Project M - Jib Sail and Rigging

[eric3a]

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[Currie]

Hi Eric,

Makes sense. Has anyone tried outboarding a factory 105% this way to see if they get better results upwind? Thanks!

~ Bob

[delevi]

Echoing Frank's comments; even if you had longer jib tracks, the clew would still extend afte beyond the shrouhds, so on a beat, you'll have poor sail shape. Any sort of sheeting inside the shrouds should be limited to a 110 jib, period. If your prevelant conditions are more than 12 knots wind, I wouldn't even mess with this and just get a standard 100-100 jib, period. If your conditions vay a lot, go with a hank-on and get a genoa + jib. If you have to have RF, which is my preference, just get a standard jib. If you're getting custom sails, you won't miss the genny much. I dissagree with the statement that in 10 knots wind, you must have a genny, and get 2 knts speed. I would agree with that at lower wind velocities, but with the new Quantum sails, making the outhaoul slack with the loose-footed main and 105 jib, I can still do 4-6 mph on any point of sail except DDW. That's w/ 10 knots wind and full ballst. (engine tilted, no bottom paint, all foils down.) Againk going back to my previous post, the genny only benefits you in 12 knots or less on a beam reach. Lower points of sail in these winds can be compnesated by the A-spinn, and higher points of sail warrant the sheeting angle of the jib.

Leon

[Currie]

Hi Leon,

I respect your opinion greatly, but I guess we'll have to just disagree on much of this (yes, even when "period" is attached to your sentences ).

I couldn't find where Frank said this couldn't be done because of poor sail shape. A flat sail percent-size can't be used to determine how close an inboarded sail comes to the shrouds because of the draft. Most 105% look like they miss by at least 1 foot, half-way up the sail, when winded (even yours). It suggests there's room for more than a 110% given that sail cut is taken into consideration, as Frank said.

Anyway, I don't want to make this more annoying for everyone than it has to be. I'll take a look at a 26M this summer and take some measurements. In the end, I still feel pretty strongly, as other have stated here in different ways, that there are sail/sheeting/slot issues with the 26M, in general. I'm happy leaving this discussion where it is until I can get my hands on one. Thanks,

Respectfully,
~Bob

[Currie]

For anyone interested...I found a nice link to the Doyle site with some scenarios for using four sheets on a jib. Besides a better sail shape when heading off the wind (as in my pics), it's used in higher winds - before one would resort to depowering to a smaller jib. The main idea is to reduce the fullness of the jib by outboard/afting, and tensioning the sheet as shown in my original diagrams (applies to both overlapping and non-overlapping jibs). In moderate to higher winds, full jibs pull to lee too much and have a poor forward thrust.

http://www.doylesailmakers.com/t10-tuning.htm

My point to this entire thread is that Mac owners typically depower when the winds pick up. A better alternative for jib sizes up to about 120%, is to outboard/aft the sheet *first* and correct the airfoil, before spilling or reefing - if the configuration allows it. The four-sheet slip-thru system in this thread is a type of barber-hauler and should do just that, even if the max jib is less than 120%.

Cheers,

~Bob

[eric3a]

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[Currie]

I was thinking of your post when I read the article

[Frank C]

I think a barber hauler would be a good option if the Mac had a toerail, but it doesn't. One might try hooking a barber hauler to the mid-stanchion base ... but we're speaking here of higher wind speeds. In moderate winds the Genny exerts enough power that I'd not want it yanking on the stanchion. Finally, the factory tracks are too short for a longer jib anyway (guesstimate they are 2' long). One can either replace the factory tracks with longer ones, or install longer tracks (4') outboard, which would be my preference.

Once you have four tracks on the cabintop, there are multiple opportunities for using a barber hauler for fine-tuning the sheeting angle ... but I doubt I'd go that far. My ideal solution is towable cars on longer, outboard tracks. I have the tracks, have the cars, just don't have the time to install any of it.

My Genoa is a deck-sweeper, so the clew is actually too low for good sheeting to the coaming tracks. My dealer suggested adding a barber hauler to improve leech tension, but it would require mounting a padeye down about mid-hull. I could picture slamming that padeye into a dock or piling ... bad idea, methinks. I did insert a QR lever below the furler drum, raising the tack by 8 inches or so.

[Currie]

My ideal solution is towable cars on longer, outboard tracks

When all is said and done, Frank, I agree with you. Ultimately, I'd like to see longer outboarded tracks on, or near, the toe rail. This would provide for better sheeting of even a 105%. I'm still a believer (even on a Mac at the moment) of outboarding, for the best control.

The interesting thing about the barber-hauler and outboard tracks is that a Mac is among the narrower class of boats, so your toerail tracks are probably what most boats would call the inboard set (running about 12 degrees to sheet for a 105%, less for a slightly bigger sail). This could be easily verified with some top-view overlays. For me, the outboard set on my future Mac would be the ones on the gunnels.

Your point about the installation is a very good one. Has the factory ever made special accomodations for anyone like this (besides projects like the Pearl)?

Cheers,
~Bob

[delevi]

Bob,

It sounds like you're going to have a field day with mods once you get your Mac. I'm really looking forward to see how all these turn out. I sure wish I did this much research before getting my boat. I would have done a number of things differently if I could do it over again.

[Currie]

Thanks Leon (and to all),

I do like hashing it out here first. Great group! I too am looking forward to more of your great mods. Thanks again,

~ Bob