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’ve noticed a recent trend on the web — or at least, on the parts of it I’ve visited. Maybe you’ve noticed it too.
Here’s what happens: you’re on a website, and one of these little prompts pops up...[to] let you know that there’s an app, and that the website you’re on...well, it’s not quite the app, is it?
...Sometimes, the website wants me to install the app — no, it needs me to install the app. It’s like a paywall, but for apps. An appwall.
In recent years, these prompts have gotten more prominent, and occasionally impassable. And I think that trend’s interesting. Why would a company promote a native app over their perfectly usable website?
It feels like a glimpse into that company’s design priorities. And it’s possibly providing us with insight into the business value they place on the open web — a medium that’s meant to be accessible everywhere, on any screen, on any device.
And it really does feel like these glimpses are becoming more common.