cutter rig without runnng backstays?

Discussion in 'Sailboats' started by urisvan, Jan 1, 2008.

  1. urisvan
    Joined: Nov 2005
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    Location: istanbul

    urisvan Senior Member

    hi alan

    sorry
    it is my ignorance, but how did you move upper forestay up! it is at the masthead.
    i only try to understand.
     

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  2. alan white
    Joined: Mar 2007
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    Location: maine

    alan white Senior Member

    I was speaking of the inner stay, not the outer one.
    The forestay would be the inner headsail stay (the jibstay would be the outer stay). The upper wire end attaches to a tang (strap of stainless steel) on the forward face of the mast.
    My suggestion was to locate the upper end of the inner stay/ tang connection closer to the masthead (top of the mast) even if it caused the inner and outer stays (headsail wires) to not be parallel. This causes the inner sail to be a bit higher aspect and also adds area.

    Alan
     
  3. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Urisvan, It would be much easier if you provided more information about what you're trying to do. The basics would include the year, make and model of the boat, the type of rig installed (many boats of the same model have optional rig choices) and a picture of the specific areas of interest.

    This medium isn't the best to gain an education, about the fundamental elements of a sail boat rigs, as there are so many "application specific" methods of dealing with the forces involved and of course the large array of rig configurations.

    In other words, what works well on a fractional Bermudian sloop may not apply on a masthead cutter. Ditto for all other rigs.

    An example of this would be the channel cutter posted above. The fixed backstay could be removed (boomkin and all) in a number of different ways.

    One way would be to use a jumper between the babystay and headstay, remove the redundant forward lower, sweep the uppers aft and take the aft lower to the masthead rather then the spreader tang as shown. Without doing panel loading calculations, it appears likely the aft lower will also need to have more sweep, but that's not certain. This is just one option, there are others available for this boat and it's rig.

    What are you attempting to do and on which yacht?
     
  4. urisvan
    Joined: Nov 2005
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    urisvan Senior Member

    i want to design something like alberg30. as seen in the picture, it doesn't have running backstays. but maybe it should have:p .
    you are wright, i think i want to see all the possibilities about rigging, sorry
    but i have to say:p :
    isn't it sound crazy? isn't it cause too much load even you put them a little more back
    and i wonder something, "did you ever seen a masthead sloop or cutter, whose cap shrouds are aft-sweeped?"
    cheers
     

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  5. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    A considerable amount of information must be fully understood, before you can attempt a design like the Alberg 30 (which was done by a well accomplished master designer). You can start with several good books on yacht design and the book store on this site has a number of the texts you'll need.

    This personal study will take a great deal of time, especially without training. You may want to consider a course in yacht design, which will speed things up for you.

    It would appear you need to also indulge in a personal study of yacht design history and its evolution. This can be done with a good library and by strolling around your local yards and marinas. Take a camera so you can study the images at home too.
     

  6. mgpedersen
    Joined: Feb 2006
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    Location: seattle

    mgpedersen Junior Member

    Yes, it's possible

    Most of the Valiant 40's were done this way. These boats had a single spreader rig with an intermediate backstay that terminated, at the lower end, at the chainplate used by the aft lower. The upper end terminated about midway up the upper panel, approximately where the staysail stay terminated. The Valiant 40s have done a lot of distance cruising and the rigs don't come down.

    Bob Perry has commented that he's gone away from that configuration though. The intermediate backstay doesn't provide a lot of aft support, or maybe a better way to say it is that it can provide the support but the price you pay is a lot more compression load. Lots of compression is what you try to avoid in a mast, so it's not the best solution (the mast section needs to be more stout to handle the load).

    I crew on a cutter with running backs, I don't find them a terrible nuisance because we only need to use them when in heavier chop (the rig is pretty stout). But then I'm one of those guys who likes to pull lines when I sail. If you are looking for the ultimate in ease of use go for a fractional rig with no running backs.

    Matt
     
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