OPTICAL FIBER COMPOUND OVERHEAD EARTH-WIRE

PURPOSE:To permit compression residual stress and increase bending fatigue strength of aluminium pipes by applying the surface processing such as sand blasting or peening to the outer surface of the aluminium pipes. CONSTITUTION:An aluminium pipe 2 is provided in the central part of a stranded wire made of Al strands or Al-St clad strands or the like, and an optical cable 3 is placed inside the pipe 2. And the surface processing such as and blasting or shot peening is applied to the outer surface of the pipe 2. Thereby, compression residual stress is given to the pipe 2 to make it feasible to increase bending fatigue strength. Therefore, even when bending stress is applied to an electric wire, the pipe 2 is not cracked and consequently an internal cable may be firmly protected so that the light transmission characteristic may normally maintained.