Wingsail or Junk?

  • 27 Jan 2020 11:20
    Reply # 8694143 on 8689411
    Deleted user
    Anonymous wrote:

    What I would do, given your situation, is tabernacle-step the pole  as a mainmast, to carry a five panel junk sail, then set the foremast right up in the eyes of the boat and have a jib set to a removable bowsprit, from this (foremast) only.

    With a mizzenmast and sail, these two small and easily manageable sails should be good for balance. Then it would also be possible to carry a good driving sail in the way of a fishermans jib/gollywobbler type sail between the fore and mainmast..... as a guadrilateral sail with its peakhauling line belayed to windward, you have  a measure of staying and have theconvenience in handling of the battened mains'l.

    Not fully sure what you mean, but here’s a drawing of what I think you mean(though I didn’t make the junk sail smaller in this picture):
    1 file
  • 26 Jan 2020 21:23
    Reply # 8689411 on 8568472
    Deleted user

    What I would do, given your situation, is tabernacle-step the pole  as a mainmast, to carry a five panel junk sail, then set the foremast right up in the eyes of the boat and have a jib set to a removable bowsprit, from this (foremast) only.

    With a mizzenmast and sail, these two small and easily manageable sails should be good for balance. Then it would also be possible to carry a good driving sail in the way of a fishermans jib/gollywobbler type sail between the fore and mainmast..... as a guadrilateral sail with its peakhauling line belayed to windward, you have  a measure of staying and have theconvenience in handling of the battened mains'l.

  • 26 Jan 2020 12:20
    Reply # 8685894 on 8568472
    Deleted user

    I’ve managed to transport my mast from the old Gaff rig it came from to the yard beside my boat. I’ve begun sanding it and resealing it. It’s in remarkably good condition, kept dry these last 4 years, but it sat on the boat it’s from for likely five before that. The builder used a treated unused telephone pole to shape it from and the smell of the all the preservative is strong as I sand.

    Anyway, I’ve realised it’s a fairly robust mast, and wonder if there’s a way I could use it unstayed? I’ve got a 10mm steel bulkhead that runs port to starboard both fore and aft of the engine room. I wonder if it would be possible to build a steep step/tabernacle to seat the mast into above the partner level and accomplish this?

    I’ve made a few drawings which I’ve attached here. 

    2 files
  • 19 Jan 2020 19:43
    Reply # 8623271 on 8568472
    Anonymous member (Administrator)

    Randy,

    I suggest you have a look at how we constructed the 48sqm sail for Edmond Dantes in 2012. There was nothing daunting about that job. As can be seen, the method used does not involve pushing a whole batten panel through the sewing machine. We only ‘sew along edges’, so the sewing machine can simply be placed at the left end of the table.

    A white sail for Edmond Dantes, part 1.

    A white sail for Edmond Dantes, part 2.

    For my last three sails of this type, I have assembled and completed the sail, first as two halves, to save manhandling the whole sail much of the time. Only at the end do I join the finished upper and lower part along batten 3 from top and add the final bits there.

    Now, even if your mainsail ends up a bit smaller than that of Edmond Dantes, the thicker Topgun canvas will mean a much heavier sail at, say 24 - 27kg (versus about 17 in ED). When you approach the point that the two halves are to be jointed, you can either choose to just do it, or to finish them as two halves with those Roger Taylor style hinges along batten 3.

    Btw. I think the hinges that Jami Jokinen makes are better. He first cuts the sail panel with a conventional barrel shape to get the camber, and then adds the hoops, all of the same length. Much easier. Anyway, this may (or may not) make the rigging job a bit easier.

    Arne


    Last modified: 20 Jan 2020 09:51 | Anonymous member (Administrator)
  • 19 Jan 2020 10:31
    Reply # 8618566 on 8618310
    Randy wrote:

    As I mentioned in another reply, the bowsprit is to me, a beneficial device, if just for the pure joy! :) I also have a mizzen sail, main sail and two foresails, but all undersized. I imagine the foresails will work fine, but I'd likely take the Main and Mizzen I have and make one junk Mizzen, leaving me having to only make one large main from scratch.

    For the Mizzen, I imagine I need the four shrouds, though, as you mention. Wouldn't I? I Could make this sail a wingsail, but actually, I think I'd i'm leaning to make both as junk sails. The challenge I have here on the mizzen is that it will hang over the stern, requiring something of a stern sprit?

    If all goes well, I hope to make it to Brest for the big festival! And ideally the AGM in Brixham.

    So I think you end up with something like the sail plan that Arne sketched for you. One or two headsails, staysail to the stemhead and flying jib on a furler to the bowsprit end, with two shrouds and forestay to support them. As big a junk main as will fit, with a high-peaked yard to clear the forestay. A small junk mizzen on a mast with four shrouds, and double sheeting, port and starboard, to make it useable as a riding sail and to avoid having a spar extending the LOA.

    On sailcloth: 11oz Top Gun is favourite for this size of boat, but be aware that making large sails out of heavy cloth is a challenge. I've made a number of large sails from 9oz cloth and would be terrified at the though of making one from 11oz cloth. It would need a very large floor and sewing table, and at least two helpers to move the weight and bulk of the near-complete sail around while the machinist moves only that part of the cloth that is near the machine.

    there's a way around this. The way that Roger Taylor devised for the sail on Mingming II, with the sail in sections, joined at the batten with alternating pocket sections on each panel, with the batten passing through them, so that it looks like a metal hinge when assembled. It would be much less daunting to make a large sail this way. I worked with Paul to make Aphrodite's sails out of 11oz Top Gun in separate panels, joined by the battens, but I'd be happy enough to make a large sail in three or four sections of two or three panels each. Anyway, make the mizzen first, to get experience in passing heavy cloth through the machine without too much total weight to manage. Another point is to think carefully about the number of layers that are to pass under the needle at once, and keep it down to three. That's easy enough to arrange along the batten pockets, luff and leech, but it's where three layers at luff and leech meet three layers at batten pockets at the corners of the panels that even the strongest machine will struggle, where you get as many as six layers of heavy cloth.

  • 19 Jan 2020 09:49
    Reply # 8618310 on 8599026
    Deleted user
    So it's back to putting in the time and effort to make a big flat junk sail with plenty of balance. Flat, because this is never going to be a boat that will go to windward in light breezes, and a flat sail will work fine when the wind pipes up. Plenty of balance, and a low yard angle, to keep the loadings low, and I hope to obviate the need for a headsail.

    The mizzen will be small, with little balance area, and often furled in fresh breezes for better helm balance. It could be a Wharram wing, to save on time and effort in making it, or it could be a junk sail, to make it more useful as a riding sail.

    Whatever the sails, I'd be thinking of four shrouds, two forward and two aft, rather than two after shrouds and a headstay (to avoid having a bowsprit).

    As I mentioned in another reply, the bowsprit is to me, a beneficial device, if just for the pure joy! :) I also have a mizzen sail, main sail and two foresails, but all undersized. I imagine the foresails will work fine, but I'd likely take the Main and Mizzen I have and make one junk Mizzen, leaving me having to only make one large main from scratch.

    For the Mizzen, I imagine I need the four shrouds, though, as you mention. Wouldn't I? I Could make this sail a wingsail, but actually, I think I'd i'm leaning to make both as junk sails. The challenge I have here on the mizzen is that it will hang over the stern, requiring something of a stern sprit?

    If all goes well, I hope to make it to Brest for the big festival! And ideally the AGM in Brixam.

  • 18 Jan 2020 19:47
    Reply # 8612914 on 8568472
    Anonymous member (Administrator)

    Randy

    The hounds limits the size (height) of the junk sail just as it does with a gaff sail. If you move the hounds upwards, I can move the yard upwards as well, and maybe even make the battens a bit longer. I would not make the sail much wider, though, since a generous clearance for the main sheet is good to have, in particular on a sail over 40sqm.  However, if moving the hounds calls for a major surgery of the mast, I suggest you leave it as it is. After all, your vessel started as a motor trawler. These are not particularly fine-lined and easily driven, so in many cases you will be motor-sailing, using both sail and engine (one lower rpm), but still burning less fuel than before.

    Flat or cambered sail.
    When I wanted to upgrade my first flat junksail to camber, back in 1990, my motive was solely to improve speed to windward. I surely got that, but I also found the cambered sail to be much more powerful on all angles between broad reach and close-hauled. This is where your sail will give the biggest help ( the two 90° wide zones between 60° and 150° from the true wind). On these legs, a JR with a really good camber (10%?) will almost double the drive compared to a flat junk sail.

    Sailcloth
    I know some are using the stout 12oz.(?) Topgun canvas, for demanding tasks, and are happy with it.

    Arne


    Last modified: 19 Jan 2020 11:10 | Anonymous member (Administrator)
  • 18 Jan 2020 18:25
    Reply # 8612403 on 8609861
    Deleted user
    Anonymous wrote:

    Bigger sail?

    There are two limitations here:
    Number one is the existing mast and the position of the hounds.

    The other is, as you point out, the position of the COE. The Chinese vessel you show us gets away with the aft-set rig by having a huge rudder, which actually acts as an aft centreboard.

    The rudder of you motor vessel  is probably not very big, and unless the propeller is working, will have little authority. To improve it, I recommend adding a big endplate onto its lower end.

    Arne


    Yes, I do plan to enlarge my rudder.

    So, what will the position of the hounds mean to enlarging the sail? I guess I'd like to get as big as possible, thinking in my mind that will improve her ability? But, I'll take the advise from you pros .

    What is the recommended for sail cloth? I am the proud owner of a walking foot sewing machine, so in theory, I should have sail making potential.  

  • 18 Jan 2020 18:19
    Reply # 8612368 on 8609665
    Deleted user
    Anonymous wrote:

    Randy,

    yes, to quote Tom Cunliffe in his book ‘Hand, reef and steer’:

    “Hounds: The part of the mast which the main
    shrouds are attached. In a gaffer it is well up the
    shaft, because it must be above the gaff-jaws.”

    Funny about the images. They are meant to be opened (after some delay) if you click on them.
    Maybe this link to my member’s photo album will work better for you.

    Cheers,
    Arne


    I never even considered opening the image! LOL I can see them fine when I do that. Go figure  


    Hounds... got it.

  • 18 Jan 2020 11:35
    Reply # 8609861 on 8568472
    Anonymous member (Administrator)

    Bigger sail?

    There are two limitations here:
    Number one is the existing mast and the position of the hounds.

    The other is, as you point out, the position of the COE. The Chinese vessel you show us gets away with the aft-set rig by having a huge rudder, which actually acts as an aft centreboard.

    The rudder of you motor vessel  is probably not very big, and unless the propeller is working, will have little authority. To improve it, I recommend adding a big endplate onto its lower end.

    Arne


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

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