Tower work and Lightning

Discussion in 'Safety - General Safety Issues' started by Wayne Bowyer, Jul 25, 2008.

  1. Wayne  Bowyer

    Wayne Bowyer Friend of the Community

    Most all of us who have been in this industry for at least a year have probably been on a tower or a tower site when a thunderstorm was approaching. Have you heard the tower start to "sizzle"? Had your hair stand on end? (for those of us who still have some!)

    When I started in this business many years ago one of the first things I remember being told by my companies' owner "If you wait till you see the lightning to come down--you've waited too long!"

    If we hear thunder we start making plans to come down. There are many good reasons to not fool around with lightning:

    1. There are on average 75 cloud to ground strikes per second world wide.
    2. The average strike carries a current of 10,000 amps and 100 million volts!
    3. Lightning can travel over 20 miles horizontally and come down in a "Blue Sky" hence the term "Bolt from the Blue"--this type of bolt is particularly dangerous. You're working under a blue sky and don't think a storm is anywhere around.
    4. Thunder will only travel about 12 miles
    5. The temperature of a lightning bolt is on average 4 times hotter than the sun!
    6. 20% of all strike victims die.
    7. 70% of strike survivors will suffer long term effects---memory and attention loss, chronic numbness, muscle spasms, hearing loss,stiffness and depression.
    8. Many strike survivors report that just prior to being hit their hair stood on end and they had a metallic taste in their mouth.
    9. 85% of victims are young children and young men age 10-35 involved in outdoor recreation or work.
    10. 70% of injuries occur in the afternoon.

    In summary----Lightnin g is much more powerful than we can hardly imagine, If you see or hear a storm coming you need to make plans to come down.
    If you can't get down quickly (safely!) then you should by all means get off the top of the tower and get inside the tower if possible. If you can't get inside then belt off on the outside and make youself a "small target". Hug the tower, don't be reaching out or off the tower. Turn off any cell phones or two-way radios you may have with you till the storm passes.

    If you're on the ground, get in your truck and get off the site. Don't stand near the base of the tower or anchor head. Don't go in the shelter! I have seen shelters completely wiped out inside due to a strike. Saw one site where the strike wiped out all of the equipment in the shelter and then bounced around the compound fence and welded the lock closed!
    You should wait 30 minutes to resume work after the storm passes due to the fact that most lightning comes from the leading and trailing edge of the storm cloud. And don't panic--if you're on you're way down and the tower takes a hit above you probably won't feel a thing--you're at the same potential as the tower--the strike will go to ground. What you don't want is the strike hitting you first and going thru you to the steel. You can minimize the chance of that happening by minimizing your "signature" on the tower. Always,always use 100% tie off while on the tower whether climbing or sitting still!

    Work safe so you can live to be here another day! Your family and coworkers need you.

    Wayne Bowyer
    Safety Manager
    Shenandoah Tower Service Ltd
    Staunton Va

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