Alberg 30 JR Conversion

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  • 03 Nov 2024 09:16
    Reply # 13426587 on 13422163
    Anonymous member (Administrator)

    Annie,

    I can see your point with a forward-raking foremast on a schooner. The annoying turbulence from the mainsail is well known to pointy-rig sailors as well.


    However, I cannot see much need for a forward rake on a schooner’s mainmast or on a JR sloop mast, unless there are issues with deck layout or interior.

    Your Fanshi and my Ingeborg are similar in size, and I, like you do a lot of sailing among islands. Accidental gybes are almost unheard of  -  it still surprises me how far I have to round up before the gybe starts (feels like a beam reach). So, yes, I too frequently sail by the lee, no problem (no Pacific swell around here, though).

    There is one thing it appears that I do differently than many: I rig my boats with only 3-part purchase on the sheet. Apart from a short stint of sailing my Johanna with 5-part sheet, the 3-part sheet has been the norm on all my boats. This both reduces friction when raising the sail, and allows the sail to swing out in very light winds.

    Btw. my sailing season is over for now, after 17 outings this summer. Time for starting the ‘coffee season’, that is, inspecting the boat now and then, lighting the little gas heater, and have coffee and sometimes a yarn with my sailing mate.
    Could be worse!

    Cheers,
    Arne



    Last modified: 03 Nov 2024 09:16 | Anonymous member (Administrator)
  • 03 Nov 2024 04:46
    Reply # 13426575 on 13425595

    Arne wrote:

    •     A forward raking mast (more than say 3°) can easily lead to increased friction when raising and lowering the sail, as the batten parrels will be more likely to rub on the mast, with that halyard constantly pulling the sail forward.
    • ·         The Chinese ‘never’ used forward rake on the masts for their mainsails. Only the foresails, generally smaller, were made with forward-raking masts.
    • ·         Badger’s foremast was set plumb, and when reading Annie Hill’s books about sailing Badger, I cannot remember any complaints about this.

    Frankly, I think that the recent use of forward-raking masts has become a fashion, or hype, with no particular technical base  -  or else the Chinese would have done it already. Annie has given a rational reason for it (hoisting sail in light winds and old swell on the east coast of NZ), but she is the only one.

    I have not noticed any increase in friction when raising the sail and certainly it comes down withut a problem.

    Badger did have have a vertical foremast and I certainly have written about the drawback of that.  Whether I included it in VOASI, I don't recall.  However, if it had had more rake, the sail would have stayed asleep much longer when we were running wing and wind.

    The other reason I love my raking foremast is that I do a lot of sailing among islands in this part of the world, where there are often turns to be made or the wind is a wee bit flukey.  The rake allows me to sail considerably by the lee without gybing the sail, which is a real advantage (if you are as lazy as I am), when you know you will shortly start heading up into the wind.

    I would agree it makes it more difficult to climb the mast.  I have so far neither had to climb it, or to lower it in its tabernacle.  

  • 31 Oct 2024 14:45
    Reply # 13425688 on 13422163

    Thank you, Arne. As expected, your clear and rational reply makes perfect sense. I put a forward raked foremast in Branwen, simply to get more sail area and because that is what the Chinese did. You're right - even a 3° angle gave a noticeable increase in friction. I did like the way it looked, though.

  • 31 Oct 2024 11:44
    Reply # 13425595 on 13422163
    Anonymous member (Administrator)

    Asmat.

    • ·         First of all, it is easier to step a plumb mast.
    •       A plumb mast is also easier to climb.
    • ·         A forward raking mast (more than say 3°) can easily lead to increased friction when raising and lowering the sail, as the batten parrels will be more likely to rub on the mast, with that halyard constantly pulling the sail forward.
    • ·         The Chinese ‘never’ used forward rake on the masts for their mainsails. Only the foresails, generally smaller, were made with forward-raking masts.
    • ·         Badger’s foremast was set plumb, and when reading Annie Hill’s books about sailing Badger, I cannot remember any complaints about this.

    Frankly, I think that the recent use of forward-raking masts has become a fashion, or hype, with no particular technical base  -  or else the Chinese would have done it already. Annie has given a rational reason for it (hoisting sail in light winds and old swell on the east coast of NZ), but she is the only one.

    Some yacht designers, like Forestier, seem to like forward mast rake, but he, like most of them doesn’t design good junkrigs.

    However, the JRA world is a free world, so one should do what one likes.
    Live and let live.

    Arne


    Last modified: 31 Oct 2024 23:28 | Anonymous member (Administrator)
  • 31 Oct 2024 11:14
    Reply # 13425590 on 13424658
    Anonymous wrote:

    David,
    generally I am not too fond of forward-raking masts, unless deck layout demands it. 

    Arne

    (full size diagram in Arne's sketches, section 8, photo 17)

    Why?
  • 31 Oct 2024 10:11
    Reply # 13425572 on 13422163
    Anonymous member (Administrator)

    So now we have almost gone full circle!

    The shown sail below has the same mast position and 70° yard angle as the first sail I drew up in 2020. Now I have lowered the AR to 1.90 to hit about 40sqm. This sail is of the same planform as the one on my Ingeborg, only a bit bigger.

    The advantage with this sail with 70° yard is that you get a tall sail for the mast length. The disadvantage is that the moderate mast balance brings the CE quite far away from the mast. This leads to higher sheet forces, but more important; when running before, the CE will sit well away from the centreline, and this makes helming harder in rising winds. The last sail I drew up for you, with AR = 2.24 illustrates the difference.

    However, there is a trick which some have used with success: By using a running TP, Throat Parrel, and TL, Tackline, one can shift the boom forward at will, and thus bring the CE closer to the mast (and CL).

    The next diagram shows how it looks with the sail (red) tilted 6° forward. This type of sail, with 10° boom rise, appears to be very well suited to this kind of tilting. This is made clearer by shoving a front view of the boat.

    To make the system work, one will, as said, need two more running lines. In addition the batten parrels must be made with adequate length, and the mastlift needs a moderate re-arrangement.

    Have a look.

    Arne


    (Full size diagrams under Arne's sketches, Section 8, photo19 and 20)

  • 29 Oct 2024 17:38
    Reply # 13424873 on 13422163

    Thank you, Arne! I greatly appreciate your time and patience! I have learned a lot as I read back and forth through the postings, and my copy of Practical Junk Rig. I think this is a great solution with the mast in the forward hatch aperture.

    I found your article from JRA Magazine Issue 76 about your mast step and partners on Ingeborg, and though I initially dismissed a more forward mast location, I am going to take a closer look that the previous thread regarding the Alberg 30 conversion with the mast step further forward. I had been concerned about the bury depth, but I think this can be resolved.

    I’m interested in comparing your last sketch with the AR 2.05 sketch you did for the mast in the forward position, but with 40 square meters of sail instead of 43.5 square meters. I think this could bring the sail down, and put the CE very close to the CE of the Bermudan rig.

    https://junkrigassociation.org/resources/photo/uTljNHN_T9II2VPclRSi4a0_AU23C3w34fu1_6KuiGi8tTD-h5QI6BUBrmBnzaRckjOKxGYdv4eMrzQ56kqgdw2


  • 29 Oct 2024 10:49
    Reply # 13424664 on 13424658

    (PS: can the word 'rake' be used as a verb, as I have done?)

    Arne


    Arne

    Yes indeed.  

    My Concise Oxford Dictionary has rake as a noun and also as

    a transitive verb (ie taking an object) as in 'he raked the mast forwards'

    and 

    an intrasitive verb (ie not taking an object) as in 'the bow of the ship rakes forward'.  

    As it happens you didn't use rake as a verb in your post , but only as a noun.  

    Please be assured that you written English is better than many if not most native English speakers.  

    And of course your knowledge of junk rigs is 'Nulli Secundus' .  

    Please keep up the good work.  We are all grateful.

    Yours aye  Jonathan 

  • 29 Oct 2024 09:24
    Reply # 13424658 on 13422163
    Anonymous member (Administrator)

    David,
    generally I am not too fond of forward-raking masts, unless deck layout demands it. However, you may have a point here. Even this little 1.5° adjustment will let me move the halyard’s slingpoint back to the 5% point (not important).

    What I would have done, is to rig the mast plumb, but have a slot in the mast step to let me  adjust the mast rake. It takes less than 50mm movement at the step to achieve 1.5° mast rake.

    Just a thought.

    (PS: can the word 'rake' be used as a verb, as I have done?)

    Arne

    (full size diagram in Arne's sketches, section 8, photo 17)

    Last modified: 29 Oct 2024 09:28 | Anonymous member (Administrator)
  • 29 Oct 2024 07:38
    Reply # 13424639 on 13422163

    That'll do nicely, Arne. Perhaps a degree or two of forward mast rake, to reduce the balance even further? 

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