pylons
Pylons
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.
Electrical pylon near Gary, Indiana
The Pylon Appreciation Society
A WebsiteIt's simple: the Pylon Appreciation Society is a club for people who appreciate electricity pylons.
Pylon of the Month
A BlogElectrical pylon in Birmingham, England.
The Fidelity Curve
How do we choose which level of fidelity is appropriate for a project?
I think about it like this: The purpose of making sketches and mockups before coding is to gain confidence in what we plan to do. I’m trying to remove risk from the decision to build something by somehow “previewing” it in a cheaper form. There’s a trade-off here. The higher the fidelity of the mockup, the more confidence it gives me. But the longer it takes to create that mockup, the more time I’ve wasted on an intermediate step before building the real thing.
I like to look at that trade-off economically. Each method reduces risk by letting me preview the outcome at lower fidelity, at the cost of time spent on it. The cost/benefit of each type of mockup is going to vary depending on the fidelity of the simulation and the work involved in building the real thing.
Four levels of fidelity
Suppose we have four levels of fidelity…
- Rough sketch (on paper or an iPad)
- Static mock-up (eg. Photoshop or Sketch)
- Interactive mock-up (eg. Framer, InVision)
- Working code prototype (HTML/CSS, iOS views)
Depending on the feature you’re working on, these levels of fidelity take different amounts of time to create. If you plot them in terms of time to build versus confidence gained, you could imagine something like a per-feature fidelity curve.
Time to build versus confidence gained
Take a simple CRUD web UI, where you’re just navigating between screens. It doesn’t take much more time to build the real version than it does to mock it when the design is simple. If you were to build out an interactive mock first, you would end up spending twice as much time in total without gaining much out of it.
Contrast that with a complicated Javascript interaction. Or a native iOS feature that requires programmer time to build out. If it takes substantially more time to build the real code version, then it may be smart to do an interactive mockup first.