Please note that I am talking about lightning on the hard. I have a keel stepped mast which is grounded via a big hunky wire to a keel bolt. When the boat is in the water, it is effectively grounded to the ocean, and that's what I want. Out of the water with the keel on wooden blocks, it is not grounded.
I am just pointing out that most people don't realize that a boat grounded for lightning in the water is not similarly grounded on the hard. I am also noting that in a boat yard with many other sailboats, it may not be necessary to make the ground especially if other boats are grounded. That is to say, many "cones of protection" provide a canopy. But that said, if my boat is on the hard and it is the only or one of a few in the yard, it'll likely be grounded via grounding rod. I am not an expert like an electrical engineer, just a nuclear physicist. - Paul E. s/v Johanna Rose Carrabelle, FL On Aug 29, 2012, at 5:25 PM, [email protected] wrote: > Date: Wed, 29 Aug 2012 20:40:15 +0000 > From: Martin DeYoung <[email protected]> > To: "[email protected]" <[email protected]> > Subject: Re: Stus-List Isaac: Lightning on the hard > Message-ID: <[email protected]> > Content-Type: text/plain; charset="us-ascii" > >>> ...but grounding it also makes it attract lightning. As there are now >>> many grounded boats, It's now likely that the safe boats are the ones not >>> grounded. << > > This statement differs from my understanding, granted I am no expert but I > have read much on the topic and have sailed (mid-Pacific, Lake Ontario, and > Puget Sound) with lightning striking the water within sight. > > The theory I put the most stock in refers to the difference in potential > between the boat and the static charge (lightning's energy). > > For example; if the ocean around your boat all has a plus 2 charge (++) and > your mast has a plus 4 charge (++++) then the mast looks better than the near > by water. When underway and faced with a lightning storm I would drag jumper > cables, chain, large gauge wire etc over the side with the other end attached > to Calypso's rod rigging. > > My expectation is connecting or bonding the sea to the mast would equalize > the potential between them reducing the attractiveness of the mast to the > lighting energy. > > I am most interested in any experiences that support or refute this strategy > in advance of my next lighting storm sail. > > Martin > Calypso > 1971 C&C 43 > Seattle
_______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com [email protected]
