wetted surface, displacement and sail area

[zenda]

Hey guys,
I'm having an anxiety attack, and need either reassurance or the painful truth. After my long search, I finally settled on the "Inga" design by Bill Atkin. I purchased the plans, stockpiled the materials, and built a lofting floor in my dirt-floored building. Now, I'm worried. Inga is undoubtedly a heavy displacement boat, but Atkin asserts that she'll be fast with the sail plan he drew for her. Please, somebody who knows, go to Atkin's plan site and calm my troubled mind!

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

[qm]

Just my gut feeling but my 18' water line by 18" board up draft with gaff rig had 260 square feet of sail and it was fast. So I think that 380 ft of sail on a 25 foot waterline with 3 feet of draft would be typically slow and easy.

[Hwyl]

She'd be fast by her contemporary standards, you're not going to be planing past Melges 24's.

You could increase the sail area with a short bowsprit and a couple of feet on the mast, a bit more roach on the sail.

I'd find someone that has sailed one (which is what you're doing here, except I'd have named the thread "Inga).

Oops, just did a search and I see you're thinking of modifying almost everything. Did you engage a designer? Was it MMD, are you going with the cat schooner?

[johnw]

By modern standards, a Cal 25 isn't particularly fast. It's a lot faster than this boat. I'd guess this boat will be faster than a Friendship sloop. Maybe you could say she's 1930s cruiser fast. On the other hand, once you're on the boat, you're where you want to be. So who cares how fast it is?

[zenda]

Hwyl,
I have discussed this with MMD, and have discarded most of the modifications. I'm planning to strip/diagonal plank it, and put on a raised deck instead of the trunk cabin. My concern is getting to hull speed in modest winds. She's got a long waterline for her LOA.

The cat schooner rig is still a possibility.

I haven't been able to find that "Inga" has been built before.

[Wiley Baggins]

Your cart MAY be before the horse. How fast do you want to go, and why? What are you willing to sacrafice for that speed (up to and including your investment in plans)?

[johnw]

Hwyl,
I have discussed this with MMD, and have discarded most of the modifications. I'm planning to strip/diagonal plank it, and put on a raised deck instead of the trunk cabin. My concern is getting to hull speed in modest winds. She's got a long waterline for her LOA.

The cat schooner rig is still a possibility.

I haven't been able to find that "Inga" has been built before.


This boat can carry more sail. I'd add about 5 or 6 feet of bowsprit, a masthead rig and a permanent backstay. That's what's been done to most of the Eric Jr.s I've seen. I raced this summer against one that was set up that way, and had a very nice, big North jib that helped a lot. Didn't give him any lee helm, either. He finished a leg behind my Snipe, which means I only beat him by 30 seconds corrected. I think I was giving him 10 minutes on about a three mile course.

[zenda]

Hey Wiley,
I've got two restricting factors, self-imposed. One, upper limit of 28'; two, seaworthy enough to "safely" round the Horn. I'm very willing to stow these plans, but I really like the Inga hull form. It's just a matter, I guess, of doing what is necessary to increase sail area. I want to be able to do 6 knots in a 15 knot wind; is that reasonable in a cruising vessel? Asking that should give you an idea of my knowledge level.

[Hwyl]

As someone should have told the Californian who just got rescued.

You would be crazy to attempt Cape Horn in this boat.

And 6 knots would be a very rare occurence in this boat.

[seanz]

with all due respect isn't sailing solo around cape horn the definition of insanity?
zenda the thing i like most about boat design is the endless variables and compromises but once you have settled on a design it is what it is.
You have chosen a displacement hull designed in the first half of the last century.
Not sure why you have restricted yourself to 28'
i've just finished reading "Rebuilding Rose,The Tale of an Atkin Packet Sloop" the boat is slightly shorter than Inga (26'vs28') but it is worth noting that on her first cruise she averaged 3 kts.
For me cabin height is an issue,even if you raise the deck Atkin says 5'5" under the cabin top beams not sure offhand of the average height of Americans.
There are a lot of more modern stock plans on the net.I'd keep looking.
And while you're looking here's some inspiration for you http://www.donnalange.com/
:D

[sv Lorelei]

My gut would be for a sprit (possibly reefing) and a sizeable light air sail (masthead Genny or a fairly small and durable Assym.) for downwind work. While 6 knots may be tenuously achievable with this boat stripped out for daysailing, your expectations for that kind of performance loaded down for long range cruising are probably a bit ambitious. I'd be thinking more in the 4.5 to 5 knot range would be a better expectation.

That said. Donna Lange just rounded the cape in a Southern Cross 28 which is a plastic double ender, so if you have timing, skill, and luck on your side, it can be managed.

[Tom Hunter]

I think your going to be slow, here is why.

I have a somewhat larger double ender, LWL is closer to 29', hull shape is similar, the Atkin your referencing is inspired by either the Block Island Cowhorn or Eastport Pinky or both, mine is an Eastport Pinky.

My boat wieghs in at 10 tons gross, Inga at 6.1. I have 727 sqr feet of sail area, Inga has 381 which means there is 72 sqr feet of sail per ton driving my boat, and 62 sqr feet per ton driving Inga. I have a gaff rig, which is actually a little bit more effcient than Inga's rig on a reach, though Inga ought to point higher to windward.

In more than 15 knts of breeze mine will go just up to 7 knots on a reach or a run, if I replaced the 16" diameter 3 blade prop I think she would hit 7 consistently. But at closer to 10 knots she goes 4 to 5, and going to windward she is much more likely to make 6 or 6.5 even when its blowing.

[Tom Hunter]

(A fat finger error caused me to lose the end of my post above)

In general I assume 4-5 knots speed when I plan my trips, 4 if I plan to sail it and 5 if it is acceptable or neccissary to run under power for long periods of time. Because Inga has a shorter waterline length and less sail area I suspect you will be a little bit slower.

I do think that you could do 6 knots on a reach in 15 (or maybe 17) knots of wind but you might be doing 5.5.

I am pretty certian that Johnw is right and this design is faster than a Freindship. That is based on a woodenboat race where Tannis was around, and some occasional sailing in the company of other Freindships. In particular I think the double enders go to windward a bit better. I have never match raced a Freindship so I could be wrong about this, but it is my impression so far.

Rather than changing the rig on this one I would strongly suggest finding a similar design that has a bit more sail area, or a living designer for consultation, or both. Of course bringing someone with design experience in to the project may take care of that depending on how much you talk with them or a decision to bring them into the project on a professional basis.

It's a nice design, I don't want to come across as trashing it I am just addressing the speed question.

[sv Lorelei]

Tom, some interesting comments there. Inga appears to be from his Colin Archer family, if anything. The Block Island boats were very pronounced V hulls with a lot of beam and an extremely straight run from stem to sternpost. Lots of reserve boyancy, and pretty handy, but not fast. Not fast at all.

The "balanced" nearly symmetric areas fore and aft means that she'll be lively at sea, but unlikely to want to auger in to a wave, so as long as you're not prone to seasickness, it should be a good sea boat, as long as you don't weigh down the ends. The bow is going to be good for little else than storage....and you'll need it for that. Think about what you'll need in ground tackle alone, and where it's going to have to go! Food and water, spares for the engine...electrical generation, radar etc. Everything weighs something and it all adds up. Its much more critical on a small boat to get things in the right place than it is on a large boat. Speed is important, but it is a secondary issue.

[johnw]

Hey Wiley,
I've got two restricting factors, self-imposed. One, upper limit of 28'; two, seaworthy enough to "safely" round the Horn. I'm very willing to stow these plans, but I really like the Inga hull form. It's just a matter, I guess, of doing what is necessary to increase sail area. I want to be able to do 6 knots in a 15 knot wind; is that reasonable in a cruising vessel? Asking that should give you an idea of my knowledge level.

Panama Canal. There's a reason we built it.

[paladin]

In a boat that size ya dunno even have to transit the canal in the water....ya sail into Gatun Lake...they hoist the thing on a flatbed trailer and haul ya to the other side, and off load ya back into the water......and I've gone around the horn in a boat that size.....and it was almost flat....helluva lot flatter than the Chesapeake Bay in the Spring....:D

[Tom Hunter]

Sv Lorelei

Of course your right, I must be spending too much time thinking about my own boat. It is more Colin Archer than East Coast workboat.

I am not certain if that makes it better or worse with regards to speed. I am not going to argue that an Eastport Pinky is a really fast boat by modern standards, though I think they move along fairly well. I have no experience with the cowhorn.

[Roger Cumming]

A close reading of Atkins blurb about his design suggests careful attention to and balancing of the important things that distinguished his work. Big changes, such as trading the cabin trunk for a raised deck, are worth never doing. An ugly boat is almost sure to be the result. Better to find a raised deck design to build. There are many to choose from. As to the speed of this boat, speed compared to what? This boat will go faster than most modern 28 footers in 30 knots of wind. Read what Atkins wrote about the boat's expected performance in rough water. It's an indication of the compromises and emphases he's made in her design. If these characteristics are what you want in your boat then build it. Atkins was one of the best. I would trust his opinion more than the peanut gallery of critics all of whom have their own ideas of what compromises should be made in yacht design.

[TomMcKinney]

If you want a "classic" looking design for the horn wouldn't a channel pilot cutter be the thing? Those thing stayed out in all kinds of nasty weather and some smaller versions have been drawn

[Varna]

I think Rogers comments on Inga hit the point home-If it fits your needs build it, but it sounds as though you want to study up on WHY it fits your needs or not. Do the learning - then you can make your informed decision, rather than the decidely dubious crap shoot of online 'peanut gallery of experts' for your course finding.
Your thread title seems to be asking a good question regards general performance. SA/WS ratio gives indication of light air performance something in the 2/1 range is considered fairly good. To find this you need to measure off your plans set sections and do a simple calc- it gives a good result. To get that calc and method info get a copy of Francis Kinneys 'Skenes elements of yacth design' You will learn more there about your Inga and WHY it IS a good design for a single handed mission to the Horn. Inga is based on the Colin Archers- PROVEN Sea boats in High sea states and winds and if built and CREWED PROPERLY(ie Sound Seamanship and common sense) will survive. Count on being rolled once or twice and very possibly losing your mast and needing to jury rig - plan for that and develop the skills to pull it off. No gaurentees of course, but none given on the modern freeway either are there?
If you have the chance to go to the Horn DO IT- few ever will. But it sounds like you may need to read and read and go sailing off shore close to home (perhaps you do that already) Some reading pertaining to your goal - several Design Books, the classic 'Heavy Weather Sailing', Seamanship books, Coast Gaurd material and courses, Emergency Safety and first aid stuff, and read the classics of solo sailors if you haven't done so, so you know what they go through- pulling a rotten tooth, setting a broken arm etc-alone in usualy crumby conditions, going aloft, repairs etc etc.. No one says it is easy, and observers say it is insane, but the reason to do it is personal to the doer, and the reward only know to the doer as well, or truely understood. A few have what it takes. Oh and some never come back. But again that is true on the freeway as well. We just forget.

Displacement relative to SA has more to do with acceleration rates, once the mass is moving its moving. Heavy boats have tremendous inertia and thus in general the motion is more 'stable', BUT this depends on many factors ( hull form and weight aloft the most important) and is WHY you want a good design from a good designer.
My favorite 28' Sea boat design is a LF Herreshoff - 'Solitaire'. In Sensible cruising designs'. Plans from Mystic. As far as rigs I like the Mast head cutter for a solo boat. So do the Pardey's and for good reason. Sprit or no sprit is personal. I like em, until you need to good out alone in the dark in 35kt and 12' seas. Oh well part of the fun;-).
Build One Sail It, and let the nay sayers sleep with their down comforters and plush little slippers. A trip around the Horn can't be for them. But for the other types it is a living thing.
Best Wishes

[sv Lorelei]

Tom H

I made quite a study of the Block Island Boats a couple years back. We were pretty close to deciding that was the boat for us because it's an easy build and an incredibly stable hull form. But it won't do well in light winds from all the anecdotal accounts I could gather of cruising versions that have been built, and I suspect it would slap in a short chop which we have quite a lot of in the sound due to various rips and currents.

I know nothing about Pinkys.

Roger and Varna both make good points. I honestly don't think there's much functionally to be gained by doing a raised deck on Inga.

There's a big difference between useable space and available space on boats this size. I know because I've sailed a 28 footer for the last 8 years and there's a huge difference in performance between being being out a solo daysail, and being loaded for a week long cruise with 4 people. There's also a noticeable difference in performance based on *how* we load when cruising. In the end it's going to be trial and error, common sense and experience that prevails just as much as hull design.

Regarding Atkins cruising designs in a general sense. If you read through both their writings it becomes evident that they favored small simple low aspect rigs for cruising craft. The premium was on safety, and sea kindliness rather than speed. The rigs, particularly on Billy's earlier boats were designed around heavy weight cotton sails and (relative to today's materials) perishable running rigging (hemp ropes typically had a life expectancy of about six months on a cruising boat).

My point here is that it isn't just the way the rig was designed then but how it will be built and used today that will affect what it's capable of. There were no light weight Code 0's or nylon Assymetrical cruising chutes back then, so the option exists. Will it screw up the helm balance? Probably. That's one good reason to go to a NA and have him run the numbers on it. Which is about what you should be doing now if you're serious about this boat.

[Tom Hunter]

There is one on Craigs list out in the bay area, try contacting the owner:

http://sfbay.craigslist.org/eby/boa/258729084.html

I think the peanut gallery comments are a bit harsh. There are some genuine experts on the forum, and there are people like me. I don't claim any expertise, but I am willing to share my own experiences with my own boat. That is not expert opinion, but it is information that can be helpful when making a decision.

We could all wait for insightful brilliance from great yacht designers, but wouldn't that suck all the fun and most of the information out of the forum?

[Tom Hunter]

This is turning into a pretty interesting thread. Sv. Lorilei if work allows I hope to bring my sloop South of the (Cape Cod) canal next summer, maybe we can fix your lack of experience.

Zenda, one thing that you did not ask about, but that occurs to me is managing the sails. Most of the authors I have read suggest that a sail becomes difficult for one man to handle between 500 and 600 sqr feet.

My main is 548 sqr feet and I am convinced that this is true. I start training before the sailing season so that I will be strong enough, and one of the things that I have learned from my boat is that people used to be a lot stronger than they are now.

Of course modern winches and roller furlling make a big difference, up until the moment something breaks. Just another point to consider.

[sv Lorelei]

There are differences in rigging philosophies too. Where we'd take for granted that a winch was necessary they'd often put a 2:1 or 3:1 tackle in place and just use more line. Pretty reliable. Not as efficient from a light air point of view because you're probably hanging a bronze or wooden block off the clew of the jib, but for club footed sails and the main, why not.

I think the peanut gallery comment was meant in a more benign way. After all, without doing the math or having experience sailing the boat, the best we can do is speak in hunches and comparative generalities. I'm certainly not qualified to be an expert and don't pretend that I am. I just sail.

[paladin]

all the above......a well designed pilot cutter is one of the best boats to circumnavigate with.....lines, sails etc are lighter, you have no need to carry multiple casks of water, food is more compact and will last as long as you will, less space is required, you have to sleep sometime and it will always be under much reduced sail. a very small engine can be used for manuevering, making water, etc and when bad weather comes, make a pot of hot soup, tea/coffee, toss out a drogue, go below and read...

[johnw]

A close reading of Atkins blurb about his design suggests careful attention to and balancing of the important things that distinguished his work. Big changes, such as trading the cabin trunk for a raised deck, are worth never doing. An ugly boat is almost sure to be the result. Better to find a raised deck design to build. There are many to choose from. As to the speed of this boat, speed compared to what? This boat will go faster than most modern 28 footers in 30 knots of wind. Read what Atkins wrote about the boat's expected performance in rough water. It's an indication of the compromises and emphases he's made in her design. If these characteristics are what you want in your boat then build it. Atkins was one of the best. I would trust his opinion more than the peanut gallery of critics all of whom have their own ideas of what compromises should be made in yacht design.


When it's blowing 30 knots and up, speed is not my highest concern. In those condtions, I'd want a strong boat and a rig that's easy to reef. Most sailing is done in less wind than that.

One factor is, do you want a fast passagemaker or a fast boat around the bouys? This boat will be reasonably fast in the reaching conditions typically encountered in passagemaking. It will carry heavy loads well and has fairly low wetted surface for a full-keeled boat. You'd be less likely to lose the rig if you had a standing backstay.

Roger, I don't think you need to insult people in order to have your advice taken seriously. It just makes you look insecure.

[Jay Greer]

This little double ender is a nice design. A version of it was in Newport Beach CA for many years. It is a pretty boat and sails well.
There is no need to modify the rig as it sails very well as it was designed. The fractional rig will work to weather better than a mast head rig will. Light head sails can be set to the head stay for close reaching in light airs. An Asymetrical chute will work very well on this boat. If you really want more power off the wind, a ringtail can be added to the main. If you wish, however, there is enough stability to the hull of this design to add a few more feet of height to the rig. However you will find yourself reefing more often.
Jay

[zenda]

Thank you all for your comments. Tom, thanks a lot for the link to Craig's list; I had no idea that "Inga" had been built before! I've emailed the seller for his experiences with her.

I have every confidence in "Inga's" seaworthiness, but was concerned about how well she'd move in light (5-15 knots) winds. I was planning to add a booster to the inventory, and maybe another light air sail, but some hulls can only push the water aside so fast. I'm reassured, though I am speaking with an NA on Sunday about her.

I decided to raise the deck because of strength; I think this construction will be stronger than a deck cut out for a trunk cabin. Also, there is much less for a malignant wave to smash.

Varna, I've read tons, especially the journals and stories of singlehanders. Moitessier is my favorite. I have sailed a good bit on the Chesapeake, but am waiting for my "girl" to slip into the water to take it any further. Thanks again, guys. I value your input; keep the string going.

[seanz]

Cape Horn The Logical Route by Bernard Moitessier
I was given this book to read a few years ago , at that time I had only a passing interest in maritime history.Now I am surrounded by books on sailing and boat building , I have been learning to sail and I am starting a woodworking course amongst other things.I plan to build a small daysailor this year then onwards and outwards.
Zenda you are further down the track than I am and frankly I'm jealous :D
best of luck from NZ

[Hwyl]

Don't even think about cape horn in this boat, by the way this "peanut" has over 50,000 miles of offshore experience.

[Roger Cumming]

I meant no malice with my peanut gallery comment - only that what the designer wrote about his design, about his intentions in designing the boat, may be more instructive than what we think about it. And before considering alterations as major as raising the deck maybe you should find a design with a raised deck. There are plenty to choose from.

I, too, am a member of the peanut gallery. Nor am I qualified to judge whether this design would be appropriate for a voyage to Cape Horn. There is a book I'd recommend, "My Old Man and the Sea", by David and Daniel Hays, about a father and son voyage to the southern ocean in a fiberglass Vertue (26 feet) which performed well. Perhaps Mr. Cleek, who knows all about Vertues, would comment.

[seanz]

I, too, am a member of the peanut gallery. Nor am I qualified to judge whether this design would be appropriate for a voyage to Cape Horn. There is a book I'd recommend, "My Old Man and the Sea", by David and Daniel Hays, about a father and son voyage to the southern ocean in a fiberglass Vertue (26 feet) which performed well.

You beat me to it,thats a great book.
Of course just because it's possible doesn't mean it's recommended.

[JimD]

...what the designer wrote about his design, about his intentions in designing the boat, may be more instructive than what we think about it. And before considering alterations as major as raising the deck maybe you should find a design with a raised deck...

Two things come to mind. First, William Atkin repeated over and over again not to mess with his designs and to build them presicely as drawn. Wouldn't surprise me if he is rolling in the grave upon learning someone wants to raise the decks on Inga.

Second, if I were thinking of building her I, too, would be a little troubled by the fact that the designer describes her as fast but so far in this forum the unanamous opinion seems to be that she won't be.

[JimD]

Don't even think about cape horn in this boat...

Why not?

[Hwyl]

Why not?

http://www.foxnews.com/story/0,2933,241781,00.html

[JimD]

http://www.foxnews.com/story/0,2933,241781,00.html

Don't see the relationship. Wasn't the horn, wasn't an Inga, wasn't zenda at the helm. You mean it can get stormy out there?

[sv Lorelei]

Here's a guy who went round in a Pearson Electra 24 foot daysailer and lived (barely). A good read too...guy was nuts!

http://easyreader.hermosawave.net/news1999/1111/Cape%20Horn.Htm

Roger, I agree that Billy Atkins knew more about his designs than most of the people building them. What I've come to realize as well over the last couple years is that a lot of what his and John's boats represent, were empirical evolutions of designs they actually actively sailed and lived with. They are incredibly well engineered and well thought out boats for the most part, and Billy shot straight from the hip as far as what he thought they were capable of and how they should be built.

However, if you're reading a blurb he wrote in the twenties or thirties, you have to interpret those words as being 99 percent valid when he wrote them, but not bible given that today we have materials and gear that hadn't even been thought of yet, and in his day they had materials that were commonly available that either don't exist today or are just plain impractical. A lot changes in 80 or 90 years, and you have to take that into account (as I'm learning).

For instance, my Tally Ho Major calls for 1-1/4 Teak almost universally throughout. It calls for 8 oz. Cotton Sails for the main and staysail. It calls for a 3/4 galvanized steel horse for the mainsheet traveller. While I imagine you could do all those things, and might even feeled compelled to follow the orignal specs if you were doing a restoration; for a new construction it makes no practical sense, unless you're goal is to build a replica. Mine goal is to build a heck of a solid sailboat (and I think that was Billy's intention as well). I feel fortunate to be able to choose from a wider menu that He had available to him, but take each and every one of those choices very seriously.

Zenda. There's much wisdom in what Roger and others are saying here. A couple of salient points here are these:

Don't try and make an Atkin's boat stronger. He already designed them like tanks. Indeed, far more structural integrity than you're going to get from virtually any other designer. Going over my THM plans there is so much overbuilding, redundant structure and thoughtfulness of purpose given over to the designs, that most of the modifications we initally contemplated, we've realized are counterproductive to his conceptualization of how the boat should function.

Lastly, I think the other peanuts and myself are correct in stating that if you feel compelled to change the design to the point where you're turning this boat into another boat, you should probably look for another boat design that meets your conceptualization of what you want in the first place. Nothing judgemental there, just factual. If you have some sailing experience, think about situations that might occur, look at the designs your considering, and ask yourself "How would I handle this" and "What would happen if"... types of hypothetical questions. Read about other people's experiences and put yourself in their shoes on your prospective boat.

A boat is a set of systems that need to work in concert with each other, harmoniously, over a wide range of circumstances. You're just a part of that set of systems. It's easy to make one part easier, but to keep them in harmony is not so easy. Keep that in mind.

[JimD]

Given that I am a novice sailor and many of you are many times the seaman I am I am given to wonder aloud how much it really matters how big the boat is when faced with the potential destructive force of an eighty foot wave? Twenty eight feet or eighteen feet, what really is the diff with a hundred tons of water bearing down?

[zenda]

As I said, I am going to speak with a naval architect tomorrow. I'll discuss the raised deck with him, as well as the sail area issue. In keeping with what sv Lorelai says, I don't see any reason not to adapt a great design to suit my purposes and the construction advances since the '30's. I'm planning to strip-diagonal plank this boat. The one for sale in San Francisco is ferro-cement of all things! I know this will possibly change displacement, and that will be addressed with the NA. To me, "Inga's" hull form cannot be improved upon for the task I'll set for her, but there are decisions that Atkin made that don't necessarily fit my parameters. I've looked for literally years for "my boat", and "Inga" is the closest I've found. If I need to, with professional involvement, make some changes which I think increase her fitness for the task, I don't see that this is unwise or doing damage to Atkin's design. His warning was not to make changes without consultation; he's dead, so I'm doing the next best thing. You guys are great, and having access to your perspectives and experience are invaluable. Thanks again.

PS. I've read Cape Horn: The Logical Route, and My Old Man and the Sea. Both great books, with very different experiences of the Horn. Then there's Tzu Hang . . .

[zenda]

Hwyl,
Is rounding the Horn potentially dangerous? Of course it is. But so are alot of things that some people consider worthwhile goals. There are smaller boats than "Inga" that have completed this passage, and some much larger that failed. Is there the potential for cold, wet death for me in such a pursuit? Again, of course there is. That doesn't mean it is not a worthwhile challenge for some of us who cherish the pursuit of extraordinary things that we can be proud of, or more accurately, experiences we can cherish in our souls forever.

[JimD]

...Just re-read what I said about the raised deck - sounded rather harsh. I think she could look really nice with a raised deck. And if you're looking for crew to go around the horn let me know :)

[Don Kurylko]

I just did some quick some quick calculations of Inga’s rig and found that, with a working sail area of 382 sq. ft., the SA/Disp ratio works out to 11.53, which puts her in the motor-sailer category. This is very low considering that anything below a SA/Disp ratio of 16 is regarded as less than optimum. A ratio of 18 would be far more preferable if you really want to enjoy sailing this boat.

The rig, as drawn, is woefully underpowered for a hull displacing 12,200 lbs and carrying 6300 lbs of ballast. This, by the way, works out to a Bal/Disp ratio of 51.6%. For a cruiser that will be carrying stores for long voyages, this is excessive. A Bal/Disp ratio of 33% to 40% is far more realistic, otherwise you risk over-loading the boat and making it even slower.

Another point to consider is the lack of salient keel area and draft, which in turn translates into a higher centre of gravity and a lessened ability to carry sail (possibly exacerbated even further with a “raised deck”). This hull will be fine running and reaching, but sailing to windward will most likely be an exercise in frustration. She won’t point very high and will tend to slide to leeward when pressed. No problem for a motor-sailer, but unacceptable for a sailboat. Your life could depend on it.

Just for interest’s sake:
A SA/Disp. ratio of 16 = 530 sq. ft. of working sail area (not including light air sails).
A SA/Disp. ratio of 18 = 600 sq. ft.
A Bal/Disp ratio of 33% = 4025 lbs.; 40% = 4880 lbs.

If you like Atkin designs, then I would suggest that Fore An’ Aft, Tally Ho or Dragon (the gaff cutter rigged version of Eric) would be far better suited to offshore sailing. Dragon, especially, would be an absolutely wonderful sea boat. A double-headsail rig is also much to be preferred for offshore work.

For anyone interested, Sailing USA provides automatic calculators for working out some of the basic formulas used to determine a sailboat’s characteristics.
http://www.sailingusa.info/design_winds.htm#Sailboat%20Characteristics (http://www.sailingusa.info/design_winds.htm#Sailboat%20Characteristics)

[JimD]

Fore An' Aft is 28' 8", (somewhat heavier - not a double ender), but carries over 700 sq. ft of sail, a lot more keel, and is a real looker as well. (Sorry, I digress)

[Hwyl]

I was going to write a subjective analysis when I felt better (had the flu this wekend) but I can't do better than Don's above.

I generally like small boats and live by the maxim "the amount of fun to be derived from boats is inversely proportional to their size". I've owned a Cape Cod Frosty < 6', and many other dinghies. When I teach sailing, my boat of choice is a J22. I make most of my money now by doing deliveries and have sailed in some inclement conditions.

I'll try to enumerate my objections.
1 The holy grail of every designer is to find a design that will be a lively day sailer and be safe in extreme conditions, I think they're close to this in boats like the Open 60's but they take a huge amount of skill to sail. I doubt that amount of versatility would work on a boat less than 40 feet, this is because sail carrying power goes up as the cube of the length. To beleive that Atkin had the solution to this 40 or 50 years ago is a fallacy, and remember that one of Atkins near contemporaries is still active in the designing world. The great Olin Stephens. I'd reccomend his book. I think it's called "All this and sailing too". Olin is a sharing sort of person (at least now) and many of today's designers have worked in his office. So if Atkin had the knowledge to produce such a boat, that knowledge would have incementaly increased.

2 The link you posted is mostly an advertisment and has a great deal of "Caveat Emptor" when Atkin says "good for long passages" does he mean "around the world" or "Boston to Bar Harbor"? I'd guess the second.
3 Specifics of the boat: It's nice to see this boat has mostly outside ballast, but 3'6" is an awfully small draft for an offshore boat. Remember that the distance of the center of gravity from the center of bouyancy translates to righting moment. With that kind of draft, the righting moment can never be very large (I'll agree that it's nice not to have too deep a keel to trip over). The propellor is awfully close to the waterline in the pictures, it would render the engine useless in anything but a calm. The outboard rudder has no protection from breaking waves and is generally considered not great for offshore(I kind of like them). The overhanging boom is dangerous for offshore work, if you need to get to the clew of the sail, you'd have to hang over the back of the boat, on the same note, I totally diagree with Atkin when he says "standing backstays are dangerous". I'm guessing that he's reffering to the possiblity of mast bend if there are no runners, but I'd say standing backstays are a life saver.
4 Size: Jim D, my old nemesis, asks about 100 foot waves, well I've never seen one and I hope I never do. I would agree that it doesn't make much difference what size the small boat is, in those conditions. 20 foot waves are not unusual, and a 30 footer in 20 foot waves is a lot better off than an 18 footer, size really counts in waves.
Then there's carrying capacity, she's a 13000lb boat as is with half of that in ballast, but if you add water and food for two months, that will severely change your numbers, say 50 gallons of water, thats 400 lbs (I'm used to working in metric and doing quick conversions), maybe another 600 lbs in food, two people at 400 lbs (for both), spares, books and clothes and you're soon up to a ton, so now you have a 15000 lb displacement with 6000 in ballast, making just a 40% ballast ratio. In a bigger boat the same amountof food, water and spares would be needed and they would not have such an impact on the ratios.

5 Modifications, have already been dealt with to a large extent, but clearly building stuff above the waterline is going to negatively affect stability.

I like the Bristol Channel cutters in this size, especially the Vertue's (much more draft) and the Lyle Hess designs, even our own Paladin's designs.

I'm not trying to destroy your dreams, just trying to add an old guys perspective.

Good luck

[Paul Pless]

Don and Gareth, thanks much for posting your opinions here.:)

[JimD]

Thread drift: Speaking of 18 footers and circumnavigations I was googling around for info on Caprice, the 18 foot plywood Tucker design that Shane Acton circumnavigated in years ago. There is a Tucker website that appears to be alive and well but doesn't look like they sell plans anymore. Oh well.

[Hwyl]

Jim you can get plans for Tuckers Silhouette here http://www.soia.org.uk/history.htm , it's a bilge keeler

[JimD]

Jim you can get plans for Tuckers Silhouette here http://www.soia.org.uk/history.htm , it's a bilge keeler

Gareth, thanks for the link but Silhouette is a little small, really no bigger or more capable than the boat I already have. So far I haven't found anything to beat the 19.5 White Swan from Selway Fisher for my pocket cruising future.

Sorry about that, zenda. We now return to our regularly scheduled thread...

[paladin]

and when you are building your boat, whatever it may be, ...remember.....a good, rot resistant plank is stronger, plywood of the same dimension is stiffer.....not necessarily stronger.....

[Tom Hunter]

Just for fun I ran the ratio calculators that Don linked to (thanks Don)

My big fat boat has an SADR of 14.5 which makes it a cruiser/racer. Actually its a workboat that has to get the fish home before they spoil, but that has not been generally applicable for about 100 years so I will take cruiser/racer.

My max hull speed on their calculator is 7.22 knots. Based on experience I think that is pretty much correct.

[Don Kurylko]

Tom,

I think the numbers on the Sailing USA site are a bit skewed towards lighter, more modern boats. Older types, like Inga, with Displacement/Length ratios over 300, should probably rate lower. My old school notes (written over 25 years ago) read: “The 1962 CCA rule set a ratio of 15.4 as the theoretical “ideal” for sloops and 15.95 for yawls. Most racing vessels exceed this and the average might be in the area of 16 to 17.5 for a modern sloop. Heavy cruising vessels will be lower of course in the 14-16 range and motor-sailers will be lower still as a rule, anywhere from 8 to 14.”

These numbers all need to be taken with a grain of salt, of course. They are generalizations at best, but still useful for comparative purposes, as long as the boats being compared are reasonably close in type, size and weight. Sail Area/Wetted Surface ratios might be better indicators of performance, but areas of wetted surface are rarely, if ever, published, so we can only go with what we can get.

Anyway, in my opinion, sail area for a serious cruising vessel should always be on the generous side, simply because of the tendency of overloading for extended voyaging. An over-canvassed vessel can be counted upon to sail well in light winds and can always be reefed for heavier weather. An under-canvassed vessel, on the other hand, will definitely be slow in light airs and certainly no faster than her reefed sister in heavy going.

Light air sails, like big gennys and spinnakers, are one way to boost performance in under-canvassed boats, but for the short-handed cruiser these can also become a liability when the winds kick up a bit. Far better, I believe, is too have a generous working rig with easily handled sail areas broken up appropriately for the size of the vessel, be it cutter, ketch, schooner or whatever; a rig that can be handled by one person if need be and, above all, easily and efficiently reefed.

[Tom Hunter]

Don,

I was expecting the calculators to go completely haywire when they ran into a 130 year old design, the same way the handicapping systems break down completely.

But allowing for the grain of salt I thought the calculators did reasonably well. I would be suprised if there is a straight line relationship between the 11.53 ratio of Inga and the 14.5 ratio of the Eastport Pinky but it does raise the concern (reflected by the group) that Inga is short on sail area and going to be slow.

One thought that might be useful is to look at a square sail for this boat. It is an old solution for an old design, so maybe it would work. I am not sure I would want it up while rounding Cape Horn, but the Horn is a long way away and it might be a useful help to get there.

[sv Lorelei]

Gareth: A bit of a thread hijack. Running the numbers on Tally Ho Major (a cutter) it comes out much like Tom's boat, with fairly high SA/D (racer-cruiser) and the rest of the numbers more in keeping for a typical heavy cruiser. As is the case for many of Billy Atkin's designs she sports an overhanging boom and running backs.

My question is this... a typical progression for a boat this size in my estimate would be (1) strike the jib, (2) first reef in main, (3) second reef in main, (4) reef staysail, (5) third reef in main, (6) storm staysail, (7) trysail. Original plans only call for two reefs in the main. I suspect once the elephants start marching you don't want that boom outside the boat to potentially trip you up.

Historically, was the change to trysail an earlier move, rather than the third reef? I'm basically a chickensh!t sailor and always tend to favor running undercanvassed if it means a more comfortable ride, so I tend to think a third reef is a good option for my style of sailing, but if the swap to trysail should be made earlier, still am concerned about getting caught with my pants down.

[Hwyl]

Gareth: A bit of a thread hijack. Running the numbers on Tally Ho Major (a cutter) it comes out much like Tom's boat, with fairly high SA/D (racer-cruiser) and the rest of the numbers more in keeping for a typical heavy cruiser. As is the case for many of Billy Atkin's designs she sports an overhanging boom and running backs.

My question is this... a typical progression for a boat this size in my estimate would be (1) strike the jib, (2) first reef in main, (3) second reef in main, (4) reef staysail, (5) third reef in main, (6) storm staysail, (7) trysail. Original plans only call for two reefs in the main. I suspect once the elephants start marching you don't want that boom outside the boat to potentially trip you up.

Historically, was the change to trysail an earlier move, rather than the third reef? I'm basically a chickensh!t sailor and always tend to favor running undercanvassed if it means a more comfortable ride, so I tend to think a third reef is a good option for my style of sailing, but if the swap to trysail should be made earlier, still am concerned about getting caught with my pants down.
http://www.boat-links.com/Atkinco/Sail/images/TallyHoMajor-1.gif

I've only used a trysail once, it was a major mistake, I think they have value in gaffers.

I'd say quite a lot different
1) First reef in main
2)Strike staysail
3)Second reef in main
4)Stike jib, raise (possibly reefed) staysail
5) For forereaching--drop staysail, flatten main (depending on how big the second reef is you might want a third). For running off, storm staysail (some staysails are made strong enough that they act as storm staysails when reefed)
6) Trail warps over he quarter, bare poles, nice cup of tea and ginger cookies.

I'd be interested to see John B's input.

[sv Lorelei]

Thanks for the response, Gareth. I'd be interested in John B's opinion too.

I'm planning on running the tack for the jib(s) out the sprit on a car with a tackle from the cranze iron (or a cheek block just aft of it), so retrieving the jib shouldn't be that much of a chore. Atkins spec'cd a wire luff for the yankee (no stay) so it's flying free (no hanks to have to worry about). The masthead jib shown above seems to have been speculative on his part, and I'd tend to favor either an assym or a light reacher instead, but that's for light air an not what we're really talking about here.

But back to the progression. Why keep the jib up? Better handling? I'm curious as it would seem you'd want to bring the rig inwards and down sooner rather than later. One of my big beefs with roller furling (even though we have it) is that not only do you lose sail shape fairly quickly, but the CE of the sail is considerably higher on a partially furled sail than it would be on an equivalent regular sail, so for the same effect you end up furling more sail in.

I was watching Lin and Larry's Storm Tactics video and they seem to opt for the trysail early. I also noticed that they don't run a club footed staysail, which I find a bit puzzling on a cruising boat. I understand you're sacrificing a bit of sail shape, but gain self tacking and only one shee to trip over. Anyway, good food for thought.

[paladin]

The cutter rig on Tana Mari was essentially copied from Jim Brown's Searunner tri's.....with the exception that the jib was club footed....
But the inner forestay was rigged with a hyfield lever with the storm trysa'l permanently bent on in a bag at the foot of the mast.
In fair weather and light winds the genoa and club jib were up and running with the main....if things picked up then the running backs were levered down and the genoa furled....when it started to get a wee bit heavy the jib was furled and the storm trysail went up and the innerforestay was levered on, and the main was reduced, usually to the top cunninghams. I can only remember one instance when I had the main fully furled, and then I elected to drop the drogue from the bow on a bridle and take in all sail, lock the steering....made some tea and soup, and sat waaaaay offshore for a couple of days. I'm the world's biggest chikkin'.....

[Varna]

Zenda, It seems you are on a good track and one I wish I could be on. If you build it you still have a boat you can choose to use as you want and go where YOU want. Moittessier had it for the call to travel the sea, and Sloacum had the situation and went how many thousandsNM in 'Unsuitable' Craft, and was taken in the end. But he was where HE wanted to be. Men and Women never should climb Everest, but they do, nor cross the 'Pond' in a bathtub size craft, etcetcetc. I've enjoyed Tristan Jones comments and views as well on the subject.
To Gareth I meant no offense and and am aware of your offshore experience, and I am only saying it is an individuals particular circumstance which guides the decision process, and I encourage that. My own 'offshore' pales to yours, but I have done other things in the same league, different venue. I haven't the cash available for 'big toys with big wheels' so I go where I can.
I have the common 'Herreshoff' affliction- another favorite dream ship is LF's 30' Dulcinea, Narrow, fast, 2 short sticks, low wetted shallow draft, all inboard sails, mizzen staysyl. Only I would prefer a small transom stern for the bouyancy gain if pooped-the only draw back to me of the canoe stern dbl end'r.
So many different types of craft have traveled the seas throughout history that arguing types and who can do it I think is only a fun pastime, and when folks get too serious about it it becomes ludicrous. The Fate/Luck/Mystery factor must weigh in the arguments. Many 'perfect' ships and crew have not made it. But too one wants to cover the bases as best one can so as not to run on dumb luck.
Look forward to hearing more on your inspired persuit-it is inspiring to see others doing these things.
John

[Hwyl]

Thanks for the response, Gareth. I'd be interested in John B's opinion too.

I'm planning on running the tack for the jib(s) out the sprit on a car with a tackle from the cranze iron (or a cheek block just aft of it), so retrieving the jib shouldn't be that much of a chore. Atkins spec'cd a wire luff for the yankee (no stay) so it's flying free (no hanks to have to worry about). The masthead jib shown above seems to have been speculative on his part, and I'd tend to favor either an assym or a light reacher instead, but that's for light air an not what we're really talking about here.

But back to the progression. Why keep the jib up? Better handling? I'm curious as it would seem you'd want to bring the rig inwards and down sooner rather than later. One of my big beefs with roller furling (even though we have it) is that not only do you lose sail shape fairly quickly, but the CE of the sail is considerably higher on a partially furled sail than it would be on an equivalent regular sail, so for the same effect you end up furling more sail in.

I was watching Lin and Larry's Storm Tactics video and they seem to opt for the trysail early. I also noticed that they don't run a club footed staysail, which I find a bit puzzling on a cruising boat. I understand you're sacrificing a bit of sail shape, but gain self tacking and only one shee to trip over. Anyway, good food for thought.

I've been trying to analyse why I keep the jib, I think that in those conditions, you want the power of the jib to keep the boat moving through the waves. Mosts boats I've sailed on, the staysail does not seem to give much power (even less with a club, more on that later). By the way, wire luffs are now purely of historical value, talk to the sailmaker, my guess is you;d go with spectra with lots of resin it. Because I do deliveries, I tend to sail bigger boats than the Pardey's and it is always easier (read safer) to go to a third reef and then bare poles.

On the staysail, even though logically the club should be really efficient, I've never found it to be, also if you have it up in a bit of a blow downwind, that boom becomes potentially lethal in a gybe.

[Hwyl]

Zenda, It seems you are on a good track and one I wish I could be on. If you build it you still have a boat you can choose to use as you want and go where YOU want. Moittessier had it for the call to travel the sea, and Sloacum had the situation and went how many thousandsNM in 'Unsuitable' Craft, and was taken in the end. But he was where HE wanted to be. Men and Women never should climb Everest, but they do, nor cross the 'Pond' in a bathtub size craft, etcetcetc. I've enjoyed Tristan Jones comments and views as well on the subject.
To Gareth I meant no offense and and am aware of your offshore experience, and I am only saying it is an individuals particular circumstance which guides the decision process, and I encourage that. My own 'offshore' pales to yours, but I have done other things in the same league, different venue. I haven't the cash available for 'big toys with big wheels' so I go where I can.
I have the common 'Herreshoff' affliction- another favorite dream ship is LF's 30' Dulcinea, Narrow, fast, 2 short sticks, low wetted shallow draft, all inboard sails, mizzen staysyl. Only I would prefer a small transom stern for the bouyancy gain if pooped-the only draw back to me of the canoe stern dbl end'r.
So many different types of craft have traveled the seas throughout history that arguing types and who can do it I think is only a fun pastime, and when folks get too serious about it it becomes ludicrous. The Fate/Luck/Mystery factor must weigh in the arguments. Many 'perfect' ships and crew have not made it. But too one wants to cover the bases as best one can so as not to run on dumb luck.
Look forward to hearing more on your inspired persuit-it is inspiring to see others doing these things.
John

John, I;m lucky enough to get paid to sail other peoples boats, as I said my preference is for small boats, I love the Dulcinea too. I just thought that Zenda was setting very unrealistic expectations for this boat. I seem to have become a little embroiled in this, I'm no expert.

I'll throw out another zinger, go back and read Moittessier's books, he sailed into the windward side of St Vincent, which means he did not pop his head out of the hatch for at least 12 hours when he ought to have known land was close. He also T boned a freight ship

[Paul Pless]

I seem to have become a little embroiled in this

LOL:)

[zenda]

The owner of the Inga that Tom linked to emailed me back. He said it was a great design (he already sold the boat). I guess it all depends on expectations and context. Don and Gareth, thanks so much for the calculations and commentary. I'm discussing this design with a NA we know on the forum, but I admit to being a bit discouraged about "Inga". Sounds like it will take quite a bit of modification to get her where she needs to be, when I could pick another design. It's just hard to find a 28' double-ender with relatively shallow draft. Maybe Reuel Parker's Isle of Shoals? That will need a much smaller cockpit, but it comes from a proven workboat heritage. Or, what about a stretched Frances 26? Could she handle the stores, water for an extended singlehanded voyage? Vertues are great, but Laurent Giles wants a fortune for the plans, and she's only 25'3".

[zenda]

Jay,
You posted a concise statement, and then vanished. I'd say that your confident assertion is the "minority report". Would you mind expanding on your comments?

[Wiley Baggins]

Zenda,

You've certainly got a lively thread going here. I can't add anything more substantive regarding the assessment of your criteria, but I will moot a design possibility (which may also be found wanting). She's a bit bigger, but that's probably to the good if you can take the additional financial hit. The link is to her build in 'glass, but it should give you the flavor of the design.

Phil Rhodes' Travellar 32/Dog Star -

http://astro.temple.edu/~bstavis/pr/traveller32.htm

[zenda]

Thanks Wiley,
She's a beauty, kinda reminds me of Chuck Payne's Leigh. I will add her to my list! Maybe, instead of sailing around the world, I'll collect great designs! :-)

The plans for this boat are available, in ketch rig, at Mystic Seaport. http://www.mysticseaport.org/library/manuscripts/coll/spcoll080/spcoll080.html#head61629896

[Jay Greer]

I have always liked Atkin designs. They are pleasing to the eye of the sailor in that the entire boat and rig are in balance to one and other. Certainly simplicity has it's virtues. I stated that, a higher aspect ratio might be suitable to make the boat perform better in light to moderate airs. However, when the wind pipes up, the added height will call for reefing sooner than would be expected with the rig as designed. Todays materiels are indeed lighter than those of the past which will make the boat a bit stiffer and so capable of carrying more sail. The bilges show a powerful midship section that also adds to the stability of hull form. The relatively shallow draft allows the boat to be used in skinny waters as well. The broad keel with only slight drag allows the boat to be hauled or beached with ease for painting and maintenance. However, the lack of deep latereal plane, in proportion to other boats of this type, make it not as close winded as would be expected of a more modern design. The buttock lines are easy and the water lines fwd are slightly hollowed below the DWL. Which will help the hull balance on the wind as make it work better to weather than non hollowed water lines would. The prismatic coeficient appears to be almost but not overly generous for a boat of this design. All in all, I see a boat that is very traditional, very sea kindly and more forgiving rather than cranky under sail. My personal choice would be to add a bit more height to the rig. Keeping the fractional head sail of course.
Jay

[Varna]

Are we gearing up for a Zenda design contest here or what? Surely there must be an obvious 28' double ender for the criteria. Careful what you wish for Zenda-I got into and have the plans-collector malady and look where that got me- high and dry at 3000'(well there are gougeous lakes and rivers) and 100 mi from sea:-}
Seriously I wouldn't underestimate the Vertue or similar hull types-narrow deep draft and high freeboard-giving more interior for a smallish boat. A thought I had in the past about highish freeboard in a offshore cruiser-buys more time in holeing/flooding situation. Some of the old designs look rakish and sexy with their low sheerlines...but not much extra to spare.
Dulcinea has a 4' bow height,around 28" least and I believe 3' stern. 7'-8" beam,7'BWL and 4' draft. I have the plans from Mystic and she is really great to reflect on, even LFH's drafting style lends to the 'Antique-ness'.
Time to dig into the books. You mentioned stores capacity-have you a time between ports max with plenty of fudge-factor? I only have thumb nail factors to go by, gleaned in books as my offshore 'passages' have been to offshore islands only 20-30NM- all daylight. Is 14# food and water a day realistic?- From Gerr's discussion in Nature of Boats. If going watermaker as a suppliment and expensive dehydrated food(yuck) the can be cut obviously. This is the area Gareth would have the real world info. Another truth is that we in our dreams imagine to romance of the thing, but I think Gareth hits a 'reality' point in his view that the actual 24-7-365 of living on a small voyaging craft can get kind of un-fun, and a hot bath will be in ones dreams-hauntingly.And the motion 24-7 can become unbearable in the wrong boat. In this respect Gareths View and advise against this adventure must be weighed and appreciated.
Gareth you have a much desired career guiding all types of craft to port-very cool and not a light weight responibility. Good on you and many Kudos and respect. Zingers welcome of course! Moittesier was a reader perhaps and may have gotten too into his book. I do vaguely recall the story in Small Boats and Big Seas- was he onward to meet his girl friend or something? Then too he lost his outfit in Cabo unfortunately and I think that was his end on the seas. But I DID like his view and decision to 180 near the end of the big race he was leading and bail back to Tahiti...noe that's a Man with prioritys:-)

[Varna]

Sorry-wrong story in the 'Big Seas' book. I read that in a library book possibly.....
Zenda- if you like Vertue, are scratch building and willing to minor-modify and consult a NA, and disagree with the no-longer Giles office too high plans prices....How about a Vertue as starting point, but expanded and modified to your purpose? +10% yields - 27'-6" on a 23'-8"lwl, 7'-11" bm,7'-4"bwl and 4'-10" draft. D=11,393, wsa gaff cutter=442,D/L 421,D2/3 33.66, SA/D 13.13 @wsa,15.36 w/ topsyl. These are based on the specs in 'Best of Uffa' showing 'Andrillot'- I believe the original Vertue. The lines, sail plan,general arrangement, and construction profile are here in a published book with linear scale markers given, which allows one to scale off and build a boat. Just as many designs in Herreshoff, Garden and other designers books give similar info, these are intended to give builders and designers the parameters to guide them in building to the designs. Gerr gave a factor in his book for a ball park 'stores' weight- divide D by 7.5 as I recall. =1520 food/water/clothes/personal gear. Vertue x1.1 likely carry a fair bit more, and with heavy scantlings allowed by the high D/L one can load to a max lwl beyond the dwl/lwl. Just rig it all to the highest D value. A mast head cutter 28' Vertue would seem a nice craft.

[Don Kurylko]

Zenda,

Don’t be discouraged! Your boat is out there somewhere.

I tried doing a search for Paul Johnson who designed and built several variations on a 28’ double ender called Venus, but had no luck. This is a lead worth pursuing though. Many of these designs have been built and have proven to be very good bluewater cruisers. They were specifically designed for just the type of voyaging being discussed. Very nice looking too.

Anyone out there got any info on these boats?

[Don Kurylko]

Okay, here we are: http://www.venusketch.com/ (http://www.venusketch.com/)

[JimD]

Sorry if this is useless clutter but Bruce Roberts has this rather interesting looking double ended 28er

http://www.bruceroberts.com/public/HTML/images/r281-01[1].gif

http://www.bruceroberts.com/public/HTML/images/r281-02[1].gif

http://www.bruceroberts.com/public/HTML/images/r281-03[1].gif


http://www.bruceroberts.com/public/HTML/images/r281-04[1].gif

...but designed for fiberglass :(

[JimD]

This John Hesp profile would be high on my list of dream boat double enders - but she's a foot and a half too long:

http://members.aol.com/hespj/rosebud/assets/images/30__Sailplan.GIF

http://members.aol.com/hespj/rosebud/assets/images/30_Acc_Profile.GIF

[Hwyl]

Now we're talking. I was lucky enough to meet Paul Johnson. The Jhn Hesp boat has no head? That double berth would be tough to use.

Edit Opps, I see the head now.

[JimD]

And my favourite:

http://members.tripod.com/mark_boden/sitebuildercontent/sitebuilderpictures/greaya3.jpg


Tony Darrall-Rew's 32 footer "Greya". After a crossing the Atlantic, Tony decided that the gaff rig was not his "cup of tea", and decided to convert to junk rig

;)

[Paul Pless]

William Garden drew several serious blue water double-enders, mostly ketches and cutters. Most notable is probably his larger design Seal, which IIRC, displaces around 36,000 pounds, but he also drew a few smaller versions of the Colin Archer types that may be of interest.

In addition to the archer type, he also drew many other more 'modern' double enders

[zenda]

Don't be offended, guys. But, my NA says go with Inga, and she's the one I chose after alot of looking. So, I'll build her with modifications advised by my NA and I'll let you know how she does when I get back from the Horn! We've got some design challenges, related to the change of construction to strip/diagonal planking, but she'll do. Thanks for all your input and encouragement. Go choose your boat and build her.

[Jay Greer]

Don't be offended, guys. But, my NA says go with Inga, and she's the one I chose after alot of looking. So, I'll build her with modifications advised by my NA and I'll let you know how she does when I get back from the Horn! We've got some design challenges, related to the change of construction to strip/diagonal planking, but she'll do. Thanks for all your input and encouragement. Go choose your boat and build her.

An excellent choice!
Jay

[sv Lorelei]

No offense at all! Welcome to the adventure!

[Don Kurylko]

A guy’s gotta do what a guy’s gotta do! Please keep us updated on your progress. I’m sure we are all interested in how your little dream ship develops.

Best of luck with the project!:)

[johnw]

So now we're all curious. What changes did the NA recommend?

[Jay Greer]

What ever you decide, I should like to make one recomendation. That is to keep the deck space usable. Building a large deck house that runs out nearly to the rails is, in my humble opinion, a big mistake! Having decks one can walk upon and work upon, sit upon and lounge upon is my own idea of what makes a small cruiser a comfortable companion. The cabin should be snug but the decks are where you will spend most of your waking time!
Jay

[Hwyl]

I thought you were the NA of choice Jay, guess I was wrong.

[Jay Greer]

I thought you were the NA of choice Jay, guess I was wrong.
Nah! I'm too unorthodox. I built a 50' catamaran once and my friends won't let me forget it.
Jay

[Tom Hunter]

Enjoy it and tell us about it.

[paladin]

whassa matta...ya built the training wheels and gave up?:D :D

[zenda]

Re: changes, NA hasn't made any hard and fast recommendations yet; I'm mailing him the complete plans, and he's going to wear out some pencils first.

Jay, I'm planning on a raised deck, nine inches above the sheer line at the bridge deck to nothing at the bow, with camber of course. I like the idea of the clean sweep of deck and no cabin trunk for waves to demolish. I'm figuring to put a 6" bulwark all around; there's alot of decisions that I'll postpone until I've got the hull built and can see it fullsize. Oh, changing the main to a fully battened, extended roach and adding light wind sails.

[johnw]

Re: changes, NA hasn't made any hard and fast recommendations yet; I'm mailing him the complete plans, and he's going to wear out some pencils first.

Jay, I'm planning on a raised deck, nine inches above the sheer line at the bridge deck to nothing at the bow, with camber of course. I like the idea of the clean sweep of deck and no cabin trunk for waves to demolish. I'm figuring to put a 6" bulwark all around; there's alot of decisions that I'll postpone until I've got the hull built and can see it fullsize. Oh, changing the main to a fully battened, extended roach and adding light wind sails.

Backstay?

[Jay Greer]

My own Common Sense Sloop "Red Witch" was origionaly designed as a raised deck sloop. I ended up changing my mind and adding a deck house which, affords protection to the helmsman as well as admitting light below through the fixed windows. I am afforded more ventelation as well. The inner sides of the deck house give a place to brace against in heavy weather thus keeping those below from being tossed about like olives in a mason jar.
Jay

[zenda]

Jay,
I googled you, and got alot of forum posts and other contributions, but no website. Is there a site that features your designs or projects?

[Jay Greer]

Jay,
I googled you, and got alot of forum posts and other contributions, but no website. Is there a site that features your designs or projects?
You can see my Common Sense sloop RED WITCH on the "Common Sense Boats" Yahoo forum under "Jay's Boats".
Jay

[Paul Pless]

Zenda, Here's one example of a well thought out (IMO) double ended medium displacement sailboat, with your raised deck and bulwark modifications already included.

http://www.chuckpaine.com/img/chuck-paine's-frances.800.jpg

thought you might be interested...

[zenda]

Paul,
Frances is a great boat, but a little small and light displacement. I had considered extending her to 28', but went with Inga.

You guys may be interested to read this observation from the new owner of the ferro-cement Inga in San Francisco.

"I am the guy who just purchased the atkin inga in san francisco. Would be happy to answer any questions and if you ever make it to this coast take you for a sail. I saw some of your discussions about the boat on wooden boat forum, dint read anything but I will tell you not to believe the people who say she needs more sail area, has plenty aready and need to reef early. The hull is extremly easily driven and I have been able to ghost along in so little wind that the speed meters on other boats in the harbor where not even spinning. I have only been out in her a few times so far but was very impressed by how easy the hull went through the water. Also very balanced even with the rail under. With the little I have sailed her theres not really anything I would change about the hull/rig. The is also an incredible amount of space with the ferro construction, way more than I expected."

[johnw]

Well, that's good news!

[Tom Hunter]

Zenda,

Thanks for adding the ferro boat owners comments, they are very interesting.

You really ought to take him up on the sailing invitation if at all possible. I don't really disbelieve him, but I do think that personal observations about performance are highly subjective.

In my own case taking the boat to a couple of races was a real eye opener. When we were just sailing around we passed a fair number of boats and there were times in light air when we were ghosting along and others were standing still too. My comments would have been similar to the ones you posted. In fact if you go into the archieve I think you can find some from 2001 or 2002.

During the races it was very different. Almost all the boats of more modern design were faster (there were a few exceptions).

I think the discrepencey happens for a few reasons. If your just out sailing you may happen to be in company with people who are not very good sailors, and you may just be outsailing them. People who race tend to be pretty good sailors or better. Also in a race your all steering for a similar objective so speed comparisons are a bit more valid.

Finally in light air your boat may be ghosting along becuase you have more air than the other guy, even if he is not very far away.

I am not saying that what the current owner says is not true, but he has not had the boat for long and may not have had a lot of time for comparison.

I do think its good news though, at least he is not writing you that the boat is a pig of the sea. :D

[Foster Price]

Hello Guys

Heres my take on the issues regarding a boat like the Inga. Firstly let me say that Inga has been on my list of favourite boats for many years, and I seriously considered having a boat built to the design before I got my current boat. Incidentally there was one for sale recently here (in NZ) too.

For what its worth my currrent boat - Otter, is conceptually quite like Inga, abeit a bit smaller. I have a similar draft, similar ballast ratio, in a hull design of a similar era. My boat is an 12.5% enlargement of the J G Alden 21'2"double ender (WB have plans), and is of the same hull form as "Annie", both were penned by Fenwick Williams. Otter at 23' 10" and 2.75 tonnes has a lot flatter floors, so would develop her power a bit differently. She also has a modern Bermua rig (350 Sq Ft) which does not have any backstays apart from swept spreaders, so for me she's is not an offshore boat by size or rig, thats for sure.

I think that under sail Inga would be quite similar to Otter, obviously quite a bit more powerful due to her increased displacement, just over twice Otter's. Built in modern materials, to sensible scantlings, I would think that Inga would carry a lot more sail than the original plans show, and as with Otter, any competent NA should be able to design an appropiate rig.

Under sail I'd think she would be fine reaching and running, but as with Otter, you'd find that these shallow hulls cannot be driven to windward once you get to the double reefed sort of stage, as the speed the rig develops upwind in heavy air is not enough to enable the shallow keel to generate sufficient lift. They are plenty stiff, but it just can't (to the best of my sailing ability anyway) be translated into progress to windward.

Under 15 knts - up wind is no problem, and we have proven it, winning local handicap cruiser races several times. But as soon as it pipes up, the bigger and more modern boats (ie better keel configurations) just disappear ahead of us.

My 2 cents worth.

PS - There are some contradictions in the SF Inga owners rely. It should be very difficult to put an Inga rail under, and I would think that this demonstrates that as a ferro boat she would perform quite differently to a wooden one. It is also impossible to beat the laws of physics and as mentioned indirectly above, in light air only a good sail area to wetted surface ratio will make a boat go, easily driven hull or not.

[ingaben]

Hi thought I would jump in here as I am the owner of the ferro inga in sf. I think what many have been saying here about light air work makes alot of sense, When I first bought the boat my first thought was bowsprit. I had sailed to Costa Rica a few years back in a 26' Ed Monk wooden boat and even with a big main and bowsprit still felt I needed more sail. However when I took Inga out the first few times she went much better than I expected. If I where building new I might consider a bowsprit. It would throw the helm off pretty bad (lee helm) but this is not nessarcily bad for running, a quite common point of sail when cruising. But doesnt seem worth the trouble to convert my rig at this point. What I am going to do though is get a masthead drifter (boat is already set up with a masthead halyard), may even experiment with retractable bowsprit for it. Would be for downwind work only and the race boats get away with unstayed sprits so figure I could to. Overall though the rig seems like a good overall balance, Atkin knew his stuff and it shows. Yes ben-bow has a lot more rig but Ben-bows displacement is almost double and about a foot more beam and more draft, not really a comparison,

My boat has a boomkin as running backs aren't really an option with a deck stepped mast. Going to make fitting the wind vane a bit tough though.

(I had a full batten loose footed main on my monk and think this would be ideal on inga, easy to reef, lots of power and good in light airs.)

As to the ferro construction. She was built to very high quality (very fair, s/s mesh) and as far as I can tell the plans were followed exactly. I plan on taking some measurment when she is hauled. But Im betting displacement is the same as the wood boat, if anything maybe a little more ballast since even though it is cement there is a lot less structure. The cement also opens up a huge amount of interior space, about 6'3 headroom, Zendas boat should be similar inside with the cold-molding. Never thought I would own a ferro boat but seeing a good one really made me rethink some of the notions about ferro I had. They have such a bad rep but done well there as good as anything and tough as hell.

As for putting the rail down, well sf bay is windy and you can put the rail down on anything if you want. Inga definetly does not stand up like my monk cutter but that is understandable as the monk was 9' beam and 5' deep, also a more powerful hull shape. I bet in cruising conditions inga will be faster though do to narrower forfoot and she is much better in light airs. I am also sailing on a pretty wasted main so lots of heeling not a lot of go helps lean her over, All in all she was about as stiff as I expected given her shape. Zenda may be able to stiffen his up a bit with some more ballast do to weight saving in construction, can't hurt. Will be nice having the shallow draft, worthwhile trade in my view.

As compared to a modern boat she is definetly slower, but to be exepected. As this boat will be my home and used for cruising the tradeoff is worthwhile in my book. I like the full keel for the usual reasons and I'm in no rush. I like, Zenda, may be taking inga to places with bad weather (Mexico was nice and all but...) I dont really want a boat that will start going ten knots or surfing, thrilling yes, but only for a few hours. She should hold her own with other "cruising" designs, even though in my experience most cruisers use thier engines a lot so hard to figure out how fast they really are.

All of these are fairly preliminary as I have only been out three times in her and not really dialed in yet, will keep you all posted as I learn more. I will also post some pictures in the next few days.

I am pulling the volvo diesel out to get more interior space and it will be interesting to see how much better she goes without a three bladed prop and apeture.

Ben Wedlock

[johnw]

Something that was done on a Blanchard 33 and might work here is to rake the mast well aft and add sail to the foretriangle. Aura, which was Norm Blanchard's own 33, was changed from a 7/8 rig to a masthead rig and had a short bowsprit added as well. She sails better than the other 33s with the original rig. Of course, for sailing in San Francisco Bay, you might not need more sail....

[zenda]

I like the idea of a short bowsprit; I think 3' sticking out the front will give me two parallel stays to hang stuff on. I was planning to order a booster (one sail sewn to mimic double headsails), but Hal Roth is making me rethink that ("Sailing Around the World"). I can't wait to see what MMD comes up with for a sail plan; he's my NA, if you haven't guessed.

[JimD]

http://www.boat-links.com/Atkinco/Sail/images/Inga-1.gif
Just wanted to remind myself of what Inga looks like.

[ingaben]

Went for another sail today, reaching and running with first reef in main, get some weather helm but not to much, was quite windy and probably could have taken in second reef. I think a short bowsprit would be nice for downmind work like this, could put the second reef in with a jib on the sprit to move balance forward. Zenda, I will be curious to see what he NA comes up with. Really loved the bowsprit on my old boat Aurora.

Ben

[David Roberts]

My guess is that many of the posters on this thread don't have the Inga plans. I do, and have studied them a bit. In common with many Atkin designs, this one has the underwater sectional shape of a football. In other words, she's really, really tender and the shallow draft isn't going to help that at all. That's why Atkin drew so little sail area and the freeboard so low. Don't change those! In any case, she will probably roll your guts out offshore, especially with so little salient keel to slow that roll. See, if you draw a football-shaped hull, then it's going to be tender, so you give it a low SA, so then you need to keep the draft down because your SA/WS ratio is already so bad.

Not all Atkin designs have these shortcomings. sv Lorelei's Tally Ho Major is one of the truly great ocean cruising designs, IMHO. That puppy can make some fast passages. Nice bilges, decent draft, transom stern for increased stability = sail carrying power. And still has an Atkinized balanced hull form.

So, I'd pay your NA to calculate the GM on your Inga and thus the Dellenbaugh coefficient, etc. You might have another think afterwards. If your guy is not too expensive, have him shrink the Tally Ho Major down to 28' or whatever. He'll have to change the beam/length ratio a bit or harden the bilges some more, etc., to keep the stability inherent in the original design. You can use Nevin's rules for scantlings. I tell everyone who will listen that design costs are the best money you'll spend. Why pay $35 or whatever for the design and then spend $40,000 on materials? That ratio is seriously out of whack, unless your $35 design is absolutely perfect and suited to your needs.

The fiberglass 28' boat that was built by Cecil Lange and Sons in Port Townsend is exactly this shrunk THM. I used to work for Cecil. It's a great boat. I can't remember for sure who did the redesign for him. I think it was Tim Nolan Marine Design.

[johnw]

I think the idea with this boat was to produce low wetted surface with large displacement so that you didn't need a huge rig. More salient keel would certainly help it to windward, but would require more sail because of the increased wetted surface. For Zenda, the question is whether this is the design compromise he wants to make. He posted the like to the plans in the first post, if anybody wants to see the underbody we're talking about.

[paladin]

The Cecil Lange boats were beauties....Many years ago before I built Tana Mari I visited the facility and was sorely tempted......but I got another invite back to Thailand so a glass boat was not in my future....Cecil must be near 80 now.....

[Mark Giegel]

I had a Cape George 36 which is I believe based on the Atkin "Tally Ho Major". I think a guy named Ed Monk, modified the Atkin design for fiberglass construction for Cecil. Am I wrong or is the 31' Cape George Cutter also an adaption of the smaller Atkin design "Tally Ho"

I am not aware that Cecil made a 28' cutter. I just set up an owner association website for the Cape George and have hull numbers for all the hulls produced, at least I thought I did. I did not see a 28' hull listed in the company records. Best to you.
Mark Giegel

[paladin]

I may be suffering from a senior moment, but I thought he had three different hulls and decks available......it has been a while....I also looked at the "Ingrid" when it was in production.....couldn't find what I really wanted....went from visiting the yard in upstate N.Y....can't recal the name...then to Washington(Seafarer)?, and then when I went overseas travelled on different R and R's to Auckland, to Cheoy Lee etc.....finally just built one....

[David Roberts]

Ah, I misremembered. The smaller Cape George boat was supposed to be a 28', but by the time the design got done it had grown a bit, to 31'.

Yes, you are right, Ed Monk Jr. did the modification to the Tally Ho Major, which resulted in the 36' Cape George Cutter. Cecil was not happy with the design, however. He thought that Monk Jr. had got the look wrong and didn't like something about the bilges. So he had a different designer do the smaller boat, with which he was much happier. Not that the 36' was a bad boat, quite the contrary. IIRC, the 36 displaced about 22,500 lbs, and the 31 about 15,500.

Going back to Inga, I think it would be fine, running downwind in the trades. One could probably choose a sail spread that would reduce the rolling. Local bay sailing would be a disappointment, but one can choose a good-sized engine and operate it like a motor sailer.

Hoping to start something, my belief is that sharp-sterned boats are not as good as transom sterns, offshore, as their sterns lack buoyancy and the sharp stern detracts from stability to a remarkable decree. I don't include long overhang canoe sterned boats, which are simply transom sterned boats with their lines carried back to a logical conclusion to increase the heeled waterline. Some don't like canoe sterns, either, as the long stern and short keel typical of the type makes a shape that can be yawed by waves approaching from astern.

Cecil used to drop by my boat show booth every year, but I haven't seen him in many years. A great guy and a great boatbuilder. He was fun to work for.

[David Roberts]

Numbers. I thought I remembered doing some calculations on the Inga design, so I looked back through my old notebooks and - yup, 30 years ago I did some stability calculations by hand and came up with a righting arm at 20° of .514', which gives a metacentric height of about 1.5', and gets me back to two significant figures! If we guess that the CG is about 6" below the LWL, then we have a GM of 2', and one significant figure, which is even better. These are some old calculations, so I'm not going to vouch for them too much.

[JimD]

... has the underwater sectional shape of a football. In other words, she's really, really tender and the shallow draft isn't going to help that at all..

http://www.boat-links.com/Atkinco/Sail/images/Inga-3.gif
According to Atkin
she will sail on her bottom, not her topsides... Several double-enders of very similar dimensions to [I]Inga have been built and are most satisfactory in every way, especially in the manner they have of getting to windward, therefore prospective builders can be sure there is nothing of an experimental nature about the shallow draft, or the other features of the design.

One supposes there is only so much that can be done if you want shallow draft, little keel, and no centerboard. You could make the bilges firmer so she could stand up to her sails better but that would float her higher and reduce draft and lateral resistance even more.

(The above musings are those of an individual with no design training whatsoever)

[sv Lorelei]

At this juncture, may I remark that Survivablility of a craft and Comfortable motion are not necessarily the same thing. They can be attributes that are congruent. However, one is not particularly indicative of the other.

[zenda]

Numbers. I thought I remembered doing some calculations on the Inga design, so I looked back through my old notebooks and - yup, 30 years ago I did some stability calculations by hand and came up with a righting arm at 20° of .514', which gives a metacentric height of about 1.5', and gets me back to two significant figures! If we guess that the CG is about 6" below the LWL, then we have a GM of 2', and one significant figure, which is even better. These are some old calculations, so I'm not going to vouch for them too much.

Hey David,
Could you translate, please? What are the implications of all these numbers and abbreviations? I'm not being sarcastic, just want to get the full import of your calculations.

[Varna]

Zenda, MMD can give you the Inga you want and a safe version as well I would imagine. What David is saying I think is that people who have studied and built boats get a 'sense' for hull shapes and the intent of the shape. Looking at Inga one is struck by the slack bilges and shallowballast placement- that raises a flag right out of the gate and leads to asking what is the ballast ratio. Herreshoff pulls this off with 45-50% ratios and is one succesful approach yeilding a comfortable form in a heavy seaway with stability low wetted and shallow draft-but it must be coupled with the correct rig proportions and weight aloft to get the 'finestkind' overall performer. Therein lies the NA art and science. And MMD is a pro so you are in good hands. I was wondering if adding a dropped ballast casting to the profile would work- just in way of the ballast like a long shallow fin keel. Personally I agree with what David is saying regards the shallow and slack bilge config, and also I 'll have a transom please. The doubles are beaut's for sure, but pass me the Transom :-) LFH Solitaire for me in 28'
John
PS- have you seen Paul Gartsides design # 145? 27' 12,000#s all glued strip diagonal, sprit etc. Has Transom though

[David Roberts]

Ah yes, nothing like throwing around numbers and abbreviations! Let's see: CG is the Center of Gravity. GM is the distance from G (center of gravity, this time) and M (metacentric height, which is the point where the center of heeled buoyancy intersects the centerline. So the higher the metacentric height, the further from centerline is the center of heeled buoyancy.

To have a little fun and play yacht designer of yore, simply print out Inga's body plan, enlarged if necessary so that the midsection is 2 or 3 inches across. Now, draw a 20° heeled waterline across it, with this heeled waterline intersecting the centerline at the LWL (Load Water Line). Next, take scissors and cut out the underwater portion of the heeled midsection. Balance the section on a corner of your triangular scale or other convenient thing, with the heeled waterline perpendicular to the edge of your balancing thingie. The distance between the balance point and the centerline is your righting arm for that section.

If you were designing a boat, you'd do this for every section and then use some complicated formulas to figure the righting arm of the whole boat. You'd also recalculate the heeled displacement and longitudinal center of buoyancy. Then you'd do it over again using a different load waterline, because some boats "roll out" and others "roll in" as they heel. So that's really a lot of work, which explains why Atkin never did it for his once-a-month magazine design articles. He just guessed. He also just guessed at the longitudinal center of gravity and at the weight of the whole thing. Mostly he guessed accurately, but not always.

Computers are absolutely wonderful. Love 'em.