Lightning Safety

[Ams11]

Any opinion or data to back this up? A large industrial facility has the current safety practice for workers during lightning on a large steel structural operating unit. The structure is 13 stories tall. The current practice is to have workers go to the 10th floor or below and continue work. The thought process is that the unit is well grounded, and the workers will be protected at that level or below if lighting would strike.

 

[weressl]

Any opinion or data to back this up? A large industrial facility has the current safety practice for workers during lightning on a large steel structural operating unit. The structure is 13 stories tall. The current practice is to have workers go to the 10th floor or below and continue work. The thought process is that the unit is well grounded, and the workers will be protected at that level or below if lighting would strike.

Have you ever heard of the Empire State Building being evacuated during lightning storm? (That the structure in question is 'open' compared to the ESB has very little effect, if any.)

 

[bphgravity]

Does the structure have a conventional lightning protection system installed in compliance with NFPA 780?

Be aware that while tall structures are often the most frequently stuck objects and that the top and protruding corners of the highest portion of the structure are the usual attahment points, many tall buildings and structures are struck along the sides at points along the lower portions of the building.

I will try to find and post the study I read that investigated this topic.

 

[iaov]

I'm not sure if this is off topic or not but I have a question about lightning that has bothered me for years. When I was in the Navy and my ship was at sea, often we would be in the middle of fierce thunderstorms. Lightning all around us but it never struck the ship. Definatley the tallest object for miles, all metal construction, and sitting in a salt water bath yet we never were struck. Does a ship like thiis discharge the air around it?? Anyone have any ideas about this?

 

[bphgravity]

Luck, good fortune, coincidence, who knows...

How are you certain the ship was never struck?

 

[iaov]

We stood out on the weather decks and watched for hours. Never heard of any lightning damage. My Chief who had been in for over twenty years said ships never got hit.:-?

 

[iaov]

Lightning realy falls into the catagory of PFM for me. I do not understand it. I fear it. I've asked questions about it before on this forum and apparently I am not the only one who doesn't know much about this phenomena.

 

[bphgravity]

I really can't say. I am sure military boats and ships have been struck, as well with every other type of water vessel.

Here is a pretty decent article on the subject:

http://www.cdc.gov/nasd/docs/d000001-d000100/d000007/d000007.html