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"Boom" doesn't describe it: A lightning strike

Discussion in 'Ham Radio Discussions' started by N1BCG, Jun 15, 2019.

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  1. N1BCG

    N1BCG Ham Member QRZ Page

    So you've got your station grounded well, right?

    This video shows the result of a nighttime lightning strike to a tree less than 60 feet away. The bolt split apart the top half of a tree, blew open a 3" deep path in driveway, jumped up to the front bumper of a Ford F150 pickup, jumped back down through the left rear wheel, then re-entered the driveway to continue exploding a trench for another 20' before reaching the house. Chunks of driveway asphalt were found on the roof of the house and in the back yard.

    "Boom" doesn't describe the sound. Setting off a Civil War era cannon next to the bed is more like it. Fine business way to wake up, eh?

    BTW, the truck was totaled by the insurance company. Ironically, just six hours earlier I commented that the chances of winning the lottery were about the same as getting struck by lightning four times. One down, three to go...
    Last edited: Jun 15, 2019
    KA2CZU, NL7W, WB5THT and 2 others like this.
  2. WZ7U

    WZ7U Ham Member QRZ Page

    NL7W and W7UUU like this.
  3. KP4SX

    KP4SX XML Subscriber QRZ Page

    NL7W and W7UUU like this.
  4. KV6O

    KV6O Ham Member QRZ Page

    Wow! Did the newly created trench follow a utility service? Part of the tree's root system? Was there damage in the house?

    When did this happen? There are a couple of websites that show recorded lightning strike and the estimated energy, I could have a look at some of the non public ones. Strikes can vary in current by quite a bit - your's might have been more than average...

    Reguardless, lighting likes a low impedance path, something there provided it.
    NL7W and WQ4G like this.
  5. KV6O

    KV6O Ham Member QRZ Page

    My access to the EGP/BLM system doesn't cover CT. It's report data looks like this:

    CURRENT 10
    DATE 6/14/2019 9:07:42 PM
    LATITUDE 38.82696
    LONGITUDE -104.91740

    Current is in Kilo Amps, this was a strike about 4000 feet from my house today. 10KA is on the light side... :D
  6. N1BCG

    N1BCG Ham Member QRZ Page

    This occurred in mid-May in Westchester County in the New York City suburbs. After hitting the tree, the path turned 90 degrees out toward the driveway. While I can see how it would follow the roots and be further carried by the roots from a stump seen in the video, significant energy still remained to blow apart the edge of the driveway.

    The truck, which had been towed away when the video was made, appeared to be a lower resistance path by comparison despite being insulated from the ground by the tires and required an upward jump. Further surprise came with another 90 degree turn and jump back into the driveway off the left rear wheel with enough energy remaining explode the top 3" of asphalt for 20+ more feet.

    The strike defied some beliefs I had regarding the path that such energy can take. For example, the feedline to AM broadcast towers typically includes a loop which appears as a high impedance path for lightning. However, this experience seems to show otherwise, twice.


    A bunch of electronic devices in the house were destroyed and numerous breakers were tripped, but amazingly, not much else happened (aside from having one's nervous system epically jarred). The service entrance was on the far side of the house so it was not a factor in the path.

    I guess when lightning has your address, the delivery will be made regardless.
    Last edited: Jun 15, 2019
    KA2CZU, NL7W, WB5THT and 3 others like this.
  7. KV6O

    KV6O Ham Member QRZ Page

    A big chunk of dead metal (truck) is attractive (better conductor than dirt), and holds a big charge imbalance. Lightning is the act of charge equalization, and it's really visible where the bulk of the current flows, but it is flowing in lots of areas. The exploding in a tree or ground is usually due to the rapid heating of water into steam, and the steams rapid expansion (1700 times the volume).
    NL7W, KA0HCP and WQ4G like this.
  8. WA7PRC

    WA7PRC Ham Member QRZ Page

    When I erected my tower + bigly HF Yagi, I complied with grounding & bonding requirements (yes, I should do more). Western WA doesn't get nearly as many strikes as many other areas but, we still get 'em.

    One day, I was standing on my kitchen porch w/ my kitty sitting beside me. We were watching the local storm activity. Then, all of a sudden there was a yuuge simultaneous...
    ... and kitty skedaddled away for a while.;)
    really want to improve my ground system. :p
    NL7W likes this.
  9. KC8VWM

    KC8VWM Ham Member QRZ Page


    T minus 10 seconds to launch... :D

    Very nice tower!
    Last edited: Jun 15, 2019
    KD4MOJ likes this.
  10. KW4GT

    KW4GT Ham Member QRZ Page

    I have an interesting lightning story, though not nearly as 'explosive' as this one.

    I was in the back of the building where I used to work and heard a loud arcing sound coming from near a breaker panel, went to investigate and found nothing amiss. Right about then someone walked back where I was and said something about how loud and close that clap of thunder was that just happened.

    The funny thing is, I never heard the thunder, just the arcing sound of the lightning strike making it's way through our building's ground system. I assume that I was right under where the lightning hit our roof, and it must have been a relatively small lightning strike since we never found any damage (other than the fact that there was a rash of failures of electronic components in our equipment for a few weeks after that).

    OH, and then there was the time I was 'hit' by lightning. Well, I wasn't actually hit by lightning but just happened to be talking on a corded phone when lightning hit the pole outside my friends apartment......DAMN THAT HURT!!!!!!! I developed a permanent case of tinnitus a couple of weeks after that.

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