Crab Claw Test

[Kevin Hutchinson]

Hello Wharram fans! I had a crab claw sail in the past  and  I was disapointed in its performance.The rig is so sexy I thought it needed another chance. So I decided to test it against a lug sail with the same sail area. My test boat was my 14' sailing Kayak(not the most efficient). Last weakend I spent three hours sailing  around a course alternating the rigs. My test results show the crab claw tacked through 130 degrees to windward. The Lug was not much better at 110 dergees. Now a good modern cruising rig should tack through 80-90 degrees. I am not a pro sailmaker and I am shure performance could be improved .So my lesson to my fellow Wharram fans is please run your own test on the crab claw before you fall in love with it and put it on a large boat....Aloha

[kim whitmyre]

Kevin, I have never sailed a crab-claw rig, but I did enjoy the launching of Glenn Tieman's tama moana, Manurere. We had the pleasure of the wisdom of a Hawaiian sailor by the name of Keiko, who had much experience in sailing double canoes. Do not sell them short!  The tama moana has a foremast and a mizzen mast, so has the virtues of a ketch rig: Glenn says now that he will never be without such a rig!

 

A steeper learning curve for the average sailor, to be sure.

[Kevin Hutchinson]

I sailed  an outrigger  with a crab claw for over a year. I can see no advantage in the rig eccept it looks cool and has a short mast. The rig  is unwieldy in strong wind , terrible to windward and can't be efficiently reefed. I have never experienced the so called vortex effect they  claim it generates. Vikings used to sail around the Northern Atlantic with square sails should we go back to using them? We should stop pretending that we are ancient Polynesians.

[kim whitmyre]

Since you have it all nailed down, I'll fade out.

[kim whitmyre]

Hans,

That's about the last time I had email from Glenn. Hopefully he'll update us soon!

 

Kim

[kim whitmyre]

Hi Sailors,

Here's a post from Glenn Tieman early on in his latest voyage, specifically about sails.

 

"The bermudan was the worst on several counts, hardest to handle, most expensive, worst performance on every point. Its harder for me to compare the crab claw with the kind if objectivity I'd like, because I didn´t switch it with another rig on the same boat as with the tiki rig. The claw is easily the least expensive and most fault tolerant, that is, easy to repair on the road. Off the wind it is definately the most powerful for the sail area but can´t set as much sail area as a spinaker. Close hauled it seems about like the tiki rig, could be a little less efficient, or not. It may be the easiest to handle eventually, when brailing is sorted out, but it gets tangled while raising and takes up a lot of space on deck (nit picking?). Tilting and spilling the claws have been effective alternatives to reefing. One big advantage to the claw is its efficiency as a ketch. The mizzen makes it far and away the best rig for all kinds of manuvering, using the mizzen as a steering sail. The mizzen also is a huge asset when it comes to heaving to.
The tiki wing sail is so perfect in every way that it is hard to surpass. I have been surprised at how well the claws work. They work in all conditions even if I can´t say absolutely better or worse in each situation. You know Manu Rere is now anchored at La Cruz near Puerto Vallarta on the tropical pacific coast of Mexico. In sailing some 1200 miles down this coast over the last two months I haven´t seen or heard of another boat using pure sail without engine. The fact that the crab claw got me here without cheating and without breaking anything is something of a testimony. Lots of other set ups just don't work in all conditions.

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12/14/2007

Yes Im sitting in an internet cafe right now.
I had a strong northerly for the first night out, said to be 20 -40k by don anderson the weather guy. I took down the mizzen to make running easier then, when tired, took down the main and put the mizzen back up so she spent the rest of the night running backwards at about 2k, head to wind, rudders raised, very nice. Reached the next day with just the small main (120 sq ft) set and the day after finally got all sail back on. It all worked very well, although the hatch seals need some more work.
Mark, Ive seen the tahiti wayfarer plans and can tell you they are fabulous. Packed with inovative ideas on everything from special techniques for home made sails to sailing techniques. For someone interested in trying alternative polynesian ideas it is ground breaking, nothing else like it.

Glenn

[Blanc Jean-Paul]

Marchaj's crab claw was in the flow symetric and not in one border. This is the reason of vortex. (la suite en français désolé pour les anglophones)    le fait de tenir la voile comme sur Waikatea ne permet pas et ne permettra jamais d'avoir le phénomène de vortex. de nombreuses vidéos montrent une réelle accélération dès l'instant que l'axe de symétrie de la voile approche de l'horizontale. Tout semble à re-découvrir dans ce domaine et j'espère à l'aide de mon projet avoir un bon terrain de recherche et de progression. Pour l'instant je construis et vous pouvez la suivre sur (archiprog.blogspot.com) .

[Scott Veirs]

Hey,

We're getting 130 degree tacks out of the 13m2 crab claw per Wharram's plans, with bamboo spars and white polytarp sails, and often with a jib.  I'm sure we can do better and occasionally am surprised at the speed and power of the rig.  Here's some more details, presented while looking forward enthusiastically to learning more about the crab claw sail -- ideally through more quantitative comparisons and assessments. 

http://econscience.org/tiki/2015/02/15/performance-of-a-bamboo-poly...