Phil Ewing over at Navy Times makes an interesting catch:

Navy engineers in March began looking into how the fleet should prepare for an attack by one of the most feared and controversial weapons of the modern age: an electromagnetic pulse.

So, even though the U.S. is working to cut nuclear weapons, we’re also preparing to operate in a world where nuclear weapons have proliferated or are set to be employed in less conventional ways– in, oh, say, Anti-Ship Ballistic Missiles.

Under the Naval Sea Systems Command (NAVSEA) Force Electromagnetic Effects and Spectrum Management Office, the U.S. Navy EMP Program is reconstituting knowledge lost after the Cold War:

“We have eight scientists and engineers who are providing Navy leadership with information crucial to assessing the fleet’s posture with regard to EMP,” said Alex Solomonik, Navy EMP Program Manager. “Navy Warfare Center EMP experts – with over 80 years combined electromagnetic pulse experience – form an extremely powerful link to past lessons learned.”

The group advises Navy leadership about strategies and safety measures to mitigate EMP damage in the unlikely event a nuclear weapon detonates at an altitude in excess of 40 miles, generating a high altitude electromagnetic pulse.

“The consequences of failing to take appropriate precautions to protect fleet mission critical systems can ultimately prove catastrophic to the Navy’s mission,” said Blaise Corbett, Naval Surface Warfare Center (NSWC) Dahlgren EMP Assessment Group Leader.

So, to do my part in building awareness of this old “new” threat, here’s a primer from the latest CHIPS:

Electromagnetic pulse is a radiated electromagnetic field, typically generated and associated with a nuclear detonation. A nuclear device detonated at an altitude in excess of 40 miles generates High Altitude Electromagnetic Pulse (HEMP), which is the focus of the U.S. Navy program. This high-altitude nuclear explosion creates high energy photons known as gamma rays. The photons collide with molecules in the upper atmosphere creating free electrons called Compton electrons, which then interact with the Earth’s geomagnetic field lines to create a HEMP.

HEMP can be characterized as a radio frequency emission with broad frequency content, high electrical field levels up to 100 kilovolts per meter, and high instantaneous power density levels that can exceed 20 megawatts per meter squared.

HEMP is composed of three components commonly referred to as E1, E2 and E3.

E1, often referred to as the prompt component, is characterized by short pulse duration and a fast rise time. The actual EMP experienced is a function of the weapon yield and design, burst height, latitude of the burst, and relative observer location from the burst point.

E2 is often compared to lightning in terms of duration and frequency content (frequencies contained in the signal), while E3 has the longest duration, lowest frequency content, and lowest field levels.

As such, E1 poses the greatest danger to individual electronic systems, while E3 poses the greatest threat to networked infrastructure, such as long line power and telephone networks. The focus of the military is primarily on electronic system impacts due to E1.

EMP is one of those hotly-debated threats. Skeptics are quite right to argue that, oh, an unfortunately timed coffee spill onto a critical keyboard poses an even greater (and more likely) hazard to naval operations.

But in a world where naval platforms are set to last for four or five decades…who knows who will have a nuclear weapon by then? Or, for that matter, how nuclear weaponry will be harnessed?


Posted by Defense Springboard in Marine Corps, Navy
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  • UltimaRatioReg


    GREAT post, and about time. As we get more “network centric” and rely increasingly on complex communication exchange, this threat looms larger.

    We used to talk about this all the time back in the “day”. Rather than use a tactical nuke against US forces, what would US response be to a smallish 100k foot atmospheric? Knocking out all communications and data systems, but otherwise causing no casualties?

  • RhodeIslander

    So what is NAVSEA having its last 2 real warship manufacturing shipyards do to be ready for this possibility ?

    General Dynamics builds the DDG-1000, DDG-51 warships and Northrop Grumman builds DDG-51, LPD, LHA, and CVN warships.

    Does NAVSEA check these 2 last American warship yards to see what they are doing for HEMP and if they have any decent quality in their workmanship for this threat ?

    Are some warship classes held to more stringent requirements for HEMP protection than other USN classes ?

    I’m afraid to learn the actual, non-spun answers to these questions.


    Its not just a threat from nuclear weapons, there are several countries that are working on electronic attack weapons that produce EMP like effects.

  • Can EMP generators focus their effects so they’re, oh, precise? In a tactical sense?

  • Rhode Islander

    COTS ! The wonderful “solution” to all our DoD ills. Quick, cheap, effective.

    Was NAVSEA aware that modern COTS electronics are now operating down in the micro-volt, micro-amp range ? Whatever NAVSEA is requiring our few remaining American shipyards to do for HEMP protection, it better be capable of reducing induced HEMP by a factor of 10 to the 6th, at least. (that’s 60dB of power intensity reduction).

    Wonder if LCS, being “cutting edge” has decent HEMP protection ? Anyone want to bet Lockheed Martin’s paycheck ?

  • Can EMP generators focus their effects so they’re, oh, precise? In a tactical sense?
    According to AW&ST, the Army seems to think so.

    So here’s a scenario, tensions mount following a naval incident in disputed waters, North and South Korea begin massing forces when a missile is fired over the Sea of Japan, and detonates with a regional EMP effect. Which side’s forces are better able to engage and win in a subsequent 1950’s environment…?
    w/r, SJS

  • heh…And the sneaky thinker award goes to STEELJAW!

    heh heh heh…

  • UltimaRatioReg


    Methinks you should check the very first comment before handing the award to SJS!

    “We used to talk about this all the time back in the “day”. Rather than use a tactical nuke against US forces, what would US response be to a smallish 100k foot atmospheric? Knocking out all communications and data systems, but otherwise causing no casualties?”

  • Derrick Lau

    Other than nuclear explosions, what are the ways one could generate an EMP to use as a weapon?

  • ozy


    Some interesting reading at Wikipedia

  • AmandaK

    I’ve come across MANY good blogs with the topic of EMP and let me just say, they all scare me. I know that this is an inevitable thing- but that doesn’t mean it’s not still frightening. People need to get their heads out of the sand and listen to the fact and GET PREPARED. Being in denial about it isn’t going to make it not happen. I came across about a month ago a Radio Blog that has different guests go on their air. A guy named Peter Huessy was on their show and talked about EMPs and other different important topics. He was on it a few different times and he’s going to be on it again on Wednesday the 13th (next week). I’m going to be listening in on it again to find out more facts with this subject. If you guys want to check it out too, here’s the link: