Application of synthetic rigging

[Gary]

My BCC Shanti just went through Hurricane Earl. During the storm Shanti was pushed into the mangroves with about 4-50kts of wind. The Dynex Dux chafed against the mangrove trees for about 3 hours. Tore up the mangrove trees but only raised a little bit of fuzz or nothing at all on the rigging.

I have more details and a photo over at http://garyfelton.com/shanti/ if your interested.

But I have extreme faith in the synthetic rigging now as far as chafe goes!

Cheers,
Gary

[davidsamuelson]

Just to add some more spice:
I read on one site ( www.moonblink.info/fibres.html ) that quote "apparently bears can chew through Vectran, but not Spectra" I wonder where they got that info?
David

Just follow the link on that page. It leads to a blog about bear-proof bags for backcountry campers. Apparently the Vectran ones got chewed up pretty easily, but not the Spectra ones.

[Mark Johnson]

One concern that I have not seen addressed... When I built our boat, I was an ABYC member, and I "lightning grounded" the mast and rigging according to ABYC standards. In the 15 years "out there" since, I have known of dozens of boats that were hit by lightning, and several within 100' of our boat. (Talk about a sphincter factor of 10)!

If one uses non conductive rigging, does the risk of side flashes killing the occupants, go up or down? How about melting the top 1' of synthetic rigging? (I have seen melted VHFs, & tricolor lights).

Have enough boats rigged with synthetic rigging, but otherwise having a WELL grounded Aluminum mast, been hit by lightning, to see a pattern of the rig remaining intact?

In my neck of the woods, over the lifetime of the boat, it has about a 40% chance of being hit! I've just never seen it discussed...
Mark

[benz]

Fervently hoping never to get struck, I have no path to ground at all on my mast. Where the HM shrouds loop around the mast, the eyes are leathered. It is my hope that if struck, the leather will keep the heat off the lines, much like a welding glove does, until the aluminum can cool. How many of your oft-struck neighbors had halyards melt in a strike? It would be interesting to know.
Incidentally, is it possible that so many people your way get struck BECAUSE they ground their masts to ABYC standards? Two schools of thought here, but something to chew on.....

[allene]

I looked at the research on lightning for an article I did on grounding and bonding so can toss 2 cents worth in (I am also an electrical engineer if that helps). If lightning wants to hit the ground, it is going to prefer the path that goes through your mast over one that doesn't assuming you are close to the charge. I don't think it is going to matter if it is grounded. Remember that lightning is different than your 12Volt circuits in that it can make air conductive. Assuming it hits the mast, there is the question of how it will get to the water. Absent wire rigging or bonding to a keel bolt, it is likely to find some wires for at least part of the trip. I know it isn't well understood but I would assume it will find a path through the hull at some point near the bottom of the mast. Probably sink the boat. My strategy is different when it comes to lightning as California is #50 in lightning strikes so there really isn't much of a chance of a strike, my mast is shorter than the boats around me, and I stay in the slip if there is a chance of lightning. The one thing I learned from the reading is don't bond your mast to your through hulls unless you want the strike to remove them. There was a strike that instantly sunk a "well bonded" boat which had all its through hulls removed by the strike.

In the process of this research, I did a calculation that showed that a strong hit would melt my rigging. My mast is wood so the rigging is the path. If it melts, so be it. I don't expect to be hit. I am more likely to die in traffic on the freeway.

This page as links to 8 articles on the subject:
http://l-36.com/lightning.php

Allen

[Mark Johnson]

Valid points. If you look for a consensus in say... the last 20 years of studies, from far different sources, there is no statistical evidence that "proper grounding" increases strikes. (I'm talking about unbiased studies by university grants and the like, Not studies by some company selling their giziwonkus.) Now, if it was so close it was going to hit the boat anyway, and you have a grounded lightning rod, it IS more likely to hit the rod than the cabin, and WAY less likely to drive the mast through the hull, or "hole it" looking for ground. This is the whole idea, and there is a LOT of research that backs that up as a way to at least improve your odds. One is only trying to improve their odds...

In my case my run to the ground plate is straight, and only 2' long of "00" wire, so I don't think that side flashes are that likely anyway?

A boat that was next to me, (an F-31 tri), and hit TWICE in one year, was not grounded, but was on a metal lift at the end of a dock. It blew numerous holes in the hull each time, and I was glad to get away from it! I think the lift was a magnet. The boat on the other side was grounded, and had no structural damage, but lost ALL electronics.

The lightning damage that I have inspected aloft, seemed to be intensely hot in only the 1' radius around where it struck, usually the paint just a ways down the mast looked fine. I would think that your leather work would do the trick. The rest of the mast is such a heat sink and all.

I wasn't considering this issue a deal breaker for synthetic rigging, just genuinely curious if any synthetically supported rigs had been hit... Anybody?
Mark

[Mark Johnson]

Allen, great link... it's like the Rosetta Stone! (My previous post was a response to Benz BTW)

I agree with you about not grounding your mast's lightning protection to your through hulls! I launched our tri 15 years ago, and after standing the rig, I had it, and ALL grounds go to the same point, per ABYC at the time. It was eating shaft zincs at an incredible rate, even though it didn't yet even have an electrical system, and was not connected to the dock. HMMMM?

After a lot of head scratching, I consulted Stan Honey about the issue. I later separated my rig & mast lightning ground system, from the bonding wire, that ran to the shaft, strut, prop, and engine. I even isolated the VHF antennae mount, etc, as the mount screw has continuity with the boat's 12v dc ground. So the lightning ground and its more galvanically active copper plate are totally separated, and my zinc consumption returned to normal.

Just for kicks, I even put a battery cable switch on the negative wire to the engine as well, (which already had a three way red)... This way, when the engine is not running, the boat's DC wiring is not in any way connected to the engine, OR therefore, the shaft, prop, etc.

Three totally separated grounding systems... the mast for lightning protection only, the boat's 12v dc system, and the bonding wire to keep underwater metal happy, and protected by the shaft zinc. (The throughhulls are Maralon)

ABYC doesn't always apply. In many cases I just do what works!

Mark