40ft Concept Design

[monrosm@shrewsb]

I am in the process of creating a 40ft concept Speed boat, im ok with the design side but would welcome some help and comments as to what the stability and seaworthiness would be like on such a design.
Any comments are helpful, flaws in the design, pointers, praise and criticism!

Picture attached!


Thank you

Stef

[daiquiri]

Hello,
We can't see the hull in that pic.
From what can be seen, there is no way for the crew to access the foredeck area. If it is a fast (planing) craft, and agressive styling calls for that, then the transom is too narrow.
From the aesthetic point of view, it looks appealing to me. It is ok as a starting point, keep improving it. ;)

[kach22i]

Pretty picture, and as something to express an idea it works. However as something to explain a functioning craft it falls way short. Daiquiri's comments are spot on as they deal with this aspect.

In your mind you have to live and work on the boat, doing the things humans do and what will be expected of the craft.

The boat will dock, the humans will sleep.

The boat will need to fuel up, the humans will need to eat.

Simple things cannot be overlooked.

About the tail taper, have you seen this?

http://www.adriaticmarine.no/marex/21-duckie/
http://www.adriaticmarine.no/upload/marex-21-duckie.jpg

Another thread you may want to read: (2 pages)
http://www.boatdesign.net/forums/open-discussion/new-designer-board-32194.html

Video of 21 Duckie:
http://www.marex.no/index_engels.html#/home/

[daiquiri]

About the tail taper, have you seen this?
http://www.adriaticmarine.no/marex/21-duckie/

...or this, too: http://www.boatdesign.net/forums/boat-design/semi-displacement-33509-2.html#post378957
See my posts #18, #22, #23 in that thread.

Similar problems have lead to similar solutions in this case. :)

[sorenfdk]

im ok with the design side but would welcome some help and comments as to what the stability and seaworthiness would be like on such a design.

Stability and seaworthiness are very important parts of the design. You have made a very nice drawing of a very good looking yacht, but you haven't designed it yet!

If you want us to comment on the design, you'll have to show us some more of it! As a minimum, we'll need a Lines Drawing (or at least a drawing showing the shape of the entire hull!) and a General Arrangement.

[J3]

I love the look and rendering style from an artistic standpoint! Look forward to seeing more of your work and/or this design as you work it. Your artistic style is great!

From what can be seen, there is no way for the crew to access the foredeck area.Not to divert this thread, but it's interesting how speedboats here have totally sacrificed safe access to the bow in exchange for a sleek profile. In the 70s (feeling old typing that) the rails were adequate and sidedecks wide enough to walk fore and afteasily. Then rails became "ugly" and started to get cut down, or even disappear. Sometimes you have rails a few inches off the deck at best, to catch your toe or so you can grab on for dear life when it's rough. Windshields became lower and sleeker angle (love the look) but you can't step over them now. Sidedecks aren't walkable any more. Hatches are sleeker flush profile but often too small to get out easily. When you do if one accidentally tips closed, you can't easily open it again so you're stuck or have to jump over the windshield and hope you don't break something or twist your ankle. Sometimes you have a tiny fiberglass rim to step on kid sized steps at best. Often nothing on the sleek boat. I love the look of these boats still, but often wonder where the common sense went when it's rough and I want to get on the bow.

[kach22i]

I love the look of these boats still, but often wonder where the common sense went when it's rough and I want to get on the bow.
Maybe some of them use concealed bow deck access hatches?

This is clean looking, could he just "scale it up"?
http://www.revenger.co.uk/revenger32/rev32ow.html
http://www.revenger.co.uk/images/32foredecklockersopen.jpg
http://www.revenger.co.uk/images/32008c.jpg

It has to be safer to go up through the inside than around the outside at some point.

Although the outside would seem quicker in most situations.

[Thomas Ask]

I liked the high speed Norwegian "snekke" photo. They are not meant to be fast but are the most delightful motorboat afloat (if you are in no hurry, especially at midsummer night with boiled shrimp and evergreen boughs on the rigging.....)

[dskira]

To design a good boat think of that:
Its night and rainy, the wind blow force 6, the waves are shorts and high, you have to go to the foredeck, and then you have to go to the aft deck.
The boat is jumping 7' to 10' and down in less than a few second, the motion is bad and you are at a real risk to be thrown overboard.
Coming back to the helm the skipper has to see what is going on in front to him. And the oil low pressure alarm goes on, the engine need attention immediately.
Down below is your family scare and not able to help for anything. They are thrown from one side to the other, and they ask you crying to go home. And you can't since you know it will be dangerous.
Sound pessimistic?
It is what happens all the time cruising. Perhaps not this year, but next. You never can be sure.
Motor or sail, the sea don't make any difference, she turn bad in no time summer or winter.
The question is: what kind of boat you will design? Do you will use the boat with your family? Are you willing to cruise in any condition with your design?
Dramatic rendering are for the auto industry and the magazine in need of filling up white pages, since the advertisement industry is shrinking. Sleek and dangerous design is just a waste of time.
Daniel

[rambat]

Contrary to the others, I say go ahead with a 24 degree dead rise aft and make it look sexy as your leaning toward. After all, no one that will be buying or using it for its fun, fast short day tripping purpose will be living aboard or taking it into any weather that might discourage their guest to sun-bath on the flat fore-deck. Designers need to keep the "Fun" boat elements separate from the house issues, they are pretty much incomparable.

[Alik]

Design is not a pretty rendering, it is development of complex object that works. Look at aesthetics, but also at perfromance, comfort, safey, cost.

There is no way to design boat without knowledge of basics in hydrodynamics, FPR/metal/wood manufacturing and industry standards.

What I see on rendering is good for car magazine, not for the sea. Sorry to say this...

[larry larisky]

Contrary to the others, I say go ahead with a 24 degree dead rise aft and make it look sexy as your leaning toward. After all, no one that will be buying or using it for its fun, fast short day tripping purpose will be living aboard or taking it into any weather that might discourage their guest to sun-bath on the flat fore-deck. Designers need to keep the "Fun" boat elements separate from the house issues, they are pretty much incomparable.

half a million dollars for fun?
fast short day tripping at 200 gallons?
not fun.
woman are fun and for half a million you can have fun. ;)

[J3]

If I ever get to the point where I have a few million extra, I think it'd be enormous fun. I'd love to have a baia :)

[monrosm@shrewsb]

Thank you for all the replies, a lot to take on board here, I agree with the things you say, but do remember this is a starting point.

From my experience starting with a wild design that is bordering on the impossible which is then rationalised through a similar process to this leaves a working design which retains some flair of the original.

Some points are obvious like fore deck access, soon to be rectified.

Plan views and a package drawing are to follow within the next few weeks. Check back to see the developments.

Stef

[gonzo]

The poll leans definetely towards a poor opinion. This is one of those fancy, computer generated designs, that would never result in a good boat.

[kach22i]

What's safer than an enclosed lifeboat?

No side rails to walk on and a bow hatch.

Dare to look outside of the norm for inspiration.

http://www.tradevv.com/chinasuppliers/airi75_p_32ebe/china-Totally-Enclosed-Lifeboat-Rescue-Boat.html
http://image.tradevv.com/2008/12/19/airi75_208574_600/totally-enclosed-lifeboat-rescue-boat.jpg

[Anytec1210]

There are plenty of people (yeah, more than others but that comes with the industry I guess) that gladly hammer eweryting down that´s not a proven design or technology from the 18 century.

If you, like many others, only settle with doing what others allready have done. I think you are on the right track. Come up with somthing crazy and then refine it to something usable, safe and fun.

Look at the Wally Eden yatch for example. Crazy? Sure! Possible? Not in the water yet but well on the way...

[Alik]

Look at the Wally Eden yatch for example. Crazy? Sure! Possible? Not in the water yet but well on the way...
Floating drawer? :) Don't call it 'yacht' please :D

[larry larisky]

There are plenty of people (yeah, more than others but that comes with the industry I guess) that gladly hammer eweryting down that´s not a proven design or technology from the 18 century.

If you, like many others, only settle with doing what others allready have done I think yo uare on the right track. Come up with somthing crazy and then refine it to something usable, samfe and fun.

Look at the Wally Eden yatch for example. Crazy? Sure! Possible? Not in the water yet but well on the way...

you will be the first one piuking all over, catapulted from one side to the other, breaking legs and other part, when your "yacht" hit force seven.
and then back to the hard, you will scream: never, never again.
i guarantee it
the law of the sea, is the only one, we are little and insignificant, so we have to have vessel in compliance with this law, and be award and humble in front of the sea.
monaco show is not a sea trial as to many people think.

[LostInBoston]

There are ways to make a tapered transom work for a performance boat. It would need a bustle extending over the drives. This would be great for surface drives with a rudder. The Alpha Z, callan 62, Mystic 50 all have tapered transoms with a bustle copvering surface drives. Buzzi's boats all have surface drives and bustles, but are mostly straight. PM or email me if you want some help to take this design further.

[mandesign]

WOW!!!! I bet that boat is super fast because it sure looks like it:P :P :P :P

[Anytec1210]

larry, you made me think about why I’ve never met any great guitar players who believe their skills on the strings, also turn them into expert guitar builder/constructors, but hundreds of sea men who all thinks that hours at the helm are equal to hours at the naval architecture academy.

Why? Well, anyone with any knowledge of boat construction knows that the laws you need to master, are the "laws of physics" rather than any "laws of the sea". What you refer to as "laws of the sea" would by developers, researchers and designers in any field instead be called "context".

If you didn’t know the lunar rover was designed to drive on the moon, it would be a quite stupid looking poor working car right? That’s context. The starter of this thread did not give any context and I’m not really sure what he really wanted but any judgements about the design can therefore only be subjective. Looks and taste, has nothing to do with performance, functionality safety or seaworthiness and judging a construction without a context, (or even worse automatically putting it into your own preset context) will only reveal that you have absolutely no clue about what you talk about.

So digging deeper into "context" you will se that there are many aspects of boating. That there are proven and safe constructions that anyone hardly would like to be in when it’s force seven (boating is not only about hurricanes you know). Canoes for example!
So how can a boat be safe and proven but not able manage a storm? Context, larry. Why is there that all top offshore racers manage just fine without any ability for the crew to even exit the deck? Context! And why didn’t I se any ice classed high sea boats (except a Norwegian one) last time I was in Florida? Context!

I would sure need some new pants if I where sitting I my car on an open deck ferry in 30 ft waves and 100 k winds. Does that mean that an open deck ferry is a bad design?

A deep knowledge about what you call "laws of the sea" is important, but only for understanding the limits of the design.

Amateurs ….

[daiquiri]

What you refer to as "laws of the sea" would by developers, researchers and designers in any field instead be called "context".
If you didn’t know the lunar rover was designed to drive on the moon, it would be a quite stupid looking poor working car right? That’s context. The starter of this thread did not give any context and I’m not really sure what he really wanted but any judgements about the design can therefore only be subjective.
Basically, without knowing the context in which this boat is designed to operate, we all should have restrained from making any comment. That's how I understand your words, and I do agree - partially.

The fact is, restraining from making comments is not what monrosm@shrewsb has asked us to do. He wanted to hear our opinions regarding seaworthiness and stability of his design.
Stability is impossible to assess from the attached picture, so people has jumped right to the issue of seaworthiness. But since the hull is not visible in the picture (only deck is) even seaworthiness can hardly be evaluated beyond few very basic observations relating to, for example, transom width or freeboard height.

So at the end the comments have concentrated on the only visible part of the boat - the deck design, trying to point out major ergonomic or functional flaws. I actually see them all as pretty much constructive objections. One need to read them beyond the verbal form, which often depend on the non-english native language of the writers, and go straight to the essence of the critics.

The alternative to that is to keep everyone's mouth shut and let the thread die, right after the first post...

P.S.:
I actually find it very interesting how the lack of design data in the opening post has lead everyone to formulate critics and opinions based simply on their personal experience and vision about what a boat should do and what it should look like. The lack of informations has led each one of us to create our default context and expectated characteristics. This guy has teased us at the beginning, and then has left us alone with our own immagination. :)

[Anytec1210]

daiquiri - a grown up beavior would be then to restrain from comments I think. Just because someone puts out the wrong question do not mean that you must give them a wrong answer. Some did however try to get better understading, but anything else is like asking someone for street directions and getting a wrong answer just because the guy you asked didn´t have the guts to tell you that he didn´t know.

Not that I don´t think hand rails are nice to have in most cases but in terms of design and context. Even i you had them, do you know anyone who would like to hang on to them in this 220 mph context?

http://blog.jameslist.com/wp-content/uploads/2010/02/phenomspeed-600x387.jpg

[daiquiri]

Not that I don´t think hand rails are nice to have in most cases but in terms of design and context. Even i you had them, do you know anyone who would like to hang on to them in this 220 mph context?

It's ok - we all have a right to disagree. As I do with this statement:
a grown up beavior would be then to restrain from comments I think.
This forum would be quiet like a cemetery if people restrained from commenting each time an opening post is lacking some data... ;)

I also guess that the others have a right to choose an existing boat type which operates in a "context" which they have envisioned, just like you did.
You have choosen an off-shore racing cat, where evidently a requirement for aerodynamic efficiency prevails over safe accessibility to the foredeck. Your experience, vision of boating, or a quick association has led you to that choice as a basis of comparison.

May I then choose this Pershing 46, which has come to my mind when I saw the rendering in the initial post, and which appears (to me) to be more akin to that design:

http://www.yachtguide.gr/images/Pershing/46/Persching_46_foto1.jpg

It does have speed, power, habitability, access to the foredeck and handrails.

It all fits, imho, my previous comment about the lack of initial data leading us to construct our own story of this boat. ;)

Cheers

[Anytec1210]

Maybe the irony in the end of my previous post wasn´t all that clear. Sorry about that but my choise of an offshore cat was to show that there very well are contexts where such a basic thing (on a boat) as handrails are utterly useless and even unsafe.

The forum do not have to be dead just because a poster lacks some data. I think that this thread was really constructive up utill the end of the first page.

[das boot]

Well personally I think the guys make very valid points with the criticism above but still an awesome looking boat, it really knocked my socks off.
I think you can overcome all of the above named design flaws and only sacrifice about 10-20% of the aesthetics. I would love to see your next revision.