30' plywood sharpie

[davesg]

I've been thinking through this design and am looking for some comments. The idea is a large trailerable coastal boat for three in Florida. LOA is about 30', beam about 7.5', draft board up about a foot. There's about 250 sq ft in the cat schooner rig (is this about right? more? less?) and an outboard well for 6-10 hp. As drawn there is about an 18" lead between the COE and the CLR. The rudder may change to a low-aspect sharpie type underslung rudder but I drew in the dinghy style kickup to see how it looked.

There is sitting headroom at the dinette area and large companionway hatches. Galley will be a small sink and portable stove, head will be a bucket, there are three large single berths and that's about it. The idea is to have the extreme shallow draft of a sharpie with some stretching out space for three to do a few weeks at a time along to coast or over to the Bahamas.

Construction will be stitch and glue over a few bulkheads and a mold in the middle. The scale is 1' to the side of a square on the graph paper.

http://img29.imageshack.us/img29/6834/cartoonyh.jpg

Here's my first try at the lines. I think there is too much flare but I wanted to keep the bottom to 4' wide for plywood. My first thought on scantlings is 3/4" bulkheads, 3/4" bottom, 1/2" sides, and 1/2" deck; any thoughts on that? I'd really like to keep all up weight for tailering under 3500 lbs. I'm figuring on somewhere around 1000-1500 lbs inside ballast.

http://img30.imageshack.us/img30/2979/30sharpielinesplan.jpg

I'm completely open to suggestions and comments. I wanted to get some feedback before doing the next drawings and starting on the construction details.

Thanks,
David

[troy2000]

OK, here goes the noob, sticking his head into the hornet's nest.:p

I'm getting ready to build a plumb-stemmed, transomed plywood sharpie, that will dry sail most of her life on a trailer. When she does go into the water, it'll be mostly on the Colorado River lakes: Lake Mojave, Lake Mead, Lake Powell. She'll be a weekender, not a cruiser or live aboard.

She'll be about 30' LOA, with a maximum beam of 8' or a little under. I'll be building to workboat standards. That doesn't mean garbage; I'm a third-generation carpenter and woodworker, and I do good work whether I'm building a house or a boat. But she'll be rugged and plain, with simple appointments and painted surfaces, mostly so I can giterdone and get her on the water. I enjoy building and woodworking. But I'm not one of those who gets lost in the process and forgets that the idea is to finish something, so it can be used.

There's going to be no fiberglass or epoxy anywhere, not even tape on the edges. Not because I don't know how to work with the stuff, but because I hate it. I hate the smell, I hate dealing with the cure times; I hate sanding it, etc.

She'll be finished in semi-gloss house paint. I have a house built in 1940 that's gotten wet more times over the years than my boat ever will. But it's always had a good paint job, and I wish the inside of the house was in the same shape as the outside....

I figure most of the beating the boat takes will be on the bottom, from sandbars and deliberate beaching. So I'll double up there, and maybe add some replaceable solid wood skid strips. If the plywood elsewhere checks or splits I'll sand, fill and add more paint. If the checking still shows, I'll live with it.

I'm sixty years old, and I'm willing to bet the boat will outlast me. If she doesn't, oh well; I'm not out to build an heirloom. My sons and grandkids may have to just bite the bullet, and pony up for a new one....

I don't have a full set of plans drawn, and may not get around to doing so. I'm a competent draftsman, but I don't have a full-sized drafting table set up any more. But obviously I'll be drawing out some of the details as an aid. I did build a 3/4"=1'"0" model a few years ago to work the shape of the hull and other basics (right before my finances went into the toilet last time), but my younger son promptly ran off with it. There seems to be some things that a man with sons or younger brothers just can't keep. Before I build though, I'll do a detailed model at 1 1/2"=1'0"....and guard it with my life until the full-sized boat is done.

What I have in mind is generally based on Monroe's Egret (to no one's surprise, I'm sure:D). But she'll be stretched to 30', and widened a tad to almost 8' on deck, without trying to fatten her any more than absolutely necessary at the chines. I'll build her by fastening the sides to a stem, then wrapping them around bulkhead frames at both ends of the cabin, and on back to the stern. Then I'll add chines, gunwales, deck clamps, etc, watertight lockers fore and aft. I may have a stringer or two if I think ishe needs it. She'll have an inside plank keel. And I'm considering rabbeting the chines to cover the plywood edges, since I'm not taping the seams (yes, I have the tools and the skills).

The cabin will have a bare 4'0" of headroom, which should give sitting room over low settees. I'm considering removable canvas side panels for the cabin, because it gets hot on those lakes in the summer. On the other hand there are mosquitoes too, and there can be some chilly winds in winter.

Instead of being double-ended, she'll have enough of a transom to flatten the run aft a little when the sides are bent in a fair curve, more like the old racing sharpies. But I'll still carry the stern up out of the water, unlike Brewer's Mystic Sharpie design. If it's on trim with no passengers, the theory is that a crowd in the cockpit should just settle her down enough by the stern to give me a longer waterline. If possible the side planks will be straight top and bottom, tapering evenly back from the bow to the stern. I'll tweak the flare, in an attempt to approximate the old recommendations to have a straight run down from the bow for the first third of loa, a smooth round in the middle third, and a reasonably straight run up from there to the transom. Widest beam will be amidships of LOA, which will put it somewhat back of amidships LWL.

I'm hoping to squeeze in a minimal v-berth forward (for two people who are close friends, or for one active sleeper), two settee berths, folding table on the centerboard, a very basic galley to port, and a simple enclosure for a portable toilet to starboard. I'm thinking of a sliding hatch big enough to give the cook headroom. If that doesn't work out, I guess we can always BBQ on deck.

The centerboard will need to be somewhat L-shaped, to give decent access to the V-berth. The rudder will be the traditional balanced inboard type, with its stock flanged so it's easier to remove. The cockpit will be self-draining, which means we may have to choose between sitting on deck or on the cockpit sole, if it works out as shallow as I suspect it will. Ballast will be bricks under the settees and cabin sole.

For a rig, I'm seriously considering the pirogue or cat-ketch setup; it's a well-proven and simple one. But I've given a lot of thought to a yawl rig, with a short bowsprit that can be run in when not in use. The jib would be boomed; the main would be gaff-rigged; the mizzen would be a boomed spritsail.

Hopefully, I'd be able to do a panic reef simply by downhauling the mainsail, and run jib and jigger. I had a flat bottomed, double ended centerboard canoe rigged that way for a while, and very rarely even used the mainsail except in light morning airs. Believe you me: I got good at yanking that main down in a hurry. Maybe that just means I was over-canvassed....

I used to draw some stares when I slid the canoe into the water, and started stepping masts and bending on sails. And an outboard boat followed me with a gal standing up and videotaping me for a long time on Lake Mojave one afternoon, back when camcorders were new.

Since I'm not as young as I used to be, and definitely not as old as I'm going to be, I figure the mainmast should have a tabernacle. I'd like to be able to swing it down, unfasten it, and slide it forward for trailering.

There'll be a narrow bridge deck, with enough room for an ice chest under it to port. I'd like to make the ice chest accessible from both the cockpit and the galley, but that might be getting too fancy.

I've also thought about a well for a very small outboard to starboard, with a mount that would swing it up a little, then tilt the prop back under the cockpit when not in use, with some sort of a flap to stop up the well at the bottom when the motor isn't in use.

A couple of questions: does anyone have an opinion on whether an outboard somewhat (not radically) off center, and forward like that in the boat with steering being done by the rudder, would work? Does anyone think the boat's too big to trailer and I should go smaller?

This seems to be an articulate, informed and opinionated bunch on this forum; I'm hoping for some interesting feedback. The target's up and loose, gentlemen....fire at will.:eek:

[troy2000]

<moderator note: two similar idea threads merged in hopes of a better conversation togeter>

I wonder if they have so many people wanting to build 30' sharpies that they should sequester us all off by ourselves in a Sharpies Forum somewhere?:D

I'm certainly no professional or experienced designer. But my opinion, speaking strictly as another amateur, is that you should give up on trying to keep the bottom at 4 foot. That much flare combined with a shallow draft is probably going to guarantee you'll spend most of your time sailing on your ear. And I'd give up on the split cabin. It looks good, but carrying it straight on through instead will make life below a lot easier. Not to mention easier to build.

I'm just filling space until the big kids get here though; don't take my word for anything.

[PAR]

Actually the "split cabin" has a lot of merit structurally, though you'll want at least a partial bulkhead there for the mast. Troy and David, there are quite a few of these types of design available currently and the wise thing would be to avail yourself of these plans. No more guessing about load paths or anticipated strain transmission or structural scantlings, just follow the plans.

I mention this because of you weight goals. When you subtract your desired (or hoped for) ballast from the full up weight of the boat, you'll have to make the whole structure about a ton or so, which seems, well naive to be frank and clearly not something derived at from a careful weight calculation study, which is how a designer does it.

There are other things I see in your two sketches that make me wonder as well and strongly recommend you acquire a set of plans from a designer. I don't mean to offend you, but there are clear and obvious flaws that suggest a novice designer with limited understanding. We can run through all of these if you like, but honestly it's a lot easier on the ego to just work from a known design, embellishing it as desired (within reason) to create you own special yacht. A number of designers, myself included, have specialized in sharpie designs and can help.

For example, you may want to consider Glen-L's "Chessie Flyer" or one of Bruce Kirby's Norwark Island Sharpies, maybe one of Jay Benford's or Ted Brewer's designs.

[troy2000]

I thank you, Par. Your comments are well-meant, and undoubtedly good advice on top of it. Unfortunately, nothing I've seen is exactly what I want in the way of a lake and river boat for weekends, as opposed to a cruiser or live-aboard.

For example, Chessie Flyer is a very nice boat. But it's a little beamy for a flat-bottom boat with sharp chines, particularly for a double ender. I don't like the steel centerboard; when I slide over a sandbar with a board down (and sooner or later I will), I want it to kick up instead of rattling my teeth. I don't want a mast in the middle of the cockpit. I haven't seen a body plan or photos from the stern, but if by pinkie stern they mean the gunwales coming to a point beyond a transom, it strikes me as an affectation and unnecessary complication. And so on....:)

Norfolk Island Sharpie: I don't need or want six feet of headroom in a boat with a 12" draft, and it has a top-heavy, clumsy look to my eyes. The rudder is way too deep for my purposes, as is a centerboard designed to drop down almost to vertical. And again, I don't really like sharing a cockpit with a mast if it can be avoided.

Brewer's Mystic Sharpie strikes me as entirely too gussied-up for something derived from the simple, clean lines of traditional sharpies. And by dropping the stern to the waterline and adding a fixed skeg, I think he negates several advantages of the sharpie-style boat.

The Egret as drawn for Woodenboat is too spartan; Bolger's stuff is too boxy to suit me; anything with a keel on it isn't a shoal-draft sharpie; and so on. You get the idea....

I have a couple of Chapelle's books in the mail, and I'll bury my nose in them when they get here. I've already been through Bolger's books over the years, as well as those of John Leather, John Gardner, Ruel Parker and others. And again I doubt I'll find exactly what I want. So I'll be back to designing my own. And I do have some experience with flat-bottomed boats, although I haven't built anything larger than 16' before. What I have in mind so far falls well within traditional sharpie parameters. I may not win any design contests with it, but I'm not worried about it being a disaster.

[Brands01]

I love the idea of building a boat to my own design, and I totally understand others who embark on the same. I'm also someone who learns well from books, and have amassed a substantial library of boat books and think it is possible to do what you're intending.

You will get a lot of experienced people on this site suggesting you buy stock plans, and they have a very valid point. But it seems you are pretty intent, and are starting out fairly well informed and open minded. Hopefully the big kids won't be too insistent on changing your mind, and will help you change your design into something worthy of the expense and time of building, although I wouldn't be expecting too easy a ride!

Good luck!

[frank smith]

Ted Brewer has a nice design all ready to go. There is also a nice one about 30' in one of Chapelles books, I think it is his boat building book.
Anyway if I was going to design my own I would stat by looking at those for some guidance

http://www.tedbrewer.com/sail_wood/mystic.htm

If you stick to the basic recipe ,you should be able to cook one up .

[frank smith]

Troy , here is Atkins LITTLE BEAR. sort of a sharpie skiff , but a lot of boat .

http://www.boat-links.com/Atkinco/Sail/LittleBear.html

http://www.boat-links.com/Atkinco/Photos/LittleBear/LittleBear-01.jpg

[davesg]

I'd like to make very clear that we're following two roughly similar design ideas here. Mine includes the posted drawings that started this thread and is for a stitch and glue lightweight double-ended sharpie with the split cabin, there is also Troy's idea for a sharpie but with a different deck and cabin and built more traditionally. Its hard to keep two discussions in one thread distinct but keep an eye on who is posting what!

The idea with the split cabin was to get that cross structure in way of the mast and centerboard trunk. This is intended as basically a 25' sharpie stretched out to 30', there just isn't enough room inside to make one big cabin, so there is a berth up forward with its own hatch. I like the layout and I realize it wouldn't be for everyone but that's why we design our own. There is a bulkhead separating the two spaces and acting as reinforcement for the fwd end of the centerboard trunk.

The Norfolk Island Sharpies and Mystic are all very nice boats but are much bigger and more complicated than I had in mind. The design inspirations I'm working from are Monroe's Egret, Reuel Parker's Egret (http://www.parker-marine.com/28shegretpage.htm), and the sharpies in Chapelle's Boatbuilding (see the 24' Sharpie.) Freeboard fwd should be about three feet, aft less than two.

Little Bear is a great boat too but still bigger and more complicated than needed. I have a 32' sloop for distance sailing and the 'big' cruises. This sharpie is for gunkholing, sailing the shoals, and trailering.

Chessie Flyer is another nice design but again, too big and complicated (though still with a displacement of 4000 lbs with 1000 in ballast). I prefer my layout to Chessie's, would like to get the displacement down some, about 6" less freeboard for and aft and of course more length. I like the cat schooner (or cat ketch) rig for its simplicity, two free standing masts with a minimum of rigging. Chessie gets me close but if I'm going to go through the effort of redesigning the rig and the interior then I might as well design the hull as well.

Given these boats as a starting off point (Parker's sharpie's displacement is listed as 2500 lbs) I don't think 3500 lbs is too unrealistic. Mystic, to my eye a much more complicated but very nice boat is listed at 5500 lbs. I'll figure less ballast than my first guess? Ultimately ballasting will occur after launch to bring things down to her lines and provide adequate stability, the exact weight isn't a major concern right now.


I'll point out up front that this is an amateur design intended for an amateur build, there are no plans for any kind of production, there are no plans for any kind of sale of the plans. There has not been any kind of weight analysis done, nor careful calculations of anything, this is a first draft and I'd like some feedback before moving onto the next layer of the design spiral (Cyrus Hamlin, Preliminary Design of Boats and Ships.)

This is completely for my own edification and education. I am an amateur with no formal training as a Naval Architect. I have plenty of reference material available, have read extensively, sailed a bit too, renovated glass boats, done plenty of woodworking, and have a MS in Design and Construction from UF.

Ultimately I'm designing my own boat not because what I want has never been done before, its because I *want* to have designed what I build, even if the boat doesn't *perform* as well as some of these professional designs. I always appreciate the more experienced patrons first reaction to a newbie being "go buy stock plans" and I think that's completely correct nine times out of ten. If I was buying stock plans I wouldn't be posting here about my own design.

Par if you'd be so kind as to enumerate your objections to my draft, that's exactly what I'm looking for.

[frank smith]

It needs a wider bottom for initial stability if you want to keep the rocker and draft minimal . You could do the bottom in 2 layers of 1/2 , no need to keep width at 4' . Too much flair , You said that . I think you have more interior in the boat then there is room for IMO . I like double ended but why lose the stability and room of a transom ?

[troy2000]

I agree, Frank; Little Bear is a lot of boat for her size. But at 8'7" beam she's pushing the envelope for a boat to be trailered without a permit. I'll have to wait until I get home and dig out my Atkins books, but if I remember right, she's also heavy for a trailerable.

And John himself cautions that she isn't fast, as does her dad about Twilight, the boat she's derived from. I'm not a speed demon, but part of the fun of a boat is to see what she'll do sometimes on a breezy summer afternoon.

Somehow over the years I've missed owning Chapelle's books, even though he's referenced constantly in other author's discussions of traditional-style craft. But I have his Boatbuilding and his American Small Sailing Craft on the way; I ordered them a few days ago.

[troy2000]

By the way Dave, I hope you'll forgive me for somewhat hijacking your thread. It does seem reasonable to combine it with mine as the moderator did, since we're both amateur designers talking about a 30' sharpie; it saves some of the members basically making duplicate responses.

But yes, people should keep in mind there are two separate designs under discussion.

[frank smith]

Troy thank for pointing that out, I am reading quickly this morning because I really have things that i have to do. But the title is good hook , and I also dig sharpies .

[davesg]

I was certainly thinking less flare and more bottom but the lure of a single width of ply was too much so I thought I'd see what the group though, I'll add some width and lay it up with a couple of layers. The rocker is there because that's what everyone says about Egret and similar sharpies, keep the stem out by a few inches at rest, and the stern too for reserve buoyancy.

I know the debate between double enders and transoms. I really love the aircraft carrier look for the 'Open**' boats, and Graham Byrnes's EC22 would be high on my list if I were to build front stock plans. I don't intend this to be a planning boat, even in ideal conditions, so I didn't see much great advantage in dragging around all that transom. If I were to go transom I think the thing to do would be to cut things off a few feet shorter and have a wide open cockpit without transom for easier boarding/swimming. That sort of compromises the traditional look and I think would unbalance the appearance with that big aft house too close to the stern. A transom would make this a very different boat and even at this early stage of concept there are some things that have to be decided, double-ended is one of them.

I can see maybe too much interior too, first draft and all that. The big thing I see is the cabinets in the saloon are too far outboard, they need to come in, the low freeboard there, about 30") means they need to be completely inside the sidedecks to have any counter at all. I may have a counter on one side and just shelves on the other. What else should I be looking at in the interior. I did some measurements on the berths/fold out table and they looked okay but I may have missed something.

My construction concept is to scarf up full size topsides (hence using DelftShip, it will expand the developed panels for me), bending those around bulkheads and a mold or two and then adding the bottom. The 30' long sides will be a bear to handle but I can find some extra bodies for an afternoon to get them in place.

Troy, no problem, lots of room in here for two discussions, I just want to make sure we don't all start talking past each other. The big difference I see between our projects is the construction method, you're looking for a more traditional project and I'm a resin and glass devotee. You'll really like Chapelle's books, it seems wild you've never come across them. In fact he's got almost exactly what you're looking for in Boatbuilding, there's a 24' Sharpie that is really quite perfect. I don't think you'll get the interior you're looking for, but maybe if you stretched things out to 30' it could hold a little more. Really any sharpie (Monroe/Chapelle type anyway) is just going to have some room to crawl in out of the weather.

[troy2000]

Dave, the last time I was considering Chapelle's books, the only local bookstore that carried them wanted stunning amounts of money for them. Or at least the prices looked stunning to me, compared to the balance in my checkbook at the time. Of course, that was pre-internet days, and it never occurred to me to ask other bookstores about ordering them.

This time around, I just looked for the cheapest price online from someone with a good rep, and saved almost forty percent off list price. It was almost too easy. If I don't watch it, I'll be building another bookcase.

[gonzo]

The bottom has way too much rocker forward. The rule of thumb is a straight or almost for the first third, then a gentle curve which can accentuate more at the aft part. It will pound and push water forward like a tug.

[PAR]

Now that I've had Jeff (the moderator) move the one thread over here, I'm not so sure it was a wise thing. I'm having difficulty keeping up with the differences.

Basically, I'm hearing you both feel the need to self design because you're not finding precisely what you want in a stock plan. You'll never find precisely what you want in a stock plan, but it can serve as a strong, balanced base for your dream ship.

Construction methods aside, the are a few ways around the design spiral. I generally, pick a target displacement range, length and hull shape. Dave your 3,500 lb. boat is certainly possible, but it will require some clever engineering to keep the weight down and you'll be quite limited with what you can do with the narrow interior. From experience I can tell you that a 28' LWL with about 4' 6" WL beam will be in this range, but you'll have very little margin. The 28' LWL NIS is 7,700 pounds with about 3,400 in ballast. This is about right for a moderately dressed cruising vessel of this size and configuration. You could decrease the amount of accommodation, by decreased internal volume which will reduce the displacement, but you lose accommodation space.

I guess the point I'm getting at is there are a lot of subtle decisions and compromises that must be kept in mind for every design. The sharpie has peculiarities specific to it's type. An understanding of these as well as the design fundamentals are necessary for a reasonable expectation of success. FreeShip (or DeftShip) are wonderful tools, but don't tell you if something is good or bad, just the volumetric results of your efforts. An example would be how do you know what amount of rocker to employ (and why) and what shape. Or do you know why the NIS designs look boxy or high roofed. I understand why Bruce has these this way and it's a good approach, considering what he was after with the design. Even Chapelle (a man I personally knew) understood the limitations of the sharpie and mentions most in he's books.

I'm not trying to talk you out of a 30' self designed sharpie, but I'm not convinced that you understand the type sufficiently to successfully design a deep water yacht. This makes me considerably more nervous then someone interested in designing an 16' pocket yacht.

In this vain, it's often much easier to use a stock plan as a base for modification. Assuming you don't move too far out of the box, most things will still be in order. I've seen Ted Brewer's sharpie without the pinky boards and it's a much better looking boat and 5,500 lbs. is the "light" displacement for this craft. In the 3 ton range would be reasonable for this size craft. Knowing you displacement and length, you can develop a rocker to suit the anticipated wave train or use the one worked out in a stock plan. Scantling issues will generally be sorted out. Who would know you used a 28' base (for example) respaced the station molds so it was 30' and designed a new rig, cabin and accommodation arrangements around the new, longer boat.

If it was me, with limited design experience I'd find a fairly fat 26' or 28' sharpie and respace the station molds. You'd have a leaner ship, with better stability, slightly more displacement, more interior volume and you could go insane designing a new deck, rig, accommodations, making it an all new boat without fear she'll embarrass the crap out of you on launch day (it happens, I can recite names). This is in fact pretty much what I did on my first build. Don't space the station molds more the 10%, 15% at most and you'll be safe, plus enough engineering left over to make anyone bald and wishing for a frontal lobotomy with a kitchen spoon.

[davesg]

I'm a big fan of stock plans, I can find a lot to love in just about any boat, my reasons for drawing up my own really are 'just because.'

I picked 30' as an arbitrary length to start with, it gives the length for the interior I want without getting completely out of hand. We could just as easily add a transom and lose two feet of the stern and make it a 28 or lose the standing space forward and make it a 26. I am of the thinking that the longer the better, all else being equal, and sharpies are a type that seem to do well long and narrow with light displacement. The displacement I'm shooting for (about 3500 lbs) reflects the intent of this design as a big skiff with two cuddies and room for three to bunk out (not counting the cockpit.) The Norfolk Island Sharpies are certainly wonderful designs, but its the 23 that looks closest to my thinking for this design (stretched of course), other than the 18 I don't see displacement listed for any of them so I don't really know how that relates to my thinking on this one.

I don't want to get hung up on accommodations here. Sitting headroom and the berths shown are the only sticking points, the large hatches supply the standing space, they are almost more like a sliding top rather than real companionway hatches.

This absolutely isn't meant to be a 'deep water' boat! Coastal gunkholing in Florida and surround waters for vacation sails is the intended use. From personal experience I would consider the Bahamas and Tortugas to fit into that description as well. This is a fair weather boat, not some survive-anything go-anywhere boat. Like a big skiff with two cuddies.

Mystic is a great design, but too big, too complicated. Instead of the standing ketch rig I'm interested in a free standing set up, instead of plywood on frame I'd like a stitch and glue type frameless construction. I don't have anything against either of those features, but they aren't what I want this time around.

This design could just as well be an open boat with three cockpits and sleeping on the seats, the deck houses are meant to enclose that space but not create a real walking around, living aboard type interior, just sitting headroom and standing under the hatches.

I've restored boats, modified existing designs, and stuck with spec, this time I want to design from scratch. I am lacking experience but in order to gain that experience I am working through this design. I realize this boat will not be as 'good' a boat as a professional, proven design might be, but this isn't about perfection or performance its my first attempt, its about floating right side up and sailing forward rather than backward.

DelftShip is a really nice program and the main reason I'm using it is for the developed panels it can unfold but I wouldn't expect it to design that boat. I think I understand the design motivation of most of the boats cited, this one is a bit different though, if I wanted a fuller interior then more draft, displacement, and higher freeboard would make sense but I'd really just like a big day sailor with an interior made possible solely by virtue of its length.

I've read Chapelle's discussions of sharpies as well as any others I could find. (With the glaring omission of Parker's Sharpies book, which is on order.) Monroe's Egret has been an inspiration as well as Presto though of course I don't completely buy into all the gushing praise for those boats I do think they were something special for their intended uses.

Attached are some updated lines. I reduced the forward rocker, widened the bottom and generally massaged some things. The shear just doesn't look right to me and the bottom doesn't seem right either. Any suggestions?

http://img5.imageshack.us/img5/2979/30sharpielinesplan.jpg

[frank smith]

This is better , I would want more freeboard . It is starting to look like an Egret . While the flair does provide a cushion of buoyancy I dont think it is good for speed .

[frank smith]

I also think the bow angle is a little shallow , might have a strong weather helm.
I try to think of them at 15-20% heel . and look at the chine in relation to a diagonal . But it is basically all in Chapelles .

Hve you thought about rudder and center board yet.

[davesg]

The centerboard trunk would run from about 10' to 16' aft of the stem. The CLR for the board is at about 14' aft of stem and about 2'4" below static waterline, with board down draft of about 4'6". The trunk is set off to stbd by about six inches to get the main mast step on the centerline.

I'm really interested in some similar designs that have used a smaller second centerboard aft for more area and balance. I don't think its needed here since I think there is enough area in the main board but its something to think about.

I had originally drawn in a kick-up dinghy style rudder hanging on the stern. The only real sharpie I have sailed was a friend's 19 footer and the low aspect ratio rudder felt really strange to me but one would fit under the stern here. The stern hung rudder would just be easier to build, use less hardware, and unless someone can tell me why its a bad idea, I think it would perform better as well.

The question of whether flair is good or not comes down to whether you're comparing it to pushing out the deck or pushing out the chine. To my mind you can make it work wither way, flared like a dory or slab sided like a Bolger design. Personally, I like the flare, but maybe a little more forward?

Could you explain the 'bow angle' for me a little? The angle in plan made by the sides coming together at the bow? Or something to do with the rocker on the bottom?

Thanks for the help,
David

[gonzo]

It is really fine at the bow and with a lot of rocker. That is a design that will be extremely finicky on the longitudinal loading. Also, running will tend to bury the bow.

[davesg]

Ah, I see exactly what you're saying, I'll work on it some more tonight and post again when I have something new.

David

[frank smith]

I'm not sure about the rocker, 3/8" to the foot would give a light craft , and fast ,1/2" to the foot is what is about average, 5/8 works out nicely for a loaded cruising sharpie , it all depends on what you are looking for.

[troy2000]

If it was me, with limited design experience I'd find a fairly fat 26' or 28' sharpie and respace the station molds. You'd have a leaner ship, with better stability, slightly more displacement, more interior volume and you could go insane designing a new deck, rig, accommodations, making it an all new boat without fear she'll embarrass the crap out of you on launch day (it happens, I can recite names). This is in fact pretty much what I did on my first build. Don't space the station molds more the 10%, 15% at most and you'll be safe, plus enough engineering left over to make anyone bald and wishing for a frontal lobotomy with a kitchen spoon.

PAR, everything in a well-designed boat is interconnected and balanced. When I've tried just 'tweaking' an existing one, I haven't been happy with the results.

I'd rather take several boats I like, and turn out a consensus design that's somewhere in the middle of what I like about their plans. And it's worked for me so far, on the few smaller boats I've built.

I should probably have held off posting until I had something substantial in the way of a design or model to show, but I got all excited when I realized, "my God! There's a place online where I can talk to people about what I'm getting ready to do.":D

add: I'm not saying I live and work surrounded by fiberglass-worshipping Philistines who have no idea what I'm talking about. But one evening after work a few years ago I was busy knocking together a flat-bottomed canoe, from some scraps of 3/8" CD shear panel, 1x2 Douglas fir furring strips and other miscellaneous scraps, all dug out of a dumpster (desperation; I was 600 miles from home). A framing carpenter stopped on the way to his pickup to ask in an incredulous tone, "yore buildin' a boat outa wood?? How ya gonna keep the worter out?!?

[frank smith]

How are the sharpie designs going ?

[YK GEO]

Dave,

The basic sharpie design is pretty forgiving, as long as you stay within the general rules recorded by Chapelle, and keep the curves fair and gentle. As to building the boat, have a look at my little boat I knocked together in an afternoon with the only plans in my noggin. It's at the thread "Sharpie skiff - Chapelle's rules". Sometimes we make small boat designing and building way more complicated than it really is.

For the size you're building, take good advice as to strength requirements. The sharpie hull type racks and twists easily, so you need plywood bulkheads and corner reinforcements to keep it in shape. Also longitudinal stringers to prevent the plywood panels, esp the bottom, from curving in. Torturing in a bit (say 1/2 inch) of transverse curve in the bottom helps a lot. Build it flat, then force the curve in and secure it with framing. If you're building taped seam, force in the bottom curve before gluing the chines together. My current project will be built upright in about 4 female molds with the curve sawn into the molds. I'll screw the bottom to the molds giving me the longitudinal and transverse bottom curves with everything held in place for lining up the sides. That way the interior of the boat will be wide open for taping, installing stringers and bulkhead, etc. Once the hull is all stuck together, unscrew the bottom from the molds, flip it over and do the outside.

Have you read Munro's book "The Commodore's Story"? Not a lot of pictures and no plans for Munroe's boats, but a good read.

Good luck with your project.

Geo

[gonzo]

The lowest part of the sheer should be about the middle so the bow doesn't look like a needle

[davesg]

I've tweaked the lines a bit, a little more freeboard, more beam fwd. I think there is too much rocker but I'm not sure how to balance keeping the stem and sterns above the static waterlines but still have the depth for the displacement the boat needs. Right now its a bit less than the 1/2" per foot of rocker. Any ideas there?

Geo - I've read your sharpie thread a couple of times and you make good points on the structure. I've only taken a cursory look at the structure, there are four full width bulkheads sketched in and the interior will all be structural. The biggest problem I see is there is 7' about amidships that doesn't have any full beam structure other than the deck house. I was going to use a mold or two there for getting the panels in the right place but I am a little concerned about torque and bending. I'll know more once I take another lap around the design spiral.

I haven't read the Commodore's Story, haven't found a copy but I have read 'The Good Little Ship' and what else I could find on Presto and Egret.

http://img14.imageshack.us/img14/2979/30sharpielinesplan.jpg

[troy2000]

How are the sharpie designs going ?

Well, I went out yesterday and bought a pile of basswood, and some 0.8mm birch plywood. I decided I was wasting my time trying to tell Delftship how the boat should be shaped. I don't have enough knowledge and experience to force a design into it.

Instead, I'm going to do what I've done in the past with smaller projects: put some wood together, and let it tell me how the boat's going to be shaped. Then I'll start comparing it to established designs, and make sure I'm somewhere in the norm. Since I'm an amateur, I have no burning desire to live or die on the cutting edge of design.....

Right now I'm just waiting for a couple of Chapelle books to show up in the mail. I have books by other authors, and it gradually dawned on me: since every single one of them references Chapelle somewhere, it would probably behoove me to look up his stuff firsthand.

I'm wrestling with LOA (a hazard of having too much time on your hands to poke at things...). Given the narrow beam of sharpies, it looks to me like I could really use up to 32' to comfortably stuff in a V-berth, a pair of settee berths, an enclosed w/c and a usable galley. Plus enough cockpit (and supporting hull aft) to let a few friends hang out topsides and enjoy the trip....

On the other hand, 26' to 28' sure sounds a magnitude or two cheaper to build. Not to mention easier to tow, launch and recover.

[frank smith]

http://schooneribis.blogspot.com/search?updated-min=2007-01-01T00%3A00%3A00-05%3A00&updated-max=2008-01-01T00%3A00%3A00-05%3A00&max-results=4

If you have not seen this check it out , Here is Parkers straight forward build ,
basic simple and strong . Note that he has created an egg crate type structure, and integrated the tanks .

[kayaker50]

Troy2000, are you building a model? If so, I'd like to know how you make a scale model from scratch. Thanks, Chip.

[frank smith]

I have used thin plywood from the hobby store , makes it easy to lay out full size .

[troy2000]

http://schooneribis.blogspot.com/search?updated-min=2007-01-01T00%3A00%3A00-05%3A00&updated-max=2008-01-01T00%3A00%3A00-05%3A00&max-results=4

If you have not seen this check it out , Here is Parkers straight forward build ,
basic simple and strong . Note that he has created an egg crate type structure, and integrated the tanks .

Very impressive. Of course, that's quite a bit more boat than I plan on building. But it's pretty much the same construction that I'll be using: sides wrapped around bulkheads.

Troy2000, are you building a model? If so, I'd like to know how you make a scale model from scratch. Thanks, Chip.

Um....well, I cut pieces to scale, and put them together like I was building the real thing. The last model of a 30' sharpie I built was 1"=1'-0", but it was a little small for working out the details. So this one will be 1 1/2"=1'-0". That means every 1/8 of an inch will equal one inch...which is going to make for a ridiculously large model, almost four feet long. I'm making it that big partly so I can do some reverse engineering and layout after I establish the basic hull: i.e., cut and fit parts, then measure them.

Of course I'm working backwards, compared to people taking dimensions off a set of plans. Instead of taking an established overall size and shape and seeing what size parts it takes to get it, I'm arbitrarily setting the size and shape of the sides and the controlling bulkheads, and wrapping said sides around said bulkheads to see what I get. Then I'll modify one or the other as necessary until I'm happy with the results, and go from there with the details.

I've built models strictly to scale from plans in the past, though. The first one I did was a Grand Bank dory from John Gardner's The Dory Book, years ago. I had a nice soft, even-grained piece of Ponderosa pine left over from some bookshelves, so I used my table saw and a planer blade to rip out a pile of scale lumber. Then I duplicated every piece in Gardner's plans, at 1"=1'-0". It was pretty much like working with balsa wood, and a whole lot cheaper.

I also built a Caddo Lake Bateau and a few other models of small boats over the years, including several of my own design before I built the real thing. It's the same idea as a traditional boat or ship builder doing a half model to take the lines from, carried to an extreme.:p

And the 45" model I'm going to wind up with this time? Sorry, but my boys aren't getting this one until I'm dead. I'll probably turn it into an r/c model. I'll have to add some ballast, and replace the pivoting centerboard with a larger, fixed keel for the sake of stability, since there won't be a scale helmsman on board with full-scale judgment....

[kayaker50]

troy2000, I for one would like to see pix of the model as it progresses. I like the idea of dealing with a real object instead of an image on a monitor. Chip.

[troy2000]

troy2000, I for one would like to see pix of the model as it progresses. I like the idea of dealing with a real object instead of an image on a monitor. Chip.

I'll start posting as soon as I have something to show, Chip; I replaced my defunct digital camera this week for just that purpose. But it'll be a little while. I'm still waiting for a couple of Chapelle's books to show up in the mail, so I can study his designs first-hand before starting mine. Between Parker, Gardner, Monroe and others I already have a decent idea what I want, but it can't hurt to study the classic work boats Chapelle recorded.

[kayaker50]

Yes, I have Chapelle and Parker. A 27-30 foot sharpie is in my future too. Chip.

[troy2000]

Yes, I have Chapelle and Parker. A 27-30 foot sharpie is in my future too. Chip.

I feel about half-crippled; I'm used to having a full-sized drafting table set up to play on. I usually kind of bounce back and forth between it and models or templates, when figuring out anything from rowboats to trebuchets.

But right now I'm spending a good chunk of my life working away from home and living in a motor home, and no longer have a 'man cave' back at the house. It's been overrun by the wife and sons for their own nefarious purposes, and that big old oak-framed drafting table 'took up half the room, and you never use it anyway..." So I'll be relying even more than usual on model-building for this project.

I'm also looking at the layout of the motor home, though. If I bought a smaller, basic computer desk and ditched the recliner, I might be able to fit one of my old drafting tables in behind the driver's seat. It isn't like I spend much time entertaining anyway. Mostly, it's just me and a few beer cans.....

[gonzo]

Seems like you are in good company

[troy2000]

Well, ratz.

The two Chapelle books showed up in the mail, and they're chock-full of information. But the boat plans which were my main reason for buying the books have been shrunk down to fit book pages that are about six inches by nine inches. They're literally unreadable, even using a strong pair of magnifying glasses.

I guess my only hope is to take them with me when I go back to work, and see if they're legible when I blow them up on the copier.

If that doesn't work, maybe I can get the drawings elsewhere. Does anyone know whether the Smithsonian owns the drawings Chapelle used in his books?

Better yet, are there coffee table sized issues of these books available anywhere, new or used?


edit: never mind; I just answered my own question. I looked it up, and all the plans shown in the two books are catalogued in the Smithsonian's Ship Plan List (American merchant ships and small craft). That runs twenty bucks. I don't know how much the black line reproductions of the plans themselves are individually, but I doubt it'll kill my budget to buy a few of them. And it beats going blind, trying to study the miniature plans in the books.

[gonzo]

The table of offsets is there. With a flat bottom boat you only need a few points anyway.

[troy2000]

The table of offsets is there. With a flat bottom boat you only need a few points anyway.
I'm not looking at his offsets to build a boat; I was looking for a quick comparison of the hulls for such things as where the maximum beam is located, where the forward flat run starts blending into the midships rocker of the bottom, the height of the stem, etc.

And I'm not kidding when I say I literally cannot read the plans, including the offsets--even using reading glasses much stronger than the ones I usually wear. They've been scaled down until the distance between perpendiculars for one of his 35' sharpies, for example, is 5-1/4 inches.

The next time I head into town, I'll stop off at a drug store and buy a big magnifying glass. Hopefully, the numbering and lettering in the plans are sharp enough to be legible when they're blown up big enough to read. If so, I can probably blow them up with a good copier, and we have one at work.

[messabout]

One of the most useful tools of the model builder is an architects scale. For those unfamiliar with such an item, it is a measuring stick with the marks and numbers reduced in various sizes. There are scales of 3/4, 1inch, 1.5 inch, 3 inch and sometimes you can find one with a 2 inch scale. With that tool you can lay out the model without much recourse to the calculator. Many office supply stores have the architect scales.

If you intend to play in the water with the model you will need to see to it that you have scale weight. Calculating model weight is simple enough. Use the cube of the scale for a denominator of the weight of the full sized boat. If the scale you are using is 1.5 inches to the foot then the scale is one eighth. 12"/1.5" = 8 and 3" to the foot will make it quarterscale or one fourth. For one eighth scale just multiply 8 x 8x 8 = 512 Say the real boat is to weigh 2000 pounds....divide.....2000/512 = 3.90 pounds or 62.5 ounces. When building to small scale like one inch to the foot, the model is not easy to build light enough. One inch scale has a cube of (12^3) = 1728 and so that 2000 pound boat would need to be 2000/1728 = 1.16 pounds or 18.5 ounces. You can see that the advantage is for the larger scales. I usually build at either 2 inch or 3 inch scale and can therefore be less concerned about the weight of the materials that I use.

[gonzo]

I have those books and it doesn't seem so hard to read the plans. Make a copy and enlarge it.

[troy2000]

Thanks for the info, messabout. I'm quite familiar with architect's scales; I was a general contractor for years, and drew my own plans most of the time for everything from patio decks to houses.

But I've never tried to deal with calculating scale weight for anything fancier than a trebuchet counterweight before, and your explanation of how to do so is very helpful. Thank you.

[troy2000]

I have those books and it doesn't seem so hard to read the plans. Make a copy and enlarge it.

Perhaps you'd like to come over and read them to me then, if you have no problem with them.

Maybe the illustrations are a little clearer or larger in the editions you have. But I've been buying books with boat plans in them for probably thirty years, and these are the first ones I've ever owned that I can't read.

And yes, I think I've mentioned at least twice now that I was going to try to enlarge them with a copier when I get back to work. If the images in the books are sharp enough, that'll work.

[gonzo]

I have a 1969 edition and the offsets and plans are really clear.

[troy2000]

I'm not sure what year these are. They're both published by Norton. The latest copyright renewal in the Boatbuilding book is 1994, with a forward by Jon Wilson, founder of Woodenboat Magazine. The other one has nothing in it but the original 1951 copyright date. But it's obviously a new edition.

They're both much smaller than the editions I remember looking at years ago in a bookstore. Those were about the size of my laptop, like the editions I have of books by John Gardner, Edwin Monk and others.

[gonzo]

That sucks

[troy2000]

That sucks

I agree. Somehow, taking plans that were probably originally drawn on 22"x30" sheets, and fitting them onto a 6"x9" book page printed on fairly coarse paper, does something to the legibility...

[Earl Boebert]

I'd suggest scanning them at 1200 dpi with the scanning software set for color photographs (I strongly recommend VuScan). Then you can use a graphics program to reduce the intensity of the paper colors and increase the intensity of the ink colors. I've succeeding in bringing up some really reduced plans that way.

Just a thought.

Cheers,

Earl

[kayaker50]

I know what you mean about the print being damm small. There are several offset tables in the very back of American Small Sailing Craft which are larger than the offsets in the text. But I agree, it should be a coffe table size book! Chip.

[troy2000]

I'd suggest scanning them at 1200 dpi with the scanning software set for color photographs (I strongly recommend VuScan). Then you can use a graphics program to reduce the intensity of the paper colors and increase the intensity of the ink colors. I've succeeding in bringing up some really reduced plans that way.

Just a thought.

Cheers,

Earl
That's a good suggestion.

There's a fancy copy/fax/email/scan thingie the size of a desk in the front office where I work. Starting tomorrow evening, I'll be working three 12-hour graveyard shifts; with a little bit of luck I can get out of the control room long enough to play with it. Then I can email the results to myself, and tweak the pics at my leisure.

Or I may not even have to do all that; with a little more luck, just a straight copy enlargement might do the trick. But it's nice to have the option.

Several years ago when I was looking at Woodenboat's reconstruction of Egret, I took the book with the study plan down to a copy center. The gal fiddled with her machines for a while until she was able to hand me some beautifully legible copies of the study plan, blown up to a scale of precisely 1"=1'-0". Then she charged me only for those copies, and wouldn't even let me pay her for the trial runs where she had wasted paper adjusting her settings.

Unfortunately, when I swung by a year or two later the copy shop had been replaced by a bookstore.

[troy2000]

Another random thought: maybe the reason shaping the bottom of a sharpie hull so it has a flat run forward, a rocker amidships, and a straight or almost straight run aft works so well is because it approximates a shallow parabola?

Yes, I know....I should post first, then drink.:D

[wardd]

couldn't you import the image into a cad package and develop xyz dims from 3 views?

may not be perfect but with some practice close enough

you'll have to know how to scale the image

[frank smith]

Another random thought: maybe the reason shaping the bottom of a sharpie hull so it has a flat run forward, a rocker amidships, and a straight or almost straight run aft works so well is because it approximates a shallow parabola?

Yes, I know....I should post first, then drink.:D

That maybe be a matter of how they were built . Forward of the center board case they just ran a plank out to the bow . Not terribly complex way to deal with it . Also when looking at a working sharpie remember that they carried a lot of weight aft of the case . So think of them loaded down 4" or more .

[troy2000]

That maybe be a matter of how they were built . Forward of the center board case they just ran a plank out to the bow . Not terribly complex way to deal with it . Also when looking at a working sharpie remember that they carried a lot of weight aft of the case . So think of them loaded down 4" or more .

According to Chapelle and others, sharpie bottoms were quite deliberately shaped that way for performance. It wasn't just happenstance or a byproduct of the construction method.

[gonzo]

Hey troy2000 if your enlargement doesn't work I can email you a copy of mine.

[PAR]

You have to remember when Chapelle wrote about sharpies, he was talking about working craft, that often would have a ton or three of oysters or fish to bring home. The shapes used in these sharpies can't be taken for the shapes used in modern craft of similar model. The reason the "run" tucks up fairly quickly is to keep the stern clear when loaded, other wise it'll drag it's butt, which kills speed. Try not to read too much into the lines of these antique craft, without veering too far from what their primary purpose was, because they didn't.

[troy2000]

Hey troy2000 if your enlargement doesn't work I can email you a copy of mine.

Thanks for the offer, gonzo. I'll be at work tonight, and should be able to try copying and enlarging sometime before I get off, unless things get hectic. I'm an operator at a natural gas compressor (pumping) station, and my job pretty much matches the definition of combat sometimes: long periods of boredom, punctuated by moments of sheer terror.

[troy2000]

You have to remember when Chapelle wrote about sharpies, he was talking about working craft, that often would have a ton or three of oysters or fish to bring home. The shapes used in these sharpies can't be taken for the shapes used in modern craft of similar model. The reason the "run" tucks up fairly quickly is to keep the stern clear when loaded, other wise it'll drag it's butt, which kills speed. Try not to read too much into the lines of these antique craft, without veering too far from what their primary purpose was, because they didn't.

One of the appeals of the classic working sharpie to me is that ability to take a load without dragging its butt. The one I build will probably be single-handed or sailed with one other person for crew a lot of the time, but I'm sure the cockpit will occasionally have a crowd in it, with people climbing in and out of the cabin.

Chapelle also talked about racing sharpies, and how they were built a little shallower and a little broader in the beam. It looks to me like those are the directions I'll head when I diverge from the classic working lines, without pushing beyond the normal bounds of the traditional hulls.

[PAR]

You'll be much happier if you design the boat for the primary use and live with some butt dragging when the crowd comes aboard. The "race" versions of the sharpie have fairly different lines, particularly aft. The run is straightened, the sides much less flare, displacement carried aft, etc.

[troy2000]

You'll be much happier if you design the boat for the primary use and live with some butt dragging when the crowd comes aboard. The "race" versions of the sharpie have fairly different lines, particularly aft. The run is straightened, the sides much less flare, displacement carried aft, etc.
Since the classic working hull was designed to carry heavy loads and I'll rarely be doing that, is there any advantage in sticking closely to it instead of building something closer to a racing hull?

[PAR]

Nope, build the racer and let it be a dog when you have 5 aboard.

[troy2000]

Hey troy2000 if your enlargement doesn't work I can email you a copy of mine.

Looks like I shouldn't have been lumping the Boatbuilding book in with the American Small Sailing Craft book like I did, gonzo. At the time I was bellyaching, I had spent most of my time with my nose in the second one, and I'll stand by what I said about it being illegible. But the Boatbuilding book is printed on smoother, almost semi-gloss paper, and I can read its drawings in good light. I blew up the plans for the 30' cruising sharpie this evening for study purposes, and they turned out very nicely.

I haven't had a chance to try enlarging any drawings from the Sailing Craft book yet. I doubt they'll turn out nearly as well, but maybe I'll be pleasantly surprised.

[PAR]

When you enlarge plans with a photo copier or an industrial camera (not used much any more except on big stuff in the printing industry), you will run into an interesting issue called lens distortion. In fact, if the image (in the book) is taken from a set of plans, it was reduced in size with an industrial camera (enter the first generation of lens distortion), when you re-enlarge the image, you add more distortion to the lines drawing (or what ever). This is usually noticeable around the edges of the image where lines clearly no long are straight.

It's caused by the image perimeter passing through the edges of the camera lens at such an angle that "parallax" occurs. A quick way to tell is to place a straight edge on the LWL and see if it's straight all the way across or better is to see if the waterlines are all parallel (they will not be if it's an image from a book). This isn't a big issue on small changes in image size, just large ones. For example, lets say the original plans were 36" wide and it was reduced to 8.3% of it's original size (3" so it would fit in a book), the distortion would be substantial and all the curves suspect (a subtle but noticeable "fish eye lens" effect on the whole image). If you decided to reverse the situation and enlarge the book image to 36" again, this would be a 1,200% increase on the size found in the book.

If you attempted to build a class racer from a set of plans derived this way, the measuring committee wouldn't pass you, because of all the deviations in the shapes that will occur. Not to mention the lines drawing that looks so nice and fine in the book will now have lines a 1/4" thick.

[troy2000]

When you enlarge plans with a photo copier or an industrial camera (not used much any more except on big stuff in the printing industry), you will run into an interesting issue called lens distortion. In fact, if the image (in the book) is taken from a set of plans, it was reduced in size with an industrial camera (enter the first generation of lens distortion), when you re-enlarge the image, you add more distortion to the lines drawing (or what ever). This is usually noticeable around the edges of the image where lines clearly no long are straight.

It's caused by the image perimeter passing through the edges of the camera lens at such an angle that "parallax" occurs. A quick way to tell is to place a straight edge on the LWL and see if it's straight all the way across or better is to see if the waterlines are all parallel (they will not be if it's an image from a book). This isn't a big issue on small changes in image size, just large ones. For example, lets say the original plans were 36" wide and it was reduced to 8.3% of it's original size (3" so it would fit in a book), the distortion would be substantial and all the curves suspect (a subtle but noticeable "fish eye lens" effect on the whole image). If you decided to reverse the situation and enlarge the book image to 36" again, this would be a 1,200% increase on the size found in the book.

If you attempted to build a class racer from a set of plans derived this way, the measuring committee wouldn't pass you, because of all the deviations in the shapes that will occur. Not to mention the lines drawing that looks so nice and fine in the book will now have lines a 1/4" thick.

That makes sense to me. But surprisingly enough, when I enlarged the plans for sharpies out of these books from five inches to over a foot, the long lines. were so straight I could split them with a metal straight edge, and stay in the lines from end to end.

I wouldn't want to push my luck and keep copying copies, though. We have some forms around here that are copies of copies of copies, back for several years. The lines are thick and mangled, the printing waves across the pages like flags in a breeze, etc.

By the way, I did get around to trying to make larger copies of the drawings in American Small Sailing Craft, and it's as I figured: while the lines and construction details are easier to see, the words and numbers I couldn't read straight from the book are also illegible when blown up. The paper they printed the book on is just too coarse and soft, and the letters and numerals turned into blobs.

Ah well....I'm not trying to build directly from plans in the book anyway. I'm just studying them to get a feel for what the general parameters of the type are.

[frank smith]

I thought I would add this picture of a Akin sharpie. John Atkin knew the type very well, and here he has designed a cruising one . You could debate that it is more of a large skiff , but a sharpie is just that.
http://www.boat-links.com/Atkinco/Sail/images/Matty-3.gif


http://www.boat-links.com/Atkinco/Sail/Matty.html

[Earl Boebert]

Dealing with distorted plans is a way of life for those of us who seek to preserve and replicate old model yachts. Even when you get an old full-size plan there will be distortion owing to the uneven shrinkage lengthwise vs. vertically; on old blueprints this can be 5% or more.

The old-timer's trick, which works remarkably well, is to lay out the stated intervals for stations, waterlines, and buttocks on a fresh drawing. Then cut the distorted plan apart on these lines and glue the pieces down on the new grids. Fair the lines again, using plenty of diagonals, and you'll get about as close as possible to the designer's original intent; remembering that, especially with models, the "real" hull appears during fairing on the building board.

Cheers,

Earl

[troy2000]

I thought I would add this picture of a Akin sharpie. John Atkin knew the type very well, and here he has designed a cruising one . You could debate that it is more of a large skiff , but a sharpie is just that.
http://www.boat-links.com/Atkinco/Sail/images/Matty-3.gif


http://www.boat-links.com/Atkinco/Sail/Matty.html

Chapelle has a double-ended 30' cruising sharpie in his Boatbuilding book. Unlike Monroe's Egret or the working sharpies, both ends are roughly on the waterline at the chines.

It has practical, if somewhat spartan, accommodations for a cruiser. I'll be referring to it while I design mine. But I guarantee one thing: the head will not be a bucket at the forward end of the cabin between berths, open to the cabin.....I'll do a portable toilet that can be carried ashore and dumped, and provide a private cubicle to one side of the companionway.

Chapelle's cruiser sharpie also incorporates what he called a "Dutch galley." A kerosene stove and a sink are built into a portable box, with a couple of drawers under the sink. The part with the stove is metal lined and insulated, of course. When the galley is in use the lid folds up, and wings fold out to create counter space. The sink drain has a flexible hose that clips to the side of the box; you drop the end into a bucket and drain the sink after you're done with it. When not in use, the box gets stashed on a shelf.

It is tempting to think I might be able to come up with something similar that sets on a chart table when in use, and stashes out of the way the rest of the time....of course, mine would probably have a stainless-steel bar sink and a small propane stove.

If I have time at work tonight, I'll scan Chapelle's drawings and post them. They're the only detailed representations I've seen of a cruising sharpie from 'back in the day.'

[frank smith]

I have seen plans for for the Chapelles double ended sharpie , Brewers Mystic
is very similar . I like the look of Chapelles better . Not having the flair of egret , it will be faster and handle better, IMO . Very cool boat .
If I were going to do it I think I would add a shallow box keel to hold the ballast and move the center board out to the side a little .

[troy2000]

I have seen plans for for the Chapelles double ended sharpie , Brewers Mystic
is very similar . I like the look of Chapelles better . Not having the flair of egret , it will be faster and handle better, IMO . Very cool boat .
If I were going to do it I think I would add a shallow box keel to hold the ballast and move the center board out to the side a little .

I had temporarily forgotten about the Mystic Sharpie; I'll have to compare Woodenboat's study plan for it to Chapelle's double-ender tonight. But now that you've mentioned it, the one was probably the inspiration for the other.

[gonzo]

I owned a 34' version that Chapelle did. They are very fast off the wind, even planing. Upwind they are fair. I was very pleased with that boat.

[frank smith]

I owned a 34' version that Chapelle did. They are very fast off the wind, even planing. Upwind they are fair. I was very pleased with that boat.


Was that a double ended boat ? How was the rudder ? I have heard that the sharpie rudders were not really good . I understand that for a working sharpie ,getting the rudder out of the way was a good thing , and while working an oyster bed you could use it to swing the stern around over the bed ,perhaps using the center board to anchor the boat . I am sure that they would turn in there own length ,and that would be good working in the narrow inlets of Long Island Sound . But I wonder if a conventional stern hung rudder might be better for a yacht version of the sharpie . It would be nice if there was a way to have a spade rudder that could be raised and lowered . I suppose you could cut a slot for the rudder ,but then you loose that advantages of an under hung rudder.

[gonzo]

They are simple rudders that do the job. Every improvement to make the sharpie more modern has more drawbacks than advantages. The sharpie rudders can be lifted for shallow water and beaching. Also, they are under the hull so won't ventilate. Wide and shallow rudders can turn at higher angles without stalling too.

[troy2000]

Well, we grow too soon old, and late smart. I just did a google search for used books, and found out the original edition of Chapelle's American Small Sailing Craft was published as a quarto back in 1951. In other words, it was about 9"x12", instead of the octavio (6"x9") size I just bought. And the sad part is that there are used ones in good shape on the internet, for about what I paid for the dinky new edition. So I guess I'm going to pay twice, because I'd really like to have the full-sized book.

More interestingly, I found out Chapelle also had a book published back in 1936, that was titled just American Sailing Craft, instead of American Small Sailing Craft. It was also quarto sized. And although I haven't managed to run down any detailed descriptions, I gather it was also oriented toward smaller craft rather than ships, and was full of drawings. There are copies of it available also, for a reasonable price. So it's a good thing payday is tomorrow, because that makes two books I need to order.....gotta love the internet. It's a brand-new way to keep me broke.

And another factoid: while I was at it I looked up John Gardner's Dory Book, because the copy I have is falling apart. I was shocked to find out it's no longer in print, and the going prices for a used hard cover ranged well over a hundred bucks. Even the paperback versions were about $75.00, for crying out loud. Guess I'll just keep sticking the pages of mine back inside the cover as they fall out....Woodenboat is coming out with a new edition in December, but I'll bet it's going to be a little book instead of the original full-sized one.