DynaRig MotorSailer, ala Maltese Falcon

[brian eiland]

Originally Posted by FAST FRED

Rope doesn't resist torque well , the sails might reef as poorly as the old setups with sewn in wire .

A simple solution (from the 1800's) is to use a chain under tension when rolling up.

The chain resists torque well with minimum tension , although sail attachment may need hand sewing.The chain sails can be bagged , SS wired cant.

FF

I understand where you are coming from, but remember I am not asking these sails to 'reef' (partially furl). They are either fully deployed or fully rolled up. The relatively short lengths of these individual 'mid girth wires' is much shorter than std forestays. Some of the synthectic riggings are much better in torque than 'rope'.

[brian eiland]

Originally Posted by brian eiland

I understand where you are coming from, but remember I am not asking these sails to 'reef' (partially furl). They are either fully deployed or fully rolled up. The relatively short lengths of these individual 'mid girth wires' is much shorter than std forestays. Some of the synthectic riggings are much better in torque than 'rope'.

Actually I'm coming back to the idea of just using 'solid rod' for these 'mid girth wires'....can be relatively small dia, so not that much more weight, handles the variation of load/no-load better than synthetics, and is cheaper and longer lasting than syns

[brian eiland]

I received a rather nice press release in an up-scale yachting publication just recently

Dyna Cat

[yipster]

compliments, thats a very very good article
did you see the rough ladybird pdf i made?
okay inspired but many paralel thoughts

[mydauphin]

Yipster, Great Ladybug PDF. Hope you build it one day. I like concept - I wonder how concept could be adapted to a large monohull ... How much sail is needed to move a 70 footer that weights 70,000 at 7-9 knots.

[yipster]

thanks mydauphin, ehr.. think others here can answer that question better and faster but did order marchaj's books.
forexample procyon has a strikable bipod. like making some schetches to see what aspects of concept to alter and have some L/B and deck dimensions.

[charmc]

Congratulations, Brian, that's a nice writeup. Hopefully good for business!

[charmc]

Beautiful design, Yipster. Hope you get the funds to build it!

[Guillermo]

Originally Posted by brian eiland

I received a rather nice press release in an up-scale yachting publication just recently
Dyna Cat

Congs, Brian. As I told you, I like your DynaRig Cat concept. Good luck!

[SeaSpark]

In one of the Yachting World articles about Maltese Falcon was a detailed explanation by Gerard Dijkstra about why the Dynarig is not suited for a sloop configuration. As far as i can remember the main reason was the the inability to trim lateral sail balance.

[yipster]

eh, ah, that my ladybird can, reefing in stages tho
this beeing the intruded thread this idea got up why not a short animation

[Pericles]

SeaSpark,

Have searched Yachting World for article about Maltese Falcon, but cannot find it. Could you post more information please?

Pericles

[Pericles]

An interesting comparison between specially rigged proa and catamaran models.

http://www.youtube.com/watch?v=s-AzmNEj0EE

Pericles

[Landlubber]

Pericles,
try these mate, she is one hell of a yacht.
http://www.ybw.com/auto/newsdesk/200...951ywnews.html
http://www.yachtingworld.com/yw/supersail/falcon.html
http://www.ybw.com/yw/blog/200609081...vid_glenn.html
http://www.yachtforums.com/forums/pe...ing-yacht.html

[Pericles]

LandLubber,

She's a real beaut!

More years ago than I care to remember, I learned about a square rigged topsail gaffer schooner that used a pulley system to deploy the rectangular sail, outwards from the foremast, on rings sliding along the upper and lower spars. I've been thinking it was Joshua Slocum's design, but I can't be sure.

The sail could be set or reefed in seconds, like pulling curtains. With a bit of tweaking it would not be too difficult to emulate the Dyna Rig by laminating the spars from marine ply and epoxy, to create a 12 degree arc and then rigging the sails, top and bottom in sail tracks. A bit of muscle power on inhaul and outhaul sheets, passing down to the deck from the outer ends of all the spars and which are then cleated off, would position the rotating mast for upwind work. A car disc brake at the base of the mast would lock things quite securely. This square rig system is only suited for broad beam fast catamarans, as Brian Eiland has so effectively demonstrated, because although the mast rotates, it is still supported by very widely positioned stays.

OK, so there are a few more ropes, but we are sailors after all. It's what we do, haul 'em up, reef 'em in. Also, I must have a mainbrace to splice and a yard arm for hanging pirates.

Avast behind, me hearties!

Pericles