field. This report continues the work initially presented at the International Wire and Cable Symposium in 1999.