Ian,
<<lug rigs were used for thousands of years we know they
work,they became unpopular because you had to change them round not
so on a Proa>>
I can see how a dipping lug could be very efficient -- smooth
airflow, nice amount of sail area up high in the wind, no boom or
mast to spoil shape or create turbulence, and so forth. I'm a fan
of loose-footed or semi-loose footed gaff rigs, such as the Wharram
wing sail (
http://www.wharram.com/site/sites/default/files/imagecache/product_full/wingsailconversion_1.jpg
) and the Norseboat gaff rig (
http://www.norseboat.com/NorseBoats_files/norse4.jpg ) for many of
the same reasons.
However, I don't see how the proa would eliminate the need to
change sides on a dippiing lug, and I don't see how a lug with a
boom would be efficient in both directions.
Could you explain?
<<therefor D shaped easy to handle and lots of power>>
Agreed. Another thing I like about the gaff rigs -- if the sail
is cut properly, you can get great shape in very light airs without
having to manhandle a batten switch from one side to another. I
loved that about my Norseboat until I sold it (I live on a
north/south inlet, and the mast just wasn't tall enough to sail in
light east/west winds).
<<ratio of 3 to 1>>
While that short/wide ratio worked well for crewed ships, it might
be a challenge when singlehanding a fast multihull. Switching a
sail like that, as with the very efficient crab's claw (at least on
a reach), could be difficult to do by one's self once the wind picks
up. You'd either need to: a) dip the sail to switch sides, or b)
temporarily put the full sail area perpendicular to the wind as the
sail switches sides during a shunt.
<<The sails should be>>
Geat link! I've seen pha, and we've discussed it on this forum
before, but I wasn't aware of this document. Thanks.
I'm even more a fan of the swing-wing junk rig than the gaff rigs,
though I'm still on the fence about it with a proa. I see how it
would work very nicely with a single mast, but if I go with a
schooner rig in order to get more sail area while fitting under
bridges, the swing-wing might get more complex. It would likely
require either rotating masts, or at least rotating booms, in order
to allow two sails in line to work in tandem.
That said, I'm confused as to how the lugger would deliver the
shape of a swing-wing in both directions without the problems
mentioned above for the 3:1 ratio low rig.
So, while I don't yet get the lug rig, I guess you could say that
I'm again sold on the swing-wing concept. I'm happy to learn more,
though. I was highly skeptical of the swing-wing at first, but then
discussion, particularly Rudolph's input, convinced me I'd been too
hasty in my judgment.
- Mike
iwood1964 wrote:
hi there,
thought I better introduce myself i'm a land-locked kite-boarder with time on my hands,if funds ever allow I will build a boat. As a kite flyer thought i'd let you in on a secret. The Vikings had better sails and sailed Proa's. The sails on harry are Marconi,right aspect wrong kite. The sails on Elementary are the right kite wrong aspect.When kite flying you get power from figure 8'ing you can't do that with the kite fixed to the deck.The time you get the most lift is at the launch.People assume higher the sail more the power,if that's so explain the spiniker it's no higher than any other sail yet provides more drive.It's the width not the length that matters,ask ya missus lol.But being female she'll want both.The Marconi rig should be built like http://www.iannewham.com/kitedesign/design.html
The sails should be http://api.ning.com/files/wuqd6jnZ447B6z-TL*zvQ-ZUY39yLmFDKR-Sfqk7aYoBauXbWMn2PzIUAkAb8irOv95w6OnGztYMbO7ylkHyUpNcISKXAEFo/ABOUTSAILS.pdf therefor D shaped easy to handle and lots of power http://en.wikipedia.org/wiki/Lugger
lug rigs were used for thousands of years we know they work,they became unpopular because you had to change them round,not so on a Proa.Size of the sail needn't be as big an area as you have I'd say for elementary try a 6x2 meter sail that's width x height so the guy with the broken masts juts needs to use the spare as a yard to try it out.How'd I come up with the ratio of 3 to 1 see;http://www.vikingage.com/vac/ship_theory.html