ZAP (EMP)! (hissssssssss)

12/15/2011 4:49 PM EST

I am curious as to whether normal Zener-type suppressor diaodes can protect agains EMP events such as would be caused by a nuclear explosion? someone I have argued this with says no, the energy levels are too high, but a lot of the suppressors can absorb a lot of energy. Anyone have any solid info on this?

12/16/2011 6:44 AM EST

A friend of mine worked as a technician in the army some time back. They were servicing some old Russian radar equipment where there was a lot of microwave diodes. They were all socket types (so you could change them) and spare ones were all packed tightly in lead (they looked like bullets on the belt). He was saying that it was because they were to survive nuclear EMP.

12/16/2011 2:51 PM EST

Was not too uncommon a requirement 20 years ago for US military aircraft. My company used to design/build product for varous military fighters and bombers and had to demonstrate EMP hardness of design. Usually it was done by analysis: only one facility that I could recall that could do the test. We haven't seen an EMP requirement now in over 10 years

12/16/2011 3:16 PM EST

I was involved with emergency communications at the state level. We have a full enclosed room with a massive door that houses all of the HF and VHF communications equipment used to communicate with FEMA. The antenna and power circuits are filtered at the entrance with EMP devices. The military provides the technical support and maintenance.
I'm more concerned with on-board computers in cars, trains and aircraft that would fail. The power grid would loose regulation of voltage and frequency. Cell phones would be lost. The only communication that would work would be the old crossbar switches and the Model 500 telephone, if any still exist. The technically advanced nations are one EMP pulse away from the caves.

12/16/2011 11:13 PM EST

Now we read that it is possible that we may get another huge solar flare in this current sunspot cycle, for some unknown reason. And the assertion is that it could take out the power grid. That could be interesting.
For adequate shielding we need both a magnetic shunt, to lead the magnetic flux past our protected device, and a conductive shield, to assure that there is no voltage gradient developed across our protected devices. My guess is that all of those low voltage plastic cased devices will not be adequately protected. A serious disconnect function, such as unplugging ones electric meter, could offer the best cheap and fast protection we would have. But I wonder, would it also destroy all of the electronic engine controls and leave us with no engine driven transportation? What would it do to the avionics in a plane? Do we even have a clue about this whole thing, or is it all speculation?

12/17/2011 3:14 PM EST

it's too much to think about protecting everything, start with predicting the failure of critical items in the essential services / utilities; and making sure that two or more backups/replacement modules are safely stored with personnel available to effect the switchover.

Weak links:
(1) anything electronic connected to an intended or unintended antenna.
(2) Include power supplies and user interface connections in (1)
(3) anything vulnerable to failure of an upstream controller or service due to #1.
(4) Anything not tested and proven to withstand EMP cannot be expected to work afterwards.

EMP magnetic pulses can be as powerful compared to ordinary AC cable fields as a static discharge is compared to an AA cell, and with the same sort of risetime.

It is not rocket science, it just isn't the way we have been doing it in commercial equipment.
Basically we are talking optical fibre communications, battery operation and metal enclosures; shielded CRTs/keyboards or replaceable user interface items like keyboards and screens with plenty of spares stored. In a hostile action, EMP assaults would be repeated in order to take out repaired equipment.
Old military radio equipment may be useful as long as you have spares and if possible trained operators..

12/18/2011 1:06 AM EST

thunder storm lightning strikes one can protect as for as to a limited level. if the strike is powerfull i have seen the antenna cable and the electronic gadget every thing gets fired to a level that it got to be rplaced. Best way is to get insured.

12/21/2011 8:28 PM EST

The disappointing thing is that despite mandates from governments (globally) and despite there being known risks of both solar and human generated nuclear EMP or synthesised equivalent pulses the whole issue of disaster recovery keeps getting neatly swept under the carpet. Yes, the military do something about it, but what about civilian hospitals that are choked with netwrks and electronic diagnostic equipment; food manufacturing and distribution industries, rail, road and air transportation services. These are essential services to the operation of modern western civilisations and we, the civilian community, need them post disaster if we are even to stagger onward.
One can build small (or large if you want) EMP generators and do the experiments for real, the results are not pretty. In regard to the suns behaviour, grab the iPhone app "3D Sun" from NASA's Heliophysics division. If you have no background in solar physics or the outcomes of geomagnetic storms this will help open your eyes wide.

12/21/2011 8:33 PM EST

Designing for EMP and high field RF is something I've done a bit of. Basic principle is that the induced pulse is proportional to line length. Your digital watches will continue to work just fine, same for your digital calipers, and probably well designed auto ignition systems too. It simply isn't true that semiconductor + EMP = dead equipment.

It's the cables that matter. Clamp diodes and filters work wonders and shielding is fundamental. Phone and power cables will suffer a bit.

Lightning can generate quite a pulse, but it's slower than EMP and easier to deal with. Lightning damage is often a matter of bulk energy (things that fail shorted nevertheless fail open if they vaporize!).

There are two levels of EMP protection. One allows disruption but not damage (you have to restart the car), and the really good stuff works through the pulse without disruption. I've designed that kind of equipment, and it's reasonably straightforward if you know what you're doing.

12/22/2011 4:56 AM EST

What worries me is that EMP does not need to be the action of a rogue nation or terrorist. Solar flares and coronal mass ejections are just as damaging. A solar "storm" in 1989 took out the power grid in Quebec, destroying a distribution transformer the size of a motor home. If the flare had been a bit stronger the eastern US grid would have gone as well.

That storm was tiny compared to the flare in 1859 that caused telegraph lines to arc and burst into flame nationwide. If a storm of that magnitude happened today, and eventually it will, it will have effects like nuclear induced EMP. It will fry many communication satellites, and will cause the entire national grid to go permanently offline until repairs are made. Those repairs are problematic because the main distribution transformers at risk are very large, take over a year to make, and are not made in the US anymore. Due to their size, cost, and usual reliability, only a few spares exist in the entire country.

These transformers and the grid at large could be protected against EMP/solar surges, but they are not. Our leaders have successfully ignored these risks for 40+ years even though it would cost relatively little to prepare for them. They do so at their (and our) peril.

Stored food and automatic weapons might be a better bet than plastic bags and aluminum foil Faraday cages.

12/22/2011 5:02 PM EST

If it is an electromagnetic pulse then its effects must be governed by inverse square law. Unless several were detonated, the effects can not be even throughout the country. There should be some effect from shielding by mountains and so on.

EMP would not affect fiber optics at all, nor likely any wiring underground.

Transformers take a long time to make because they are not made up in advance because there is no demand for them and there are cost considerations. In the event of destruction of numerous transformers, priorities would be altered considerably by manufacturers and government.

Why increase costs tremendously all around for something which is impossible to accurately model? There do need to be contingency plans, but they can in large part be made along the lines of major catastrophes such as earthquakes where power and communication would be unavailable for extended periods of time anyway.

12/26/2011 2:23 PM EST

I won't mind been called naive, but I am more of an optimist and see this threat more of a scare tactic by the hawks and trigger happy pesimist. Are we really looking for boogy men?.
if there were such an massive EMP event in the future, I would be more concern with the biological and radioactive side-effects.

12/26/2011 8:37 PM EST

I would think that the greater issue is (if it does happen, not that I am too worried) the food supply chain and infrastructure. Given the loss of power here in the NE during the October snow storm, it was a major problem not the first day or two but as the widespread power outages extended many days. Most folks have some food on hand (a week maybe more), many have gas for a generator (not weeks worth of stored gas only a few days), but everyone relied on the fact that the power outage was only temporary. If a real significant EMP event were to happen, all bets would be off. There is just no reasonable way to protect from that type of event. Lets just hope we never have to face one.