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"Pjoa" build by Janusz Ostrowski in Poland

Page history last edited by TdeM 15 years ago

Based on works of Cz.Marchaj, on crabclaws sail execellent features, published in "Aerodynamics of Sailing", I continued with my own research on this rig but in full scale. It was fruitfull effort.

Gathered old photos and drawings I've started with model for concept proofing.

Model sailed unattended and, once set on tack, followed the wind changes without remote controll in somehow mystic way.

There was no reason to find out myself, what makes CrabClaws and proa such marvellous combination.

Model testing in aerodynamic tunnel is always limited  to some features and based on arbitrary made assumptions.

Full scale vessel allows for accurate sensing what happens, how and why - one can feel, and react, interactive build and test hypothesis, adapt the way observations are made.

I wanted real experience, so after collecting old drawings, with inspiration of Harmen's Hielkema "Toroa" and adviced by Gary Dierking, I prepared plans and built Pjoa.

Stories are here:

2002-2003 model and 2007 model MkII

2003-2004 - building Pjoa: vaka, ama, spars and cut of crabcalws sail

2005- launch (text in preparation)

2006- Baltic journey, etak I (text in preparation)  (etak is term used in polynesian native navigation technic meaning part of yourney between stars on path)

2007- Baltic journey, etak II (text in preparation)

2008- Baltic yourney, etak III (text in preparation)


That's how Pjoa looks (click image to enlarge):


Comments (1)

Othmar Karschulin said

at 2:14 am on Dec 2, 2009

Hi Janusz,
yesterday I got a photo from Helmut (Naxos), which shows Pjoa with a reef in the sail. Can you tell me/us your experiences with it? I am thinking also about a practicable reefing method for my new 26 ft boat.

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