Real scale measurements of yacht's mast accelerations

Dismasting is one of the most serious hazards for sailing boats. This event is mainly due to structural defects, poor maintenance or adverse weather conditions. For what the last aspect is concerned, it may be associated to two types of loads: the direct action of the wind on sails and accelerations caused by ship motions. The aim of this paper is to focus on the accelerations induced on the mast by ship motions using seakeeping analysis validated by real scale measurements carried out on two sailing yachts during their transfer trips from South Africa to Italy. After measurements, the recorded data have been analyzed, reordered and related to the weather conditions encountered during the transfer voyage. Then seakeeping calculations have been carried out in order to compare numerical prediction with experimental values. Finally, acceleration values to be considered for preliminary mast scantling, were derived.