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.
Scale refers to how we perceive the size of an element or space relative to other forms around it. All things – a tea cup, a building, language, entire eco-systems – consist of smaller components. It is the relationship of the smaller elements which determines the character and degree of life of the whole.
Objects which contain a high degree of life tend to contain a beautiful range of scales within, which exist at a series of well-marked intervals and have clearly recognizable jumps between them. To have good levels of scale, it is extremely important that the jumps between different scales of centers not be too great or too small.