Not all the towers along a transmission line are identical. Look closely at a tower where the line makes a sharp turn and you will likely find it is wider and beefier than other towers along the route. The added strength and weight are needed to resist the unbalanced pull of the conductors, which might overturn an ordinary tower. These special towers are called deviation or angle towers.
The transmission-line tower everybody knows is an Erector Set latticework of steel girders and diagonal braces. The techniques for designing and building these towers are the same ones used in constructing steel bridge trusses or crane booms. The individual pieces can be made cheaply from rolled steel and then bolted together on the site. This last point is more important than it might seem: transporting a fully assembled tower 100 feet tall is an awkward and expensive business.
Learning to design is, first of all, learning to see. Designers see more, and more precisely. This is a blessing and a curse—once we have learned to see design, both good and bad, we cannot un-see. The downside is that the more you learn to see, the more you lose your “common” eye, the eye you design for. This can be frustrating for us designers when we work for a customer with a bad eye and strong opinions. But this is no justification for designer arrogance or eye-rolling. Part of our job is to make the invisible visible, to clearly express what we see, feel and do. You can’t expect to sell what you can’t explain.
This is why excellent designers do not just develop a sharper eye. They try to keep their ability to see things as a customer would. You need a design eye to design, and a non-designer eye to feel what you designed.