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Re: [J28Sailors] Re: Heavy Air Sail Plan / Trimming / Tuning

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  • Jason Smith
    Lenny, Yes, you interpreted vang sheeting correctly. Using this technique in theory allows the main to remain flattened/depowered while easing the mainsheet
    Message 1 of 10 , Jun 16, 2009
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      Lenny,
      Yes, you interpreted vang sheeting correctly.  Using this technique in theory allows the main to remain flattened/depowered while easing the mainsheet to decrease the angle of attack (past what the traveller can provide) in gusts.  Using the vang + heavily eased mainsheet effectively "twists off' the top of the leech in the same way easing the sheet on its own.  My understanding is that it makes it easier on the mainsheet trimmer, rather than have to haul against the sheet in heavy air to (re)flatten the main.  This may be a poor explaination....does it makes sense?
       
      I have a reference from J-Boats discussing heavy air sailing: 
      "Upwind in heavy air, sail under the main alone, with maximum mast bend, vang on hard, flattened main with open leech, boom over leeward  edge of cockpit.  In this trim, you can maintain  6.5+ knots to windward without getting the rail under by 'feathering' up or easing the main instantly in the puffs."
       
      Can anyone describe the shape of 'flattened main with open leech"?  This is a bit confusing to me as I always though flattening the main by hauling in the mainsheet 'closed' the leech, easing the main created twist and opened the leech.
       
      This is an interesting discussion, as we have John and myself using the vang sheeting technique and Lenny's dinghy experience advocating a different trim process.  Let's hear from others in the group, if possible. 

      On Mon, Jun 15, 2009 at 8:58 PM, Lenny Reich <lsreich@...> wrote:


      Jason: I have never encountered the term "vang sheeting" before, but I take it to mean putting the vang on pretty hard while playing the main sheet to spill wind in the gusts.

      If that's what you are doing, it certainly will contribute to excessive heel when the wind pipes up. The vang keeps the top part of the mainsail from twisting off, and the gusts will thus act hard against it. Because the top of the sail is further from your waterline than the lower part of the sail, the lever arm that the force acting on it has is greater -- hence more torque (torque = force x distance), which gives you more heeling.

      So, use little or no vang if you are trying to keep the boat on her feet.

      My first 20 years of sailing were in dinghies, where you learn pretty quickly how to avoid excess heel because things can get very wet in a hurry! Righting a swamped boat in lots of wind and sea can be NOT fun. ;-)

      Lenny


    • thconway1
      I think this boat does great in 15-25 upwind full sail. I assume these pointers are for racing, so you need a main and jib together. I definitely pull the
      Message 2 of 10 , Jun 16, 2009
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        I think this boat does great in 15-25 upwind full sail. I assume these pointers are for racing, so you need a main and jib together.

        I definitely pull the backstay to max. This will induce mast bend and help flatten the main. I do not use vang sheeting. I will snug the vang when sheeted in, but nothing beyond that. My boom is flexible enough that it will bend with too much tension on the vang.

        I sail with the main sheet on hard and trav down. Only the back of the sail will work in this alignment. When a puff comes in, I'll feather the boat so the jib gets light and may even have a little luff. This is just for the 20-30 seconds it takes for the puff to blow through.

        If needed, I will ease the sheet and leave it out. I do want to depower the top of the main, so I will not rely on the vang to keep the sail from twisting off up top. I prefer to lose the top when overpowered.

        Outhaul and Cunningham are maxed in this condition.

        If I have to, letting the main completely lose its power may be necessary. I find that if I have the trav down and I am still overpowered, there is little else the main can do with vang sheeting. It is barely staying full with the trav down.

        Unless I am in big waves, feathering will work. If the waves are stopping us, I will be forced to occasionally dump the main via the sheet and let the jib power us through waves. I move the jib lead back to let the top of that sail twist off as well.

        I have not had to think about speed in these conditions much since I will outpace any racing boat in the big breeze. I was even over the line once in a 25 knot breeze and caught back up to everyone in less than 2 miles.

        I think there is a point around 20-25 true where things need to get looser instead of tighter. The backstay should stay tight, but I will let the sails twist off quite a bit to lose extra power. I doubt this is a best practice, but with the gear in mind, I am trying to avoid overloading the boat.

        --- In J28Sailors@yahoogroups.com, Jason Smith <jason3317@...> wrote:
        >
        > Lenny,
        > Yes, you interpreted vang sheeting correctly. Using this technique in
        > theory allows the main to remain flattened/depowered while easing the
        > mainsheet to decrease the angle of attack (past what the traveller can
        > provide) in gusts. Using the vang + heavily eased mainsheet effectively
        > "twists off' the top of the leech in the same way easing the sheet on its
        > own. My understanding is that it makes it easier on the mainsheet trimmer,
        > rather than have to haul against the sheet in heavy air to (re)flatten the
        > main. This may be a poor explaination....does it makes sense?
        >
        > I have a reference from J-Boats discussing heavy air sailing:
        > "Upwind in heavy air, sail under the main alone, with maximum mast bend,
        > vang on hard, flattened main with open leech, boom over leeward edge of
        > cockpit. In this trim, you can maintain 6.5+ knots to windward without
        > getting the rail under by 'feathering' up or easing the main instantly in
        > the puffs."
        >
        > Can anyone describe the shape of 'flattened main with open leech"? This is
        > a bit confusing to me as I always though flattening the main by hauling in
        > the mainsheet 'closed' the leech, easing the main created twist and opened
        > the leech.
        >
        > This is an interesting discussion, as we have John and myself using the vang
        > sheeting technique and Lenny's dinghy experience advocating a different trim
        > process. Let's hear from others in the group, if possible.
        >
        > On Mon, Jun 15, 2009 at 8:58 PM, Lenny Reich <lsreich@...> wrote:
        >
        > >
        > >
        > > Jason: I have never encountered the term "vang sheeting" before, but I take
        > > it to mean putting the vang on pretty hard while playing the main sheet to
        > > spill wind in the gusts.
        > >
        > > If that's what you are doing, it certainly will contribute to excessive
        > > heel when the wind pipes up. The vang keeps the top part of the mainsail
        > > from twisting off, and the gusts will thus act hard against it. Because the
        > > top of the sail is further from your waterline than the lower part of the
        > > sail, the lever arm that the force acting on it has is greater -- hence more
        > > torque (torque = force x distance), which gives you more heeling.
        > >
        > > So, use little or no vang if you are trying to keep the boat on her feet.
        > >
        > > My first 20 years of sailing were in dinghies, where you learn pretty
        > > quickly how to avoid excess heel because things can get very wet in a hurry!
        > > Righting a swamped boat in lots of wind and sea can be NOT fun. ;-)
        > >
        > > Lenny
        > >
        > >
        > >
        >
      • andersenhans15
        ... Hi Jason, I notice that your dad has a J34, we have some interest in getting a J34 some day! Could I get your dads E:mail or would you give hom mine? Would
        Message 3 of 10 , Jul 22, 2009
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          --- In J28Sailors@yahoogroups.com, Jason Smith <jason3317@...> wrote:
          >
          > We had a good sail yesterday in the Chesapeake, a front blew through
          > and brought us NW winds. Conditions were 15-18knts, with gusting to
          > 22-23.
          >
          > I have to admit, I prefer to sail more upright, with moderate heel. I
          > don¡¦t mind the heeling in general, but what unsettles me is in the
          > gusts when the boats feels way overpowered and doesn¡¦t *seem* to want
          > to stiffen up. I am comfortable up to about 15 degrees of heel, but
          > when we keep going, I tend to bail out, either dropping the traveler
          > or heading up (or both). This probably has a lot to do with my
          > general lack of heavy air sailing experience. But, I have sailed on
          > my folks J/34c in similar conditions¡Kwhich seems so much stiffer and
          > better able to stand up to the gusts. Where I on the /28 tend to heel
          > more and maintain speed, the /34c puts her shoulder down and
          > accelerates, any increased heeling angle happens much slower.
          >
          > Everything I read tells me these boats should be good to 15-20knts
          > apparent upwind with a full main and, I suppose either a full or
          > partial genoa (depending on size). I have a newer North full batten
          > main and 145% #1, which I can reasonably reef down to 110-120%
          >
          > So I have a multiple stream of consciousness question:
          >
          > Those of you that sail your /28s in heavy air, what sailplan are you
          > using and how are you trimming out. For example, how far do you pull
          > the backstay down¡Kto the stern rail pulpit? Are you vang sheeting the
          > main, or dumping the mainsheet in gusts, or something entirely
          > different? For example, the 34c with, 2:1 admirals cup mainsheet
          > arrangement, can get the boom below perpendicular, say 15-20 degrees,
          > to the mast to really flatten the main¡K.is this even possible with our
          > 6:1 tackle on the 28? At what wind speeds are you reefing, and what
          > sail gets reefed first? Is there a heel angle that the boat really
          > stiffens up (that maybe I haven¡¦t gotten to yet ƒº). What size genoa
          > are you setting in these conditions¡K.it is necessary to keep the
          > center of effort forward, correct?
          >
          > Long winded, sorry! I appreciate any feedback.
          >
          > Jason
          >
          Hi Jason,
          I notice that your dad has a J34, we have some interest in getting a J34 some day! Could I get your dads E:mail or would you give hom mine?
          Would like to know how he likes the boat and where he is sailing mainly.
          Do they all come with the Wing?Bulb Keel?, how does it sail to Weather?
          andersenhans 15.
          Thank You.
          Hans.
        • jason3317@gmail.com
          Hans: Nice to hear from you. Yes, my folks have the J/34c (cruising). . They all came with the UFO (wing type) keel. It sails to weather with excellent
          Message 4 of 10 , Jul 22, 2009
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            Hans:
            Nice to hear from you. Yes, my folks have the J/34c (cruising). . They all came with the UFO (wing type) keel. It sails to weather with excellent stability. You can email Dad at blueheron147@....

            Jason

            Hi Jason,I notice that your dad has a J34, we have some interest in getting a J34 some day! Could I get your dads E:mail or would you give hom mine?Would like to know how he likes the boat and where he is sailing mainly.Do they all come with the Wing?Bulb Keel?, how does it sail to Weather?andersenhans 15.Thank You.Hans
            Sent from my Verizon Wireless BlackBerry
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