Wind Tunnel Measurements of the Performance of Canoe Sails From Oceania

01 October 2018     Editor    5 Comments.

In what is no doubt the longest headline ever at Proafile, The Journal of the Polynesian Society has published a paper by Anne di Piazza, Erik Pearthree and Francois Paille on their wind tunnel research results. Apparently inspired by C. A. Marchaj and his wind tunnel testing of various rigs of working sail, including the “crab claw”, the new study expands the range to a wide variety of Pacific rigs:

The primary objectives of this paper are twofold: (i) to test different traditional Pacific rigs in a wind tunnel, rank their relative performance, and compare these results with other studies, in particular Marchaj’s “crab claw”; and (ii) to question developmental implications of such results and consider whether the geographic distribution of the various rigs could shed some light on the history of settlement within Oceania.

Much thanks to G. Baron for the submission!

 rigs / pacific / crab claw 

5 Comments

09 Oct - 07:53

Wade Tarzia

Remember the German windtunnel tests by the fellow whose name I forget right now, who refuted many of Marchaj's results? I still have his test results saved, which he posted to the old Yahoo Proa-file forum.

09 Oct - 19:07

Editor

I do remember that. http://multihull.de might have it online.

11 Oct - 18:41

Guido

Be nice to have some understanding she's on the utility of these rigs, the wind tunnel tests are interesting (especially regarding further development) but possibly a bit limiting when it comes to understanding why some of these plans had such longevity.

12 Oct - 09:33

Wade Tarzia

Locale wind conditions, typical use of the boat (what courses sailed for trade/visiting, what fish chased, etc.) , what materials (lengths, strengths) locally available, and of course local buildability/repairability and kindness toward available sail materials -- Asian countries sometimes suffered when being brought into a global economy -- adoption of factory fertilizers for crops enslaved farmers to global prices, adoption of outboard motors (etc.), similarly. These would be some of the factors I would first posit as arguing for longevity of plans. The notion of "tradition" goes without saying, though traditions show both remarkably longevity in the face of Western colonization and in many cases remarkable delicacy (susceptibility to destruction). One might wonder to what extent a rebellion against Western encroachment helped some of these traditional plans survive, where there was energy left for cultural pride. These designs now so often figure in cultural revival/pride projects, and perhaps cannot always be layed on the shoulders of point-origins -- galvanizing figures such as Herb Kane and Ben Finney for Hokulea -- but there also must have remained other kinds of forces to keep things alive -- perhaps in some cases the geographic backwaters -- Mau Pialuig and Satawal come to mind, although he was asked to join revival education rather than having put himself forward, but there could have been no Mau without a Satawal to have produced and sustained him into this period.

20 Oct - 14:45

Joan Pons

That the Ninigo and Massim sails perform so like an air plane wing and thus so well seems really logical, but I'm surprised with the crab-claw from Santa Cruz, and it matches quite well Marchaj results ! One caveat to the analysis is that the wind gradient in real conditions is what makes sail twist important, and this have been left out of the study.