Me and some friends are doing a project for statics where we compare the designs of different transmission tower designs. I'm looking for a direction to start. Does anyone know why different designs are incorporated for different type of transmission towers. There are three basic kinds of transmission towers (tension, suspension, and transportation). I am thinking the design is based on the weights of the wires (heavier wires require a design the supports stronger weights). Just wondering if there are other hidden design factors.