Hi!

Transform the mast to a wing mast with a wishbone boom. Then attach two forestays and play with headsails. Some work, but you already have a good solid mast to go on.

Regards,

Arttu

Nol Twigt [noltwigt@yahoo.com] kirjoitti:
>
> Let's start with advantages:
>
> There is not much power on the sheet. That makes the rig very simple and
> very easy to handle.
>
> It is a self tacking system. Not much work when tacking. Shunting
> requires more power, however it is also kind of easy.
>
>
>
>
> I have whole list of disadvantages from all sort of angles.
>
> The main thing is simply a matter of control. We have lots of shallow
> waters int the Netherlands. If you want to sail on the Waddenzee for
> example, you need to be able to sail with the rudders (almost) pulled
> up. This is impossible with an easy rig that is positioned in the middle
> of the leeward hull. End of story.
>
>
>
>
> Now let's look at the aero rig from other angles.
>
> Let me start with a matter of taste, so my cards are open on the table.
>
>
>
>
> Subjective arguments:
>
> - I do not like the way an easy rig looks. It does not look
> 'aerodynamically right'. Usually if things do not look fast they are not
> fast.
>
> - It looks kind of unnatural because it seems to be lifted from the
> ship. It is not one with the ship.
>
> - The look and feel is kind of lazy. Not interested, taking things too
> easy. Statical, almost dead.
>
>
>
>
> Mechanical arguments:
>
> - The strongest forces are the vertical forces on the forestay and the
> leech of the mainsail. These enormous forces are countered by a boom
> that must be very strong and will be very heavy. This is not an elegant
> solution. It is brute force.
>
>
>
>
> Sailors arguments
>
> - On the Blind Date the boom connected to the mast with a hinge. The
> result is that you can not trim the mainsail and the jib independently.
> You want much tension on the luff of the jib and little tension on the
> leech of the main. The topping lift could solve that problem, but that
> does not work on both bows. Two topping lifts would be better, but that
> would mean an extra line to take care of after every shunt. It would
> make it an a little less easy rig.
>
> - You can not sheet the mainsail and the jib independently. You can not
> steer the ship with the sails. You can not play with the waves and the
> sails.
>
> - There are situations where you want to let go the mainsail without
> changing the jib. For instance when you are overpowered in a gust. In
> strong winds the mast has so much friction that it does not turn when
> the sheet is released. Not safe.
>
>
>
>
> Applied on a proa (controlling and steering the ship with the sails)
>
> The COE (Center of Effort) is behind the mast. This is necessary to get
> some power on the sheet and to make the rig turn when the sheet is
> released. The result is momentum 1 that makes the ship want to turn its
> nose into the wind.
>
> The mast is placed on the leeward hull. The COE is on the leeward side
> of the ship. The result is momentum 2 that makes the ship want to turn
> its nose into the wind.
>
> Momentum 1 + momentum 2 make the ship by definition out of balance.
>
> The balance can only be restored by using big strong rudders. The back
> rudder is used as a daggerboard.
>
> This is again countering enormous forces with other brute forces: not
> elegant.
>
> In shallow waters, when you need to pull the rudders up, the ship will
> be out of control. Momentum 1 + 2 are not countered anymore. The ship
> will turn it's nose into the wind.
>
>
>
>
> Applied on the Visionarry proa's
>
> Visionarry looks modern, light, fast, like a flying saucer or a fighter
> plane, hi-tech.
>
> The aero rig looks old fashioned, slow, low-tech.
>
> On a light ship that is built for speed, control is a crucial factor.
> The aero rig is static and does not contribute to the control of the
> ship. It needs extra control for it self.
>
>