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.
As we walk about a site and talk to people, we can note our observations. At this stage, we try to store the information we gain in some accurate way, carry a notebook, or a camera and tape-recorder, and make small sketches. The notes we end up with can later be used to devise design strategies.
We do not just see and hear, smell and taste, but we sense heat and cold, pressure, stress from efforts of hill-climbing or prickly plants, and find compatible or incompatible sites in the landscape. We note good views, outlooks, soil colours and textures. In face, we use (consciously) all our many senses and become aware of our bodies and responses.
Beyond this, we can sit for a time and notice patterns and processes: how some trees prefer to grow in rocks, some in valleys, others in grasslands or clumps. We see how water flows on the site, where fires have left scars, winds have bent branches or deformed the shape of trees, how the sun and shadows move, and where we find signs of animals resting, moving, or feeding. The site is full of information on every natural subject, and we must learn to read it well.