Single mast or double mast?

Discussion in 'Boat Design' started by ExileMoon, Jul 3, 2017.

  1. ExileMoon
    Joined: Oct 2009
    Posts: 33
    Likes: 3, Points: 8, Legacy Rep: 45
    Location: Shanghai

    ExileMoon Junior Member

    Single mast  sailing boat.png double mast sailing boat.png
    I'm thinking of a 40-foot sailboat. According to the common practice, do ordinary ding sailing. So that the height of the mast will be relatively large, the bottom of the ship had to install the protruding keel to ballast.

    I would like to be able to make a shallow draft boat, the mast made of two, so that in the case of the same sail area, the mast height can be lower. This does not require a deep draft of the balloon.

    The lower mast does not need to be reinforced with a cable, so the whole structure is relatively simple.

    Some people say that this boat is called "old man ship". Meaning that the boat is easier to operate and does not need to be adjusted too much.
    I think it should be a good thing.

    But this kind of double mast sailboat rarely seen.
    What is the reason?
     
  2. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 476, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    To directly answer your question, this isn't a rare rig and is fairly common, though certainly not as common as other more conventional divided rigs.

    It seems you're making some uninformed assumptions about righting moments, shoal draft 40' yachts, free standing rigs, etc. You'd be best advised to seek a set of plans, stock, semi or full custom for your shoal draft 40'er, as you don't have the understanding (yet) to self design a craft of this scale.
     
  3. Angélique
    Joined: Feb 2009
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    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    Hi Exile Moon,​

    See the below links for info about the Cat Ketch rig of which most also goes for a 40'er, and an example of a design that features the goals you mentioned . . :cool:


    [​IMG]

    Tad Roberts' Bluewater Future Cruiser series: - 28' - - - 38' - - - 44' mk II

    [​IMG]
    ↑ Tad Roberts Bluewater Future Cruiser 44' mk II sketch, which has the below comments incorporated in the design. ↑

    Boat Bits ---> April 03, 2012: Some short list musing = Quote source ---> Februari 27, 2012: A quick chat with Tad Roberts

    ‘‘ . . . . What changes would I make? Well for one, I'd look seriously at bringing out the coachroof to the hull sides as I've always wanted a flush deck boat and the added strength would be no bad thing. I like the rig as drawn but I can't help thinking that a high aspect balanced lug schooner with jib would seriously rock the house and surprise a whole lot of folks on a performance level... That said, just as it is, it is some seriously awesome boat! . . . . ’’

    Good luck !!
     
    Last edited: Jul 5, 2017
  4. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 476, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Have a look at a "Freedom 40" and, maybe do some more research.

    [​IMG]
     
  5. Angélique
    Joined: Feb 2009
    Posts: 3,003
    Likes: 328, Points: 83, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    Here's a drawing of the Freedom 40 AC and the 40 CC, you can't build for the money that buys you a good used one, and you'll sail right away . . :cool:

    [​IMG] - - - - - - - - - - [​IMG]

    Very capable boats, but they need beach legs to stand upright when drying out and they're not as shallow as the Tad Roberts Future Cruiser kind of boats.

    Below a Freedom 35 centerboard version which is for sale in the Netherlands, but for safety reasons I'm not happy with the far off center companionway she sports...

    [​IMG]

    [​IMG]

    [​IMG]

    Good luck !
     
    Last edited: Jul 4, 2017
  6. Windship277

    Windship277 Previous Member

    I would get rid of one of the centerboards. Ya dont need 2. More drag and another place to leak seawater.
     
    Last edited: Jul 15, 2017
  7. Windship277

    Windship277 Previous Member

    That is a sweet boat.
     

  8. Windship277

    Windship277 Previous Member

    Yes its simple but wont go to weather like a "mastshead" rig (I know Par hates it when I say marconi).(Ill tell ya though Par, I really like some of the boats at your site). Design your boat for what you are going to use it for. If open ocean and deep water are an everyday event and anchorages are deep, you dont want a centerboard. You simply dont need one. If your destinations are to weather and your beating a lot, you want a masthead rig. Theres a reason there are so many masthead sloops around. Currents will make a masthead rig more desirable too. Sail handling is increased because of the size of the headsl. Now you need 2 expensive sails instead if one. Certain boats sail around on mooring or at anchor. More windage. But...lol, I DO love the cat ketch/yawl whishbone rig. My advise is like the other gentleman's...take your money, buy the Freedom cat ketch, spare yourself years endless aggravation and go sailing.
     
    Last edited: Jul 15, 2017
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