Immediately after the No.9119 typhoon which caused severe damages in transmission lines in West Japan, electric power utilities asked Central Research Institute of Electric Power Industry (CRIEPI) to carry out the studies on the local wind resistance design of transmission tower-conductor systems. To promote the studies, CRIEPI organized a committee and three sub-committees (wind observation sub-committee, wind simulation sub-committee, and wind-resistance design sub-committee). The purpose of this paper is to describe the investigation results by the wind simulation sub-committee, which proposed a simple criterion of special topography, made a basic wind velocity maps, and developed a wind simulation computer program named "1-wind".
