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Thread: The case of the missing mizzen

  1. #1
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    Default The case of the missing mizzen

    My Gillmer Blue Moon, Pipa, has a couple of rig modifications. The mast is short enough that a yardless topsail can't be set, the jib stay is attached higher (level with the gaff peak), it has an extra pair of shrouds instead of running backs, and it was built with a Marconi mizzen, but a previous owner got rid of the mizzen spars, step, boomkin, etc. All that remains is the sail which seems to be in good condition. I'm looking to bring a mizzen back into the picture (and eventually a topsail too). It just so happens that Pipa's mizzen and my Atkin Vintage's boomed, sprit mainsail are both 50 sq. ft.

    My dream here is to come up with a mizzen for Pipa that can easily be removed and used to sail the dinghy. I figure it may be stayed on Pipa and probably unstayed on the dinghy as the rig will handle much lower wind speeds. I figure there are three obvious options:

    1 Make spars for the Marconi mizzen that this Blue Moon was designed with. Modify the dinghy to suit.

    2 Make spars and sail for Blue Moon's balanced lug rig. This seems a highly peaked lug and I imagine that the Marconi sail would present a similar center of effort.

    3. Modify my sprit rig so the sprit and boom and rotate on a fixed mast and stay my existing mast when it's doing mizzen duty. Make a heavier sail for mizzen duty. Swap sails as I like.

    Options 1 & 2 would require moving the mast step/forward thwart aft in the dinghy. If the distance moved wasn't too great, though, it could improve rowing trim much of the time and actually make a usable forward rowing position feasible (the designed one is lousy, too narrow and only trims well with a much lighter person forward). Taller masts would also have the advantage of being able to set a taller mizzen staysail if I ever got around to getting one of those. Option 3 would have the advantage of spars that can store in the dinghy. I welcome thoughts and opinions on the merits or downfalls of any of these options.

    Here's some links to see the sail layouts as-is:
    http://www.atkinboatplans.com/Dinks/Vintage.html
    https://photos.app.goo.gl/VdEB3AUmDjrw6YJA6

    Here's the Blue Moon's standard rig layout (not mine):
    http://www.maritime-identity.com/wp-...on-gillmer.png

  2. #2
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    Default Re: The case of the missing mizzen

    If it can be unstayed in the dinghy, why not on the bigger boat, no room for mast bury? I had similar ideas, the sprit boom rig seemed the best compromise for both purposes, just needs a jigger set astern to take the mizzen sheet.

  3. #3
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    Default Re: The case of the missing mizzen

    Yeah, the mast bury is a limitation. The mizzen is designed to step on the transom above the tiller. As such, this leaves 6" from the bottom of the step to the top of the partners. The rake of the transom is such, too, that if you wanted to step it on deck offset to one side of the tiller for more bury, it would have to move forward quite a bit and be raked well aft to clear the main boom. It's an interesting possibility, but I have a hard time imagining just what kind of rig would be ideal in that case. Call it option 4 if you like. I don't mind having stays on the rig in it's mizzen role, as that creates some nice places to stow a boathook, or a life ring, and gives some nice handholds near the stern. You can see how far aft the main boom comes in the standard sail plan image I linked to above.

  4. #4
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    Default Re: The case of the missing mizzen

    I do not think i have any pictures, i used a several layers of ply overhanging the transom with a hole in, and then glued a pad lower down with a shallow mortice to take the mast foot. Not as much rake on my transom as yours, but you can always use the lower "step", for just that purpose . If i can find pic i will post it.

  5. #5
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    Default Re: The case of the missing mizzen

    This might give you the idea....





    Im not 100% i will use a similar set up on the next boat, as the mizzen might get loaded with crap like antennas and radar reflectors, so i might end up being a bit oversize for a dink.....

  6. #6
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    Default Re: The case of the missing mizzen

    The strength of the mizzen mast must be strong in proportion to the stability of the boat, not the area of the sail. The mast for the dinghy should be considerably lighter. I'd go with two masts.

  7. #7
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    Default Re: The case of the missing mizzen

    John, I have plans for both the mizzen mast (lug) for Blue Moon and the Vintage mainmast. Both have a maximum diameter of 2 1/2", despite the difference in their lengths, 13' and roughly 9' 6". Therefore, the Vintage mast is actually heavier for its length. If what you say is true, I can only presume that the staying is what leads to the mizzen mast being thinner for it's length. Based on these dimensions, it would seem that a stayed/unstayed combo would work. Effectively, the stays would provide the extra strength the mizzen needs for its reduced mast bury and the Blue Moon's greater stability, if I understand your point correctly.

  8. #8
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    Default Re: The case of the missing mizzen

    Or perhaps the Vintage mast is stronger than it needs to be. Either way, if it meets design specs, it should work.

  9. #9
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    Default Re: The case of the missing mizzen

    So do you tow the dinghy behind the Blue Moon all the time? If that's the case, I really like the idea of being able to easily pull the mizzen from the mother ship to be dropped into the dinghy. But it must be a quick and easy process -- no tools required, all lines to be cast off with one hand, and so on. Ideally, this means no stays. But if that can't be done (and it does look difficult) then the operation is going to get awkward. And in that case maybe it's better just to have separate sail and spars for the dinghy where the whole package will drop inside it bundled with the oars when not in use.
    -Dave

  10. #10
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    Default Re: The case of the missing mizzen

    That's a very funky arrangement for the lugsail mizzen in the boat's sailplan drawing (funky to the point where it probably doesn't work very well). With the halyard tied so high on the yard, the yard can't have the normal aft-heavy balance that standing lugs need in order to generate adequate luff tension (which is also what keeps the yard from going vertical every time you tack or ease mainsheet tension). For a lug, you would be better off cutting about 3' off of the mizzen mast and tying the halyard about 40% of the way aft of the yard's heel. For something with a pretty similar profile and the taller mast, you would probably do a lot better modifying the luff edge and turning it into a gunter sail.

  11. #11
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    Default Re: The case of the missing mizzen

    Thanks for the pics for your mizzen setup, skaraborgcraft. I can't imagine how to make something like that work with the rake of my transom, though...short of putting a hole through the transom or having the step well outboard where it would need additional bracing.

    Dave, yeah I tow a lot. In Maine, it's wicked convenient. Heck, the Vintage has about 8000 nm of towing on it now, including a trip to Georgia and back. It tows better in heavy weather without the weight of a rig stored aboard. I agree that it should be easy to move the rig, but I think it only needs to be as easy as setting up a stowed dinghy mast. Heck, given the preciousness of stowage aboard a Blue Moon, that's not even a hard requirement for me. My quick and easy idea for the mizzen shrouds is that they're tensioned with lashings and attached with pelican hooks at the bottom. Spliced loops at the top make them slip off the masthead easily when downrigging.

    Todd, it's interesting that you bring up the funkiness of the highly peaked lug. I've wondered about that myself. It seems like a jib headed sail would have less spar weight and set almost the same sail profile whether rigged as a gunter or simply laced on a one-part mast. Looking through the pictures of Blue Moon's sailing that I've found it looks like luff tension on the mizzen might be a problem. I've wondered if the person who built this Blue Moon wasn't more clever to go the jib-headed route. In John Leather's Gaff Rig book (1973), his description of the Falmouth Quay Punts, upon which the Blue Moon is based, is interesting:

    https://photos.app.goo.gl/2F12fiPgt6Bfmtn2A

    Not only did they traditionally sport jib-headed mizzens, but elsewhere Leather suggests that they're an ideal mizzen for gaffers. I also like the idea of being able to set a large, summer lugsail or a reaching staysail if I ever get carried away in the quest for more canvas.

    Another rig difference which I forgot to mention is that there are no spreaders on my mainmast and the chainplates are insanely heavy (still trying to figure out why on that later point...for crane lifting, maybe or they were just lovely left over hardware from another boat).

    The shorter mainmast without spreaders seems to bring the rig a bit closer to the working boats it was based on. I also note that the original rigs had single shrouds rather than double shrouds which would make for less rigging to hassle with. They do appear to have had offset and deck stepped mizzens, though. I could possibly go this route if I cut the last few, unused inches off the main boom and gave the mizzen a moderate aft rake. Might give a nice look with the offset bowsprit Pipa already sports and look a bit more traditional and workboat like. Not that that's a requirement, but it is my leaning.

  12. #12
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    Default Re: The case of the missing mizzen

    I don't have a problem with using a high peaked lugsail for the mizzen, but it you're going to do it, it should be rigged properly. This one is not.

  13. #13
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    Default Re: The case of the missing mizzen

    Interesting, Todd. I just reread what you wrote earlier. Cutting 3' off of the mast would almost make it the size of my current dinghy mast. Might be able to experiment with a lug easier than I thought...

  14. #14
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    Default Re: The case of the missing mizzen

    One of the decisions you will need is a boomed sail, lug or not or loose footed. the loose footed needs a longer boomkin but there is one less spar to worry about. you'll need to check the foot against the length of your dinghy. i've been happy with my standing lug mizzen on my similar sized nigel irens romilly which has an off set unstayed mast but you need to pay attention to it when towing. i do like that it is set up to be brailed.
    Ben Fuller
    Ran Tan, Liten Kuhling, Tipsy, Tippy, Josef W., Merry Mouth, Imp, Macavity, Look Far, Flash and a quiver of other 'yaks.
    "Bound fast is boatless man."

  15. #15
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    Default Re: The case of the missing mizzen

    Ben, that'd be a long boomkin, indeed! I figure it would need to stick further outboard than the long bowsprit to sheet well on the wind. A easily brailed sail is a treat, though. Could you share pictures of your mizzen setup?

    Here's a great pic of one of the original Falmouth Quay Punts, I.C.U. The mizzen spars look quite a bit beefier than Blue Moon's and you can see a lot of how the traditional rig is a bit different. (Pic from John Leather's Gaff Rig book.)


  16. #16
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    Default Re: The case of the missing mizzen

    [QUOTE=marujo.sortudo;5739037]Ben, that'd be a long boomkin, indeed! I figure it would need to stick further outboard than the long bowsprit to sheet well on the wind. A easily brailed sail is a treat, though. Could you share pictures of your mizzen setup?

    Here's a great pic of one of the original Falmouth Quay Punts, I.C.U. The mizzen spars look quite a bit beefier than Blue Moon's and you can see a lot of how the traditional rig is a bit different. (Pic from John Leather's Gaff Rig book.)
    /QUOTE]

    I don't have a pic of my Romilly underway but there are plenty on the web.
    Ben Fuller
    Ran Tan, Liten Kuhling, Tipsy, Tippy, Josef W., Merry Mouth, Imp, Macavity, Look Far, Flash and a quiver of other 'yaks.
    "Bound fast is boatless man."

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