The 90° and 180° stability tests
To know the capacity of the sailboat to right itself two tests are realized: -A 90° test, which allows to obtain thanks to a software, the curve of stability and the capacity of theoretical auto-recovery - The 180° test for the 60'Open, realized on a dismasted boat, which brings the life-size proof of its righting-up capacity. We are at the origin of this test. We encourage hardly the runners realizing it, considering the realization of the test simple and easy compared with a solo world round.
TEST at 90° Objective of the test: obtain the precise position of the center of
gravity of the boat. The boat is tipped up then maintained in the horizontal position thanks to a placed belt around the bulb of the keel, raised by a crane. A spring balance is fixed at the head of mast. The height of water is noted on the edges of the hull. The means are had so to position the centre of application of the Archimède push (L). The test consists in measuring the tension exercised by the mast when the bulb is not any more maintained. Knowing the physical relation binding the various elements: F*L=Displacement*D, it remains to extract D which gives the precise position of the center of gravity.
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| Then the stability software gives the numerous properties of stability of
the boat, notably the surface of the stability curve, the capacity of auto-recovery. The software that we use is BHS, distributed by Design System to Antibes (Nicky Danese).
TEST at 180°
Although one can not completely avoid that the boats turn over, one gave himself for objective to verify life-size that with a simple action, the crew can rignt a 60 feet, dismasted, in plain water.
No method is imposed. The crew can act:
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| This test also shows the general awareness of the security to the public. This test was realized successfully on the Dominique Wavre's monohull. (In March, 2000)
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