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/


Another thread you may want to read: (2 pages)
http://www.boatdesign.net/forums/ope...ard-32194.html

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

[daiquiri]

Originally Posted by kach22i

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

...or this, too: Semi-Displacement?
See my posts #18, #22, #23 in that thread.

Similar problems have lead to similar solutions in this case.

[sorenfdk]

Originally Posted by monrosm@shrewsb

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]

Originally Posted by J3

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



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]

Originally Posted by 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.

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.