Re: [harryproa] Re: Rare Bird Sailing

I would think it would only be a problem if the natural frequency of the mast and the waves is the same, This is very unlikely as the mast would have a high frequency and the waves would be much lower. I would think it more likely that there would be wind induced oscillations in the mast, but even this seems unlikely. The biggest real problem is likely to be if there is play in the mast bearings of a rotating unstayed mast, allowing it to rattle, but this could be dealt with by clamps or wedges to be used in such conditions.

Cheers,

Peter

----- Original Message -----

From: Todd

To: harryproa@yahoogroups.com.au

Sent: Friday, August 10, 2007 8:07 PM

Subject: [harryproa] Re: Rare Bird Sailing

Hi Peter,
Yeah the whip effect of mast in high wind and wave. Could it be
self perpetuated to self destruction?

--- In harryproa@yahoogroups.com.au, "Peter Southwood"
<peter.southwood@...> wrote:
>
> Hi Todd,
> Is there any reason why it should be worse than a stayed mast in
these circumstances?
> I think the worst would be a stayed mast with some slack in the
rigging which would rally bang around producing shock loads. An
ubstayed mast should have less windage, lower centre of gravity and
a bit of flexibility to reduce the jerk loads. There might be a
slight whiplash, but I dont think it will be too bad unless the
bearings are loose.
> Has anyone done a load analysis of the alternatives?
> Cheers,
> Peter
> ----- Original Message -----
> From: Todd
> To: harryproa@yahoogroups.com.au
> Sent: Friday, August 10, 2007 7:36 PM
> Subject: [harryproa] Re: Rare Bird Sailing
>
>
> I like the idea of the unstayed mast. I just think of it a giant
> windsurf mast. Mast could be made for specific design
> characteristics. You could have whole line, race ,cruise, and
> weekend worrior ;) Either way the bend of mast and twist of sail
> would seem forgiving and more efficient on a "vertical" rig.
>
> I only wonder what it will do under bare pole gale force wind in
> 8metre seas? Thats a general question what would any boat mast
that
> I might buy do under such circumstance.
>
> Todd
>
> --- In harryproa@yahoogroups.com.au, "proajunk" <laburnumho@>
> wrote:
> >
> > Mast Bend
> > A stay from mast head / top of jib to the windward hull may
help,
> > without unduly compromising the weather-cocking abilty of the
rig.
> >
> > The mast would still be designed for full load without, the
stay
> (s)
> > would just to reduce the bounce.
> >
> > What do you think?
> >
> > Mark
> >
> > (I have a Hirondelle cat, boy do I hate those nasty stays, not
> > allowing me to spill wind. It like driving with an acelerator
> stuck on
> > 3/4 throttle, don't thik car drivers would accept that one,
why do
> > sailors!)
> >
>
>
>
>
>
>
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