An Atkin variation on the Seabright Skiff

[ishmael]

Hello,

I just got a bunch of plans from Tony Hunt. One of them I've fallen madly in lust with. It's called Heart's Desire II. A profile can be seen on the "Good seaboats, 18 to 25 ft." thread, pg three. If I become courageous maybe I'll try posting the lines.

Anyway, it is just under 23 ft. over all. It's a double-ended chined hull. Imagine a typical chined hull, but with the keel being a boxed arrangement, like a Seabright skiff's.

This gives substantial headroom, though not full for my 5'11'' frame. It places the engine down low, and with a horizontal prop shaft. Two of the advantages of this arrangement.

One question that comes to mind is that Atkin doesn't specify any ballast. This suprises me no end. I would think such a hull, with a 288 ft. cutter rig, would need to be ballasted with say 1200 lbs of lead pigs down in that box.

Any thoughts?

[Bruce Taylor]

Nice!

[ishmael]

Thanks Bruce. Isn't that a lovely looking little packet?

I wonder about ballast though.

I wish I could post the lines, they are quite something to my eye. Rather than what we've come to know from ply construction of single chine hulls, with flat sides and slab lower hull, it's a joy of curves.

The topsides are to be planked lapstrake and the bottom carvel, and aside from some of the bottom forward it is all curves. An intriguing project says I.

[Dave Fleming]

Jack, what IDEAL volume is the plan from?

I found it on John K's site volume 38 of the IDEAL series.

[ 01-28-2003, 05:31 PM: Message edited by: Dave Fleming ]

[ishmael]

Hi Dave,

I'm not sure, all I have is photocopies. Maybe Tony will chime in.

[ishmael]

Maybe I should move this to B/R, but I just wanted to bring it back to the top.

Some thoughts: It seems a fairly complex construction to my relatively neo-phyte eye. Sawn frames, with a chine, carvel bottom with lapstrake topsides. The extent of detail in what I recieved rather minimal also, so I'd have to work out my own fastening schedule etc.

My preliminary thought would be to start out building upside down, over a low strong back and then flip it to plank the topsides. I was also contemplating that boxed/plank keel last night. It calls for oak or green heart with a plank that is almost twenty inches wide at its widest. Seems that is going to move a lot.

I wonder if any of these were ever built, being in some ways the maunderings of a genius.

Any thoughts would be appreciated.

[Bruce Taylor]

Jack, it sounds like you'll need to do some calculations to determine the amount of ballast (surely it needs some...maybe a big stash of salt pork and canned dog food to last you until you can buy a fine fat roti in the Windward Isles).

There are rules for such things, and I can dig them out of Skene's if you don't have them at hand.

[ishmael]

Bruce,

Thanks, I just saw this.

If I get to the point of buying materials and lofting I will need all kinds of help. Thanks for the offer.

It has to be ballasted, the only question is how much? As one will, I've been studying his information. There are some construction details that I find questionable, such as cedar for the clamp and shelf, and spruce for the deck beams. but they are minor.

When I get closer to a decision I'll post the lines to get reactions on the hull as a sea boat. Being shallow (2'7") and with inside ballast I wonder about its open water capabilities. Not that I plan to cross an ocean, but the Carribean can be very nasty, or so I hear.

It is also small for my estimated time of departure, sometime around my turning fifty, but as I get older I realize how little a person needs.

Cheers,

Jack

[Dave Fleming]

As far as specifying Greenhart for the design.
That was then, this is now and, I am sure there are other woods that will do as well, the current favourite seems to be Angelique but Purplehart would probably do also. Go visit the Forest Products Lab site and do some lookey-looing on woods and their properties, why don'cha?

[ishmael]

Dave,

My thought exactly. The only large timber in the boat is the plank keel, roughly 20 ft long, 20 inches wide at the widest, and four inches thick. Given it's importance to the entire structure it would be a place to put some money for a very nice piece of stock. Angelique was what I arrived at too, though it would likely be possible to find a piece of white oak too. Stability would be something to look at between the two.

If I build this little lovely I'm gonna be counting on your sage advice my friend.

Jack

[Dave Fleming]

If I build this little lovely I'm gonna be counting on your sage advice my friend.

Jack

Groan, oh the responsibility of it all. I think I need a nap nay....its after 3:PM time for a RUM bye Gum.
<insert big grin here a bit dry around the edges though>

[ishmael]

It's a tough job Dave, but someone has to keep us relative neophytes on the straight and narrow.

I've done some lofting, I've done some traditional construction, but both have been awhile. Much will come back, but I'll have a bunch of questions. I'll always look forward to your answers.

For example, on due consideration I've changed my initial reaction that the boat ought begin building upside down. Rather it ought be set up upright, with the frames braced on that plank keel. You do get the picture: the keel is a "box", with the plank at the bottom and the planking forming it. Sawn frames, with a chine. So...how do I sufficiently brace the frames without wooden rafters overhead? [img]smile.gif[/img]

[Dave Fleming]

So...how do I sufficiently brace the frames without wooden rafters overhead?

Hmmm, good question but should we be discussing this in the B&R Forum? A place for everything and everything in its place, ya folla?

Let me know about that and if anybody else is reading this please don't hesitate to comment on the appropriateness of the discussion to this Forum.

I thank you.

[ 02-02-2003, 07:17 PM: Message edited by: Dave Fleming ]

[ishmael]

Ya lost me there Dave. Is there something we need to discuss in private?

Where else should I ask questions regarding setting up a sawn frame boat in a steel building, except in building and repair?

It was a joke, a dig, a bon mot, a sarcastic commment.

[ 02-02-2003, 07:27 PM: Message edited by: ishmael ]

[Dave Fleming]

Nay Laddy Buck, ye got me all wrong.
Just wanted to make sure that I was not discussing something here in Designs and Plans that may well belong in B&R, is all.
I'd rather discuss my oddball idea in the full light of the Forums than in a PM. If that is OK with ye?

My ulterior motive is to do my part to keep at least B&R and D&P free of the dross that goes on in the cellar, ya get my drift?

[ 02-02-2003, 07:45 PM: Message edited by: Dave Fleming ]

[ishmael]

Dave,

I get your drift, and I will move this to build/repair at some point. I'm just am unsure how to do that, so I continued it here.

When I get closer to building it will find its way topside.

Not that I think it irrelevant at this stage. Someone contemplating a design ought consider how they are gonna build it too, ya folla? [img]smile.gif[/img]

So how do you brace the frames in a building without good overhead nailing? I imagine good bracing of the frames by proper alignment with stringers. Afterall, boats such as I suggest have been build sky-clad, for millenia, eh?

Surely you don't fear infection by these questions, so it must be me.

[ 02-02-2003, 08:02 PM: Message edited by: ishmael ]

[holzbt]

Jack- I have a feeling that the 4" thick greenheart keel is the ballast.

[ishmael]

Holbzt,

Yep, thought of that, though he specifies either w.oak or greenheart.

Maybe I'm just missing what the hullform demands, but it would seem something more than a heavy wood keel and Palmer Baby Husky hunkered in the bilge.

[Dave Fleming]

220+Sq.Foot main is not that big and perhaps with the engine and a heavy keel plank with some inside ballast for trim it might just do. The design doesn't strike me as a fast sailer more like a motor cruiser with decent sail assist.
At least something to think about.

For braceing the moulds without an overhead to brace to, how about an A-frame or H-frame with braces to the concrete floor held bye some metal clips bolted to anchors in the floor. Have done similar using a Hilti Masonry Hammer Drill and the sleeves and bolts that Hilti sells. Braces out to the steel pilasters or verticals of the bents. It isn't a big vessel so going "David"*
is not going to be a problem.

*going *David* = building hell for stout or almost overbuilding/bracing. For an expample see the Barn Restoration album on my Imagestation albums.
<insert big grin here>

[ishmael]

thanks Dave.

[ishmael]

Dave,

Regarding the size of the rig, and whether it's intended as a sailboat or a motor sailor.

288 sq. ft. is more than the working sail on a Folkboat if I'm not mistaken. Granted a different type.

But this is the kind of feedback I want. Assuming it isn't intended to be ballasted beyond the hunk of iron in the bilge called a motor, and a few lead pigs, just what is this boat intended for?

Lust doesn't equal love, if ya folla.

[Dave Fleming]

just what is this boat intended for?

Ah now, we are trying to second guess the designer.
It would be interesting to read Mr.Atkins words on this design. Fairly shallow draft,and on second look 6HP is not that much so perhaps the boat is intended to be primarily a sailer. It must fit some particular requirement/s. Atkin, the elder, seems to have had a soft spot for the Seabright skiff type as a perusal of the IDEAL series on John K's site will show a number of variants of the type. It would most likely sit on its own bottom pretty well. A scan of the Body Plan would be of help in this regard. The accomodations seem on the spartan side for most today but not when it was designed, I'm thinkin'.
V-bottom would reduce the rolling tendency of a full rounded hull but again that Body Plan would be sweet to see.

[ishmael]

V-bottom would reduce the rolling tendency of a full rounded hull but again that Body Plan would be sweet to see.

And I've got a scanner, we (myself and this dad-blasted machine called a computer) just don't see eye to eye. I'll try in the next day or two. Thanks for your kind attentions.

It is as I've described it: a chined hull evolving into the boxed keel with sweet curves, but I agree, a lines plan is worth a thousand words.

Anyone able to post the rules for going to imagestation and back? I can't seem to find them on our search function.

[Dave Fleming]

I might be able to walk you through it but why not get our resident Guru, Donn W., to really 'splain how it's done?

[ishmael]

Just a re-post of the link where it's well explained would do. I printed it out once, but...