Adventures in EMP

Prepare for the inevitable, and have fun doing it!

Stuart D. Gathman <>

Last updated: Dec 18, 2015

The Threat

Our sun regularly fires plasma torpedoes (called Coronal Mass Ejections or CMEs by boring scientists) in all directions. Every 100 years or so, it scores a direct hit on the earth. Whatever part of the earth happens to be facing the sun experiences what is called an Electro Magnetic Pulse, or EMP. NASA estimates that there is a 12% chance of this happening every decade. The chances of personally experiencing an EMP event are double the chances of experiencing a home fire. A nuclear weapon exploded at high altitude, while not killing anyone directly, creates a man-made EMP (known as HEMP) that is even more destructive than the natural solar variety.

History of EMPs

In 1859, an EMP event called the Carrington Event wiped out much of the telegraph infrastructure of the time, including the transatlantic cables laid just weeks before. In 2012, a storm of comparable strength barely missed. In 1989, a CME hit northern Canada, blacking out their electrical grid.

You may not have to wait for the sun. In 1962, a Russian above ground nuclear test caused EMP damage, not as widespread due to the low altitude. At the same time, the US was conducting tests in the South Pacific, and Starfish Prime at 400km was effectively an EMP attack on the Islands of Hawaii. On April 16, 2013, North Korea launched unarmed missiles in a trajectory to an optimal EMP strike on the US. North Korea has nukes, and thus their Dear Leader has demonstrated that they can take us out any time he wishes. We can hope that that is sufficient for Dear Leader's ego (especially considering the certain retaliation). But Iran has also demonstrated an EMP trajectory from Iranian ships in international waters. Iran does not yet have a nuke, but unlike North Korea, their rulers have a religious commitment to destroy the US.

Detailed engineering description of solar and nuclear EMPs by Jerry Emanuelson
2015 Statement before Congress of Doctor Peter Vincent Pry, source.
2008 EMP Commission report.

Part of the Solution (the fun part)

There are many ways to prepare for an EMP. You could buy land in the boonies, stock up on guns, ammo, emergency food, and farm or hunt as civilization collapses around you. Too bad for those city slickers. However, that solution is too lonely for my taste.

Doctor Pry's statement estimates that 90% of the US will die in an EMP. However, the primary cause of all that death is a breakdown in communications and transportation. Although there will be a massive change in standard of living following an event, backup means of communication and transportation can prevent the widespread death.

Here are some areas that need backup for people in the cities to survive:

It is important not to envy the people that will become very rich meeting these needs.

My interest is in preparing a mesh based backup to the internet. An EMP event will not take out the entire world. You will not be able to watch movies on this backup internet - but grocery stores would be able to order from suppliers. Hopefully, other smart people will be fascinated by the other challenges. Like enabling trucks, especially, to survive an EMP event. (Cars may not be worth the investment - they are essentially a luxury in the city.)

The main things needed to be able to bring up a backup internet are:

  1. EMP Protection. None of the equipment will be any use if it gets fried by the EMP.
  2. Power Generation. Bicycle generators (the bicycle doesn't need protection, just the generator and regulator/charge controller), batteries, diesel generators (can run off hemp oil if the government ever stops banning hemp even though it isn't a drug), treadle desks to charge your laptop with power drill while you work (the desk doesn't need protection, just the power drill and regulator/charge controller).
  3. Mesh Networking. Small, low power, Wifi routers running open source software with mesh networking, directional antennas for longer distance point to point links.
  4. Computing Equipment. Laptop computers and smart phones to use the internet once we get it back up in some form. Small switches for local LANs. Bloated web pages like facebook and amazon will be VERY slow to load. People will need to use chat applications instead of voice as much as possible.
  5. Drills. Every 6 months to a year, we all break out backup equipment (not all of it - in case an event/attack happens during the drill), and pretend there is no utility power or local ISP internet. The drill coordinator will designate a distant location as the closest internet gateway. How quickly can we create the local mesh to replace broadband providers, connect local meshes, and ultimately the gateway within one of the local meshes.

Mesh Networking

Amateur radio enthusiasts already participate in providing emergency communication during disasters, including setting up wireless LANs and internet. This is great for hurricanes and floods, but they are prohibited by law from carrying encrypted communication on their networks. This does not meet the requirements of allowing business and banking transactions.

My current plan is to use batman-adv to join the wifi equipment in a neighborhood into the wireless equivalent of a cable provider. Directional line of sight links will join local meshes with point to point links. Instead of emulating traditional BGP routing, inter-mesh links will use manual routes (which would make failure of a point to point link problematic), or more often will connect nodes running the cjdns protocol, which creates an IP6 VPN that requires no central allocation of IP addresses and routes automatically.

But how will I connect to my bank?

There is still a need to connect to "clearnet" (what cjdns enthusiasts call the traditional internet) in the rest of the world that escaped the direct EMP. This is most easily done via IP6, as just the smallest possible IP6 space allocated to the gateway is huge compared to IP4, and more than enough to spread to the entire affected area (even the entire US). However, some IP6 LAN protocols like SLAAC will not work on the smaller subnets (less than 64 bits) that such an emergency scheme would create. Static address assignment and dhcpv6 will work fine, however. The cjdns protocol directly supports tunneling IP6 and IP4 over the cjdns mesh.

But my bank doesn't support IP6! (The backward idiots)

Some enterprising business will be happy to run NAT64 if you pay them or ask them nicely. Similarly, there are many VPN companies who will be happy to tunnel IP4 access to you.

EMP Protection

My current idea is an ordinary steel file cabinet, with equipment inside further protected by something like these faraday bags. The problem with using only a file cabinet, is that the cracks around the drawers and smaller than wavelengths we have to worry about, but they are long enough to form a slot antenna.

advice on protecting electronics from a "prepper"

Power Generation

For working at a laptop without utility power, a treadle desk generator is my personal favorite. The drill and charge controller need to be protected. (But not the treadle or desk.)

For powering networking equipment, batteries charged by a bicycle generator are more practical. Both batteries and generator need protection. (But not the bicycle.)

In many areas, solar battery chargers will be practical. (My area is usually hazy or overcast, and crystalline solar panels are weak.)

For those with large enough shielded storage, a fuel powered generator would be wonderful (until you run out of fuel). With luck, you'll have enough to stay up until the trucking companies are back in business so you can buy more (much more expensive) fuel.