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Swordfish

Page history last edited by Kevin 9 years, 5 months ago

12/21

Arrgh.  Laptop just crashed.  Happily, for once I bought the warranty.  Ha!

 

My green boat loads on the trailer with the ama on the truck's driver side.  Swordfish has the ama on the passenger side.  Last time I worked on the green boat's rig in the driveway the wind was the wrong way, so I had to turn the boat.  Today working on Swordfish's rig, the wind is also the wrong way, so I had to turn it around.  Sigh.  My life is very hard.

 

So I rigged a way to mount my tilting mast, rigged some ropes and a windward stay, and put the mast up:

 

 

Ok!  You know, this tilting mast stuff always seems fine until you do it, then it certainly does seem like a lot of axes of movement all at once...

 

Onwards.  Now I put the sail up.  Hurrah!

 

 

Pretty good.  The leech seems very loose.

 

I shunted the rig by hand.  Pretty easy.  Then I raised and lowered it a few times, messing with where the halyard goes on the yard and how much angle to allow in the mast.  The tack angle of the sail is really too large, I'd like to have the boom higher.  But when I move the attachment point down the yard and allow more mast angle, I get this:

 

 

Sorry it's so blurry, it was getting dark.  The mast angle is most alarming, no?  And if I move the tack of the sail to the bow the boom is parallel to the sheer, or even below parallel.  Makes me think about boom ends hitting the water, and not being able to blow the sheet when the boat's about to go over...

 

So, I think.  I consider.  Perhaps the answer is to cut the sail.  The leech seems very slack.  I could put a fold in the sail and sew it up, and at the same time fix the leech lack of tension and raise the boom.  Or, I could fit the longer mast Skip was using.  That would let me have less mast angle, and also attach the mast higher on the yard.  Like this:

 

 

Please pardon my amateur photoshop efforts. 

 

All very interesting.  I can see the appeal of the sail, but I'm a bit worried about the number of moving parts.  Perhaps I'll make a smaller version.  Or perhaps I'll just go sailing on a day that's not too windy, that's what I'm leaning towards right now.

 

Moved a set of cheek blocks to the bows to allow shunting the sail all the way to the ends.  The car gadget is really neat, but I have a sneaking feeling the sail might shunt better with the yard end loose, just allowed to ride along the rail.  We'll see.

 

12/20

 

Started taking stuff off the boat and looking at it more closely.  Lots of interesting details.  I actually set up the mast and messed with the spar a bit, that's a very clever system Skip came up with.  This is the double car system on the boat before I unpacked it:

 

 

 

You can see the spar in the first shot, that goes on the foot of the sail.  The car that travels on the spar is connected to the car on the track, and between them you can much better harness the foot of the sail in a shunt.  Very clever.  In the second shot you can see that the cheek block is not all the way at the bow, so to use it with a crab claw I think I have to move it.  But the double car system on the spar is very clever.

 

Also had to fit a cover.  It's looking like rain, and that's a big cockpit to have to bail out every time it sprinkles.

 

I started thinking about the board issue.  So, a) the CE of the crab claw will be way forward.  And b) the boat is pretty slab sided already.  And c) the ama is pretty deep and v-eed.  And d) the rudders are Speer sections, as good backwards as forwards.  Hmmm...

 

This is the rudder all the way down:

 

 

So, what if I just leave both of them down all the time, or all the time I'm not going downwind?  The lateral area added by the front rudder will be way forward, ok.  But the CE of the sail is way forward.  The point would be to load up a higher aspect ratio foil than the hull.

 

It's not a terribly deep foil for a boat this length.  But I'm thinking here of sort of matching a low AR sail with a low AR hull/foils, and pointing at about 50 degrees off the wind.  We'll see.  It's an interesting idea, mostly because it involves me going sailing rather than building anything...

 

Also took the mast out and laid it out on the yard with the sail.  More than long enough:

 

 

So that's good.  I think I'll fit the universal joint from my old mast to the base and use that.

 

Quite enjoying taking everything apart and figuring out how stuff works.  Buying a boat is cool!  Hey, look at this!  This is already built, I didn't have to build it at all!  And look at this!  I didn't have to build this either!  Wow!  I haven't bought a boat in years, it's really enjoyable.  It's like a treasure hunt, I'm "discovering" blocks and cleats and lengths of good line and so on all over, it's great.

 

Off to coach fencing, more tomorrow.

 

 

12/19/10

 

Ok, here we go.  My finals are done, I'm off teaching for a few weeks.  So today I got the crab claw out of the garage:

 

 

and laid it out on the yard to take a look.  160 ft^2 or so.  I haven't looked at this sail in several years.  I built it, put it up on my green boat, and tried an afternoon of yard shunting.   I was not encouraged.  I finally settled on a schooner rig for the green boat.

 

Part of the problem on the green boat was the sort of free and easy nature of the end of the yard while shunting.  My green boat was not designed with a yard end sliding along the lee side in mind, so it had stuff that stuck out.  Very bad.  Yard got stuck.  I think I finished about one shunt in three without getting off the boat and untangling something.  So I gave up on the crab claw for a while. 

But I never throw anything away.  Ask my wife.  So the crab claw stayed in the rafters, waiting.

 

Meanwhile, Skip sold me his proa P52.  Lovely! 

 

I put P52 in a covered storage thing five minutes from my house and forgot about it.  For a while.  But it's been in my mind; what a great winter boat!  Why, I bet you could sail that boat in a sweater and jeans!  Crazy. 

 

So the time has come, I think.  Today I took the green boat to the covered storage, found that Swordfish had a mostly flat tire, remembered I had a 12 volt pump in my back seat. pumped up the tire (80 psi!!!  Good grief), put the green boat away and got Swordfish home.  Now I'm all ready for adventures in re-rigging.

 

I really like the boat, but I don't like the rig.  Sorry, Skip.  On the other hand, I have hopes for the crab claw.  One of P52's, now Swordfish's, more endearing attributes is a lack of any excrescences on the lee side.   In fact, instead of obstructions, she has a rail!  With a car!  Wow:

 

 

 

How convenient.

 

That's her in my driveway. 

 

The basic plan is to use the crab claw.  Skip built some rudders, which you can see here:

 

 

 

So I need to fit some kind of board, I think, and the crab claw.  I'm taking a pretty relaxed view of VMG.  My hard line in the sand is, I have to be able to make progress to windward in 20 knots of wind, sustained 20 with gusts higher.  Have to be able to make progress.  Beyond that, I'd like a nice winter boat, something I can stay dry in while sailing.  And I've always wanted to try rigging and sailing a crab claw.  So, we'll see. 

 

Here are a few more shots of the sail:

 

 

 

 

 

 

The last pic there is the mast base from the Gibbons rig mast I thought I might use.  I think it's too short.

 

I think the sail is a little overbuilt :)  When I built it a few years ago I wasn't really familiar with the idea that a crab claw is a very low stress sail, so I overbuilt the corners quite a bit.  No harm but a bit of extra weight, I guess.  It's made from an old mylar jib.  The gussets along the boom were to take some of the shape out of it.

 

A few more of the boat:

 

 

 

So the plan is, tomorrow I start taking stuff apart and trying to fit the crab claw to the boat.  And trying to figure out what sort of board it needs...

 

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