Book recoomendations to better understand hull designs

[gstanfield]

I'd love some suggestions for better understanding hull design, in particular what makes a good displacement hull other than "rocker" I understand the differences in the hull types pretty well, but I'd love to know them better from a design standpoint.

Thanks for any recommendations.

[JimConlin]

Two good books:
The Nature of Boats by Dave Gerr
Understanding Boat Design by Ted Brewer

[gstanfield]

Thanks Jim.

[Sayla]

I'd love some suggestions for better understanding hull design, in particular what makes a good displacement hull other than "rocker" I understand the differences in the hull types pretty well, but I'd love to know them better from a design standpoint.

Thanks for any recommendations.

Elements of Yacht Design by N. Skene
Seaworthiness; The Forgotten Factor by C. Marchaj

sayla

[CapnJ2ds]

Howard Chapelle's "Yacht Designing and Planning" - and any/all of his other books.
All those in the above posts - Marcaj's "Seaworthiness" is a must if you're considering what has become the norm in plasticyot design.
Maurice Griffiths' "Little Ships & Shoal Waters", "Dream Ships" & "60 Years a Yacht Designer".
All of Uffa Fox's (pre WWII) books, very good for comparing/appreciating types.
T. Harrison Butler's "Cruising Yacht Design & Performance" (Not sure my ancient brain has recalled the title properly.)
Any of the old "MotorBoating" magazine's "Ideal" series. These have designs by many designers, but most especially Billy (and later John) Atkin.
Any books by yacht designers or about their designs, e.g. Bob Perry, Bill Garden, Pete Culler, Jack Giles etc etc.

[Spokaloo]

Don't forget the John Gardner books that talk about specific designs. They are all more of a case study type presentation (similar to the beginning of Gerr's Nature of Boats book), and are provided with plans to build each of them. There are several available and I'd recommend buying them all.

Culler's books are great as well for understanding the effects of why this or what that.

E

[Tom Painter]

LFH, "The Common Sense of Yacht Design"
reprint here: http://www.dngoodchild.com/ if you cannot afford a $300 1st edition..

Why it ever went out of print I'll never understand.

[gstanfield]

Thanks again to everyone for the good input.

[boatkid]

Skene's is available on Googlebooks for zip. Just search 'yacht design' and it comes up, then you can save as PDF if you like or just browse it online. It is the original one I believe, so alot of it is outdated. Speaking of outdated, somewhere in the book, it pretty much states that taking the lines off of models is outdated. Gheez, first I hand draw, and even back then carving shapes was 'outdated'. That's gonna be the name of my little ship, "Outdated". Well, it's getting late, so I had better go clean the gas lamps and visit the privy.

[paulf]

Hi George,
I'm a member of SNAME, they have some publications that you may be interested in.
They are part of the series, "The Principles of Navel Architecture"

Strength of Ships And Ocean Structures. By Professor Alaa Mansour and Donald Liu

The Geometry of Ships. By John Lechter

[TR]

What constitutes a "good" displacement hull will depend on who's talking and what the aim is. For instance a VLCC is a displacement hull, as is an H28 and a Nutshell pram. A "good" displacement sailboat hull will look different than a "good" displacement powerboat hull. This is because each load (displacement) and speed (actually speed/length) has an ideal hullform, and the limits are rather tight. For instance a 20' LWL hull traveling at 4.5 knots (S/L = 1.0) has an ideal CP (prismatic coefficient) (google it) of .52 and ideal LCB (longitudinal center of buoyancy) of about station 5.1-5.2). Speed the hull up to S/L of 1.34 (6 knots) and ideal CP is .62 and ideal LCB moves aft to roughly station 5.4. Speed her up some more to a S/L of 1.7 (7.6 knots) and ideal CP is .69 and LCB should be close to station 6. What we see happening here is as relative speed increases the ends of the hull get fuller and the midsection gets smaller.

Each of the books above will give some examples of displacement hulls, but most are pretty biased as to what a "good" one might look like. I would say that Ted Brewer's book is about the least biased in any particular direction. Books like Skene's assume you know what a "good" hull looks like and just shows you how to draw it out and do the required calculations. "Everything but why" in the words of Dylan Thomas.

[Monkey Butler]

To me it sounds like the OP is interested mainly in power boat designs. If so then take a look at this article.

http://www.tadroberts.ca/about/pdf/p...d-function.pdf

Great read Tad. Do you offer the plans for Ironbark?

[TR]

Do you offer the plans for Ironbark?

Thanks Monkey........See this http://www.tadroberts.ca/services/sm...ent/ironbark28 for info on Ironbark. Just this morning I received some beautiful photos of the first Ironbark launched in Norway.

[gstanfield]

Thanks for the continued input gentlemen. I am indeed more interested in power boats than sailboats and what makes for an efficient, seaworthy hull design.

[CapnJ2ds]

Ok, if it's power you're interested in, Douglas Philips-Birts "Motor Yacht Design" and Robert Beebe's "Voyaging Under Power".
William Garden's books (again) and maybe George Buehler's "Troller Yachts", though I generally think of the latter as an addendum to Beebe.

[TR]

Ok, if it's power you're interested in, Douglas Philips-Birts "Motor Yacht Design" and Robert Beebe's "Voyaging Under Power".
William Garden's books (again) and maybe George Buehler's "Troller Yachts", though I generally think of the latter as an addendum to Beebe.

If you can find it the Phillips-Birt book is pretty good as a general reference, at least he's not blatantly selling anything. It includes an actual chapter on resistance and he covers many of the technicalities in understandable language, there's also a useful glossary of ratios. The examples shown are all over 40 years old (very English) and appear a bit bizarre today.

The first edition of Voyaging Under Power is good, the examples shown (of other designers work) are mostly excellent boats. Beebe wasn't giving the hard sell (though he's definitely selling) and was smart enough to mostly stay away from what he did not know. The technicalities of hull design are avoided. The revised 3rd edition of Voyaging Under Power by Leishman is an extended Nordhavn sales brochure and is not to be taken seriously concerning naval architecture.

Buehler's book is another sales brochure and is filled with mistakes concerning the science of naval architecture. He advocates his flat-bottomed dory designs and his hard-chine deep-vee designs as the best hulls for ocean voyaging. I would just avoid it.

[Dave Lesser]

Two good books:
The Nature of Boats by Dave Gerr
Understanding Boat Design by Ted Brewer

Ditto

[wtarzia]

I disagree about Brewer's book. He stops short on some critical explanations for beginners that would really make some topics clear. In other words (from what I remember), he is good at defining terms, but not so good at explaining the real world implications of those things when you vary them in hull design. For example, prismatic and rocker -- I remember getting far better explanations of those things from competent amateurs off internet discussion groups. Brewer's book needs one more draft -- if he substracted some self-promotion from that book, he would have plenty of room :-) -- Wade

[TR]

With hindsight every book could be improved or expanded, if you want a complete purely technical explanation of some factor the SNAME "Principals" mentioned above is the "bible", but also pretty dry going. And they don't necessarily relate things or answer the "why" part. Explaining complex technical issues in non-technical language is a great skill in itself.

To be clear my reviews above are not meant to be derogatory in any way, I'm trying for honesty........Anyone who sits down in front of a clean sheet of paper, draws a boat, builds it, and goes sailing has my utmost respect. The nature of the business is that some small craft designers are more philosopher or artist than technician, and that's as it should be. We need these people just as much (perhaps more) as we need the scientists.

[paulf]

If you want imperial answers and the physics involved, then it’s Scientists and Engineers you should be talking to. You may need to do some homework, but it’s not impossible.
The trick is to also be able to incorporate the beauty, grace and aesthetics of a fine design and have all the technical requirements addressed. There is the art of it.

[donald branscom]

A simple book, Howard Chappelle's "American Small Sailing Craft: Their Design, Development and Construction ".
It talks about what different hulls do best and why.
Photos and examples.

Amazon books.

[donald branscom]

If you want imperial answers and the physics involved, then it’s Scientists and Engineers you should be talking to. You may need to do some homework, but it’s not impossible.
The trick is to also be able to incorporate the beauty, grace and aesthetics of a fine design and have all the technical requirements addressed. There is the art of it.

The best book for the layman that is easy to understand and dispells many myths is
C.A.Marchaj's "Aero-Hydrodynamics of Sailing " You do not need to know math.

When you see some racing boat designs you will see how silly some are, and you will
be confident when you talk to some of those folks at the club. (Donald Branscom)

See photos of actual tank tests of designs that were failures but look real trick.

[paulf]

Those look like excellent referances! I'm ordering Aero hydrodyanimics of sailing ASAP. Chappelle as well.

But at some point the ugly math creeps up on you!.... Sorry.


If you want to get into design, learn all the Math and theory Involved ! I'LL BET TR and Brewer know it well!!!

[wtarzia]

If you want imperial answers and the physics involved, then it’s Scientists and Engineers you should be talking to. You may need to do some homework, but it’s not impossible.
The trick is to also be able to incorporate the beauty, grace and aesthetics of a fine design and have all the technical requirements addressed. There is the art of it.

--- I am not sure if you were replying to me, but I will pretend you were anyway. What I meant in my previous post was that I did not think Brewer pushed the limit on narrative explanation. He stripped most math/graphs away to make the book seem amateur-friendly, but needed to expand on verbal techniques; this is where metaphors, examples, playing with variables and then explaining effects, come in. Marchaj did this a little better despite the loads of professional math he also used. I think Bolger's writing style sometimes hit on excellent narrative technique, as well. I am not ignorant of the challenges involved, having once been a technical writer for Pratt & Whitney, and once asked to assemble/edit/write a rocket engine and spacecraft textbook (I was doing my PhD in medieval saga to give you a sense of where I was then -- and it wasn't close to rocket science). The book was to orient engineers coming in from college from various engineering fields, and also to use for non-engineering staff to understand the product they were helping produce -- a complex audience, in other words. I would ask engineers to better explain some equation and I would get another equation to explain it :-). It was a tough, fascinating project that opened my eyes to the needs of technical style. Writers of texts for 'nautical architecture' face the same issues, and they vary in the success of their solutions of course; mishaps generally occur in accomodating their best-guess construct of the audience. -- Wade

[paulf]

--- I would ask engineers to better explain some equation and I would get another equation to explain it :-). It was a tough, fascinating project that opened my eyes to the needs of technical style. Writers of texts for 'nautical architecture' face the same issues, and they vary in the success of their solutions of course; mishaps generally occur in accomodating their best-guess construct of the audience. -- Wade

Agreed!

[TR]

American Small Sailing Craft, The Aero-Hydrodynamics of Sailing, and Seaworthiness, the Forgotten Factor are all all fine books, but they deal strictly with sailing vessels. The original poster is looking for writing on efficiency and seaworthiness of (I assume smallish) powerboats. Because of the difference in propulsion and characteristics info on sailing vessels does not (IMO) apply to modern power boats.

Power boats have more initial stability and less ultimate stability than a sailboat, the VCG will be much higher. There is little underwater area to be acted upon by waves or current, the rudder will be far smaller and low speed handling will be worse, heaving to, lying ahull, or even running off in bad weather may not be possible in the powered vessel. Vulnerability at sea may be far higher in a powerboat with large superstructure and forward windows.

Efficiency in a power boat comes down to having the correct hull shape (minimum resistance) for the anticipated cruising speed. Very few (if any) powerboats today are designed for a speed/length ratio of 1.0-1.2, (ideal CP =.52-.55) which is where non-planing sailboat hull design is.

[CapnJ2ds]

American Small Sailing Craft, The Aero-Hydrodynamics of Sailing, and Seaworthiness, the Forgotten Factor are all all fine books, but they deal strictly with sailing vessels. The original poster is looking for writing on efficiency and seaworthiness of (I assume smallish) powerboats. Because of the difference in propulsion and characteristics info on sailing vessels does not (IMO) apply to modern power boats.

Power boats have more initial stability and less ultimate stability than a sailboat, the VCG will be much higher. There is little underwater area to be acted upon by waves or current, the rudder will be far smaller and low speed handling will be worse, heaving to, lying ahull, or even running off in bad weather may not be possible in the powered vessel. Vulnerability at sea may be far higher in a powerboat with large superstructure and forward windows.

Efficiency in a power boat comes down to having the correct hull shape (minimum resistance) for the anticipated cruising speed. Very few (if any) powerboats today are designed for a speed/length ratio of 1.0-1.2, (ideal CP =.52-.55) which is where non-planing sailboat hull design is.

Mmm...... Yes, but a bit generalised and a bit overstated.

More initial stability and less ultimate stability? Little underwater area? Depends on the individual vessel. It's not difficult to design a ballasted motorboat with adequate watertight freeboard that has good ultimate stability.

Rudder far smaller? Low speed handling will be worse? Quite the opposite in displacement hulls, in my experience. ( Have held a commercial ticket for over 40 years.) in displacement motorboats the smaller rudder (if it is indeed smaller) is compensated by the constant prop-wash over it. I've handled a few fin keel/spade rudder keelers and yes indeed, they handle very well at close quarters, but my own moderate displacement launch will do it better.

Very few (if any) powerboats today are designed for a speed/length ratio of 1.0 - 1.2 (ideal CP = .52 - .55)? A bit overstated, IMO. thanks to Robert Beebe, Ed Monk, Bill Garden, Arthur de Fever and not a few others, there are a good number of powerboats designed for this speed range. Quite a number are also designed to run locally at higher S/L ratios, but at the lower one for long range trips - the Fleming 55 and the Krogen Express come to mind as examples. We should remember that Paulf, our original poster, said he was interested in displacement hulls.

Marchaj's "Seaworthiness" should be mandatory reading for any one designing seagoing small craft, power or sail.

[Harbormaster]

Another with some fun powerboat discussions hidden in his articles is Weston Farmer's "From My Old Boatshop." Gives some good historic perspective that might be helpful.

[TR]

Yes, but a bit generalised and a bit overstated.

Depends on the individual vessel.

Cap......The world is wide , no specific vessels were mentioned in the thread.........

Robert Beebe, Ed Monk, Bill Garden, Arthur de Fever

None of whom are currently practicing........

Fleming 55 and the Krogen Express come to mind as examples. We should remember that Paulf, our original poster, said he was interested in displacement hulls.

Both semi-displacement and thus outside the discussion of displacement hulls (IMO) despite whatever their PR states.......

Marchaj's "Seaworthiness" should be mandatory reading for any one designing seagoing small craft, power or sail.

I agree, that and so much more........

[donald branscom]

Agreed!

That is why children in this country have a hard time learning math.
Lousy math teachers who come up with x=3 (3 what????? never found out) and wonder why we were not interested in math.
They need to apply formulas to actual everyday problems.

SKEENE'S' Elements of yacht design has EASY formulas that actually work and you will get the SAME answer as the EXAMPLE. (not rounded off etc.,.) His book has one of the best formulas for designing a mast and the formula was so simple I was able to work it out with a pocket calculator.

[donald branscom]

--- I am not sure if you were replying to me, but I will pretend you were anyway. What I meant in my previous post was that I did not think Brewer pushed the limit on narrative explanation. He stripped most math/graphs away to make the book seem amateur-friendly, but needed to expand on verbal techniques; this is where metaphors, examples, playing with variables and then explaining effects, come in. Marchaj did this a little better despite the loads of professional math he also used. I think Bolger's writing style sometimes hit on excellent narrative technique, as well. I am not ignorant of the challenges involved, having once been a technical writer for Pratt & Whitney, and once asked to assemble/edit/write a rocket engine and spacecraft textbook (I was doing my PhD in medieval saga to give you a sense of where I was then -- and it wasn't close to rocket science). The book was to orient engineers coming in from college from various engineering fields, and also to use for non-engineering staff to understand the product they were helping produce -- a complex audience, in other words. I would ask engineers to better explain some equation and I would get another equation to explain it :-). It was a tough, fascinating project that opened my eyes to the needs of technical style. Writers of texts for 'nautical architecture' face the same issues, and they vary in the success of their solutions of course; mishaps generally occur in accomodating their best-guess construct of the audience. -- Wade

The best explanation is the "hot rod version"

Otherwise a non GEEK that does know the theory and the math but also knows that the big picture
is more important than some of the details. I could say a boat hull has high initial stability and make sound like I am very smart or I could say, The boat rocks around with the slightest wave and makes the crew worn out even though it resists tipping over. OR I could talk about prismatic coefficients and righting moments,or I could say the boat has a slow movement in the water and the crew hardly noticed how rough the water is and that the mast almost touched the water. "The hot rod version"