self supporting mast & tabernacle?

Discussion in 'Motorsailers' started by phillysailor, Apr 8, 2019.

  1. phillysailor
    Joined: Nov 2012
    Posts: 10
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    Location: Media, PA

    phillysailor Junior Member

    Has anyone created a tabernacle which enables self-supporting masts on a motorsailer?

    My spitballing is for a modest sailing performance motorsailer est 46-48’, preferably cat ketch with easily rigged and doused masts. To facilitate the “easily,” investment in a carbon fiber mast would be made, both for weight benefit and ability to flex with gusts.

    My concept is pair of tubular braces angled out port and starboard supporting a 12-14% mast height tabernacle that would drop the mast level with a pilot house roof. The boom gooseneck would be on the back of the tabernacle with space between each for the stowed sail.

    As the mast pivots forward to land in the tabernacle the mast step would be “jacked” or screwed down until weight was taken off the pivot pin and the foot lands snugly in a fitted well or “shoe”, fixing the foot in place.

    The forward face of the mast would have a strut pinned to a car riding on a track. The strut would lie flat against the mast when horizontal, and swing to be quick-pinned to a hardpoint forward on deck (or to substantial bulwarks forward if those were present) as the mast approached near vertical. The inboard end of the strut, the car on the mast track, would be pulled down on the track to a spot below the pivot pin to “engage” its tension bracing the mast into the tabernacle.

    The mast itself would be raised and lowered via a line from the aft bottom of the mast through the base of the tabernacle, through a clutch and to the halyard winch.

    Obviously, ground tackle considerations would impact where the strut lands on the deck, and running back stays might be rigged in certain conditions. A more thoughtful mast step design must be possible.

    Any thoughts?
     
  2. philSweet
    Joined: May 2008
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    Location: Beaufort, SC and H'ville, NC

    philSweet Senior Member

    What do you mean by self-supporting? Do you mean free-standing, shroudless, stayless?

    Carbon is a waste here. This is where you go the other way and use a telephone pole or steel flagpole. You're looking at about 1000 pounds for the main mast and main tabernacle, and that's fine on a 30 - 35,000 pound motorsailer.
     
  3. Squidly-Diddly
    Joined: Sep 2007
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    Location: SF bay

    Squidly-Diddly Senior Member

    I'm a fan of the concept, I think.
    But a sketch, no matter how rough, would really help.

    What is the reason for wanting to take the masts down? Low bridges?
     

  4. Angélique
    Joined: Feb 2009
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    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    NIS boats offers high tabernacles for free standing masts on their 18', 23', 26' and 29' sharpies, just for the idea...

    NIS boatsProducts (scroll down for the tabernacles)

    Forum member Manie B envisioned a low tabernacle for a keel stepped hand raised and lowered and hand slide down mast for a 5 m (16' 4 27⁄32") sailboat.

    See the thread: Manie's Microcruiserpost #963 and further.
     
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