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Grady, AM radio antennas are usually located nearer to the ground than FM antennas. The broadcast signal from an AM antenna can result in structures such as cranes becoming charged, resulting in high voltage, low current arcing. One of the oil tankers in our fleet reported that at a certain dock they experienced getting shocks when putting slings on the crane hook. The crew discovered if you held a small fluorescent bulb near the crane hook you could get it to light, Uncle Fester style. We found that there was an AM radio antenna nearby that was used occasionally by a radio station. When in use at the same time the ship's crane was being used the crane would become charged. In checking with commercial crane operators, this was a known phenomenon. One operator told us that they had issues when working on San Francisco Bay. It took some time, and a solution was worked out with the refinery, radio station and new safety practices for crane use on our ships. Oddly enough I probably was 30 years into my career before this problem was ever encountered. Bob

“A nuclear detonation is unwelcome in nearly every circumstance” is the understatement of a lifetime 😂 Great video Grady, really enjoyed learning about this!

I'm a retired electron pusher. I started as a microwave radio tech in the USAF (honor graduate Keesler AFB 04/1978). Over a 40+ year career, I moved from RF Tech to Engineering Tech to Design Engineer to PCB Layout Engineer to Senior EE with a major defense contractor. In fact I worked as a contractor since 1996, wearing many hats and mostly in aerospace and military design. Consequently, I have worked at times intimately with EMP and as SI (Signal integrity) oversight for an engineering department developing large integrated circuit test systems. My favorites were spacecraft and satellite design. The space environment is pretty unforgiving, and those devices typically cannot be brought back for repair. They have to function in the harsh environment of space. Your video was an excellent overview. My only comment is that the study you referenced specified a 1 megaton HEMP (high altitude EMP) detonation. That sounds a bit like hunting moose with a .22 rifle. In a tactical situation intended to disrupt, say, the United States, I would expect at least a 10 MT if not 20 MT device, and possibly more than one, e.g. one over the Appalachians at a latitude between ew York and Washington; oneover central Texas, and one over the Sierras on a latitude between San Francisco and LA. This would hit major population and technology centers while taking down all three major grids: NS along the East Coast, EW across Texas and the south-eastern US, and NS along the West Coast. As for the solar induced equivalent, we are actually overdue, statistically speaking, for another 1859 Carrington Event level solar CME (coronal mass ejection) impact. That one burned telegraph wires in two and set operators' equipment on fire, which was the most advanced electrical technology at the time. We just missed an even larger CME by less than 2 weeks in our orbit in 2012. It would have been a technology killshot. As you stated, the fast E1 pulse would couple into virtually all conductors, even the smallest, inducing spikes in the traces on integrated circuit (IC) silicon dies. We briefly discussed this in an IC Fabrication course I took around 2002. The copper traces on a printed circuit board (PCB), where components are typically mounted and interconnected, are also ready made antennas for the E1 pulse. I focused on PCB layout and signal issues for about 18 years of my career. The E2 period does indeed have many characteristics like lighting, and many lightening arrestors should handle it. The E3 pulse is another matter. In EMP and HEMP situations it is able to induce ground currents. In a solar CME induced planetary scale EMP, these could be significant, dwarfing the regular man-made HEMP. These are the currents most likely to destroy large grid regulating transformers and even generators. They can travel into electrical loops by a "sneak path", using the ground connection to enter electronics not designed with a robust power connection, and traveling "up" to the power source (normally the input power). Needless to say, a reverse current of high magnitude would be devastating to most equipment. I _DO NOT_ have experience in large scale power distribution, "The Grid", but warnings I have read indicate it, too, could be susceptible to such high reverse currents. Add this to the directly coupling E1 pulse, and there could be significant current and high voltage spikes tnduced into the windings in both transformers and generators. These transformers and generators are not off the shelf components, as the video stated. These are custom built OVERSEAS. In a worldwide event like the solar-induced EMP, it is very unlikely these will be replaced soon... if ever. Consider the events in New Orleans in the two (2) weeks following Hurricane Katrina. Once it became apparent that services like electricity, phones, and water were not going to be immediately restored, the social structure began to crumble. When it became known that supply trucks were not going to be able to resupply the supermarkets, the normal "three days of food on the shelves without resupply" was stripped in TWO HOURS. I also have a degree in psychology, and human dynamics in events like this are one of my areas of interest. One of my best friends had family in the area in Baton Rouge, and they experienced predatory behavior escalate as well. Given a probable loss of the power system due to Grid failure, collapse of the financial system due to loss of the communication system - no internet means no banking system, loss of transportation for food resupply, and loss of refrigeration for existing food storage AND medicines, and the situation in many urban areas will probably be much worse than the few weeks following Hurricane Katrina. Don't forget that no communication, no transportation (gas pumps run on electricity even if the vehicles' computers were not fried), and totally dark cities at night means no police or other order enforcing bodies. It could become very dire very quickly. Read _One Second After_ for a fictional depiction of a small town following an HEMP event written by an expert in EMP. This book was given to congressional members when a bill to harden the electrical grid was under consideration. My thoughts about that book were expressed exactly by the Naval Captain that wrote the epolog: I would love to have been able to read this as a work of science fiction, but I knew all too well that everything portrayed was entirely possible.

I like how calmly this guy talks about the end of civilization

As an electrician, I have been involved in a lot of interesting construction projects. My favorite and most memorable one was an entire building that was built with EMP shielding. Just like an MRI room. It was a building to house the control center of a major city’s grid control. It looked very much like your footage of the grid control center in this video. I think you could do an entire long-form video about the engineering that goes into MRI rooms. They have copper walls and EM filters and wave guides. They can be huge or fairly small. The world-renowned company ETS-Lindgren is one that has done all the shielded rooms and buildings I’ve ever seen. They’ve done secret projects but also lots of health-care projects.

VERY surprised you didn't mention 1962's Starfish Prime (1.5MT) which was over Johnston Atoll and it's subsequent EMP knocked out power and phones here in Hawaii for at least a few hours. Hawaii is nearly 900 miles away. Some LEO satellites also got knocked out because of it. It's a perfect answer to the videos question and a literal what would happen in the real world.

Additional notes about transformers: Even small substation transformers cost $MM's. Additionally, they're often custom-sized specific to the substation they are installed at and the lines they are tied to. Manufacturers make them to order and they often have multi-year order-to-deliver dates. Even repairing a transformer can take over a year.

You make some incredibly thorough, highly educational videos. I just discovered this channel and I must say, I love it!

Man, these Election Day ads are getting out of hand. Now I don't know which EMP plan to vote for! 🤣

You might find this interesting regarding an AM tower. Back in the early 1980s I worked at a radio station and for the AM side of the station, the tower was out behind the building. During storm there would be these pulses that would run through the system such that they would spike the needles on the monitoring needle gauges (old school). I would go outside to look at the tower and you could see and hear electrical pulses running down the guy-wires. It was amazing and scary at the same time. I never knew why it would do that (I'm not an electrical engineer or anything) but I assumed that the air was, like, "charged" from the surrounding storms and that was interacting with the "AM waves" and generating electrical current that was grounding down the guy-wires. Do you think AM towers still do that or do they ground them differently now?

This is a great topic! Thanks for sharing, enjoyed watching!

It's terrific to find an educational UKposts video once in a while. Thank you.

One critique from a EE. In your Marx Generator experiment, you can see the spark jump to the picture frame. So, the resulting damage is more likely from the high voltage entering the case and not the EMP pulse triggered by the spark.

I actually had a VERY nearby lighting strike that fried my home router, and my brother's next-door. We had a Cat5 cable connecting our homes, running down the wall and underground. This seems to have acted like an antennae and allowed the EMP generated by the lightning strike to fry both of our home routers connected via that cable!

I once used a vandegraf generator to build up a surface charge across a bunch of my students holding hands and standing on desks to insulate them, when we discharged the person-circuit, it caused the television in the room to turn off and was not able to turn back on immediately. Wasn't able to reproduce that day but we had a fun few days of discussion afterwards

Great Videos Thanks! As a Power Supply Designer for many years, I remember an experienced senior designer when I was fresh out of school told me: "When a transformer core saturates, it's just a piece of wood!"

Your demo with the EM generator and multimeter is very similar to a bizarre flaw I discovered in a multimeter just a few days ago. I was using its continuity testing mode and suddenly it started beeping when I moved it near a printer. The EM waves produced in its power supply were apparently generating enough power in the leads that it mistook them for a closed circuit.

The EPRI study is a source I've been using for years on educating other amateur radio operators regarding hardening electronics against EMPs. However an EMP is not my fear, a Carrington Event level CME is and is much more likely.

I used to work for a defence contractor producing military avionics [military radios for military aircraft], and we used to test for EMP in our military radios... and I remember the test set was able to generate a pulse with a 1KV peak in a 1ns rise time. This is a lot faster than lightning, which is typically 1KV peak, with a 1 microsecond. This is the EMP spec that we used for testing our avionics systems, as we had special test rigs for testing the effects of EMP. The power supply rails, such as the 5 Volt rail, had special zener diodes that would short out the power supply rails, and was designed to detect the gamma ray flux. It would create a short glitch for the radio, but protect against surges that might occur. In fact we tested a muzzle velocity radar unit, by putting it into a reactor, and the protection circuits worked. In addition that filter connector that connect to the radio system also had special EMP filters to protect the avionics.

Thanks for all of the helpful information. Great job!

Protection and control engineer here - I design the control systems that trip the breakers using the digital relays mentioned in the video. Very informative way to explain this paper to the public, in a much more interesting manner! There are many utilities that are currently buying concrete control houses or having their control houses shielded with elaborate copper shielding systems on critical bulk electric system sites. These approaches (largely) mitigate the issue of E1 pulses affecting the control relays. It's proven much more difficult to prevent damage from the E3 events, as the protective relays we use now won't necessarily detect those conditions and trip everything offline. Furthermore, while your control relays may be shielded from most of the issues, your voltage transformers and current transformers out in the yard will not be as protected. If you can't rely on the data coming into your relays, you can't effectively trip and protect your equipment.

Just got my signed copy of Engineering in Plain Sight. This book is totally stuffed with fascinating knowledge presented with Grady's signature teaching style we all know and love.

Excellent presentation! I just subscribed! Very well broken down to us who are simple laymen.

I had no idea the Navy did testing like this. My grandfather was a part of the LCS for the Boxer and had many stories to tell, and it’s awesome to stumble upon one of the things he assisted with

At a major company I worked for in 1980, we had in-house courses, one was EMP and SGEMP. Bottom line, big transformers running near capacity can be destroyed by the third stage of an EMP because of the dissipation from a big DC current component. This fella I think is underestimating it.

In 2014 I was in an electrical maintenance program at my local college and one day I asked one of my instructors how long we could survive a widespread power outage. His answer: one month, yes...two months, no. It was sobering to realize we're only one massive solar storm away from utter catastrophe.

You missed something. A high voltage relay has a mechanical backup just in case the power is lost to the GE 745's (or whatever they are using). So even if a EMP hit the grid, it's still going to shutdown to protect the grid. A restart can take place with operators controlling the system. And yes, the grid does have lightening protection which reaches 1 gigawatt worth of power. Once the EMP has passed, the grid will reset and they can bring everything back up. There are many lightening protectors in the grid so you might lose some of the relays but not all of them and threw the SCADA control system will act as a controller to any part that might still be down. In short, an EMP will take the grid offline, however it will come back up within minutes of the event.

Love these videos, you have great knowledge and insight

I sincerely appreciate how much attention you pay to pointing out when your demos are just decent conceptual illustrations as opposed to full on science experiments. That nuance gets lost way too often and it’s rad that you’re so careful with that. Great work as always!

I got a tour of a Coast Guard station once and the final thing they showed us was standing next to their thousand foot antenna was holding a fluorescent light up near it and the light lit up. They also showed us where some protesters jumped the fence surrounding the antenna (plus the fence surrounding the Army base it was part of), anyway, they spray painted on the concrete base of the antenna. That person came within inches of becoming a very crispy critter because of the amount of amps that was in that antenna. Needless to say, we walked away with a heck of a lot more respect for those tower antennas.

Great channel! Keep up the good work!

Superb. Simply superb. Such fascinating well researched and well explained content, thank you.

I am so in for a "threats to the grid" series!

The most disastrous effect is the creation of a strong, slowly-varying DC voltage across the long transmission lines, as you mentioned in the video. In such event, along a transmission line, the DC voltage causes the HV transformer to explode and the wires to melt, while the transients disable all the inductive loads. Thank you for the great video, Regards from the UK, Anthony

Love juicy engineering details.

Great video, as usual, Grady! After your explanation of the grid protections, and reading MG50's great comment below, it sounds like the E1 pulse would toast the delicate electronics and relays designed to signal and protect the slower/more mechanical protections built into the grid, leaving them unprotected. Then the E2 and E3 could really "fry the bacon", leaving us in camping mode.

Grady, thanks for taking complex engineering concepts and breaking them down to easy to understand explanations. I always look forward to your posts!

Just got your book and immediately went through it! Since I'm an artist, I examined the illustrations, and found a joke in almost all of them! The seagull flying away with your hard hat; the bird pooping on top of it while you eat your lunch...wonderful! I'm assuming since the little character has a red hard hat that it is you...which reminds me, whoever did your hat/glasses logo is really good. It's very effective in its simplicity. OK, back to reading some more and hopefully learning some engineering. And yes, I love the book! I may pass it on to a friend's kid, who is really intelligent and curious.

You are a good teacher. Thank you.

Great post. I really enjoyed this

I love your videos so much! I'm really a huge fan. Although this is a bit different from your normal videos this is still right up my alley. Electricity and EMR is so interesting and fascinating. Likewise I'm always keeping my eye out for infrastructure around me. Because of you I actually know so much more about my surroundings which I was always so curious about. Thanks for taking the time to share your passion with others, it has impacted my life in a good way. Thanks and have a good one.

Grady, I have received your book and I have to say that it's great, clear concise and easy to understand. I knew when I ordered it that it would be based on North America but it is still a very useful text. The badges were a very nice and unexpected bonus. As an avid subscriber, all I can say is from one engineer to another, I tip my hardhat, well done sir!

Wonderful explanation of this phenomenon.

I bought your book "...Plain Sight": fun and useful reading but perhaps a bit basic for my background. The "Keep an eye out" diagrams are a high point. More would have been welcome as I was hoping for a "guide to weird engineering structures seen from roadways" or something like that.. Overall good work, and thanks!

This topic reminds me of a book I read titled, "One Second After" that is a fictionalized story about 3 EMPs in this manner detonated to cover the entirety of the United States. It sounds like from your description in this video, the total damage in a real life scenario wouldn't be as bad as detailed in the book, but the book provides a good frame of reference for some downstream effects of a world without power, specifically on communications, logistics, and especially healthcare and the social ramifications of suddenly finding ourselves in this situation without preparation.

Edit: You already updated the corrections and errors list in the description! Really nice to have that. Og comment: 10:32 - audio error where you mention a solar event disrupting Earth's Gravity. (Sorry, I know that you're going to get a lot of these.) Really great video otherwise, very interesting topic and well researched information!

Thanks! My 95 year old uncle was heavily involved in the 1950s, conducting research on electromagnetic radiation releases for our government was more than curious concerning the yield of the Soviet nuclear detonations made at the time. Still secretive, my uncle mainly discussed the primitive conditions of his accommodations in the Pacific and Alaskan areas; than the study of electromagnetic pulses. Great video.

This video was fascinating! You have to do a video on the effects on the grid from a Major Solar Storm

Grady, you deserve an award for your work. Awesome quality, absolutely no bias, wonderfully presented. Will subscribe to curiosity stream today. Thank-you!

Thanks for this very accessible education. I’m very interested in the complex relationships you explain. The curated slides and graphs you find and show are equally revelatory of the underlying principles. I really enjoyed this episode!

Grady, you're a Genius! I'm not saying that I completely understand everything you said, but what I do pick up on is a tremendous help! Thank you Sir!

Please make a second part which tells us what we are supposed to do if that happens.

Thanks for putting this out. I've been correcting people about EMPs for years and it is frustrating to not have a source that is fairly definitive while also keeping it simple enough for the average person to understand. I spent a lot of time reading through the papers available on this. Some were difficult to find. I'll be interested in what source material you found and your future videos on this subject. Well done so far.

(Edit) The Carrington event was another example of what happens when DC offsets are applied to the power grid, although back then it affected little more than telegraphs. If such an event were to happen today it could be catastrophic, probably much worse than a nuclear EMP. It's so scary the sun can in theory decide to do stuff like that without warning.

Thank You for this video

thx for the link

Back in the early seventies, my dad, who worked for Honeywell, was trying to develop an EMP proof re-entry guidance system for ICBM's The concept, was to use fluid dynamics as a form of current in a circuit.

As a kid, around 1950, I saw a live telecast of a nuclear explosion in Nevada. The TV microwave relay system had been built that far west by then. The countdown reached zero and then the picture broke up because an EMP took the camera off-air. But it took only a few seconds and some good whacks to get a picture of the mushroom cloud on the air. Vacuum tube electronics is much more resilient.

Thank you for the video.

Most excelent video🙏

Living in a hurricane area, I see how crazy people get after just a few days with no power…and this is an area we expect to lose power…or should. Imagine weeks/months for large regional areas.

Great job on the book, its even better than I was expecting!

Great book called Burning the Sky goes over in depth Hard Tack and a whole bunch of other high altitude test. Excellent read.

Very informative

@Practical Engineering, EPRI is typically pronounced 'ehp/ree' in the energy industry! Source - I've worked in the energy industry for 7 years! Always love your content!!

My father worked in civil defense for decades. Back in the 80s he told me the weakness in restoring our power grid was the glass insulators. They were manufacturer in Belgium and the US didn't have a stockpile. He also believed suitcase "dirty" bombs could cause more damage because of their size, portability, and ease of detonation.

Nice work

11:02 Interesting... WSM 650 AM had a tower that at one time was the tallest structure in Tennessee. I lived ~2 miles south of it. >30 years ago when I'd pick up the home phone, I could hear the radio station on it.

I have an electrical engineering degree. This was one of my favorite/interesting videos of yours, I watch you all the time! Thanks!

We use more electronics than ever before, but that might not be as big of a problem as it first seems. I've read that while smaller electronics are more vulnerable to spikes, at the same time, modern electronics are more hardened against electromagnetic interference, and their small size means that they'll be less exposed to the waves as well. I think in the end, it may depend on the location of the devices, their quality, and maybe even their orientation if they survive or not. Though let's hope we never have to find out.

I like the view from the John Hancock building at 13:59. Reminds me of the times I was in my dad's apartment when he used to live there as the chief stationary engineer.

You should hear the 'growling' that comes from a step-up transformer during a solar magnetic event. We monitor temperatures and ground current much more frequently during such a storm. Great video!

BTW, I'd recommend your book to anyone who wants a really clear, concise explanation of various common engineering applications. Well written, beautifully illustrated, read this instead of nerding out on twitter or something! A real book, held in a pair of human hands--what a great idea! Get the book! You'll love it!

7:34 I discovered early in my broadcast engineering career that a two-stroke string trimmer will create similar effects. I had the announcer/DJ look out his window at x:55 on Wednesdays to make sure the landscaping crew wasn't on the same side of the radio station building as the dish antennas for the network news. If they were out there, the jock would run out and give them a ten minute break, so the top of the hour news wouldn't be interfered with. The RFI coming from the Weedeaters would swamp the C band LNA if they were within line-of-sight.

The three letter combination "USB" has two very separate and distinct definition. One USB refers to upper sideband which is a form of voice transmission sounds the nearly switched position on your receiver call the SSB or single side band or side band and selecting that position will allow you to understand ham radio voice transmissions.. Went out to use of that switch, ham radio voice communication is hard to understand. So if you're little receiver radio does not have a SSB or USB switch then you won't be able to understand many voice ham radio transmissions. However the abbreviation USB is also used in ham radio language to refer to hey kind of socket that will be on the side of the computer. And then utilization the abbreviation USB does then refer to radio communication but instead very kind of socket that is used on computers. These are two totally different utilizations of the same 3 letters and can cause confusion.

Your video does a great job of explaining the effects of a Nuclear EMP. As you stated, the E3 will add a DC component to the AC input to a transformer. If this causes the transformer core to become saturated there will be no back EMF and the current will only be limited by the resistance of the winding. This excessive current will quickly burn out the primary winding of the transformer.

Thanks for adding to my knowledge base! Retired now, but was an FCC-licensed electronics tech for several decades. I knew EMP is a problem. but now I know how and why.

Very interesting, informative and worthwhile video. I would be helpful if you did a video on how to protect personal devices ( smart phones, tablets, flash drives, walkie-talkies) from an EMP and a CME. Do Faraday bags offer sufficient protection? Many thanks.

I had a lightning bolt strike my apartment building. I don't think it hit any mains supply as nothing tripped - but one corner of my living room had basically everything fried. I later learned that is where the lightning rod's ground wire was routed, so it seems the EMP induced from that line caused an overload in appliances within about 3m (10 feet) of that corner, including my amplifier, television and a digital clock.

How appropriate of a topic. Thanks for the additional info.

I was at a meeting at EPRI a few years ago where I heard an interesting presentation about challenges associated with a black start of grid, with one of the potential causes being EMP. I hope one of your future videos addresses this question.

I studied electrical engineering at the University of Waterloo focused on electromagnetics and spent my last work term at DREO (Defense Research Establishment Ottawa) doing research on nuclear electromagnetic pulse in 1993. Ummm... that's probably about all that I can legally say but I appreciate your video for providing insight into a topic that few people know anything about.

Fantastic video

As a power system engineer, I enjoy the heck out of your perspective! Can't wait for the next one. Don't love the disconnected stock photo at 5:25 though...

The utility I consult for is somewhat prepared for an EMP strike. There are a handful of hardened buildings that are basically Faraday cages storing relay equipment. The newer control houses also provide more protection

my power went out as i was watching this, amazing timing. seems like it was recloser action

I helped publish hundreds of EPRI reports while in SF. They took the job internal though. This reminded me of those days. That is a common California thing, where people worked for a place then became contractors later then later the company took the opportunity back. It was my roommate who actually worked there in person. The PREPRESS days for before the dot come bust.

I hope you have a video planned on the solar flare that ignited telegraph wires. Such a cool video. Thanks for all the content!

Could you follow this up with a video of the effects of a massive CME effects on the grid?

super cool video!!!

Great topic and discussion - faraday cages for everyone and every home

Excellent video! As someone that hardens critical communications sites this was the first video that I can’t find any real faults with on the subject! Thanks for making a video that’s based in science vs just scaring people!

So refreshing to hear some science-based commentary. Love all your video.

Glad I ran across this video. I just received an ad trying to sell prepper supplies saying that we're gonna have a nationwide 1 year total blackout. Sounds like a bunch of hype after watching your vid. Thank you

VERY interesting - My Dad was involved via SRI Institute for the DoD in some of the testing measurements - they had a pair of former trailers attached to an old Victory ship down in the Southern Ocean - I believe, south of the Tasman Sea. He'd also be involved in Operation Fishbowl and other such projects after finishing his Masters in EE (I was conceived during Fishbowl ). He TRIED to explain it when we were in our early teens... he had some GREAT slides from the measurement sites.

It's worth remembering that we have a constant, immense nuclear explosion going off 8 light minutes above the ground, and it sometimes behaves badly. Large solar events are certainly a concern to grid designers and operators. I wonder how much the mitigation efforts of the past few decades vs solar events will also help vs EMP.

I work as a HEMP Test Engineer in the defense industry... and as someone in such a small community, I like seeing more light shed on this topic so thanks for that! And I also appreciate that overall you've done a good job of presenting an accurate (enough) high level overview of the subject. However, if you'd like to make some edits for correctness, give me a ping :)

Man that was a fascinating and well put together presentation.. I feel absolutely paranoid and terrified now lol

Thanks!