Good, Asmat

I bet the rise in performance when going from flat sail to 6% camber is bigger than ‘the next jump’ would be  -  from 6% camber to 8 or 10% camber. I think the 2-sail junk will perform better than a 4-5sail gaff cutter or ketch will do.

You mention Hong Kong parrels. They have nothing to do with batten stagger when the sail is being reefed, only with the set of each panel when hoisted. The parrels you plan to use  -  maybe combined with Slieve’s very clever combined battenparrel/downhaul will probably make the Hong Kong parrels redundant.

Chers,
Arne

 

 

Asmat,

I can see the point in keeping your boat reasonably upright, but remember two things:

• 1.      The photos you have seen of La Chica have most probably been taken when she was racing. Who worries about the cook’s wellbeing while racing?

• 2.      The point with using sufficient camber is to avoid being underpowered when the wind drops to F4 and below. This means you will be sailing more and motoring less. You may still decide for a maximum heel of, say 20°, but that can easily be achieved by reefing.

Arne

PS: What it the displacement and length of your boat

 

Arne has pretty much spelt it out. LC has 12% in her foresail and 10% in her main. She is a heavy boat and needs all the drive that she can get. I don't think she has to much camber at all. Indeed I suspect that I could go to 14% in the foresail but unless I could somehow increase the separation between the two sails, 10% is as much as the main can handle (foresail back winds the main).

Zebedee and LC sail hard against each other every time they meet (which has been a few times this summer). Zebedee is faster downwind (which is as it should be as her LWL is longer and she is lighter) but LC is faster to the windward. We have not really worked out why that is but we are coming to the conclusion that it could be that LC's in sails the shape is much more controlled. She has a carefully profiled entry that gives the desired 8 deg entry angle and by using the shelf foot method of construction the sail shape is more controlled. Also her sails are built using traditional sail making techniques and so distort less than those built using Arne's simple methods. That is not to degenerate Arne's methods which are great (I use method 'B' to join the panels and create the batten pockets) but they are lightly built and there is a price to pay. Of cause there is a price to pay when you build sails my way as well... that is time. Instead of just taking a week or so, LC's sails took three weeks of 8 hour days.

As for Annie's Fantail, if anything, she needs more camber not less.

Camber,
here we go again...

During all those years since I introduced 10% camber to Malena’s sail in 1991 (hinges) and later gave her 8% camber with baggy panels (1994), these numbers seems to have been regarded as over the top, somehow. One strong argument has been that I don’t sail offshore with it, so I cannot know what I am talking about  -  my boats are ‘Fjord Flyers’  -  end of discussion.

Well, here is my answer:

• 1.      With the generous rigs that I give my boats, we will be down on 3 – 4 panels in F5+ conditions. In that case, the dominating part of the sail will be the three top panels, which have been cut with much less camber. What more harm can these baggy, but reefed-away panels do offshore than inshore? And yes, strong winds may blow along the fjords as well, and since the chop there is lower than offshore swell, I may even hang on to sailing in stronger winds than I would do offshore. I have actually sailed enough offshore to know that we tend to reef a lot more conservatively there than in wave-protected waters.

• 2.      Ok, then, let’s say that I am a fair-weather sailor and know nothing about what it takes to sail offshore. What then about Alan’s Zebedee  and Paul’s La Chica? Both their new sets of sail have been given real camber, around 10% +/-. Both Alan and Paul appear to thrive immensely well with their new rigs. Are they too in the camber extremist class now, and do you expect that they will soon come to their senses?

• 3.      I have a couple of books about ordinary sailmaking, and I have made a few of those sails as well. Nowhere in those books is there any warning of any kind against cutting  proper camber in offshore sails. Only the storm jib and trysail is cut flat. Why then should we make a special offshore rule for junk sails and not for gaff sails or Bermuda sails? Is it just ‘felt that’?

I don’t buy all this common sense. Instead of deciding for an amount of camber, depending of inshore or offshore sailing, I let the total displacement and displacement/length of the vessel be the dominating factors. If the vessel is in the Colin Archer league, I would go for maximum achievable camber in the lower panels, say 10 -12%. On medium light and trim boats I would start with piling on a fairly big sail for good downwind performance. Then I would cut the camber in the lower panels to about 8 %. This, less powerful sail will let me carry almost as much sail area when close-hauled as when running. On a really trim flyer, say a Skerry Cruiser or sharpie (or even a trimaran), I may reduce the camber to 4-6%, mainly to make use of these boats’ characters and go fast to windward, both speed-wise and VMG-wise.

Cheers,
Arne

PS: Eight percent camber (= 1/12.5) is actually moderate or ‘middle of the road’ camber, according to the books. The resulting bagginess in junksails may look extreme, but it is not what we see that counts: It is what the incoming air molecules see...

 

Ketil Greve wrote:

Hi Graham,

I have been sailing Edmond Dantes a few seasons now, having reefed and shaken out reefs, dropping and hoisting sails a few times. I can assure you that the battens land just how they please, but I have never had any problems with snagging at the rear end of the sail. Any problems occuring is at the other end, but are easily sorted, but I have to move to the mast to sort snags with parrels/ Hong Kong parrels. Hong Kong parrels sometime gets trapped under the next batten and has to be freed. I have thrown away the luffhauling parrel as it dit not do any significant differece. I have a shock cort tied to the boom to stretch the luff, and ties the battens as I reef to have a taut luff, (good for performace). I find the rig much simpler and easier to use than anticipated after reading all the hot air theory in the various foras discussing this wonderfully simple and efficient rig with the unfortunate name Junk Rig.

Regards

Ketil Greve

Thanks Ketil, I just saw your comment.  I hope that I will soon be discovering a few things first hand as I hope to be sailing with my junk rig by the end of May.  I ended up with an HM type sail modified by David Tyler, with 4% camber and a yard topped up to 70 degrees and a bit shorter than the battens.  I am sure I will make a lot of mistakes at first but with the help of JRA members and the rig's ease of adjustment and refinement, should eventually get it sorted out.  Then its back into cruising mode!  I'm living on a contruction site at the moment!