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.
For others, perhaps especially those artists who worked with light and transparency and were involved in the birth of the Light and Space Movement, an immaculate surface is a prerequisite. Helen Pashgian explained this very clearly:
“On any of these works, if there is a scratch... that’s all you see. The point of it is not the finish at all – the point is being able to interact with the piece, whether it is inside or outside, to see into it, to see through it, to relate to it in those ways. But that’s why we need to deal with the finish, so we can deal with the piece on a much deeper level”.
The importance of a pristine surface calls for a very low tolerance to damage by the artists. The feeling is shared by Larry Bell:
“I don’t want you to see stains on the glass. I don’t want you to see fingerprints on the glass... I don’t want you to see anything except the light that’s reflected, absorbed, or transmitted”