Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 25-11-2020, 00:55   #121
Registered User
 
hzcruiser's Avatar

Join Date: Aug 2008
Location: Sydney, Australia
Boat: Roberts 45
Posts: 1,033
Re: Lightning Protection for Electronics

Quote:
Originally Posted by Sailing Ohm View Post
[...]
Now those fuzzy little lightning diffusers I would call snake oil...
[...]

I wouldn't dismiss them, as they allow smaller static charges to dissipate into the water. Only one doesn't see them as lightning and hence thinks they're doing no good... it might be a matter of measuring such pulses through a coupled line in order to tell what's happening.


This could be an idea for a relatively simple device, extending a lightning warning sensor to also show how often owns own lightning arrestor got energised.
I deliberately avoid writing "hit", as a direct hit is likely to cause lots of damage, but even a close-by hit induces enough energy into stays and masts to wreak havoc. And for those latter ones the grounding system works well, it seems.


My own steel sloop got hit at least once into the insulated backstay. The MOB marker post was tied to it and has an aluminium core. From the marks on the post and black spot on the deck I could tell the strike jumped the gap from the backstay to the pole and into the deck.
I've since replaced the HF radio and tuner.
__________________
Fair winds,
heinz

https://www.timantra.net
hzcruiser is offline   Reply With Quote
Old 25-11-2020, 04:33   #122
Senior Cruiser
 
GordMay's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 49,085
Images: 241
Re: Lightning Protection for Electronics

Quote:
Originally Posted by hzcruiser View Post
I wouldn't dismiss them, ...
However, most everybody, that's studied the the subject, dismisses them (lightning diffusers), as I've often previously illustrated/substantiated.
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is online now   Reply With Quote
Old 25-11-2020, 06:11   #123
Registered User

Join Date: Jan 2014
Location: Panama City FL
Boat: Island Packet 32 Keel/CB
Posts: 995
Re: Lightning Protection for Electronics

In my Freshman physics class we had a Van De Graaff generator and the pointed vs rounded rod works and works 100% of the time. You could hear the charge dissipate using the pointed end and could not move that rod fast enough to get a strike. Flip it around and the rounded end would produce a WRAP every time. We must have run that test a couple of hundred times by anybody with bal## enough to pick up the rod (heavy rubber gloves just in case).

In the real world I think most knowledgeable think just too much charge building up too fast to make much difference. Kind of like pis#### in the Ocean and hoping to see the water level rise.

Some recent schools of thought is that rounded air terminals (lightning rods) will do a better job of attracting the strike to the LPS vice say the corner of the building but most of the systems are still using the old style. Old habits/ myths die hard in this business.

If you travel the highways of Florida you can sometimes see a tall pole mounted array beside the roads, looks like a large shiny umbrella. Love to have been in on the sales pitch on that deal.


Frankly
Frankly is offline   Reply With Quote
Old 25-11-2020, 14:34   #124
Registered User

Join Date: Jan 2014
Location: Coffs Harbour, NSW
Boat: FreeFlow 50 cat
Posts: 1,336
Re: Lightning Protection for Electronics

In case anyone hasn't seen the ultra slow motion of lightning strikes from the SloMo guys, here is their vid of it from Singapore, showing lightning striking all around ships at anchor in the harbour.

The good bit starts at 5:00 min point if you want to skip the talking part.

Frighteningly beautiful....

BigBeakie is offline   Reply With Quote
Old 26-11-2020, 01:08   #125
Sos
Registered User

Join Date: Sep 2011
Location: UK
Boat: Woods Flica catamaran
Posts: 499
Re: Lightning Protection for Electronics

Frighteningly beautiful....

Perfect description
Sos is offline   Reply With Quote
Old 02-12-2020, 10:44   #126
Registered User
 
hzcruiser's Avatar

Join Date: Aug 2008
Location: Sydney, Australia
Boat: Roberts 45
Posts: 1,033
Re: Lightning Protection for Electronics

Quote:
Originally Posted by CF32907 View Post
Hi All, CaptVR here.
I was a marine surveyor for 25+ years, done lighting damage for all major underwriters. Been to a dozen seminars on lighting and lightning protection.

Thanks for the insight! Is it possible though that you only get called to those cases where a direct hit caused major damage whereas many other boats might be protected from harm due to close-by strikes using simple measures as discussed ?
__________________
Fair winds,
heinz

https://www.timantra.net
hzcruiser is offline   Reply With Quote
Reply

Tags
electronics, lightning, rot

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Lightning protection for a catamaran Crak Multihull Sailboats 51 23-07-2021 01:17
Built-in Lightning Protection for Electronics stillbuilding Marine Electronics 8 23-02-2010 00:42
Lightning Protection JusDreaming Health, Safety & Related Gear 57 03-10-2007 10:25
NFPA 780 Lightning Protection Systems GordMay The Library 0 16-01-2006 03:53
Lightning Protection Stede Electrical: Batteries, Generators & Solar 5 20-11-2003 17:27

Advertise Here


All times are GMT -7. The time now is 04:38.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.