Cruisers Forum

  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 22-01-2021, 09:20   #31
Registered User

Join Date: Dec 2017
Posts: 28
Re: What is this heavy copper cable?

We have a moulded in keel (Nicholson 45) and have been hit by lightning. I did some hard thinking and research about how best to fit lightning protection and I didn't really come up with a permanent solution. Apparently taking the hit down the shrouds is not a good idea; it can cause insidious damage which goes undetected until the mast falls down. Taking the hit down the mast seems preferred but with a moulded keel, grounding is difficult. Drilling a new hole for a big grounding plate didn't really enthuse me.

So I have a big fat copper cable with one end that clamps to the base of the mast and the other end dangles over the side with a large copper dissipater. OK, it's a pain to fit it when there is a risk of lightning but it did work when we were hit. We got a side flash through the deck to some internal wiring (which blew out) because lightning doesn't like making sharp bends. But basically it worked OK.

If anyone has better ideas on lightning protection for moulded keels, I'm all ears.
IanTrail is offline   Reply With Quote
Old 22-01-2021, 09:47   #32
Marine Service Provider

Join Date: Feb 2012
Location: Kauai Hawaii
Boat: home built 31' Hartley Tasman
Posts: 168
Re: What is this heavy copper cable?

Definitely looks like grounding on the chainplates/stays, and I bet it is attached to your keel as well....leave them on if you get the boat
sailorladd is offline   Reply With Quote
Old 22-01-2021, 21:24   #33
Certifiable Refitter/Senior Wannbe
Wotname's Avatar

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: C.L.O.D.
Posts: 12,149
Re: What is this heavy copper cable?

Originally Posted by boatpoker View Post
No, it does not attract lightning. I've done a number of lightning strike investigations and yes they are pretty much useless as 3,000,000volts at 30,000amps and moving at 270,000mph will vaporize that conductor in an instant.
This is 90 gigawatts so certainly some lightning strikes could be of this magnitude but my understanding is the average strike is more like 10 gigawatts and by definition, half of them will be less than 10 gigawatts.

I would rather have something that mitigates some strikes rather than nothing.
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is online now   Reply With Quote

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
More than one Cable in a Cable Clam? sully75 Electrical: Batteries, Generators & Solar 18 22-02-2020 06:54
How heavy is too heavy? Arrandir Anchoring & Mooring 45 09-03-2017 04:35
1 Guage Starter Cable v. AWG 6 Boat Cable Gone2long Electrical: Batteries, Generators & Solar 0 10-01-2017 06:35
For Sale: 50' Telephone/Cable TV Combo Cable off-the-grid Classifieds Archive 5 27-10-2009 12:00

Advertise Here

All times are GMT -7. The time now is 19:29.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.