Galion 22 conversion

  • 07 Oct 2021 22:02
    Reply # 11151041 on 5070195
    Anonymous member (Administrator)

    Hi Jami. At one time I began collecting numbers, wherever I could find them, relating to the split junk rig. I didn't get very far, but here is what I have at present: (you can click on it to enlarge)

    (As you know, these shelf foot sails have a designed camber (which would be the camber if they were made from tin plate) and useful enough when comparing shelf foot sails with shelf foot sails. However the actual camber of the soft cloth sail will be greater, and if comparing with conventionally cut sails, the camber needs to be measured when the panels are inflated, the way Arne does it.

    No-one seems to have done it yet with a SJR panel. I just need to add that disclaimer).

    I am very happy with the way Serendipity sails, including to windward, but we don't yet have much in the way of objective comparisons. Emmelene looks to be sailing beautifully in the photo in the current home page "featured boat" and Chris is happy. Amiina (the model for most of the subsequent SJR rigs) has proved successful. The parameters for your sail would seem to be within the "successful" range, so if you are a little unsatisfied, maybe we need to look for other parameters which are not shown here.

    The one which comes first to my mind is "balance". I have a feeling that when going to windward the lion's share of the work is being done  by the jibs, and the wash from the jibs may be (not sure) may be slightly degrading the performance of the mains panels, because on my boat it is the mains which begin to lose that pressure difference first, when pinching up to windward. It seems to me the important point about the SJR is that to get the best from it, the jibs need to be as large and powerful as possible (the limiting factor being the sail's dynamic balance point). This notion is reinforced, in my mind, by a high performing bermuda-rigged trailer boat I once owned (a Noelex 22) which went to windward like a witch, in any decent sort of breeze, on staysail alone - and with beautiful helm balance too. The stay sail in this case was a 3/4 rig, but with fairly long foot - not quite a genoa, but it was a powerful little staysail and it pulled like a mule. (The hull was superbly proportioned too, of course).

    Therefore, it seems important to have as great a jib chord as possible. So, the balance ought not to be too much less than the proven 33%. (And for those who are contemplating a SJR for the first time, not too much more either! Be sure you understand the balance calculation for SJR - it is not quite intuitive, and a mistake here could have consequences as 33% is probably not too far from the limit of what is workable. Sorry Jami, you will know all this this, its just another disclaimer which needs to be put in here.)

    As you will know, if you were to increase the jib cord on your sail, this may affect the balance calculation, depending on where the extra cloth is placed. If the extra cloth of a new jib were to be added to the leech (reducing the slot width) then the balance calculation won't be affected. If the extra cloth is added to the luff and the battens extended forward accordingly, then the calculated balance will be increased, and the proven limit, to date, is 33% - though we are all waiting for someone to try 35%, which Slieve has found successful on model swingwing racing boats. If there is room to move, within the envelope of your sail plan, then new jibs and extended battens might be worth the shot. It would be interesting to know what is the current calculated balance of your sail, and the slot width - better still to see a diagram of your sail with all these measurements. A diagram would save a lot of words.

    A "thought experiment" suggests to me that if the jibs are made ridiculously small, (say, a balance of 5%) they would merely interfere with the main, and in that case the boat might sail better without them. I am not saying for one moment that your jibs are "ridiculously" small, but they may be a tad too small, and it would indeed be interesting to follow your suggestion, and before the season is over, just for fun, try your boat for sailing without them. I expect a SJR with no jibs would be at least as good as any other cat-rigged sloop, sail area for sail area.

    My uninformed suspicion is, maybe the SJR really needs that 33% balance to perform at its best, and maybe if there is only room in the design for 25% balance, or less, then a contiguous sail might be a better choice. And it would not surprise me if you find, with larger jibs chord, that your boat would be more powerful to windward.

    Its one of those many things that we won't know until someone tries. We all still have much to learn. 

    (PS the main panels collapsing first, when coming up into the wind, is normal I think. The two-part sheeting for this type of sail works very well on my boat, not really any extra hassle and perfect for controlling twist).

    (PPS for those contemplating SJR for the first time, all this talk about balance is fairly important, because the sheeting forces are quite light on a SJR, and if you go over the limit with balance there is a risk that in a high wind it might not be possible to luff up or to let fly the sail! A runaway junk, helmsman with eyes on stalks, scrambling to the windward side to stack out for dear life while at the same time trying to put the helm down, would be an impressive sight - I wouldn't want it to be me!

    There has been a suggestion also, that if the battens start bending, this might exacerbate the problem - so we don't want to be right on the limit with balance.)

    Last modified: 08 Oct 2021 01:39 | Anonymous member (Administrator)
  • 07 Oct 2021 11:39
    Reply # 11146963 on 5070195


    it looks like I will have to make new jibs during winter and lengthen the battens accordingly. Oh well.

  • 06 Oct 2021 18:57
    Reply # 11145251 on 5070195


    Jib cord is 1090 mm, main cord is 2530 mm, mast slot is 170 mm.

    Camber both mains and jibs 10%. Mains have 90 degree shelves.

    Jibs as per instructions.

  • 06 Oct 2021 06:01
    Reply # 11143808 on 5070195


    could you give the critical measurements (main and jib cord lengths, the split/gap size and the cambers on the jibs and mains), pleae?

  • 05 Oct 2021 19:50
    Reply # 11142618 on 5070195

    Very hard to compare sail shape from a photo Jami, but this sail goes to windward very well. Short chop and light boats requires power; we have unreefed in those conditions to get somewhere upwind.


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  • 05 Oct 2021 12:31
    Reply # 11141566 on 11140296
    Slieve wrote:

    Thanks, Slieve, for chiming in. I appreciate this.

    1. You are right - the main luffs sit right behind the mast edge (aft), not on the mast (or the centreline). This will be an easy fix.

    2. The lower mast diameter is 120mm and the split is 200mm. I would think this is enough, or is it?

    3. This is potentially true. However, the hinges on this sail are so "tight", that there is probably very little air going through. Probably.

    4. The camber on the jibs has been done along your instructions (was it something like 15% or...?). I have also re-measured this from the sail (by measuring the lens, not the actual formed camber) and checked that it's ok. 

    5. I have tried different sheeting arrangements and traveler-like systems to be able to sheet in as much as possible. I haven't noticed a drastic effect to the pointing ability.

    6. Some of this is easy to swallow, some of it not so much. We have to remember, that I have sailed this same hull with a (tired) BR, a Hasler-Arne -type JR and a SJR (oh, how good a laboratory my boat would've been if I just were more engineering-oriented). I strongly feel that the ability to fly through chop has severely been affected by lack of drive towards the wind. 

    7. The whole chord length is 4000mm, of which the main takes 3000, the split 200 and the jibs 800mm. As you can see, the balance is less than instructed. One of the possible solutions for our situation would possibly be lengthening the battens 150-200mm and sewing now jibs (as I said on an earlier post).

    Last modified: 05 Oct 2021 13:43 | Anonymous member
  • 04 Oct 2021 22:31
    Reply # 11140296 on 5070195

    Hi Jamie,

    I've just found this thread and have noted some points here which will probably raise more questions. From the videos -

    1. Luff of the main panels seems to be some distance behind the mast, and not alongside the centreline of the mast. The available drawings of the batten-parrel/ down-hauls are not ideal. If I remember properly the latest version starts by tying the end to the batten some half to three-quarters mast diameter behind the main luff, going round the mast and over the batten, before down the outside to level with the bottom of the lower batten. Here it goes through a thimble, nylon in my case with the burrs removed, up over the lower batten and round the mast to tie off the same half to ¾ mast diameter behind the main luff. The downhaul is tied off to the thimble.

    2. I can't remember how wide you have made the split but the mast diameter looks to be almost the same, so in the present set-up could be blocking the airflow.

    3. I appreciate the easy construction of the separate panels and the 'hinge' along the battens, but there is undoubtedly an air leak and a loss of pressure here across the sail. I don't know how much the loss might be, but it certainly will not help the performance, and may cause unwanted turbulence on the leeward side.

    4. In the videos the jibs look fairly flat and not very cambered. Similarly, the leech of the jibs seem to be fairly 'close in', and it looks as if you are not getting a very wide 'sheeting angle'. It's impossible to tell this from pictures.

    5. It's difficult to see how close you are sheeting the rig in towards the centreline in the videos. I found that I could sheet very closely as on a cruising Bermudan rig and still be driving, but I had a VGM meter on the bulkhead which was a great help in evaluating the rig, and a great help in getting the best performance. Once I got used to the closer sheeting then I didn't need the VMG meter.

    6. The Galleon hull and keel shape are probably not the greatest for close hauled performance, particularly is a short sharp chop. Poppy was a bit of a 'blunt punt' when faced with the wind against tide 'Solent chop', but the keel was quite good. Even so, I rarely got a chance to compare the performance against cruising Bermudan boats as they always motored in those conditions. In the Island Races we could stay with similar performance hulls, but I was always sickened to see the FolkBoat derivatives just slice through the chop as each small but steep wave hit like a heavy rubber hammer. There are hull shapes and hulls shapes, and the Galleon is not a FB!

    7. I can't remember what percentage balance you have ended up with, but it may be a little short of the optimum. The jib chord id 80 cm, but what is the width of the split and what is the main chord?

    8. How clean is the hull bottom. It takes very little growth to make a big difference.

    Some of these points will undoubtedly degrade you performance but by how much, and which are the most important are difficult to suggest from the videos. The SJR boats I've sailed have all shown close hauled performance at least as good as their cruising Bermudan cousins, and better performance on all other points of sail. By sheeting in very tightly it is possible to outpoint Bermudan rigs, but the VMG will fall off. Even so, it is handy to be able to pinch under control in a a narrow channel or past a moored boat.

    By the way, I suggest one top panel and without a split for ease of sailmaking and to allow for slight inaccuracy in sail-making. I've only built one rig with a split in the top panel and found it critical to make, and with the tapered height it was not so easy to calculate the camber and sheeting angle.

    What do you think,

    Cheers, Slieve.

    Last modified: 05 Oct 2021 09:04 | Anonymous member
  • 03 Oct 2021 21:58
    Reply # 11137643 on 5070195


    Hard to tell on a video but I get the impression you could haul in the sheet a bit more.

    The jibs are at a wider angle then the mains so you can sheet in further then your previous sail.


  • 03 Oct 2021 12:50
    Reply # 11136756 on 5070195
    Anonymous member (Administrator)

    Would it be possible to only remove the middle jiblet and install a temporary version instead, which can be adjusted with respect to slot opening? 
    This could give you some answers.


  • 03 Oct 2021 09:54
    Reply # 11136623 on 5070195

    …but before the sea freezes, I might take off the jibs altogether and see what happens with a high-AR unbalanced mainsail only.

       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
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