A saver strategy would probably be to use a wind vane, but that would
require a serious change to the steering system, and probably isn't too
desirable on any variant of an Elementarry. I'm not sure how I would
set that up.
A tiller pilot would eat up power, but maybe not an excessive
amount. You'll have a light boat, and assuming that you won't be
asleep during a passage if the wind or seas are high, the autopilot
won't have to do too much correcting. You might be able to get away
with using less than an amp of power, even with a vastly over-spec'ed
Raymarine ST 4000 which will handle boats up to 6,500 Kg. An ST 1000
or 2000 will use even less. I believe all three can be patched into a
wind meter to steer according to the wind. The ST 4000 requires a
separate control head (more reliable), while the other two are
self-contained (more convenient).
The downside of the autopilots with which I'm familiar is that they
only respond to gradual wind shifts over a span of a minute or two.
Only a wind vane or a high-end autopilot would be able to make instant
corrections.
A single 100 watt panel should be able to take care of things if you
steer by hand while awake.
Or, you can use a towed generator you mention. Here are some links:
http://www.onpassage.com/Alternative_Energy/Water_towed_generators.htm
Hamilton Ferris also makes a unit.
Do let us know what you choose. I'm only halfway through a
multi-year catamaran renovation, and won't be able to start a Harry for
at least few years. It's always good to hear what people are doing
with the proas.
- Mike
oceanplodder2003 wrote:
All true,
still want to get out there and try it. harry, like any fast
multi is going to be a problem for any self steering. An electronic
auto pilot might handle the changes in apparent wind but I distrust
them and don't want to have to generate that much electricity. I read
somewhere about a system that used a towed impeller to produce
hydraulic pressure and hydraulic logic, excess power was fed into the
batteries, sounded promising, but it seems to have disappeared.
--- In harryproa@yahoogroups.com.au, Peter Raymond <pramsec@a...>
wrote:
>
> G'day Oceanplodder,
>
> Slocum sailed from Thursday Island to Cocos Islands in seventeen
days and
> according to him was only at the helm for three hours in that
period.
> But remember
> that "Spray" was a long keel boat , heavy, with good directional
> stability. It is also
> probable that Slocum had steady winds from one direction though he
does
> not say
> much about that. The rig he had at that time was that of a yawl.
>
> Straight sailing was something that proa builders seemed keen to
achieve
> so it may
> be possible to achieve though its sensitivity to weight placement
may
> result in a lot
> of restriction of movement on board.
>
> Perhaps some proa owners could try to sail dead straight for at
least
> one hour and
> see how much movement was necessary to achieve that and how much
desired
> movement
> was prevented for the same reason.
>
> Regards,
> Peter Raymond
>
>
>
>
>
>
> oceanplodder2003 wrote:
>
> >-
> >
> >
> >
> >
> >I've also thought about this and I'm convinced it's possible,
probably
> >easy with the schooner, lately I've been considering the una
rig and
> >that should be possible too.
> > The schooner rig- Remember that Slocum got Spray to steer
downwind by
> >over easing both sails, should be relatively easy to do
something
similar.
> > With the una rig my thoughts are to adjust balance by having
the
> >forward rudder used as a daggerboard and by raising or
lowering it
> >balance should always be perfect, then adjusting to self steer
> >hopefully becomes possible.
> >Just read that, wasn't too clear, hope it was understandable.
> >
> >
> >
> >-- In harryproa@yahoogroups.com.au, "doha720"
<doha720@y...> wrote:
> >
> >
> >>G'Day,
> >>
> >>Here's a question that no one would probably tried yet.
> >>
> >>Can you put a sail up so that it is pulling somewhere
forward of the
> >>mast, tie the rudder straight forward, and hace the boat
sail itself
> >>downwind overnight?
> >>
> >>On the Schooner rig this could be the forward mainsail
sheeted out.
> >>
> >>Actually I was only thinking about the schooner rig and
haven't
> >>thought about the single rig they have on the biger boats.
> >>
> >>This is to saingle hand across a stretch of water taking
more than a
> >>day.
> >>
> >>Doug
> >>
> >>
> >>
> >
> >
> >
> >
> >
> >
> >
> >
> >Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
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