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The hull of the one third scale test tank model of AUSTRALIA II

Date: 1981
Overall: 730 mm, 300 kg
Display Dimensions: 1205 x 1245 x 6740 mm
Medium: Wood, paint
Credit Line: ANMM Collection Gift from America's Cup Defence 1987 Limited
Object Name: Test tank model
Object No: 00000701
Place Manufactured:Nederland

User Terms

    The hull of the one third scale test tank model of AUSTRALIA II. Built by the Netherlands Ship Model Basin and designed by Ben Lexcen.

    The hull is divided into sections by thin black vertical grid lines and a single red water line mark.
    SignificanceOf all the memories generated by the victory of AUSTRALIA II at the 1983 Americas Cup, it is the revealing of the hull of the boat that features most prominently for many. Tested and tweaked over many years the hull is still synonymous with its designer, Ben Lexen.
    HistoryThere is a complex set of choices and compromises that have to be made in relation to the best proportions and shape of the keel and hull around the desired hull dimensions and sail plan area allowed by the rule. There are always penalties along with advantages. In this case one of the significant penalties was the greater wetted surface area and resultant drag, coming from the addition of the large wings. With the aid of the tank testing using one-third scale models and computer simulations it was possible to trial a variety of models generated from Lexcen’s basic concept, often making gradual changes as suggested by the testing. When the model with the best ratio of gains to losses was identified, the final design was then able to be drawn.

    The revolutionary keel development met with opposition by some Americas Cup participants who claimed Cup rules were violated in letting boat designers to test boat models in model basins that were not in their native countries. In the case of AUSTRALIA II this testing was undertaken in the Netherlands with Dutch technicians Peter van Oossanen and Joop Sloof carrying out much of the engineering analysis. While the opposition was overcome at the time, the controversy did appear again when it was later claimed by van oossanen that it was he and not Lexcen that developed and fine-tuned the winged keel design and had in fact been silenced by Alan Bond.
    This claim was never substantiated and Lexcen supporters point to an earlier designed boat by him, TAIPAN, in the Australian National Maritime Museums collection which features, a winged keel.

    "KEN BEASHALL: In them days, you could never design a boat without the tank testing, and somebody in the tank testing should be given the credit. And I suppose this is one way of Peter saying, "Well, let's -how 'bout throwing a bit of credit my way."
    (ABC 7.30 Report - 14 October, 2009).
    Additional Titles

    Assigned title: De romp van het eenderde grootschalige test tank model AUSTRALIA II

    Assigned title: The hull of the one third scale test tank model of AUSTRALIA II

    Assigned title: Der Rumpf des ein Drittel Skala Testtank Modell von AUSTRALIA II

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