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 walked around with a map, penciling in X’s wherever there was a barn or shed. For the next three days, I covered four kilometers in all four directions. Living toward the outskirts of town, there are still a good many farmers in the vicinity. So it came to a considerable number of barns—sixteen altogether.
I carefully checked the condition of each of these, and from the sixteen I eliminated all those where there were houses in the immediate proximity or greenhouses alongside. I also eliminated those in which there were farm implements or chemicals or signs that they were still in active use. I didn’t imagine he’d want to burn tools or fertilizer. That left five barns.