wind/wave limits for old IACC yachts

Discussion in 'Stability' started by lead_ior50, Sep 23, 2011.

  1. lead_ior50
    Joined: Jun 2008
    Posts: 2
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    Location: los angeles

    lead_ior50 New Member

    you might remember some of the '95 and newer boats breaking in relatively benign conditions (example one Australia 35 in San Diego in 1995, even though arguably there was some crew error involved) ). If I recall correctly, IACC race comittees would cancel races above 20 knots, but often wind speed is not even so critical as compared to sea state. Does anyone have knowledge of the design briefs for these yachts, specifically '92 and '95 vintage. Some of the charter outfits have taken these yachts out sailing in pretty strong breezes but usually flat waves.

    For example, would you want to be on one of the old '95 vintage yachts beating into 6-10 foot waves for hours without a life raft on board ?

    then, as a follow up question: Many of these older IACC yachts doe not have a lot of stringers / bulkheads..
    has anyone seen people owning these yachts going ahead and retrofitting stiffening inside the boats to make them
    more sea worthy. What about the keels? are they designed to last one season of IACC racing ?

    apparently high winds are not the problem, it is the sea state and "user error". Once beating into steep choppy 6 foot plus waves, all bets are off ? I saw some IACC yachts inside, and there seem to be very few stringers / bulkheads forward. Also it seems - looking at some finite element analysis of IACC yachts (saw a stress distribution diagram of AUS 35 published somewhere) the highest loading is at the leward genoa track in the deck. so, shock loads there and slamming loads in the lower bow section would be the worst case scenario. What about the keel box? most IACC yachts have the "slotted" keel -hull connection which seems to be much stronger than the more conventional keel flanges bolted against the hull. Yes keels have fallen off but in many of those cases prior grounding or other issues were at fault..
  2. cracker
    Joined: Sep 2011
    Posts: 12
    Likes: 2, Points: 0, Legacy Rep: 44
    Location: Queensland

    cracker NA

    I've approved one for 6 ft waves, but 10 foot, no way without a liferaft!

    Keels, whole show is designed to be highly stresses and heeled in competition. In charter should not be anywhere near these loads. That said, I still wouldn't approve for 10 ft waves without a lot more information.
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