Gaff rig with jib?

Discussion in 'Sailboats' started by CardboardKing, Mar 31, 2013.

  1. CardboardKing
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    CardboardKing Junior Member

    Okay, I am getting to the point in the construction of my cardboard PD Racer that I need to start thinking about the sail rig. I like the traditional look of a gaff rig with a single jib, and so I'd like to try putting one of those together. In addition to the appearance, I want the ability to have a shorter mast and still have a decent amount of sail area.

    Can anyone explain to me roughly how a rig like this works? Or point me in the direction of some information that's already posted that can help me? I've downloaded several boat plans that include sail plans, but they all seem to assume that you already know a great deal about sailing, sails and rigs, so they don't tell you where the ropes go or where they come from or where or how the sails are supposed to move when you operate them...I'm at a loss. I don't even know whether a gaff is suspended by ropes or wires or if it is held up by its connection to the mast. Does it rotate up and down or is it fixed to the mast?

    Any help would be greatly appreciated. Thank you!
     
  2. TeddyDiver
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    TeddyDiver Gollywobbler

    How about a visit to library? Or Amazon? For starters THE GAFF RIG HANDBOOK by John Leather!
     
  3. gggGuest
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    gggGuest ...

    Typically a gaff will have two halards plus an attachment to a track or something on the back of the mast.
    One halyard, called the throat halyard, will run to the bottom of the gaff where it slides up and down the mast, while the other one, called peak halyard, will run to a point along the gaff, usually around half way. On larger boats this one may be attached to about three points to spread the loads.
    To rig you'll usually start with the sail unrolled and the gaff lying alonside the boom. Both halards are usually pulled up at the same time until the luff of the sail is as tight as required. The peak halyard is then pulled up a bit further and used to fine tune the sail shape.
     
  4. Doug Lord
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    Doug Lord Flight Ready

    Heres a sketch that may help: ( click for larger sketch)
    Note: halyards usually run down the forward face of the mast and are shown angled here for clarity
     

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  5. messabout
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    messabout Senior Member

    CK if you are not sure of how the sails operate, I submit that you will have more initial success without a jib. Learn to use the main efficiently then re-rig the boat and experiment with the jib/main combination if you feel that must have a foresail.

    For a beginner I would not think that the gaff rig is the best first choice either. A simple sprit rig will get you plenty of area on a short mast and have fewer strings to pull while getting some experience. Probably less expensive too. The sprit rig is suffiently powerful once you get the hang of it.

    A book: 100 Small Boat Rigs by Phil Bolger has a lot of basic information about all manner of rigs. The book does not tell you how to sail however. The book is inexpensive at Amazon and elsewhere.
     
  6. PAR
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    PAR Yacht Designer/Builder

    Agreed a gaff wouldn't be the reasonable choice for a boat like this. Simple and efficient would be the logical route. A sprit is a good choice, lots of area with minimal aspect. A truncated Bermudian or old school leg 'o mutton proportions will be lighter and offer some advantages, if coupled with a sprit boom. I wouldn't suggest 101 rigs by Bolger, as it'll just confuse a novice. A lanteen also has some to offer, again short spars and simplicity. Forget about the gunter and other extra spar rigs, just two are necessary for the most part. Loading will be interesting with all the leverage a rig will add. Exploding hull sides, might be a reasonable expectation with a gust on a cardboard craft.
     
  7. alan white
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    alan white Senior Member

    You might try to find an actual gaff sailboat somewhere and examine the rig close up. Better still, ask the owner if you could raise the sail and see how things are adjusted and tied off. A picture is worth a thousand words but reality is worth a thousand pictures.
    It's true the gaffer is a somewhat complicated rig compared to a typical triangular sail. However, that being said, it is a very practical rig in terms of working in various conditions. It can be dropped more easily without heading the boat directly upwind. It uses a shorter mast which allows stowing the spars onboard, usually within the length of the boat. Most gaffers have low tech parts and pieces allowing you to save a lot of money on fittings. The gaff has enough weight to assist dropping the sail without tugging. In other words, its a relaxed and predictable rig that can be very enjoyable to work.
    The triangular rig has a lot of advantages too. Obviously, it is the preferred rig nowadays. Much can be said about its superiority in many cases, but a lot of that has to do with the fact that the gaffer hasn't been pushed technologically nearly as far as the marconi rig. After all, why spend millions creating faster and faster rigs when the rig itself has essentially been replaced by triangular sails? No matter how much you improve it, it has a bit less potential than the marconi rig, or at least it's perceived that way, so why try?
    I own a gaffer myself. I love the rig for its beauty as well as all of those strings and complication. It just looks right. I get so many positive comments out there on the lake from people in typical fiberglass triangular sail rigs, and isn't that enjoyment worth something in contrast to high tech boats? We don't sail only for performance. We also sail for aesthetic reasons. And the gaffer almost always is the better looking rig.
     
  8. CardboardKing
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    CardboardKing Junior Member

    Okay, so let me re-phrase this and see if I'm starting to understand.

    The gaff is not actually connected to the mast - it just slides up and down as you raise and lower the sail. It's kind of like an upside-down window shade. As you pull the halyards, the gaff is pulled up the mast and the top edge of the sail with it. Is that right?
     
  9. troy2000
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    troy2000 Senior Member

    Right. If you're really interested in gaff rigs, I second TeddyDiver's recommendation that you read John Leather's book. I found it in my local library about fifteen years ago, and thoroughly enjoyed it on top of learning a lot..... If I had a gaff rigged boat, I'd buy my own copy.
     
  10. PAR
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    PAR Yacht Designer/Builder

    The disadvantages of the gaff rig on your boat just out weigh any aesthetic considerations. Your boat will have questionable stiffness and strength, so unless you invest in a carbon fiber gaff, spectra sails and lines, you'll just find it in the cockpit with, probably rather suddenly after a gust. You should be looking into the lightest, most practical and efficient rig, not one that suits your aesthetic concerns. The most important thing a rig can do it motivate the boat, without coming down in you lap. If you want aesthetics, than I suggests a flame paint job as a better option, that weighs a lot less and doesn't affect sailing ability or stability. Lastly, a jib will likely require at least a single set of shrouds. You could cut the jib luff with a considerable hollow, but this is a crap shoot and considering your sail making abilities . . . Think simple, light and efficient and leave the 100 year old technologies, to the boats with enough mass to carry them.
     
  11. motorbike
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    motorbike Senior Member

    Google Optimist, and yould be on the right track, or get over to duckworks where they specialise in this kind of craft, for more ideas on rigs etc. As PAR has wisely advised, a gaff is heavy, cumbersome and useless, if you really want a gaff then buy a (much bigger) gaffer with it already sorted.
     
  12. alan white
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    alan white Senior Member

    Gaffs are not heavy, cumbersome, and useless. They are often married to hulls that are slower, older types, which were built differently from modern sailboats. Put a modern high tech and high aspect gaff rig on a J30 and you might be a bit surprised at the performance. The gaff rig could be made with aluminum parts, spectra lines, full batten high tech sails, high aspect dimensions, and so forth. The reason nobody has done this is because those who like the rig appreciate its looks as much as anything else and wooden spars, leather, and bronze are infinitely nicer to look at than cold aluminum.
    I personally like gaffers because of the character and aesthetics. I don't race much. I make all my own fittings---- wooden cleats, copper chafing patches, jaws and spars----- everything made for very little money in my own shop.
    It isn't as if gaff owners are mistaken. They simply like the rig for their own reasons. I know gaffs are somewhat slower on the wind but so what? I like looking skyward and seeing that lovely rig against the sky. I like the creaks I hear and I like the look of varnished spruce and easily spliced three strand dacron rope. Heck, I like splicing that rope and whipping the ends just so. Such things make me FEEL good.
    Why assume the poster is interested in the fastest rig when he obviously chose the gaffer because he liked the look? Sailing is not only about speed. It's about many other things too. I have seen many sailors who only race but seldom go out just to enjoy the day. I don't judge them but they are not doing things "right" because they own a go-fast modern rig. Nor am I right either, except I'm doing what does me the most good.
     
  13. Doug Lord
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    Doug Lord Flight Ready

    I'm not recommending this type of rig but I feel it is important to point out that in racing, where rig design is open, rectangular mains and even square top jibs are seen more and more. The square top main is what I consider a modern version of a gaff but instead of a gaff the head of the sail is supported by a diagonal batten. These sails have great advantages in ease of depowering and configuring twist for the conditions. Rectangular mains have proven faster than triangular mains in the most advanced sailplans. Again, I am not recommending this for the cardboard boat but I wanted to mention that this development has occurred.
    Most monohull ocean racing classes like the Volvo and Open 60 utilize square top mains. Most all small and large new multihulls use square top mains, including the mod 70's and others.

    Pictures: Left-an Aussie 18 with square top main and square top jib,Right-a 28' monohull with square top main:

    click for larger picture-
     

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  14. sharpii2
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    sharpii2 Senior Member

    A gaff rig's two talents

    A gaff rig has two talents that other rigs do not have.

    1.) the ability to dump up to half the sail area very quickly while still having enough sail up to proceed, and

    2.) having more points of adjustment to deal with sail cloth stretch.

    starting with the first.

    A properly rigged gaff sail can release its Peak halyard, while leaving its throat halyard tight. What will happen then is the aft end of the gaff will will drop, causing the sail area above an imaginary line, drawn from the end of the Boom to the throat, to collapse and to blow off to leeward. this is quite useful when dealing with a sudden gust. Once the gust is over, the peak can be pulled back up, restoring full sail area quite quickly.

    Now for the second.

    back in the 17th, 18th, and 19th centuries, sail cloth was mostly made out of flax, a material that could stretch a great deal over time. It was quite common to make sails somewhat smaller than their intended area, so they would have room to stretch. They didn't always stretch evenly and the gaff gave an extra point of adjustment at the top of the sail. For this reason, the gaff rig was used up until the 3rd decade of the 20th century as a racing rig. The acceptance of Egyptian cotton, a natural material that stretched quite a bit less, led to the gaff rig finally being replaced by the Bermudan one.

    Looking at pictures of the last racing gaff rigs, I often see the gaffs damned near vertical.

    When it comes to your cardboard pdracer, the first talent is the one that is of the greatest use.

    Pdracers have a considerable amount of initial stability. I estimated a pdracer of my design had almost 1,000lbs of initial righting moment, with me sitting on the side deck.

    This is way more than what is needed to drive her and would be used to keep her upright in a sudden gust, or to get that last nth of speed out of her in a race.

    Your cardboard version may not be able to stand up to such stress.

    To keep the boat upright, in such a situation, one generally relieves the sheet line, letting the sail flutter uselessly to leeward.

    With a gaff rig, you would have a second option.

    Though the gaff rig needs two halyards and a kicking strap for the boom (to keep the end of the boom from rising, once the sheet lines are let out), none of this gear has to be heavy or cumbersome. You can have a single part sheave for each.

    Gaff itself could be just a broomstick and the kicking strap could be just a just a length of light chain, or a thick line.

    A jib of any kind usually means some kind of shrouds and or back stays.

    There is a type of jib that often didn't.

    That was a balanced jib (see attachment below).

    It is set on a boom, not a head stay, and has a pendant set about 20 to 30% aft the front end of the boom. This pendant attaches to the boat.

    This sail sets reasonably well even if the mast sags a bit.
     

    Attached Files:


  15. motorbike
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    motorbike Senior Member

    Point taken on the handiness and aesthetics if a gaff rig, and if the OP is wants one then surely he is allowed his dream. My point is that a gaff rig on a cardboard pd racer is more of an affectation but hey thats what pd racing is about having fun. Probably not worth all the extra string etc when a sprit rig like that on an opti will give a low aspect sail with arguably a better set. Given that, there are always going to be compromises, although a pd racer wont be going upwind in a hurry with any rig. Re DL comments on square tops, sure there is an improvement in performance, but those boats mentioned retain a long luff and have the hull form and/or ballast to carry the extra sail aloft. I dont think you can compare a VOR to a pd racer on any level.
    [​IMG]

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