Glad you passed that bit of info along, John, about the core is strength, cover is friction and protection. Tom B On Fri, Oct 28, 2016 at 1:40 AM, John Schinnerer <john@eco-living.net> wrote:
OK, thanks... And that means you have a double braid, not single. And it's a "core dependent" double braid, meaning the strength is all in the core and the cover is just protection and friction.
So - having now done a bit of basic research on 'traditional' vs. 'high-tech modern' line - the original advice on cutting core out of 5/16" for pennant knot should NOT be applied to core-dependent line! Only to polyester double-braid where core and cover share the strength.
cheers, John S.
On 10/27/2016 11:35 PM, Keith R. Martin wrote:
Yeah in thinking about it it may actually be 6mm.. But the outer cover is not dynema (only the inner core is) and has reasonable friction coefficient... Given it's smaller diameter I need quite a few wraps on the winch but it works okay.. It wasn't really a deliberate selection just something I had left over in the shop from rigging on another boat..
Keith R. Martin, P.Eng Serenity, Hull #353
On Oct 27, 2016 11:27 PM, "John Schinnerer" <john@eco-living.net> wrote:
PS on this - APS site info page on lines says, re Vectran &
Dyneema/Spectra single braid:
"When winching or cleating either material, a cover is required to provide grip, bulk and protection." Other line info sources say similar.
The CB involves both a winch and a cleat...sounds like double braid is more appropriate?
cheers, John S.
On 10/27/2016 11:13 PM, John Schinnerer wrote:
Thanks Dave, Tom also, I now recall seeing this somewhere in the MSOG
site or the like, in notes from Jerry.
Is there an "official" recommendation for knot to tie off? Sounds like the figure eight hitch is working for at least one of us. There's lotsa knots in the world...and I see at least one project on MSOG site where a shackle & eye splice was used.
And 5/16 was maybe based on line available in "the early years"? We've got stuff now half that size and twice as strong. Keith, didn't you post a while back you were using 5 mm something for pennant? And David has 6 mm.
How do those single braid (or other braid) small lines do at getting enough friction on the winch when raising the CB?
cheers, John S.
On 10/27/2016 11:45 AM, Dave Scobie wrote:
here is Jerry's recommendation for the cast iron board pennant line -
The line used to raise and lower the CB is 5/16... The trick is to cut away about 4" of the internal core and use that part to tie off at the CenterBoard, making the knot small enough to fit properly in the CB Trunk.
:: Dave Scobie :: former M15 owner #288 - http://www.freewebs.com/m15-name-scred :: M17 #375 SWEET PEA - http://www.m17-375.webs.com :: Sage 17 #1 - AIR BORN - http://sagemarine.us/sage_17.html :: Sage 15 sloop #001 - ASOLARE - http://sagemarine.us/sage_15.html :: SageCat #000 - SAGECAT - http://sagemarine.us/sagecat.html
On Thu, Oct 27, 2016 at 11:52 AM, John Schinnerer <john@eco-living.net
wrote:
PS - this is a pennant for the heavy cast iron keel version M17!
Not the lightweight newer one. In case I wasn't clear...
thanks, John S.
On 10/27/2016 10:49 AM, John Schinnerer wrote:
Thanks all for the feedback on this.
> > I expect I'll find a bulky knot in the fat pennant line when I lower > the > board...I'd be happy to just get it down to half an inch. > As it is, with the trailer I have, the rear roller is behind the > keel/CB > when the boat is fully on the trailer. In shallow launching > situations > where the stern isn't deep enough to float off the bunks, the CB > protrudes enough to catch on the roller and stop the boat sliding > back > off the bunks. > > What is recommended or best options for pennant line replacement? It > has > some kind of one-color double braid on it now, pretty fat, 3/8 I > would > guess without going and measuring it. > > Definitely interested in knots & usage. Not a lot of major > references to > the figure eight hitch, but I found a few. I know the "regular" > figure > eight well from climbing/mountaineering but hadn't heard of the hitch > version. > One video on figure eight hitch says "for light duty" and "not the > most > secure knot" but obviously it's worked for you David. It would be > under > tension all the time if used for the CB so in that case I think it > would > be pretty secure. If alternately slack and tight, I can see how it > could > slowly loosen itself in some situations. > > cheers, > John S. > > >
-- John Schinnerer - M.A., Whole Systems Design
- Eco-Living - Whole Systems Design Services People - Place - Learning - Integration john@eco-living.net - 510.982.1334 http://eco-living.net http://sociocracyconsulting.com
-- John Schinnerer - M.A., Whole Systems Design
- Eco-Living - Whole Systems Design Services People - Place - Learning - Integration john@eco-living.net - 510.982.1334 http://eco-living.net http://sociocracyconsulting.com