ANNE DI PIAZZA, Aix-Marseille Université, Centre National de la Recherche Scientifique (CNRS), Ecole des Hautes Etudes en Sciences Sociales (EHESS), Centre de recherche et de Documentation sur l’Océanie (CREDO)
FRANÇOIS PAILLÉ, Ecole Nationale Supérieure de Mécanique et d’Aérotechnique
To understand the sailing performance of traditional canoes in Oceania, we replicated ten sail rigs and tested them in a wind tunnel. Measurements of lift and drag forces demonstrate substantial differences in their performance. At low heading angles, from about 30° to 80° off the wind, three sails (Massim, Ninigo, Santa Cruz) are remarkable for their higher efficiency. Three other sails (Tonga, Hawaii, Tahiti) are remarkable for their lower efficiency from heading angles of about 90 to 130°. In between, four more sails (Arawe, Micronesia, Vanuatu, Marquesas) have roughly similar performance to each other. The ranking of these sails is followed by a description of their distribution with inferences on historical evolution of canoe rigs.
Journal of the Polynesian Society 123(1): 9-28; DOI: http://dx.doi.org/10.15286//jps.123.1.9-28
“Traditional” approaches to canoes and voyaging in the Pacific consist mainly of recording seafaring techniques (Gladwin 1970, Lewis 1972, Thomas 1987), documenting canoe building (Damon 2000, George 1998, Tilley 2002), experimental reconstruction and/or sailing in the few remaining traditional canoes (Finney 2003, Lewis 1972, Thomas 1987), measuring canoe performance at sea (Doran 1972, Finney 1977), and in computer simulations (Avis, Montenegro and Weaver 2008; Di Piazza, Di Piazza and Pearthree 2007; Evans 2008; Irwin, Bickler and Quirke 1990; Levison ,Ward and Webb 1973). Another tack consists of predicting hydrodynamics of vessels or aerodynamics of sails in towing tanks, wind tunnels or with computational flow models. To the knowledge of the authors only one such study, on the Marianas flying proa, has been published to date for the Pacific (Jackson and Bailey 1999), although in a recent paper, Irwin (2008) discussed the utility of such an approach.
Important early wind tunnel experiments were conducted by Czeslaw A. Marchaj, National Finn sailing champion in Poland, Research Fellow in the Department of Aeronautics and Astronautics at Southampton University, and later an independent aerodynamics consultant. His publications such as “Sailing Theory and Practice” written in the mid 1960’s, followed by “Aero-Hydrodynamics of Sailing” (1988), “Seaworthiness: The Forgotten Factor” (1986) and “Sail Performance: Techniques to Maximise Sail Power” (2010), have become classic references. His involvement in many different research projects, such as rig design for a 12-metre America’s Cup challenger, and development of sail rigs for Third World fishing fleets, also led him to study the Polynesian “crab claw” rig. During his long career, one of the important hypotheses he developed is that “the practically extinct crab claw type of sail -once used by the Polynesian seafarers—is superior to the fiercely guarded product of racing and rating rules”, namely the triangular Bermudan sail (Marchaj 2003: 161).