Steel messenger strand consists of six wires wrapped around a center wire. The most common variety is carbon steel with a zinc coating. The zinc coating provides cathodic protection (CP) to the steel, meaning that red rust is prevented even on the cut ends. Steel messenger strand consists. Primary coated single mode fiber, filled, loose tubes, assembled around the Central Strength Member (CSM),filled core metallic moisture barrier, inner polyethylene sheath, galvanized steel wire armour and polyethylene outer sheathed optical fiber optic telecommunication cables complying with. This Specification covers the design requirements and performance standard for the supply of optical fibre cable in the industry. XCOM ensures a stable quality control system for our cable products through several programs including ISO 9001, ISO 14001 and OHS. 3xcable (1st) options 3xcable (2nd). Fiber optic cables for outdoor applications are engineered to withstand the more demanding conditions seen outside, from environmental extremes to mechanical forces. These are the cables you see strung along telephone poles (aerial), installed inside an underground duct, or even buried directly. The galvanized steel wire strand is used for overhead ground lines or electrical power transmission lines.