In case the substitution of a ground wire or phase conductor is not possible or not an economic alternative, additional cables can be installed. The only function of these cables is to house and protect the optical fibers. A universal solution for all voltage levels is the Metal Aerial Self-Supporting (MASS) cable. This is a small size metallic armoured cable for additional installation in the centre of the pylons. To minimize additional loads, weight and diameter are strongly reduced. The typical diameter range of MASS cables is between 9 and 12mm only. The armouring is only optimized according to span length and sag requirements because the cable does not have any electrical function.
