Influence of the Drag Coefficient on Communication Towers

This paper discusses some of the recent wind loading procedures for the design of lattice towers. In particular, the paper focuses the attention on the drag coefficient of communication towers with square and triangular cross-section and with flat-sided and circular elements. It provides some background behind the normative methodology of the current specialized codes and its relationship with results of experimental tests. For this purposes, different load patterns were adopted from the application of the normative methodology of the following countries: Mexico, United States, India, Japan and Australian-New Zealand Code. Additionally, the paper provides examples based on actual communication towers to illustrate the lack of consensus and to identify uncertainties in the procedures. The paper concludes that the complexity of most current wind design procedures is not justified and it pretends to help to make rational decision by designers.