Crab Claw Rig

[3189t]

After taking part in the building of two cornish luggers and helping a friend build his replica 1920's Mevagissey tosher http://www.woodenboatbuilding.co.uk, i thought it was time for me to bulid something ethnic as well.
I have two months off over the summer and I am hoping to build a proa or catamaran, either strip planked or plywood.
For ease, cost, and simplicity i have been looking into the crab claw rig and there is alot of infomation out there but i was wondered if any of the members of this site could offer up any knowledge on the subject.

[USCGRET1990]

There is alot of building and design folks here:
http://www.boatdesign.net/forums/sea...archid=1105125

[JohnRPollard]

3189t,

The late Robb White's son, Wes, has built a good-sized proa with a crab claw rig. He has been testing it and writing up some of the results over the past year or two. His reports appear in various issues of Messing About in Boats. Wes sometimes lurks over on the builder's forum at Wooden Boat, so you may be able to contact him directly there. I can't remember what his on-line "handle" is, but his father went by "Old Bingey" so if you search his name you might find a discussion of the proa in which Wes participated. Good luck to you.

[Tartan34C]

What information are you looking for? The AYRS has published some information and C. A. Marchaj did wind tunnel testing and some of the data was published by International Marine in 1996 in the book Sail Performance. Design data is available in some other papers if you need to design a rig.
All the best,
Robert Gainer

[labatt]

There's a person on the trailersailor.com Precision forum who has a home built cat with a crab claw rig. He loves it. You might want to ask around over there.

[JohnRPollard]

I forgot to mention that CLC has plans available ($69) for a plywood proa. It's not a crab claw rig, but I've seen this one in person and it's a fascinating little boat:

http://www.clcboats.com/boats/pacificproa.php

[Jeff_H]

I attended one of Tony Marchaj's lectures that included a discussion on the crab claw rig. In essense it produced a very large amount of drive for its drag and side force. It offered a lot of potential for small light weight, low stability craft. As I recall the short comings is that it did not point very well and so would not be well suited to a higher performance hull form. There are also issues that aspect proportions had to be within a fairly narrow range which made reefing for heavy air, or even dealing with a wide wind range, rather difficult if not inherently impossible.

Jeff

[Giulietta]

I had to google for what it meant in Portuguese. The Claw rig. THANK YOU...

Up until the end of the 1940's there were thousands of boats with crab rigs in the rivers of Portugal.

I love the looks of those rigs and if I am not mistaken, there are a few of them up north in the Aveiro River (where my boat was bilt by the way).
I sailed in one when I was 14, it was soo cool....I remember it so well.

These boats tended to be very very long and narrow beam, and the keel was a drop board that would be on either side. They were true work horses.

This type of rig was widely used by 1700's to 1900's for fishing downwind, and for cargo boats carrying salt and merchandise from boats moored off the Tagus river, in front of Lisbon.

I am searchin to see if I can show you some of these boats we had here with those sails.


Also..look here INTERESTING, but you wont understand a word...but some examples of what I spoke about.


CLICK HERE

AND HERE

[Jeff_H]

Alex,

I think you are thinking of a Lateen Rig. The Crab Claw rig is a very specific Polynesian Rig that looks a bit like a lateen rig, except that it has curved differing length yards at the top and bottom of the sail and a very hollow leech.

Jeff

[Giulietta]

Jeff...I and Robert have been exchanging pm's about that too.

The problem is I can't find the photos, so I used the link above that shows a few of the hulls I saw the Crab Claw rig.

What I told Robert was that the Portuguese brought back form the Polynesia, as well as from China and Indic Ocean, several types of sails, and including the claw rig.

In fact, the Gaff rig name in Portuguese is "carangueja", which means crab....

See here

There is no knowing where one starts and the other finishes...or who was born first..the egg or the chicken...

I saw that sail here, I can see the written reference everywhere, but no photos...sorry

Go to google and type" CARANGUEJA VELA TRANSLATE"