Balance at different points of sail

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  • 30 Apr 2023 15:29
    Reply # 13185595 on 13185429
    Anonymous wrote:

    Cal 29 (from sailrite website) not showing the large overlapping genoa.


    try: Cal-29 on sailboat data

    From what I can tell, the picture they show at the top is from a Cal brochure... at least it matches the boat in the brochure I have a copy of. The line drawings seem identical to the line drawings in the copy of a manual I was able to down load as well. The genoa seems to end at the rear of the cabin as drawn but of course it would never look the same while sailing. The sail I have matches any of the publicity photos or drawing I can find. The line drawing you showed from sailrite looks like the foresail is not really drawn in as it seems to show just the stays and there seems to be no sail foot.

  • 30 Apr 2023 10:35
    Reply # 13185429 on 13180446
    Anonymous member (Administrator)

    Cal 29 (from sailrite website) not showing the large overlapping genoa.


  • 30 Apr 2023 07:13
    Reply # 13185394 on 13185227
    Paul wrote:

    If 18% is the designed lead, that is what you should be using. Modern boats tend to have large leads. In the past, the most boats did not have enough lead

    Meaning they are designed with larger leads or their keels are better shaped?  Funny to think of my 1969 boat as modern though... maybe that means I am still young.

    and the crews suffered accordingly. To date, almost everyone of my conversions could have done with a little more lead, not less.

    Good to know.

    David wrote:

    I sailed on a number of Bill Lapworth designed boats when I lived in Los Angeles. They are generally well balanced and he produced some fast boats.

    Yes any of the people with experience with this boat have said they felt it was well balanced... time to go sailing.

    Next question: The stock sail pattern has main and genny. I have calculated centre of area with the Genny at 100% rather than 160% (I think ?) and I end up with CA right on the mast. I could calculate with full size which put it slightly aft of the mast (it seems to change CA less than I would have thought) but then lift is towards the lead anyway...

    While I was trying to keep the mast where it is, I think the amount of work to move it is not much. To have it where it is right now still means removing the mast support and building a step and partners. however, the present mast position seems to put the CA too far back, 10% more at least depending on AR. So I will try drawing up a few more more with mast ahead of the head and ahead of the V-berth.

    Len

  • 30 Apr 2023 01:31
    Reply # 13185242 on 13180446

    Hi Len,

    I sailed on a number of Bill Lapworth designed boats when I lived in Los Angeles. They are generally well balanced and he produced some fast boats. Plans should be available for most of his designs and would give you details of the center of area for the sail plan and the center of lateral resistance for the hull.

    The way I judge a boat for balance is to haul in the jib until it is correctly adjusted for the point of sail. Then I pull in the main sheet until the helm balances. I find that if the main is under sheeted then she will carry too much weather helm and if oversheeted then lee helm. Incremental adjustment should tell you how much by and give a good indication of balance. If this is done on multiple headings from hard on the wind to broad reach it will give a good picture of her balance.

    All the best with the conversion, it will be the best thing you ever did for the boat!

    David.

  • 30 Apr 2023 01:24
    Reply # 13185227 on 13180446
    Anonymous wrote:

    I bought a CAL 29 last fall and am finally looking at taking her out after suffering a cracked rib a few months ago. I have been looking at the CA as compared to the CLR (without rudder, I think I need to recalculate) and the stock sails (assuming 100% jib) CA is close to 18% lead (it would be more with rudder in CLR). From any discussion I have read, this seems high. However, I have not read anything anywhere that indicates this is a problem.


    If 18% is the designed lead, that is what you should be using. Modern boats tend to have large leads. In the past, the most boats did not have enough lead and the crews suffered accordingly. To date, almost everyone of my conversions could have done with a little more lead, not less.

    In practice, especially if you have a low aspect rig, broad reaching tends to be the point of sail were lack of balance makes itself most felt. It will of course make it's self felt to the windward as well but in my experience, you've more chance of trimming it out on that point of sail.

  • 29 Apr 2023 15:22
    Reply # 13184894 on 13184750
    Pol wrote:I wonder if there are any junk rigged boats that you and your wife can get a sail on locally? Although there can be a bit more string, they tend to heel less than other rigs, there is much less sail flapping (if any at all), and the whole thing is so much more relaxed. Raising sail one panel at a time is kinder to beginners as well while we find our feet.

    I have only seen one in the Comox Harbour a few years ago on a mooring ball (or anchored?). Oh, and China Cloud on the mud even more years ago now. There are are a few on Quadra Island as well, or at least I have seen some while we are visiting. But not any where I have been able to talk to the owner.

    Your boat will probably turn under power better one way than the other?

    I stand on the stbd side of the tiller under motor. My knee keeps it right but if I am going to leave the helm, auto pilot is my friend.

    Sounds like your berth gives you plenty of practice in finding THAT out!  

    Yes, prop walk is a thing! Very useful for doing 180s in a tight space.

    Len

    Last modified: 29 Apr 2023 15:23 | Anonymous member
  • 29 Apr 2023 09:52
    Reply # 13184750 on 13180446

    Hi Len,

    It sounds as though you are going about it the right way. I wonder if there are any junk rigged boats that you and your wife can get a sail on locally? Although there can be a bit more string, they tend to heel less than other rigs, there is much less sail flapping (if any at all), and the whole thing is so much more relaxed. Raising sail one panel at a time is kinder to beginners as well while we find our feet.

    Your boat will probably turn under power better one way than the other? Sounds like your berth gives you plenty of practice in finding THAT out!  

    Pol

  • 28 Apr 2023 22:56
    Reply # 13184428 on 13184244
    Polwrote:

    Hi Len,

    I am quite new to studying balance in detail so I still have a lot to learn but, having converted a gaffer to a junk rig (30'loa/6 tons) in 2018 what I did discover was that hard on the wind is where you may discover any significant "imbalance". In a moderate sailing breeze the well-balanced cruising boat should be capable of sailing herself upwind without any other input than well-trimmed sheets.

    That was my thought as well but thank you for confirming my thoughts.

    If you are thinking about converting your boat to JR, my advice is "don't delay"!!

    I don't want to delay... but I don't want to get it wrong either ;)

    Our gaffer was transformed (and I am a life-long gaff rig sailor, and am fortunate to have sailed some of the best of them), so I would get a copy of Practical Junk Rig, read all you can on here (starting with Arne's extensive writings on the subject of balance, conversions etc) and go for it! One sail on your boat in a fair breeze should be enough to tell you how she is.

    I am pretty new to the game. I self learned sailing in a dinghy as a child but since then have done no sailing (when I was in command and not much with someone else), though lots of boating. We took the boat out over night and just motored. To be honest, my biggest worry was getting out from the harbour. My mooring is rafted up in the fishermans dock so either I back all the way out around a few corners or turn around in about 50feet of space first. While it didn't go as planned (turn around counter clockwise) it went just fine and we turned around clockwise and were off... no touching any boats, docks or rocks. We motored across Baynes Sound to a bay where we anchored and stayed the night. My other half wants to take things slow and so no sails :P something about not taking time away from the helm while "driving" even with an auto pilot and 5.2Kt :)

    Anyway, this is a family experience and my wife is excited about learning more but it will be one step at a time. Next time we should get some sails up too, she has to get used to me leaving the helm and feeling comfortable she can take over in the mean time.

    I just loved the cutting out of the underwater profile in a piece of card, and finding the balance that way. Can't recall if that was in PJR or Arne's notes.

    Yeah, for some reason I thought I had to do that without the rudder (even though it did not make sense to me) but both the PJR and Arne's notes say or show with the rudder, so I need to cut out some more cardboard and try again.

    I was hoping to be able to keep my mast in the current position and use an SJR but the CA looks like it may end up too far back. Moving the mast about 2 feet forward might be an option (bit of a pain getting into the V-berth but doable as the entrance to the V-berth is somewhat offset from centre). Or the next placement would be ahead of the V-berth at the aft end of the chain locker. The Forward position may be too far forward for either a PJR or cambered (Arne style) without a mizzen (ketch or yawl) to bring the balance back in line.

    My CAL 29 does not look like anything has been altered in sail plan or under water area. The rudder is stock and so is the prop placement (though the Atom 4 has been replaced with a diesel). We like the stock cabin layout as it fits our family really well. I do not think putting the mast mid V-berth will fly  ;)  However, a big beefy mast step that could serve as a step up to the berth might be ok. It would mess with the forward hatch though...

    Good luck with your conversion.

    Thank you. I think it will be the best thing for both my wife and I... even if I need to get a powered winch handle for the halyard.
  • 28 Apr 2023 19:08
    Reply # 13184244 on 13180446

    Hi Len,

    I am quite new to studying balance in detail so I still have a lot to learn but, having converted a gaffer to a junk rig (30'loa/6 tons) in 2018 what I did discover was that hard on the wind is where you may discover any significant "imbalance". In a moderate sailing breeze the well-balanced cruising boat should be capable of sailing herself upwind without any other input than well-trimmed sheets. If she can't do that, then maybe she has a rig balance or rudder problem. Gaffers normally are quite heavy on the helm, and ours was no exception although not as bad as some. When I moved her mast nearly four feet forward to take her junk sloop rig, many bystanders said it was too far forward and I did have my own doubts. However I reckon I was lucky because she sailed like a dream and we put her tiller steering back on to celebrate. At that point I realised that with her gaff rig, she really did have a weather helm problem!

    If you are thinking about converting your boat to JR, my advice is "don't delay"!! Our gaffer was transformed (and I am a life-long gaff rig sailor, and am fortunate to have sailed some of the best of them), so I would get a copy of Practical Junk Rig, read all you can on here (starting with Arne's extensive writings on the subject of balance, conversions etc) and go for it! One sail on your boat in a fair breeze should be enough to tell you how she is.

    I just loved the cutting out of the underwater profile in a piece of card, and finding the balance that way. Can't recall if that was in PJR or Arne's notes.

    Good luck with your conversion.

    Pol

  • 25 Apr 2023 20:44
    Message # 13180446

    I bought a CAL 29 last fall and am finally looking at taking her out after suffering a cracked rib a few months ago. I have been looking at the CA as compared to the CLR (without rudder, I think I need to recalculate) and the stock sails (assuming 100% jib) CA is close to 18% lead (it would be more with rudder in CLR). From any discussion I have read, this seems high. However, I have not read anything anywhere that indicates this is a problem.

    Which points of sail are most likely to show problems with balance in the sail plan? It would seem to me down wind would be least likely to show a problem. When I have been sailing with the previous owner, he tended to do a lot of Genny only sailing (150%ish) because of health concerns (raising the main is a bit much for him after setting genny. It is hard to tell how the balance was because he used an auto pilot for all steering and I did not think to try hand steering. However, it did not seem to be a problem. I will say however, that he was quick to go iron jib for anything upwind at all.

    Anyway, my plan is to spend this summer getting to know how she sails with the current rig. Any ideas on which points of sail to pay particular attention to would be helpful.

    Last modified: 25 Apr 2023 20:46 | Anonymous member
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