If I could do a yawl conversion on my C-40...

Discussion in 'Sailboats' started by souljour2000, Jun 30, 2012.

  1. souljour2000
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    souljour2000 Senior Member

    A while back PAR mentioned that my C-40 was a good candidate for a yawl conversion. I am learning to understand a bit more about rigs these days and after doing alot of reading I am very interested in doing just that.I really love the utility that a good yawl rig offers such as the abilty to sail backwards off a mooring, balance the helm easily without auto-helm or windvane, mounting optional equipment(radar, wind gen, etc,) lift a dinghy,etc using the halyard,etc.
    It won't be any time soon that I do this conversion but I want to start thinking about the size mast I should be looking for so I can keep an eye out for one on the cheap...
    ...There's alot of considerations but this seems a good place to start (other than hiring an N/A which I can't afford right now).
    I guess a bigger mast like one off a Tanzer 22 (that I can get cheap right now...could always be cut down...as I experiment with the install..so bigger the better...I want it to be a robust mast...and possibly unstayed... not too tall...I just want to be able to fly a riding sail at anchor and have a big enough flag back there to help balance the rig going to windward..and the other forementioned attributes that a jigger or mizzen can offer. Experimenting would also be easier with an unstayed mast so I want to learn about any pros and cons of a unstayed jigger (yawl mizzen)mast ...would provide less stern clutter for instance...or whether I would be better advised to have traditional shrouds....It depends on the size mast ...the smaller the mastthe easier to rig unstayed of course. A tanzer 22 mast is probably too big. Attached is a pic of "Bird", a nice C-40 based out of Pensacola which is a good photo for reference.
     

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  2. bntii
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    bntii Senior Member

    My Rhodes was converted over by the last owner.
    She is of the vintage that the yawl rig was offered as an option from factory.
    To change over, rig was simply copied from what was done stock as the design and placement was already worked out in all the particulars.

    Any chance the C-40 offered as a yawl?
     
  3. souljour2000
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    souljour2000 Senior Member

    Yes.. It was offered as a yawl...at least towards the end run of what would be a total of 55 boats which likely included the prototype "Sabre"....which won some big races back then...Yes....there are maybe a couple known yawl conversions...maybe one or two originally done at factory. I don't know . Whether they were authorised by Charlie Morgan or were done by other designers is not known to me..here are a couple pics i found of known C-40 yawls...all I can find right now .
     

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  4. souljour2000
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    souljour2000 Senior Member

    In the two pics above...it's hard to tell but the yawl on the right appears to have a mast that is a couple feet higher than the pic on the left...but the yawl on the left has a longer jigger boom...These subtleties are of interest to me..,I think I would like as big a jigger and boom as I can support on the stern without getting into Ketch territory...That way I can really get some power when sailing jib and jigger in rough seas/strong wind...and also get a boost when sailing a beam reach.
     
  5. PAR
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    PAR Yacht Designer/Builder

    The yawl conversion on a C-40 isn't particularly tough, but the main is cut down a bit, if for no other reason but to decrease the E dimension. The mast remains where it is, but the nearly 19' boom is usually cut down to 17' to 17' 6" (or so). The back stay is usually split or Y'd and lands at the aft end of the cockpit combing (outboard of it). A reasonably mizzen staying base isn't so bad on the C-40 as other CCA's, but still limits mizzen height to a degree.
     
  6. souljour2000
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    souljour2000 Senior Member

    PAR, right..yes...I think you mentioned something earlier about cutting down the main boom a bit yes...I have read that must be done to create as much room or space as you can so that there is room for the air-stream to re-assemble itself so to speak so that there is not so much "dirty" air back there that could hamper the aero-dynamics of the main...Btw...the mizzen-staying base would have to be built up off that sharply sloping stern rise...but i think i could do it...as the area where it would likley be in right inside that stern-most hatch thingy just before the taffrail...I did some more reading last night on Eric Sponberg's fine website and there was an interesting section about unstayed masts which upon reading has convinced me that I would like to make the jigger mast unstayed for sure..Seems I would have to glass in a pedestal on the inner hull of the stern...and then more support as well where it comes through the hole inthe that platform thing on the stern a bit forward of where the hatch is on that stern platform thingy(which must have a name...I want to say poop deck..but that is probably reserved for larger ships..and seems antiquated...but I like antiquated terms...
     
  7. PAR
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    PAR Yacht Designer/Builder

    Free standing sticks are wonderful in small craft, where they are affordable. In larger craft, you get into the holly grail territory with prices. I see very little advantage to a free standing mizzen on your boat, unless you can cock it to weather a bit. I've been playing with this feature with a small ketch and it does wonders upwind. Previously, upwind the mizzen was pretty much just along for the ride, offering little drive, but canted to weather 15 degrees, the whole top 2/3's of the mizzen is pulling hard and pushing the boat up into the wind much better. Of course, this mizzen is easiest if it is free standing.

    On your C-40, I wouldn't get too fancy. You'll need in the vicinity of 130 to 140 sq. ft. in the mizzen. Assuming some purchase depth and a free standing stick about 30' long, the base will be in the 6"+ diameter range, with a 4" masthead. This also assumes you'll fly a fairly effective (read big) mule from it too. That's a hefty hunk of stick, so now you're looking at saving weight, which means bring your first born and a cross cut saw to the negotiating table.

    Your boat just will not have a preformance justification, to warrant the cost of a free standing spar. A stayed birdsmouth mizzen, will be in the 3.5" (heel) 2.5" (masthead) range, which is a practical size and about .8 pounds per foot if a reasonable species.

    This isn't to say the yawl rig should be discounted wholesale, but that a freestanding mizzen is over reaching a wee bit on this particular hull form.
     
  8. souljour2000
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    souljour2000 Senior Member

    Wow...I like that idea of warping out the top of the mizzen to weather though..how do you do that on your ketch btw..I mean...sounds like something that they did with chinese sampans and the like...though...Well..thanks for all the sage advice again...not to mention speicfic parameters...I guess i was worried about cockpit clutter what with the shrouds for the mizzen which I might assume would be a set of lowers and a set of uppers...On the other hand..not having any shrouds would seem (and look) weird to me I think anyways..so I will take your advice and save some bucks as well. I am not giving up on the idea in any event as I love the idea of high-utility rigs/sails in boats and I'm in love with split-rigs right now...though now after some thought I would want to go as sfairly firm minimum to bother with the conversion at all?..Thanks in advance.My boat is similar size to the concordia yawls I have noticed...though not likely to sail so well as one of those...Those boats of course were highly sought after(still are) but i suppose it was as much for their sea-kindliness as much anything to do with that size range and rig that caused them to be so popular.
     
  9. PAR
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    PAR Yacht Designer/Builder

    The mizzen shrouds will fall aft of the cockpit and typically are a single lower and cap shroud. A hefty cruiser may want double lowers. A slight swept back spreader arrangement is normal as the mizzen isn't heavily loaded, except when flying the mule. The wires do "muddy" up the stern areas a bit, but being as far outboard as they can go, not as bad as you might think.

    My canting mizzen is as simple as it gets. The stick is cockpit sole stepped, at the aft end and has a hoop bolted to the deck beam at the forward end of the aft deck. The hoop is a snug fit for the mizzen and the mast's heel fits in a cup. Originally, the hoop or ring that held the mast at the partners was a "U" shaped thing, with a "gate" that was closed, when the mast was stepped, locking it upright. I replaced this "U" shaped piece with a stainless ring that the mizzen slides into. The ring has a single 1/2" bolt welded to it, which passes through the deck beam. This permits the mast to pivot, but still "captures" it at the deck beam.

    The heel cup is the thing that moves and it's a HDPE cup that accepts the heel of the mast (which also rotates). This cup sides in a HDPE tray that runs athwartship. Attached to the forward side of the cup, is the worm gear sleeve from a trailer jack. At the port end of the track is the pinion gear and extended crank from the trailer jack. By turning the crank, the pinion turns the worm, which pushes or pulls the sleeve on the mast heel cup. It's a little Mickie Mouse, but does work. You have to be fairly quick with the crank in a turn, as it's 20 cranks from centerline to all the way to one side. I can do this in 5 seconds, but the butt kicker is going from full over on one side to the other, which is 40 cranks. I can do this in about 7 - 8 seconds, which is a pretty slow tack. I've toyed with luffing the mizzen and cranking, but the system isn't really robust enough to trust this way. It's just an experiment to see what I can get from it. A better arrangement can be devised. My first attempt at this used a sheet traveler arrangement, which was fast, but lacked "positive" control. The mechanical setup has good positive control (I can stop at any point without worry), but is a lot slower (typical). Hydraulics would be the way to go, with a few pumps, you can shove the heel back and forth pretty easily.
     
  10. sean9c
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    sean9c Senior Member

    Don't forget that you may need a boomkin or someplace for the mizzen sheet to attach.
    And, depending on where you are and your situation, if your marine measures boat length between verticals that your slip rent will go up
     
  11. PAR
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    PAR Yacht Designer/Builder

    The sheets have enough purchase near the transom to permit an inboard setup. A boomkin would only be necessary for a really big mizzen. A mid boom sheet would fall straight down, a 3/4 length sheet wouldn't be at much of an angle. An end of boom sheet would likely need something, but in light of the other options . . .
     
  12. souljour2000
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    souljour2000 Senior Member

    Thanks for all the precise info guys..PAR, that canting rig you have sounds very functional and innovative...I like the idea of rotating mast but I'll probably go traditional set-up though I might double the lower shrouds as you mentioned...Hope PAR is right and I don't need a boomkin Sean...I suspect he' right and it would need be very small if i did need one i would venture to say. How do those work anyways?..Is it a double-sheaved block at the apex of the V-intersection where you can run one sheet through the top and the other through the bottom sheave? Well..I hope I don't need one...Aftern initially wanting bigger..I now want smaller sail area..just enough for a mule to give a push on a beam reach...Otherwise..I am just looking for windward and even off wind course stability rather than speed and good anchor riding behavior... as well as just having a second rudder of sorts..an "air rudder" ...if you will...for various adjustments in a myriad of underway conditions which the jigger affords...It does sound like it's gonna be a bit crowded right but hopefully just at the furthest stern platform area... but I have heard many people like having the shrouds and a mast there as it makes for a more secure feeling in the cockpit in terms of handholds...thanks again for the helpful replies..
     
  13. philSweet
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    philSweet Senior Member

    One thing to consider is whether or not you can design it so the mizzen stays and splitbacks are identical to one of your main lowers. If you carry some of your old rigging around as spares, this can save a bit of space. It might work out or it might not. Obviously, there are more important things to worry about, but it is a nice-to-have. It may just be a matter of chainplate design and turnbuckle selection or using a short penant below the turnbuckle to make it work out. Your windgen can go right at the top above the shrouds.

    (edit) just realized the boat in the pic isn't yours. Ignore the windgen comment.
     
  14. Stumble
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    Stumble Senior Member

    if you are concerned about having a replacement shroud, don't mess with carrying around an old stainless one. You have to carry the longest shroud you have since anything less reduces the usefulness of having it dramatically, and since you replaced it already, do you really want to trust it once another shroud fails somewhere?

    If you do want to carry a replacement, get a piece of Dynex Dux in the same size as your shroud, the leingth of your longest shroud plus 6'. This will allow you to splice in a replacement around from line that is stronger and has less stretch than what you would be replacing.

    And remember the overwhelming cause of demasting isn't shrouds breaking, it is chainplates failing.
     

  15. philSweet
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    philSweet Senior Member

    Stumble, Having lived for ten years in the world's center of derelict sailboats (the Florida Keys), I'd say the ratio of shroud failures to chainplate failures is greater than 100:1. Maybe the new composites are changing that, but the only chainplate failures I've seen were the result of repeated dock bashings on the bowplate. Getting driven under the dock edges or having the tide raise the boat and catch it under something will tear them if you do it for long enough. It's a simple matter to decide which piece you want to have fail and what the failure mode will be, and then design the stuff that way. I and others prefer that it ain't the hull or the chainplates. As far as bowplates go, I prefer to see a welded reinforcement that causes the fold point to be well above the deck. This way it can be welded back together on the boat, which I've done twice. (Really good deals on boats often come with the stipulation that it has be be gone by sundown or suchlike).

    I do carry my longest old stay an a handful of wire clamps, but I also carry some of the old rigging for a more permanent solution. I'm not at all interested in using synthetic shrouds or stays on my boat. I have a running mile of line if I need to jury rig something. If I popped a shroud in the Bahamas, I'd just fit an old one and carry on until my next haulout. Which is why it's nice to have them all of a length on a knockabout cruiser.

    edit. OK you said demasting, not rigging failure. I don't have as much info on that one. It may well be in safety's interest to have the mast go overboard in one piece rather than crumple onto the deck, but I would still design it to fail at someplace other than the chainplate, such as at a tieplate pin combining separate shrouds to a single chainplate.
     
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