[Public-List] Mainsheet diameter

Jonathan Bresler 262alberg30 at gmail.com
Wed Nov 1 07:43:41 PDT 2017


Chris,

Measured the lines on Constance yesterday.  The mainsheet is 7/16", which
works well for me.  Either 7/16" or 1/2" would be fine, it seems.
Hamilton Marine appears to have a nice price on New England Sta-Set 1/2" by
80' for either $72 or $63 depending upon color.  Recently got
a replacement spinnaker halyard, 3/8", from them.  Quite satisfied with
either shipping and the product.
https://shop.hamiltonmarine.com/products/sta-set-rope--flecked-colors-and-solid-colors--47647.html

The bargain bin has 100' of 1/2" Sta-Set-X for only $87
https://shop.hamiltonmarine.com/products/rope-sta-set-x--white-red-fleck-blue-fleck-green-fleck--47649.html

On a related note, the jib sheets are 1/2" feeding into Lewmar 30
self-tailing winches.  1/2" is just too big for those winches.  The line,
which
is not new, is getting chewed up.  Expect to replace it this year with
7/16".  The Lewmar website (https://www.lewmar.com/node/11526?v=24970)
says that the 30ST winches can handle line from 8-12mm or a bit more than
3/8" to a bit less than 1/2".

Jonathan

On Tue, Oct 31, 2017 at 11:06 PM, Chris Martin via Public-List <
public-list at lists.alberg30.org> wrote:

>  Thanks, again. Again!
> Revamping this old girl is part learning experience, part frustration and
> always interesting. Moving from the antiquated winch, 3 points and a cleat
> to a traveller and modern 'mainsheet system' is just another example of my
> overthinking and feet dragging. Garhauer 4:1 it is and I think I'll give
> 1/2" a try. I saw some reference to the 'cheap' garhauer MT-1 track system.
> Yikes, talk about inflation! Nice stuff though, I think I owe the boat some
> shiny new parts.
> The list is long but my motivation is gaining steam, watch out!
> Thanks again
> Chris
>     On Tuesday, October 31, 2017, 1:29:39 PM EDT, Gordon Laco via
> Public-List <public-list at lists.alberg30.org> wrote:
>
>  We’ve got SURPRISE’s mainsheet rigged 3:1, so the load in the hand is
> somewhat higher.  That led me to use 5/8”, not for strength, but for
> comfort.  I fitted blocks large enough to handle this comfortably, so
> there’s no issue with friction when it’s running out.
>
> I used to have 3:1 with the option of pulling down the dead end to make it
> 4:1 as originally rigged, but found years went by without the need for
> this, so 3:1 it is.
>
> I like 3:1 because when rounding the leeward pin there’s so much less
> sheet to haul in when starting back up the course... and of course the lack
> of the extra turn in the tackle relieves friction.
>
> Funny thing about friction and blocks... Harken has us all trained to feel
> we need ball bearings but the fact is that ball bearings are only superior
> in narrow circumstances, and always in low load situations, such as light
> air sheeting and easing. (that goes for things like outhauls etc too).
> Plain bearings (stainless steel on bronze) are best in high loads with
> regard to both strength and low friction when hauling in.  And, (here comes
> the real heretical observation) this is true for winches too...
>
> But I’m sure most won’t believe it...
>
> Gord
>  #426 Surprise
>
> On 2017-10-31, 1:08 PM, "Public-List on behalf of Stephen gwyn via
> Public-List" <public-list-bounces at lists.alberg30.org on behalf of
> public-list at lists.alberg30.org> wrote:
>
>     The mainsheet, with it's 4-to-1 purchase, is never under very heavy
> load.
>     The diameter is more about what's comfortable in the hand. I use 10mm
>     which works out to somewhere between 1/2" and 7/16", but closer to
> 1/2".
>     It's fine. The jib sheets are single lines, and listening to the sound
>     as they are tightened and doing some undergraduate physics, the tension
>     is sometime 700lbs, still much less then the breaking strain of 10mm
>     polyester line.
>
>     SG
>
>
>
>     On 10/31/2017 07:28 AM, public-list-request at lists.alberg30.org wrote:
>     >  Great resource, thanks George.
>     > Is everyone using 7/16" for the mainsheet? I planned on 1/2", bad
> idea?
>     > Thanks
>     > Chris
>
>     --
>     ------------------------------------------------------------
> -------------
>     Stephen Gwyn                        | Tel: 1-250-363-3136
>     Canadian Astronomy Data Centre      | Fax: 1-250-363-0045
>     Herzberg Astronomy and Astrophysics | Cell: 1-250-885-6969
>     5071 West Saanich Road              | E-mail:
> Stephen.Gwyn at nrc-cnrc.gc.ca
>     Victoria, BC, V9E 2E7, Canada      | http://astrowww.phys.uvic.ca/~
> gwyn/
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-- 
Jonathan M Bresler
S/V Constance Alberg 30 #262
Annapolis/Eastport MD


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