Thread: GIS as a sail-and-oar boat

Thanks for replies guys. I've been thinking a lot about this idea and I take seriously all the little consequences of making changes. I've built a lot of boats, almost all to the plans as closely as possible and never strayed from the plans without consulting the designer and using a lot of good reasoning founded in some informal training and experience in boat design. You can tell, perhaps, that my reasoning is based on experience, too. At this point it is clear to me that I need the ability to have a lug-yawl; and I need all the rest of what the GIS offers too...so with that out of the way...

Some are obvious changes but the big one is keeping the sail plan balanced as Michael mentions. If there is a will there is a way...many of Oughtred's designs are rigged with an extra mast step or two...the Caledonia Yawl has three partners for dealing with sailing Lug alone, with mizzen, and in a reefed position. Moving the mast forward is a trick because of space...the arrangement below is elegant...

[IMG]file:///C:/DOCUME%7E1/MEREDI%7E1/LOCALS%7E1/Temp/moz-screenshot.jpg[/IMG][IMG]file:///C:/DOCUME%7E1/MEREDI%7E1/LOCALS%7E1/Temp/moz-screenshot-1.jpg[/IMG]http://homepage.mac.com/peterhyndman/GIS/construction.html#

Sorry, if the picture doesn't work, but it shows the mast step area near the bulkhead.

So, one solution is to have a hole for the mast forward of the bulkhead, in the sealed tank and boxed in with limber holes into the space with the current mast step. This aft mast step would stay for sailing w/o mizzen. When I take the mizzen I step the mast in a forward position...it probably won't be two far forward...exactly how far forward can be figured out pretty straightforwardly. How to integrate the construction into the current set up will take more thought, but it seems worth looking into. Another consequence, besides adding some complexity, is that we take away a little space and thus flotation from the compartment, but we can add that in the form of some floaties under the middle thwart. At the outset, I don't see any need to change the D/B position. The adjustment occurs in stepping the mast forward. Mik, is there a specific reason that you don't want to step the mast further forward? What is your guestimate on how much further fwd it would need to go. Do you agree with my approach?

Mik, I agree a tall narrow mizzen would be best...I like sprit rigged ones, but that sometimes necessitates a boomkin...where to sheet down to is the question...a boomkin is doable, or sheeting to the top of the transom if the mizzen has a boom with crutch. Now, I don't think we'd need nearly 30 SF...I sailed a wonderful Tony Dias designed high aspect lug-yawl called Harrier. She had this tiny heavily raked mizzen that was 12 Sf at most...very small rigged with a sprit and you take off the sprit and roll up the mizzen and pull it out...so easy. And that little mizzen made our week of sailing very comfortable and manageable in open water. I've lied ahull to put a sail up and it can work, but in a chop it would be VERY uncomfortable and make raising sail much mroe difficult...lying head-to-wind under mizzen makes 40 knots gusts and 3 foot whitecaps a picnic..I know this from experience...as long as there is plenty of leeway you can really relaxe when the boat is lying this way. (Now, I wonder how the skiff will lie head-to-wind compared to other boats I have sailed and done this with). Once we stopped for lunch under mizzen! So, one thought is maybe a 9' tall mizzen with a 15 SF mizzen maybe 20 SF (and only taking 60% of that in calculating CE....). If it were a high aspect mizzen it'd pull back the CE maybe a few inches...we can fix that by moving the lug mast forward and having a second partner...dealing with the bulkhead fwd of the current step is the trick. We can figure it out.

That Salcombe yawl is striking...I've never seen one. It is very clever how they appear to deal with the tiller-mizzen problem: by stepping the mizzen on the aft deck so the tiller can swing below it. (On our Goat we'd probably simply offset the mizzen stepped in the aft tank and with a boxed in step/partner) I think the yawl is absolutely gorgeous (and sketching a mizzen onto the Goat profile, which I did, looked very cool), all functionality aside, and I do think this will make the Goat even better or provide another option. I'd still be interested in hearing from the other fellow you mention, Michael.

My timeline is that I have a block of time to do this project between late December and when my second child is born!!!! And after that I have commission starting. Anyway, I'll be a better Dad if all personal projects are out of the way by next summer and that would be the goal and so I'd start in January...and I realize that my mods make the project longer but I'd still be building the designed Goat, and can add the mizzen a little later so long as the mods are planned out. But I do want to figure this out in the next few months, before I start the boat, is that doable for you Michael...the rest of the year is available and I can work on this too with some drawings. Perhaps we can talk about how to collaborate. I'd be happy also discussing a bit over the phone and making a call to you, which is sometimes a little more personal and better at communicating intentions and excitement.

Lets keep ideas flowing. I'll try to stay open minded and not get overzealous about the idea. Thanks for dealing with me.

Cheers,
Clint

Clint:

Should be finishing my GIS soon, and sail is on the way as well.

We will be sailing the same waters (Portland, Maine), so I take all your points.

One question -- do you need the mizzen just to keep the boat into the wind while you raise/lower the lugsail, or would you intend to use the mizzen at all times. If only the former, could you add a light duty mizzen to be used for only that purpose that could be easily struck while using the larger lugsail (for example, using a roller furling mechanism)? That way, you could perhaps avoid center-of-effort necessitated changes to Michael's design. (That could have the salutory side effect of keeping Michael from having an embolism, stroke or some other mishap. I've had a lot of fun building the GIS and wouldn't want to hasten his demise!)

Just a thought. I'd be happy to let you experiment with my GIS for this purpose

Dana

Howdy Guys,

Thanks for talking and co-operating so well on this! I actually never imagined that there would be small groups starting to work together around the world!!

Really! Never thought of it.

The Salcombe yawls do have the mizzen offset just slightly. I would be keen for the mast to be fairly tall as it will make the weathercocking more definite as well as make the handkerchief much more in balance with the feeling of the mainsail.

I think it may be possible just to slide the mainsail a little forward with the standard mast position to make sure that the mizzen carries some load. That is one of the advantages of the balanced lug. You can shift it a little back and forward without moving the mast. The main restriction is the halyard position ... it can only go halfway back along the yard (for obvious reasons)

Best wishes
Michael

Dana, If I step the mizzen in a boat I usually keep it there b/c I am pretty sure it will be used, but I have also just left it behind and stepped the main in the aft partner...

Mik, Would it be possible to obtain a scale drawing of the boat that I can "play with" to see what would work best and I can post here with your blessing.....I might rather move the mast fwd to make more room for the hankerchief mizzen so that one sail isn't crowding the other (something I found when I went through this process with a dory). A sail plan drawing may be all I need although a drawing showing the mast and partner location together would help me figure how far forward the mast would have to move. I'd also try moving the sail fwd as you suggest and post that...I'm afraid of ruining the perfect proportions you've created in the lug. I'd also want to look at sheeting of the mizzen and how that might work best. May I work on this with your blessing and a couple drawings? I'd be very happy to share what I do here for the benefit and learning of others.

You've created this international community of GIS freaks; that must feel pretty darn special!

Best,
Clint

Nah Clint,

I have simply designed a nice boat. The freaks are responsible for organising themselves!!!!

Warms the cockles of my heart!

I'll see about posting a drawing with a scale on it.

MIK

...for the help