To identify and describe general requirements for direct real time capability monitoring systems for overhead transmission lines. The specifications will include such general conditions as placement and number of monitoring sites, accuracy and resolution requirements frequency and reliability of communications and relationships between measured quantities and line clearance. The scope will not include any commercial comparisons. The study will be limited to direct measuring systems as defined in the Electra 197 which involves systems directly attached to the line or tower. It will exclude indirect systems such as weather stations