Experimental Study of the Effects of Dish Antennas on the Wind Loading of Telecommunication Towers

A several number of communication lattice tower collapsed in the past years due to strong winds in Cuba, most of them with a high number of dish antennas. Antennas generate a modification on the wind flow around the tower acting as a screen against wind load and transmitting strong efforts to the tower members. Structural design under wind loads of latticed towers is concerned about the approach to take into account the effect of dish antennas and their interference at different positions in the tower. In this paper, an experimental study in a boundary layer wind tunnel was performed to obtain the drag coefficients and the interference factor on a square section latticed tower with dish antennas. The tower was divided into three sections, which were studied with one and two dish antennas. Results show that interference factor can achieve values smaller and greater than the unity for dependent on the wind direction and relative position of dishes on the tower section. Drag coefficients for sections without antennas are in correspondence with codes.