Steady and storm sails in displacement powerboats.

Discussion in 'Powerboats' started by wavepropulsion, Jun 1, 2018.

  1. wavepropulsion
    Joined: May 2010
    Posts: 90
    Likes: 5, Points: 8, Legacy Rep: 29
    Location: Uruguay

    wavepropulsion Pirate Member

    Hi to all.
    I never found anywhere references to use sails in powerboats.
    As seen in lobsterboats, some trawlers, the riding or steady sails are understanable to help stabilize the boat or to point into the wind. Generally this sails corresponds to boats with a high cabin up front and balances the center of lateral windage.
    Another kind of sails I seen in small doryes here where I live are like a jib or staysail to help motoring downwind.
    Boats in the firsts Bermuda to NY races used to be displacement with high lenght beam ratio and also used a triangular little sail near the bow. A la Al Grover, when he crossed the North Atlantic used a similar rig to ride a storm in a heavier-beamier boat.
    Ancient rowing long boats as the warships of greeks used a kind of high bow probably to catch the wind and this can help balance the boat in cross winds compensating with the drag of the oars to keep direction (is a simple supposition, wish not to be very silly, because is making equal or almost the effort of the oar in lee side with weather side, otherwishe the weather side oar will do more effort to mantain the same heading and so diminish speed by wasting the lee side stroke).
    Some yawl sailboats can be sailed in all points of wind only with the mizzen (bigger than in ketches), under certain circumstances.
    I have much questions about, I not pretend to be a designer but a buyer of plans or already done boats. But to do the right choices, or slightly modify some designs, I need to know how things works. In first, some cuddy cabin launches as seen in the UK, displacement or planing, have a very huge cuddy cabin up front. This can help to balance the boat? Most powerboats I know point into the wind if left alone, this ones seems to do the opposite, go straight downwind. How is considered this when designing a cuddy cabin or pilot house? I seen some fast boats with a kind of bimini angled to midships, is just looks or is to be considered as a function regarding windage?
    The main question I have is to use a simple small sail, to the bow or to the stern of rowing boats, motor boats to compensate yawing, rolling, etc., and at the same time wich can be doubled as an auxiliary way of propulsion, saving to have a secondary motor. And how the size and location is calculated, or can be calculated (seems intuitive, but much things are counterintuitive).
    Not talking about motorsailers here, wich can be a good alternative (I had read a good article about by Tad Roberts), but pure motorboats, designed purely as power boats. Very small sails was used with advantage in other times, and now when is duscussed about efficient displacement hulls, is something I personally consider. If the skipper don't intend to go into the wind, and if the sail is small, doesn't need more ballast, stability form, reinforcements or more appendages than the original design has.
    Thanks in advance.
    (Edited to say sorry for my english, still learning yet).
     
    Last edited: Jun 1, 2018
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