Design Flaws

[elcapitan]

I want to innovate a design creating a solution for a flaw in today's design of boats. Has anyone encountered a problem, or has anyone thought of a problem in today's design?

[messabout]

elcapitan;

There are about a zillion observable design flaws in boats. Boat design is at best a series of compromises.

You have not given us enough information. Is the flaw that you suggest, a hydrodynamic one or an esthetic one? Does it relate to comfort, safety, production cost, longevity, material choice, What ?....

[kach22i]

I bet he is a lawyer looking for work.:D

Is this for educational purposes?

If so, we have a forum for that which may help you.

EDIT:
http://www.boatdesign.net/forums/showthread.php?p=101775#post101775
im 15 from nc and am in great desire to work in the boat building industry. ultimately i want to own my own company and build offshore center consoles, and pleasure boats. i want to take some classes on engine repair, fiberglass systems, marine electrical, the works. though im only 15 i want to get some expieriance and knowledge of everything. i want to start early basically because there is so much that is needed to be learned, and i want to learn as much as as i can. does anyone know of any classes or even books on the subject? anything to help me out and further my knowing on the subject.

Okay, at 15 you are a fresh clump of clay ready to be molded, many people will wish to leave their impression on you but not all good.

I'm no expert, but as an architect I'd have my student list all the major parts of a building as an outline. Then fill in the blanks, starting from the top or bottom or with what you know best. Example: "Roof", we have total structural failures to lack of flashing or improperly installed drip edge..........covers a lot of ground. Boat construction is similar in that it may be a fault in the design, the building process or in the materials themselves.

[elcapitan]

Im looking for a hydrodynamic or aesthetic flaw to use for a project for my architecture class, and my engineering class so anything that can correlate either or deal mainly with just one would be good.

[FAST FRED]

Get a current copy of Pro boat builder , and you will find a graph of fuel consumption vs speed.

Perhaps 1 boat in 50 can meet even the lower 70% standard .

With fuel prices where they are WHY so many grossly fuelish boats exist , might be worth some study.

FF

[Loveofsea]

IMO, the most common design flaw in production boats is that the center of buoyancy is such that water accumulates at the transom while at rest. That characteristic is responsible for the majority of capsizings of small craft. From a design standpoint, that is a tough nut to crack but it can be done.

[tom28571]

IMO, the most common design flaw in production boats is that the center of buoyancy is such that water accumulates at the transom while at rest. That characteristic is responsible for the majority of capsizings of small craft. From a design standpoint, that is a tough nut to crack but it can be done.

Could you explain more fully what you mean by this? I confess that I do not follow these thoughts.

[Poida]

Elcapitan

As an ex marketing person and I assume you want to design a boat minus the flaws that people will want to buy. And make you rich.

Go to some boat ramps start a conversation with people and explain you want to design a boat and ask them what they like and dislike about their boat to get some ideas.

When people buy a boat unless they have had other boats they may not know their boat has a flaw, they probably think that's what boats do.

People buy generally on appearance and since the salesman/women is not going to tell anyone a boat has a flaw, a flawless boat will probably not sell any better.

However if you can design a boat that will help the salesman to sell it, he will promote it because he has an easy boat to sell.

What surprises me when I visit boat shows is that boats seem to be for fishing or entertainment.

The fishing boat has lots of standing room in the back for the crew to move around in, live bait tank and a cutting table.

The entertainment boat is fitted with seats normally moulded in with a table maybe a fridge and a small wash basin.

The men like the fishing boat, the women like the entertaining craft.

Why not design a boat where the seats come out along with the table and any cushions at the back leaving you with a fishing/diving boat.

Cars do it, seats lay down in wagons to convert it into a van and some vehicles have removable seats. I've yet to see that concept used on boats.

Good luck with your designs and when you do become rich don't forget your old mate Poida.

[kach22i]

IMO, the most common design flaw in production boats is that the center of buoyancy is such that water accumulates at the transom while at rest. That characteristic is responsible for the majority of capsizings of small craft. From a design standpoint, that is a tough nut to crack but it can be done.

Sounds like a good topic. Could tie into the layout or design on an architectural level if it means moving the engine. Perhaps tie it into FAST FRED's suggestion and maybe go with a split hybrid system (or revised hull design) if that would help.

People buy generally on appearance and since the salesman/women is not going to tell anyone a boat has a flaw, a flawless boat will probably not sell any better.

This may be the "simple" idea which will allow you to get your arms around. It has architectural implications too.

I would still start with an outline, I hated outlines but they do get the juices flowing. It's often better to cover a small part of a large problem completely that to just skim over and just touch a much larger topic.

[dougfrolich]

here is a defect in a new boat that needs some improvement.

[Loveofsea]

When water enters the hull from what ever source, in most boats it will run to the transom weighting it down. The more water the more weight; the process is exponential. If the water accumulates in the center/belly, it would give the boater precious moments to correct the problem before capsizing. Of course this is advantage is for worst case scenario.

For those of us who use our boats in earnest, we may only need that design feature need once in a life time, but when you do, it may very well be the difference between life and death (in WCS).

When i built the Good Skiff, i accomplished "water accumulating in the belly" by doing this:

view looking broadside at the boat. The Y datum plane runs fore and aft touching the bottom of the hull 2/3 forward of the transom. Aft of that point the hull rises on a flat plane to 3" at the transom. Fwd of that point, the hull rises 6" on a parabolic hook to the bow. I should mention that this is a flatbottom skiff. i use a 2,000 gph in the belly to protect the nights on the water, and i use a self priming pump mounted on the transom while underway. Obviously, when the boat is under way, the water will run to the transom.

If you could convince manufacturers to eliminate this design flaw that is common to virtually all small craft, it would definately save lives.

[kach22i]

Just so people like myself get all the terms correct and can follow what is being said, I offer this image.

http://www.uspowerboating.com/images/boat%20parts.jpg
http://www.uspowerboating.com/primer.htm

I have noticed that some of the sail boat diagrams are not labled the same as power boats. Is the rear panel of a sailboat still called a transom?

It would help me to know what type of "flatbottom skiff", doing a google image seach results in conflicting drawings.

http://images.google.com/images?svnum=10&hl=en&lr=&q=skiff+drawing+&btnG=Search
Samples:
http://www.clcboats.com/images/boats/jimmyskiff_drawing.gif
http://www.mskiff.com/images/voyager23d.jpg
http://www.duckworksmagazine.com/01/articles/boatbuilding/1/fig3.gif
http://www.duckworksmagazine.com/01/articles/boatbuilding/1/pic2.jpg

[lewisboats]

A flat bottomed craft is one where the bottom is flat from side to side as in the skiff above. The curve in the bottom from front to back is called rocker and is found on flat, Vee and round bottomed craft. The best way to look at it is if you were to cut the boat like a slice of bread. If the bottom is flat...flat bottomed, if the bottom has a vee shape...etc.

Steve

[kach22i]

A flat bottomed craft ...............

So the "Jimmy Skiff" is not a true "flatbottom" despite the section cuts being flat, right?

I mean to ask; the "rocker" (parabolic hook to the bow) of the Jimmy Skiff is an example which should or should not be included in the "Loveofsea" design suggestion?

[Loveofsea]

Lewis, the black broadside image of the Jimmi skiff that kach provided shows the 'Y' datum plane. That skiff has a full hull rocker, but is a true flatbottom because the 'X' datum is parallel to the horizon--flat.

I love the flatbottom design, i couldn't run these seas the way i do in anything but a flatbottom. They are without a doubt, one of the most sea worthy designs possible.

One fatal flaw that most designers of flatbottoms make is tapering the bow to a V. That negates one of the most important aspects of a flatbottom design--flat entry that virtually eliminates bow steering in heavy following seas. I looked at a number of designs before i built the Good Skiff and all of them either had a V entry, engine well, or a strange rocker that was not conducive to a planing hull.

There are a number of things you must do to make a flatbottom work well in seas. The most important is to induce exaggerated transom lift, then there is the weight displacement. For instance, i hold 54 gals of fuel in portable tanks that nest under the deck. All of that fuel is in the fwd 1/3 of the hull.

[elcapitan]

What about reducing back end slide on boats, skiffs in particular. I know that when on my skiff and at hight speeds, taking sharp turns can cause the back end to slide around or fishtail. What if a small skeg like feature was placed on the transom that would help prevent a slide in the backend allowing you take tighter/sharper turns at higher speeds. Does that sound reasonable?

[kach22i]

What about reducing back end slide on boats, skiffs in particular. I know that when on my skiff and at hight speeds, taking sharp turns can cause the back end to slide around or fishtail. What if a small skeg like feature was placed on the transom that would help prevent a slide in the backend allowing you take tighter/sharper turns at higher speeds. Does that sound reasonable?
Sounds like a simple problem with more than one simple solution. Meaning this should be "bite sized" and something you could chew.

Perhaps torque on the hull from hydrodynamic forces being unequal or changing on you could be responsible for the twist.

I was kind of dealing with this at another level recently, perhaps this thread will help.

Link:
http://www.physicsforums.com/showthread.php?t=149427

AlephZero
the key is drawing a free body diagram.