Forgot password

Pondering Seablossom's rig

  • 21 Oct 2011 09:55
    Quote
    Reply # 728479 on 726309
    Anonymous member
    Hi Jeff,

    I have just uploaded a preliminary sail plan based on the info that I currently have. It's in your Seablossem folder Propesed Junk Sail . The sail is Arne's Johanna sail, scaled to fit Seablossem and then stretched a little to get more sail area but still to fit your mast. The mast is about as far forward as is viable. At 465 Sq.Ft you have 18% more sail area than the standard rig (which is 394).

    Check if the clearances are adequate and we can then fiddle as need be. The CE of the junk sail is in the same horizontal position as the original. As the junk sail is quite forgiving with regards to balance, I see no issues there.
    Last modified: 21 Oct 2011 19:15 | Anonymous member
  • 21 Oct 2011 03:08
    Quote
    Reply # 728288 on 728267
    Anonymous member
    Jeff McFadden wrote:

    The mast can stand anywhere from 44" back from the bow to 68" back from the bow, which would be very close to the coachroof.  If it works for your design I would prefer to stay another 4 to 6 inches forward, say 62 to 64 inches back from the bow, for interior uses.  This latter request is not critical at all.

    Thanks for your help here!

    Jeff

    Hi Jeff,

    I take it the measure you give me (from the bow) is to what would be the center of the mast or is it the forward/aft edge that you are thinking of? It makes a 4inch difference so you'd want me to have it right.

    David's Mk1 eyeball comment is spot on, I'll jungle things till they come out right. I'll also be trying for as much sail area in as I can, as the rig is easy to reef and if I remember correctly (it;s awhile since I sailed on inland waters) inland lakes generally have light winds (breezes) than the opposite.
  • 21 Oct 2011 02:48
    Quote
    Reply # 728267 on 727902
    Deleted user
    Paul Thompson wrote:Hi Jeff,

    I have done a basic drawing, but need the following info before it can be of much use.

    LAP - so that I know how much mast we have.
    Mast diameter - so I can double check its suitability for the job
    Position - You need to tell me the preferred position for the mast and give me a measurement from the bow to the center of that position. You can use King Henry's thumb for the measurement don't worry about metric measures.

    Right now, as close to the forward edge of the coachroof as possible looks good but this may or not be viable depending on the structure underneath.

    As soon as you are able to give me the above info, I'll post a preliminary sail plan.

    I came home today and took all these measurements and entered them into a file in my (allegedly) smart phone.  Now as I come in to send them to you I see that it ate them.  I'll go out tomorrow and measure again, and perhaps we can make more progress.

    General numbers by memory:  Length above partners is 32 feet.  Bury will be about 44 inches, but the sail will have to be raised higher to account for the cabin top, to about 64 inches, so available length above partners comes out to 30 feet 6 inches.

    The mast is 8 inches in diameter at the partners, made in birdsfoot fashion.  I'm not sure how thick the boards are.

    The mast can stand anywhere from 44" back from the bow to 68" back from the bow, which would be very close to the coachroof.  If it works for your design I would prefer to stay another 4 to 6 inches forward, say 62 to 64 inches back from the bow, for interior uses.  This latter request is not critical at all.

    Thanks for your help here!

    Jeff
  • 21 Oct 2011 01:40
    Quote
    Reply # 728186 on 726309
    Anonymous member
    Jeff, just looking at the drawings with a mk 1 human eyeball, and without going through all the formal design process (which I believe that Paul has already started), it would seem to me that Seablossom should have quite a low aspect ratio rig, and the mast for it is likely to be vertical, and placed just forward of the feet of the current forward berths, in the old sail locker. The mast for a higher aspect ratio rig would probably go a bit further aft than that.
  • 21 Oct 2011 01:15
    Quote
    Reply # 728147 on 728009
    Anonymous member
    Annie Hill wrote:Actually, it was King Edward II who defined the inch:  as "three grains of barley, dry and round, placed end to end, lengthwise".

    Unhulled, obviously.

    Thought everyone knew that :-0
    Everybody seems to have a different story and no doubt they are all wrong. See:
    https://secure.wikimedia.org/wikipedia/en/wiki/Inch for more than you ever wanted to know on the subject of irrational inches/systems of measurement.
  • 20 Oct 2011 21:46
    Quote
    Reply # 728009 on 726309
    Anonymous member
    Actually, it was King Edward II who defined the inch:  as "three grains of barley, dry and round, placed end to end, lengthwise".

    Unhulled, obviously.

    Thought everyone knew that :-0
  • 20 Oct 2011 19:19
    Quote
    Reply # 727902 on 726309
    Anonymous member
    Hi Jeff,

    I have done a basic drawing, but need the following info before it can be of much use.

    LAP - so that I know how much mast we have.
    Mast diameter - so I can double check its suitability for the job
    Position - You need to tell me the preferred position for the mast and give me a measurement from the bow to the center of that position. You can use King Henry's thumb for the measurement don't worry about metric measures.

    Right now, as close to the forward edge of the coachroof as possible looks good but this may or not be viable depending on the structure underneath.

    As soon as you are able to give me the above info, I'll post a preliminary sail plan.
  • 20 Oct 2011 15:10
    Quote
    Reply # 727716 on 727665
    Anonymous member
    Jeff McFadden wrote:
    Jonathan Snodgrass wrote:

    Just a thought or two ...  Slieve McGalliard's Poppy's split junk rig has significant area ahead of the mast and therefore presumably could or should have the mast set further aft than a simple junk rig.  The main intended advantage of the split rig is better performance, including to windward.  However, an advantageous side effect is that the area forward acts as a damper giving a softer gybe.  Could it be that a split junk rig could accomodate a mast at the same position as intended for a bermudian rig?  Would the current position of Seablossom's mast be suitable for a split junk rig with a large area of "jib" forward?  The disadvantage would presumably be that it might not then be possible to re-use the current sails, boom, yard and battens - ouch!  It might  however be worth at least asking the question at this stage, if only deliberately to eliminate the posssibility. 


    Jonathon, thanks for the thought. In this case, though, moving the mast would in itself be an advantage. It hogs much of the floor space in the already minimal cabin of the little 27 footer. By moving it forward I can arrange to have the chain locker forward of it, lockers to both sides of it, then probably the head just aft of that with the cabin amenities filling the remaining space.
    Jeff
    Good.  jds
  • 20 Oct 2011 14:15
    Quote
    Reply # 727665 on 727600
    Deleted user
    Jonathan Snodgrass wrote:

    Just a thought or two ...  Slieve McGalliard's Poppy's split junk rig has significant area ahead of the mast and therefore presumably could or should have the mast set further aft than a simple junk rig.  The main intended advantage of the split rig is better performance, including to windward.  However, an advantageous side effect is that the area forward acts as a damper giving a softer gybe.  Could it be that a split junk rig could accomodate a mast at the same position as intended for a bermudian rig?  Would the current position of Seablossom's mast be suitable for a split junk rig with a large area of "jib" forward?  The disadvantage would presumably be that it might not then be possible to re-use the current sails, boom, yard and battens - ouch!  It might  however be worth at least asking the question at this stage, if only deliberately to eliminate the posssibility. 


    Jonathon, thanks for the thought. In this case, though, moving the mast would in itself be an advantage. It hogs much of the floor space in the already minimal cabin of the little 27 footer. By moving it forward I can arrange to have the chain locker forward of it, lockers to both sides of it, then probably the head just aft of that with the cabin amenities filling the remaining space.
    Jeff
  • 20 Oct 2011 11:14
    Quote
    Reply # 727600 on 726309
    Anonymous member

    Just a thought or two ...  Slieve McGalliard's Poppy's split junk rig has significant area ahead of the mast and therefore presumably could or should have the mast set further aft than a simple junk rig.  The main intended advantage of the split rig is better performance, including to windward.  However, an advantageous side effect is that the area forward acts as a damper giving a softer gybe.  Could it be that a split junk rig could accomodate a mast at the same position as intended for a bermudian rig?  Would the current position of Seablossom's mast be suitable for a split junk rig with a large area of "jib" forward?  The disadvantage would presumably be that it might not then be possible to re-use the current sails, boom, yard and battens - ouch!  It might  however be worth at least asking the question at this stage, if only deliberately to eliminate the posssibility. 
       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

                                                              Site contents © the Junk Rig Association and/or individual authors

Powered by Wild Apricot Membership Software