On Wed, 13 Aug 2008 13:50:51 -0700, in message
tions
"Capt. JG" wrote:

"Ryk" wrote in message

I cleat the furling line, then tension the sheets around the winch by
hand. Using a winch handle could overstress things, but hand tight on
a winch is the same as hand tight to a cleat. I don't think I have any
line on board that I could overload by hand.


I don't like putting stress on a winch if I don't need to. Perhaps that's
just me.

I think I could probably overstress the jib sheets around the winch if I put
my back into it, but that would be foolish. There is a difference in the
size of the line, and it seems to me that just by weight there would be more
pressure from the jib sheet side.

If you are pulling on a line fed around a winch the tension will be
the same on both sides (neglecting friction). The mechanical advantage
comes only from the handle and gearing combined with the friction on
the drum.

Ryk

"Ryk" wrote in message
...
On Wed, 13 Aug 2008 13:50:51 -0700, in message
tions
"Capt. JG" wrote:

"Ryk" wrote in message

I cleat the furling line, then tension the sheets around the winch by
hand. Using a winch handle could overstress things, but hand tight on
a winch is the same as hand tight to a cleat. I don't think I have any
line on board that I could overload by hand.


I don't like putting stress on a winch if I don't need to. Perhaps that's
just me.

I think I could probably overstress the jib sheets around the winch if I
put
my back into it, but that would be foolish. There is a difference in the
size of the line, and it seems to me that just by weight there would be
more
pressure from the jib sheet side.

If you are pulling on a line fed around a winch the tension will be
the same on both sides (neglecting friction). The mechanical advantage
comes only from the handle and gearing combined with the friction on
the drum.

Ryk


Which line do you think you could put more tension on before the line
breaks? The furling line or the jib sheet? Seems to me that most people
would have plenty of experience putting jib sheets under a lot of tension,
yet would not put a lot of tension on a furling line. It's a lot easier to
put more tension on a jib sheet, which could lead to furling line failure.


--
"j" ganz @@
www.sailnow.com

On Fri, 15 Aug 2008 11:45:07 -0700, in message
ons
"Capt. JG" wrote:

Which line do you think you could put more tension on before the line
breaks? The furling line or the jib sheet? Seems to me that most people
would have plenty of experience putting jib sheets under a lot of tension,
yet would not put a lot of tension on a furling line. It's a lot easier to
put more tension on a jib sheet, which could lead to furling line failure.

For an example, a 5/16" StaysetX furling line has a tensile strength
of 3000 lbs, while a 1/2" StaysetX jib sheet has a tensile strength of
8500 lbs. Allowing for the mechanical advantage produced by the
furling system[1] it would be hard to say which would fail first. My
suspicion is that you would do major damage to your sail before either
line would fail.

I agree that loading up the sheets of a furled jib using the
mechanical advantage available with a handle in the winch would be a
bad idea.

Ryk


[1] In a typical drum system the torque loads will balance between the
sail load and the furling line. When the sail is fully out there is no
torque, thus no furling line load. When partially or fully furled the
sail load will produce a torque of approximately the wrap radius times
the sheet tension, while the furling line will produce a torque of the
furling line tension times the drum radius (plus any remaining wraps
of line). The result is that the maximum tension in the furling line
is probably 1/4 to 1/2 the tension in the jib sheet and considerably
less when the sail is only partially furled.

On Fri, 15 Aug 2008 17:12:51 -0400, Ryk
wrote:

I agree that loading up the sheets of a furled jib using the
mechanical advantage available with a handle in the winch would be a
bad idea.

Isn't that exactly what happens during normal sailing?.. (reefed)

"Ryk" wrote in message
...
On Fri, 15 Aug 2008 11:45:07 -0700, in message
ons
"Capt. JG" wrote:

Which line do you think you could put more tension on before the line
breaks? The furling line or the jib sheet? Seems to me that most people
would have plenty of experience putting jib sheets under a lot of tension,
yet would not put a lot of tension on a furling line. It's a lot easier to
put more tension on a jib sheet, which could lead to furling line failure.

For an example, a 5/16" StaysetX furling line has a tensile strength
of 3000 lbs, while a 1/2" StaysetX jib sheet has a tensile strength of
8500 lbs. Allowing for the mechanical advantage produced by the
furling system[1] it would be hard to say which would fail first. My
suspicion is that you would do major damage to your sail before either
line would fail.

I agree that loading up the sheets of a furled jib using the
mechanical advantage available with a handle in the winch would be a
bad idea.

Ryk


[1] In a typical drum system the torque loads will balance between the
sail load and the furling line. When the sail is fully out there is no
torque, thus no furling line load. When partially or fully furled the
sail load will produce a torque of approximately the wrap radius times
the sheet tension, while the furling line will produce a torque of the
furling line tension times the drum radius (plus any remaining wraps
of line). The result is that the maximum tension in the furling line
is probably 1/4 to 1/2 the tension in the jib sheet and considerably
less when the sail is only partially furled.



I suspect you'd do major damage to the furling mechanism before either
broke.


--
"j" ganz @@
www.sailnow.com

On Thu, 14 Aug 2008 22:33:26 -0400, Wayne.B
wrote:

On Thu, 14 Aug 2008 19:16:22 -0700 (PDT), "
wrote:

On Aug 14, 7:20*pm, "Bill Kearney" wrote:
It's really important to take them down
before a major wind event.

Yep, tried to warn a fellow slipholder of this. *Then Ernesto came through
and ripped it to shreds. *A couple of us were around tending to lines. *It
only took about a minute to wreck it.

The best thing to do if a major storm is coming is to remove all sails
from the rig. A poor second best for a roller furling headsail would
be to wrap the spinnaker halyard around the sail, which should prevent
if from unfurling.

The force of a full gale or hurricane has to be experienced. The wind
will get under any loose corner and rip it to shreds. Once it starts
the whole thing goes, wrapped or not.

Even if tearing the sail is removed as an issue, the extra windage the
rolled up "sausage" adds is still a big problem.

I usually remove the boom as well, due to windage,l for hurricane
warnings. It makes a difference.

wrote in message
...
Even if tearing the sail is removed as an issue, the extra windage the
rolled up "sausage" adds is still a big problem.

I usually remove the boom as well, due to windage,l for hurricane
warnings. It makes a difference.


http://www.nhc.noaa.gov/refresh/grap...large#contents

On Aug 12, 12:01 pm, "Roger Long" wrote:
"Edgar" wrote

Why do you think you need to do more?

Because I've seen the mess when a sail has come unrolled at the dock and
also on a mooring. I depend on the wraps normally but put a sail tie on for
heavy weather or when leaving the boat for a long period. ...

A sister "ship" (boat) of ours was lost when the upper section of jib
unfurled and caused them to drag anchor. I take the jib off when I'm
not going to go sailing for a couple of days. It lasts a lot longer
and would have to crawl back on deck and get itself out of its bag to
do any harm. I don't understand why folks leave the jibs bent on when
they are away from the boat or expecting heavy weather.

-- Tom.

wrote in message
...
On Aug 12, 12:01 pm, "Roger Long" wrote:
"Edgar" wrote

Why do you think you need to do more?

Because I've seen the mess when a sail has come unrolled at the dock and
also on a mooring. I depend on the wraps normally but put a sail tie on
for
heavy weather or when leaving the boat for a long period. ...

A sister "ship" (boat) of ours was lost when the upper section of jib
unfurled and caused them to drag anchor. I take the jib off when I'm
not going to go sailing for a couple of days. It lasts a lot longer
and would have to crawl back on deck and get itself out of its bag to
do any harm. I don't understand why folks leave the jibs bent on when
they are away from the boat or expecting heavy weather.

-- Tom.

I am amazed that even here in a Norwegian winter some owners just have their
boats hauled and simply leave the jib rolled up all winter just as they left
it last time they sailed.

On Aug 20, 2:42 pm, "Edgar" wrote:
wrote in message
....
I am amazed that even here in a Norwegian winter some owners just have their
boats hauled and simply leave the jib rolled up all winter just as they left
it last time they sailed.

I know folks who spend a week a year just working on their boats
varnish but can't find ten minutes to stow the jib properly. Clearly,
I'm missing something 'cause leaving the jib bent on indefinitely just
doesn't make any sense to me.

-- Tom.