[pct-l] Lightening risks using external frame pack?

[Yoshihiro Murakami]

This will be a good guideline for the lightening.



JEMS. 2009 Apr;34(4):36-8, 40.
When lightning strikes: bolting down the facts & fiction.
Usatch B.
JEMS. 2009 Jul;34(7):18.
Abstract
MYTH: There's no danger from lightning until the rain starts. FACT:
Lightning often precedes the storm by up to 10 miles. A reasonable
guideline is the "30-30 rule," by which you count the seconds between
the flash and the thunder. If the time span is less than 30 seconds,
seek shelter. Additionally, wait a full 30 minutes from last lightning
flash to resume outdoor activities.



2011/2/8 Ben Crowell <pctcrowell11 at lightandmatter.com>:
>>I use to use an external frame pack and got nervous about wearing it during thunderstorms.
>>Anyone know if there is any research showing if you are more likely to git hit/killed with a big
>>lightening rod array - er, external frame pack - tied to your back?
>
> Lightning rods work because they have a pointy tip. Whenever you have a conductor with a tip or
> a knife-edge, the electric field around the apex or corner is greatly increased. This is likely
> to cause an electric discharge to start in the air right near the tip. If your aluminum tubing
> in your pack doesn't have pointy tips on it, this won't happen.
>
> The frame might conceivably even have some protective value.
>
> For comparison, if you're caught in an electrical storm, one of the smartest things you can
> do  is to get inside a car. Even if the area around the car is struck directly by
> lightning, you are likely to survive, because the volume inside the metal framework is
> shielded from electric fields. This is similar to why you can't get a cell phone signal
> inside a building that has a lot of metal in its building materials. It's called a
> Faraday cage.
>
> With an aluminum external frame pack, I would expect the only effect of the frame to be
> to act as a Faraday cage and protect your gear in case you're hit by lightning. Maybe
> that would be nice, because it would make it easier for the cops to identify your charred
> remains and notify your relatives. If you're hiking the PCT with your beloved pet ferret,
> stuff the little guy inside your pack when the thunderbolts start falling, and maybe
> he'll survive to inherit your estate.
>
>  Ben
> _______________________________________________
> Pct-L mailing list
> Pct-L at backcountry.net
> To unsubcribe, or change options visit:
> http://mailman.backcountry.net/mailman/listinfo/pct-l
>
> List Archives:
> http://mailman.backcountry.net/pipermail/pct-l/
>



-- 
Sincerely
--------------- --------------------------------------
Hiro    ( Yoshihiro Murakami )
Blogs http://completewalker.blogspot.com/
Photo http://picasaweb.google.co.jp/CompleteWalker/
Backpacking since about 1980 in Japan
2009 JMT, the first America.
2010 JMT, the second America.
------------------------------------------------------