BYYB Forums

When I ship a set of study plans I usually include a profile (powerboats) or sail plan that is suitable for framing. Most folks like to hang their project up and stare at it a while as they assemble materials and convince the other half "it'll be fun . . ." This is the reason I provide the "finished" profile drawings.

I don't have a web site to advertise my efforts and frankly haven't had the need, but this year seems I'll likely set one up, probably for other reasons, such as you've mentioned Tom. I have to admit I'm a tad intimidated with web sites, but a friend and fellow designer has talked me into doing something and that it's not as bad as it may appear (setup wise)

I do have a small gallery here http://byyb.org/cpg143/index.php?cat=10036, also one at MessingAbout.com http://www.messing-about.com/photopost/s...ppuser=619 and BoatDesign.net http://www.boatdesign.net/gallery/showga...puser/2040, both of those under PAR, which is how most folks on the internet know me. The MessingAbout site may ask you to become a member, but it's painless and free.

One of these days I imagine, I'll get one up and running. Jim Sanders and I worked up and opening page a while back.
http://elconquistador.org/RYDWeb.html
, which might look something like this.

Greetings,

Very nice.

Swordfish looks like a screamer ... 34 foot daysailer with long overhangs, fine entry, counter stern, rounded combings ... this is what boats are supposed to look like.




Has she been built yet?

Yep, she's been built and you're observations are correct, it's a fast boat. I used some old school techniques to get cheat the rules she was designed around. Those lovely overhangs dramatically increase the LWL as she heels over (and she does heel), increasing her speed potential in light air. You can see she has pretty firm bilges, but interestingly enough her sailing lines don't fatten much when heeled, making for an easy to steer boat that tracks will. The stub keel below, houses the centerboard, so it doesn't intrude into the cockpit area.

This is the third rig on her. Her original fractional sloop rig took full advantage of the gains I got from cheating other rules for her class. It also required a large crew to man her, which the owner found difficult to find, so the rig was cut down to a masthead sloop, then again to a masthead yawl. She's a wet boat to windward, but I don't know of many fast boats that aren't. In a rough go she can hobby horse a bit if you're not paying attention and she's not a boat you can single handle very well, but she fits her design brief.

Greetings Ian,

I had a few moments alone with my Delfship-equipped laptop, so I whipped up a few drawings of a raised deck weekender. I figured I would push the cabin sides right out to the inside edge of the top rub rail. The first cut was horrible. I drew the boat with vertical sides and it was truly ugly. Looked top heavy. So I canted the cabin sides in by about six inches to match the angle of the lead of the shrounds and the results were not half bad.

I had to dispense with the front hatch as the deck just gets too narrow. I also smashed down the crown in the deck as you get forward to make sure the jib club foot has room to swing, besides that looked better too. As drawn with a dead horizontal deck, the inside cabin height is just shy of 40 inches, which is more than enough for a six foot tall person to sit up in. If you need more headroom than that, you could probably tilt the back end of the raised deck upwards by a few inches without destroying the look. Finally, with the cant of the cabin sides matching the lead of the shrouds you have the option of bending the chain-plates right around the hull side and up along the cabin sides to place the turnbuckles up above the "new" raised deck.

Here are the images ...








Cheers,
Tom

I acctually think that looks pretty good. It must increase the cabin space a bunch, I wonder how that would look on a vacationer 8)

Brian.

Tom, thank you so much for those drawings. They show a vast improvement over my hand drawings. The design of the cabin you have drawn is much prettier than what I had envisaged. I had indeed planned to match the angle of the shrouds and bend the chain-plates at the shear, but I had thought that I would have to cut off just aft of the mast as in the most forward part of the original design. Also my drawing only allowed head-room of 38". What you have done with the forward end really looks great, and does not require you to step down to the fore deck, besides giving two more inches of head-room. thank you again, I think this is it! One question, If you used a direct radius for the curvature of the cabin-top/deck in your drawing what was it. Or did you change curvature at the outer sides? Again what did you use? "Crushing" down at the forward end has made all the difference. I think this has made for quite a nice looking boat as opposed to the chunky cut-off style I had drawn. As for the club-foot I will not be using that, maybe on the staysail of a cutter, but not on this sloop rig. Again many thanks, you have brightened my day.
Ian.

Greetings Ian,

Actually, I'm not sure what the radius is. The software I was using is DelfShip (formerly FreeShip), which models surfaces using a set of reference points that form a control net based on B-spline mathematics. You can then move the reference points around to bend the surface meshes this way and that. If I remember correctly, I started with the original cabin bulkhead of the stock Weekender, stretched it a little taller, then moved the top corners out to within six inches of the hull side. So the curve in the drawings would be just a tad flatter than what was in the plans.

However, there is no reason why you could not just use the curvature they had in the original plans and just make the curve a little longer to span the extra distance out to the new cabin side location. In fact, this would lead to a little more headroom. While I was goofing around with the control nets I noticed that you can increase headroom by adding quite a bit of crown to the cabin roof and not affect the overall look of the boat. The cabin sides however are a different story. Add an inch or two to the cabin sides and it directly affects to the look of the boat.

Plywood bends easily in only one direction at a time, just like a piece of paper. So the roof should be a conic section to avoid torturing the plywood. You can achieve this easily by using the same curve for all of the deck beams. Obviously as you go forward the beams get shorter in length, but they should still be the same curvature. The last little smash down section of deck forward of the first deck beam will probably have to be cut from a separate piece of plywood as it bends a different way than the rest of the deck.

If you are really serious about make a raised deck weekender, then how about building a scale model first so that you can see what the boat will really look like in three dimensions, and to get an idea of the problems you are going to run into. Obtain a three sided architectural scale and choose a scale that results in a model with a length of two or three feet … bigger is better. When I built my model weekender, I used a metric scale to measure out inches directly onto thin birch plywood from the local hobby store. It doesn’t matter which scale you uses as long as 200 units comes out to between two and three feet long. (e.g. the boat is 16 feet * 12 inches = 192 units long)

A few parts of the boat will change drastically. The cabin bulkhead obviously gets taller and wider. The front half of the original deck needs to be cut down to just a sliver thick enough to define the front shape of the boat and to hold stringers top and bottom. The front bulkhead needs to get taller and to be hollowed out to more of a ring like an airplane fuselage ring, maybe even replaced by several located where the deck beams will land, or maybe eliminated all together. The mast box can be cut down to be just a few inches tall to locate the bottom of the mast. Since the top of the cabin becomes the new front deck, and that deck is now much wider, it will have to be cut from more than one sheet of plywood and either scarfed together or butted together with butt blocks running down the center of the deck between the deck beams. The hardest part will be determining the shape of the parts for the new cabin sides and the angles on the cabin-sides-to-deck stringers. You might make the cabin sides taller than needed, attach them to the boat, and then use a laser level, or a water level, or just a really tight piece of string to mark off the top edge to cut down to.

The nice thing about doing this on a model first is that mistakes are relatively inexpensive. When you do finally get it all right, you can take measurements directly off the model for the full sized parts. Finally, the finished model makes a niece conversational piece of furniture for the home or office.

Hi there Tom,
I just realized while reading your mail above that actually it is easy enough to calculate the rad. using the chord of the circle generated by the beam minus the six inches each side and the additional height.
Using the sides as the nominal, making them parallel to the waterline, to determine all the rest, is definetly what I was missing. I was making the crown parallel to the water, and ending up with a chunky messy look because as you say the sides are what determine the look.
There is no doubt about it I will have to take the time to build a model as you suggest. Right now is probably a good time to do that anyway, since I am stalled on actually building the boat. Funny how circumstances can suddenly change. We are now in the middle of selling our house and moving, (not far), so I am hoping to negotiate that I can retain use of my present workshop for six months or so. Thank you for your interest and help Tom, I do appreciate it very much indeed. It is nice to realize you are not alone, and others are out there to help and advise .
Keep sailing!
Ian.

ow....my brain hurts.... :lol: