Free-Standing Mast

Discussion in 'Boat Design' started by Sailor Jerry, Apr 27, 2013.

  1. Sailor Jerry
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    Sailor Jerry New Member

    I have a 32 ft Dreadnought that I'm currently in the process of rebuilding. Basically I'm replacing everything except the fiberglass hull, including ballast. In rebuilding the boat I am planning on making it a sloop with a free-standing mast.

    Does anyone have and opinions on how possible this is or how much I would need to reinforce the cabin top, etc.? I am gathering as much information as possible on the topic and have begun the search for a naval architect but appreciate any additional input people might have.


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  2. philSweet
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    philSweet Senior Member

    I think a freestanding rig will cost you more than several of these boats have recently sold for in well maintained condition. Why do you want one?
  3. Petros
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    Petros Senior Member

    Welcome to the forum.

    anything is possible, but the question is it financially feasible and wise. All of the bending moments from the sails will be transmitted through the mast and into the hull through the mast partner and the mast step. This means a completely new custom mast, and completely rebuilding and reinforcing the hull around the area of the mast to adequately transmit all of the heeling moment forces to the hull.

    the conventional mast and rigging act like a truss so the shrouds pull against the side of the hull with the mast in compression, giving it the distance from the center-line to the gunwale as your fulcrum length. with a cantilever mast you only have the width of the mast as your fulcrum, multiplying the forces by about 10 times or more (depending on the dia of the new mast). This will also add a lot of weight.

    What I am saying is it is a structural redesign of the whole deck/hull around the area where your mast will be. This may also affect the amount of useful space inside the hull as well. Yes it can be done, but it would be at great cost.

    I do not know if these boats have any resale value once restored, if it was a classic design and well respected you may well wipe out any resale value after your are done. Particularly if the redesign affect the utility of the boat.

    If you just want to clean up your rigging and simplify everything, you might compromise and have your navel architect suggest ways to just reduce the amount of rigging you currently have. A more modern conventional rig that you can buy used and adapt to this hull that saves weight and improves the performance. This would greatly improve the value of the hull.

    Make sure you find an experienced NA that is familiar with these type of boats and their history/resale value, etc.

    Good luck. Post pictures of your progress!
  4. PAR
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    PAR Yacht Designer/Builder

    I agree with Petros in that your most reasonable approach, would be to clean things up with the new rig, rather then re-engineer for a freestanding stick. The change to sloop isn't very difficult and using a Westsail 32 rig would be the logical, available option (several hundred built, though mostly ketches). You may also want to look into Atkin's Eric (or one of the many Archer knock offs) for a sloop rig, though these will need some modernization. A freestanding rig wouldn't offer much, on a hull form as burdened as these. Look to put up at least 750 sq. ft. of working sail.
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    FAST FRED Senior Member

    A low cost freestanding mast can be found as a lamp post at most air ports and alongside many highways.

    A Sawsall and a pickup , some dark night???

    The wall thickness will be high , so you might need more ballast.
  6. michael pierzga
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    michael pierzga Senior Member

    Dont know about a free, standing mast but in the shipyard there is an old triple spreader alloy rig laying on its side outback the garbage could probably get it for free, then stand it up. The end result would be a Free standing rig
  7. micah719
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    micah719 Plotting Dreamer

    Power blackout night would be safer than BB-gun night.....actually purchasing a new one might be even more advisable, they're not expensive.
  8. gonzo
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    gonzo Senior Member

    If all you are keeping is the hull, it would be much cheaper to build a new boat. As it is, you will have to take everything out and then clean and prep the old hull. Also, you will pay a Naval Architect to measure and backwards engineer the hull to be able to calculate the new structure. The hull is no more than 5-8% of the total cost of a vessel.
  9. bajansailor
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    bajansailor Marine Surveyor

    Eric Sponberg has done a lot of work with free standing masts, and he posts on here - here is a link to a boat he was involved with that was converted from a conventional rig with stays to a free standing rig.
    However the value of this new rig is probably several times the value of your boat, even if she was re-built / re-fitted with a conventional rig.
  10. dougfrolich
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    dougfrolich Senior Member

    A free standing mast is simple enough. But a sloop rig with a freestanding mast is more complicated, but do-able i.e. Juan K did an IMS boat with an impressive shroudless rig.
    I would recomend keeping simple i.e. a cat rig ( ).
    the trick is matching the bending characteristics of the spar to the RM of the boat.

  11. Petros
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    Petros Senior Member

    good link to Eric Sponberg's website, it was an interesting read. but here is the salient point on doing it as a retrofit, quoted from Eric's article:

    " Usually, the cost of reinforcing the hull and deck in an existing boat for a free-standing rig involves more cost than it is worth, particularly on an older boat. But Bryan and Carey were committed to doing the best mast construction job possible."

    So they were willing to pay more than it was worth to get what they wanted, also it appears the owners did all the work themselves. So it may not be so prohibitive if the owners have the time, the skills and the willingness to perhaps double the time it takes to do a renovation, it can be done. I am sure those materials not inexpensive either. Looking at the design of the hull and keel of the Dreadnought, I would say there would be likely little improvement in pointing ability because of the very low aspect ratio keel.
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