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.
I learned years ago how important it is to shoot the same subject and location over and over again.
The practice teaches a photographer how to form deeper relationships with the subject, and better understand how the primary subject interacts with secondary elements – like the way high tide may introduce a stunning new reflection, or how a blaze of stars in a dark sky might be the missing element that lifts the image to new heights.
Revisiting a subject also serves as valuable “practice.” You cannot develop your skills in anything without a healthy (or obsessive) amount of practice. It always surprises me to find out aspiring photographers think that they can simply photograph their two-week vacations once or twice a year and come home with compelling imagery! It doesn’t work that way.