A Field Guide To The North American Substation

August 22, 2024 by Dan Maloney 15 Comments

Drive along nearly any major road in the United States and it won’t be long before you see evidence of the electrical grid. Whether it’s wooden poles strung along the right of way or a line of transmission towers marching across the countryside in the distance, signs of the grid are never far from view but often go ignored, blending into the infrastructure background and becoming one with the noise of our built environment.

But there’s one part of the electrical grid that, despite being more widely distributed and often relegated to locations off the beaten path, is hard to ignore. It’s the electrical substation, more than 55,000 of which dot the landscape of the US alone. They’re part of a continent-spanning machine that operates as one to move electricity from where it’s produced to where it’s consumed, all within the same instant of time. These monuments of galvanized steel are filled with strange, humming equipment of inscrutable purpose, seemingly operating without direct human intervention. But if you look carefully, there’s a lot of fascinating engineering going on behind those chain-link fences with the forbidding signage, and the arrangement of equipment within them tells an interesting story about how the electrical grid works, and what the consequences are when it doesn’t.

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Tech In Plain Sight: Field Guide To Power Plugs

April 12, 2023 by Al Williams 72 Comments

It is the bane of worldwide travel: there isn’t just one way to get AC power from the wall. The exact connector — and what you can expect when you plug in — differs from country to country. Even if you stay home, you must account for this if your designs go places and expect to plug into the wall. If you’ve ever looked at a universal adapter, it is full of prongs and pins like a metallic porcupine. Where do all those pins go?

Of course, there are some easy ways to sidestep the whole issue if you don’t need AC power. Much low-power gear now just provides a USB or barrel connector. Then you can use an area-appropriate adapter or charger to power your device. Batteries work, too. But if you need to plug in, you will run into other kinds of plugs.

Switching power supplies have helped. In the old days, many things expected either 125V or 250V and didn’t work with the opposite voltage. Switching power supplies often allow a wide input range or have a switch to select one range or the other. These two voltages will cover almost any situation. If you have something that must have one voltage or the other, you’ll need a transformer — also called a converter — to step the voltage up or down. But most often, these days, you just need an adapter. There are slight variations. For example, some countries supply 100V or 110V, but that usually doesn’t make much difference. You also need to understand if your equipment cares if the AC is 50 Hz or 60 Hz.

Most of the power sockets you’ll find around the world will fall into one of several categories. The categories range from A to N. Even among these, however, there are variations.

Type A

For example, the common type A plug and socket are what Americans call “two prong.” If you live in the US, you’ve probably noticed that the plug is polarized. That is, one pin is slightly wider than the other so the plug can only go in one way. The wide pin is connected to the circuit neutral. The maximum load for this connector is 15A. It is difficult to find type A sockets anymore, other than on cheap extension cords or things like lamps that pass through their electrical connections to a second socket. Type B is far more common and type A plug will fit in a type B socket.

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Field Guide To Shipping Containers

April 7, 2021 by Kristina Panos 94 Comments

In the 1950s, trucking magnate Malcom McLean changed the world when he got frustrated enough with the speed of trucking and traffic to start a commercial shipping company in order to move goods up and down the eastern seaboard a little faster. Within ten years, containers were standardized, and the first international container ship set sail in 1966. The cargo? Whisky for the U.S. and guns for Europe. What was once a slow and unreliable method of moving all kinds of whatever in barrels, bags, and boxes became a streamlined operation — one that now moves millions of identical containers full of unfathomable miscellany each year.

When I started writing this, there was a container ship stuck in the Suez canal that had been blocking it for days. Just like that, a vital passage became completely clogged, halting the shipping schedule of everything from oil and weapons to ESP8266 boards and high-waist jeans. The incident really highlights the fragility of the whole intermodal system and makes us wonder if anything will change.

A rainbow of dry storage containers. Image via xChange

Setting the Standard

We are all used to seeing the standard shipping container that’s either a 10′, 20′, or 40′ long box made of steel or aluminum with doors on one end. These are by far the most common type, and are probably what come to mind whenever shipping containers are mentioned.

These are called dry storage containers, and per ISO container standards, they are all 8′ wide and 8′ 6″ tall. There are also ‘high cube’ containers that are a foot taller, but otherwise share the same dimensions. Many of these containers end up as some type of housing, either as stylish studios, post-disaster survivalist shelters, or construction site offices. As the pandemic wears on, they have become so much in demand that prices have surged in the last few months.

Although Malcom McLean did not invent container shipping, the strict containerization standards that followed in his wake prevent issues during stacking, shipping, and storing, and allow any container to be handled safely at any port in the world, or load onto any rail car with ease. Every bit of the container is standardized, from the dimensions to the way the container’s information is displayed on the end. At most, the difference between any two otherwise identical containers is the number, the paint job, and maybe a few millimeters in one dimension.

Standard as they may be, these containers don’t work for every type of cargo. There are quite a few more types of shipping containers out there that serve different needs. Let’s take a look at some of them, shall we?

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North American Field Guide To Rail Cars

December 9, 2020 by Kristina Panos 55 Comments

Trains are one of the oldest and most reliable ways we have of transporting things and people over long distances. But how often do you think about trains? Where I live, they can clearly be heard every hour or so. I should be used to the sound of them by now, but I like it enough to stop what I’m doing and listen to the whistles almost every time. In the early morning quiet, I can even hear the dull roar as it rumbles down the track.

I recently got a front row seat at a railroad crossing, and as the train chugged through the intersection, I found myself wondering for the hundredth time what all the cars had in them. And then, as I have for the last twenty or thirty years, I wondered why I never see a caboose anymore. I figured it was high time to answer both questions.

Boxcar

Boxcars are probably the most easily identifiable after the engine and the caboose.

Boxcars carry crated and palletized freight like paper, lumber, packaged goods, and even boxes. Refrigerated box cars carry everything from produce to frozen foods.

Boxcars (and barns for that matter) are traditionally a rusty red color because there were few paint options in the late 1800s, and iron-rich dirt-based paint was dirt cheap.

Flat Car

Standard, no-frills flat cars are the oldest types of rail cars. These are just big, flat platform cars that can carry anything from pipe, rail, and steel beams to tractors and military vehicles.

Flat cars come in different lengths and are also made with and without bulkheads that help keep the cargo in place. Some flat cars have a depression in the middle for really tall or heavy loads, like electrical transformers.

Auto Rack

As the name implies, auto racks carry passenger cars, trucks, and SUV from factories to distributors. They come in two- and three-level models, although there have been specialized auto racks over the years.

Perhaps the strangest auto rack of them all was the Vert-a-Pac. When Chevrolet came up with the Vega in the gas-conscious 1970s, they wanted to be able to move them as cheaply as possible, so they shipped the cars on end. If you’re wondering about all the fluids in the car when they were upended, a special baffle kept oil from leaking out, the batteries were capped, and the windshield washer fluid bottle was positioned at an angle.

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A Field Guide To Transmission Lines

June 11, 2019 by Bryan Cockfield 122 Comments

The power grid is a complicated beast, regardless of where you live. Power plants have to send energy to all of their clients at a constant frequency and voltage (regardless of the demand at any one time), and to do that they need a wide array of equipment. From transformers and voltage regulators to line reactors and capacitors, breakers and fuses, and solid-state and specialized mechanical relays, almost every branch of engineering can be found in the power grid. Of course, we shouldn’t leave out the most obvious part of the grid: the wires that actually form the grid itself.

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Intro To The North American Traffic Signal

August 7, 2017 by Dan Maloney 78 Comments

Traffic lights are so ubiquitous that we hardly give them a second thought, except to curse their existence when they impede us on our daily drive. But no matter how much it seems like traffic lights have the ability to read our minds and tell when we’re running late, they’re really not much more than a set of lights and a programmable controller. Simple in practice, but as usual, the devil is in the details, and for a system that needs to work as close to 100% of the time as possible, the details are important. Let’s explore the inner workings of traffic signals.

Electromechanical Timing

The traffic lights and crosswalk signals at an intersection are only the public user interface, of course. The interesting stuff is going on in the control box. There’s at least one at every intersection, usually a plain metal cabinet set back from the road, sometimes camouflaged with public bills or graffiti. But inside are the guts of what makes an intersection work and keeps vehicle and foot traffic moving smoothly and safely.

Unsurprisingly, most traffic signal controls started out as purely electromechanical devices. Cabinets were chock full of synchronous motors turning timing wheels with cams to cycle the intersection’s lights through the proper sequence. One old time controller that was common up until recently was made by Econolite, and the insides are a paragon of sturdy design.

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Tripping Out: A Field Guide To Circuit Protection

October 19, 2016 by Dan Maloney 68 Comments

My introduction to circuit protection came at the tender age of eight. Being a curious lad with an inventive – and apparently self-destructive – bent, I decided to make my mother a lamp. I put a hose clamp around the base of a small light bulb, stripped the insulation off an old extension cord, and jammed both ends of the wires under the clamp. When I plugged my invention into an outlet in the den, I saw the insulation flash off the cord just before the whole house went dark. Somehow the circuit breaker on the branch circuit failed and I tripped the main breaker on a 200 amp panel. My mother has never been anywhere near as impressed with this feat as I was, especially now that I know a little bit more about how electricity works and how close to I came to being a Darwin Award laureate.

To help you avoid a similar fate, I’d like to take you on a trip (tee-hee!) through the typical household power panel and look at some of the devices that stand at the ready every day, waiting for a chance to save us from ourselves. As a North American, I’ll be focusing on the residential power system standards most common around here. And although there is a lot of technology that’s designed to keep you safe as a last resort, the electricity in your wall can still kill you. Don’t become casual with mains current!

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