"Larry W4CSC" wrote

"Jack Painter" wrote

outer docks. In the aftermath, we heard there was a lot more damage
from collisions than from lightning, and that is amazing considering
how many yachts I saw get struck that night.

I've read the webpage from FL. Very interesting research. The mast looks
tall when you're standing at the bottom of it looking up, but in the
overall height of a thunderstorm FIVE MILES HIGH, our masts are like a
dimple on the dining room table, and not much of a "target".

"You're standing in the safest place in Sumter County. There is a cone of
protection against being hit by lightning provided by my tower and you're
now standing in the middle of it. Hang onto the tower leg and feel the
current going through it." I burned my hand a couple of times as the huge
BOOMs went off over my head a thousand feet up. The huge bridge cables
JUMPED from the surge of electrical EMP hit them, many times.

Though the "tower" on the sailboat is very short, in comparison, I like to
think that if you have a proper grounding system, like the professor
describes on his webpages, you are also in a tiny cone where the blast
will
mostly be shunted AROUND you, which is why your car is so safe in a
thunderstorm. The current surge that kills goes AROUND the the steel body
of the car....Steel ships and boats do that....Plastic, not so good.

Indeed. That Florida study explains that there are very few examples of
sailors (on sailboats) being hurt or killed by lightning. That is due to the
cone of protection as you said, but it does not normally extend to anyone
touching those shrouds or mast! To some extent you are bonded to the system
when standing on deck and could be in a very high voltage condition without
feeling much current due to the bonding. While HV lineman aloft use that
principle safely every day, boaters are advised to remain below deck and NOT
touch anything conductive during a lightning storm.

Similarly, while "under" the cone of protection of that high transmitter
mast, you were indeed safe. But on your way over to it and back from it, you
are both lucky you lived to tell the story. The voltage gradient between
your two feet on the walk nearby could be thousands of volts during a
discharge let alone a strike.

Best regards,

Jack