Did a dream got shattered?

In conclusion, as I do not think I will get much further on the questions I have.

Which electric river boat design, will, when it capsize, turn itself back on its belly?.

Yes, I agree with you, provided the battery banks are properly and strongly mounted. Could you please tell me which one.? That could be the design I possible would like to buy.

The Hartley4.jpg does that in #1. It will turn back after it has been rolled. None of the designs , which I have seen so far, can do that.

So, again my question. What must I do to make the instability, which seems to be engraved in some reader's mind, less of a problem.

Make the keel taller, and ensure not to exceed the designers weight?
Mount the 2 keels differently? i.e. at an 90 degree angle against the hull? instead of parrallel with each other?
Add a center plate version, to the allready 2 keels?
The designer has provided me with all those very fine detailed drawings
Bert

 

Well folks, you want like it, but …..

How more I am calculating, how more I come to the conclusion that we have a problem with copyright in this industry and not a real problem with instability.

Yes, if we reduce a tanker of 500 meter to 10 meter, it will be wobbling all over the water, but it does not necessary means, that it will sink.

Thus we dealing here with a copyright problem whereby the industry has not got their act together and some clever NA came up with a nice story, that if you reduce a design , the boat will sink, because it is unstable.

So what I have thus done, is written to the Myth Busters, the famous American TV program and have asked them to do the following.

Take the by 13% reduced plan , which is a proper displacement hull and have asked them to get a plan from another designer, also for a displacement, exactly the same size hull and do the comparison.

If the by 13% reduced plan is more unstable than the off the shelve bought displacement plan, I will profoundly apologize to everybody.

If the Myth busters however conclude, there is no noticeable difference in stability between the 13% reduced displacement hull and a hull from another designer , you apologize to me.

Is that a fair deal?
Bert

 

Yeah,
if it was that easy..........

But it is´nt. Though I guess I have some insight after 35 years in the industry, I would NOT claim to be able resizing a given design.

But, our abilities are not all the same, of course.................

 

Well Bert like me you have gained enough from your design books to be dangerous. Where we differ is in our approach to the holes in our design knowledge. Me, in the absense of knowledge I will tend to lean towards what has historically worked in the past rather than forge on ahead into new design territory. I guess the lessons I have learned from the sea and my bank have a lot to do with that.

Good luck with your approach.

 

<mod note: insulting line has been removed>

what you are saying is, that 2 displacment hulls from 2 different designers are not the same. The one will flip over and the other is stable.

Bull.

Both displacment hulls should be similar in performance, otherwise what you are saying is to be extreemly carefull in selecting your designer for a boat.

What I do agree is that the original size displacment boat is substantial more stable than the reduced one.
Bert

 

Well Pierre, I feel sorry for you that you selected the wrong designer and had some financial set backs. I will not start building a boat, untill I have clearly in my mind formulated, that what I am going to build, is safe. Thus, let see what the Myth Busters has to say. Bear in mind I selected a very good designer. All what I have to get is proof, whether 2 displacment hulls has bad variations in them.

Just that the King says: jump off the Eifel tower, I bend my head and jump. I am not made like that. I want hard evidence, and so far I came to the conclusion it is not that black and white as many people think.

 

Oh man, I love this thread!!!! The dreamer who will listen to no one (except the Myth Busters) and a bunch of good willing knowlegable people who are are taking this all a bit too seriously, or at least pretending too...

Great food for thought however. Keep it comin'

My 2 cents worth (minus 13% if you want): get a special permit to tow a larger boat.. (I recollect that was the basic problem)

 

That you are serious about Mythbusters being a possible solution to your problem is telling.

Why do you think the industry has not got their act together over copyright protection?

Even if the industry doesn't have their act together, lawyers do. From what I can tell, it might cost $100 to accuse you, but it will cost you $1000s to defend yourself.

 

Why don't you give answers on questions I still haven't received answers on in previous threads, instead of insults. Show me that you are knowlegdable.

Show me.

Bert

 

Nobody in this audience has really proven that the 13% reduced boat has become an absolute danger for life.Bear in mind I selected a very good designer. TOM has kindly explained that the stability will be reduced if a plan is reduced. I appreciate that. However I have calculated that the reduced boat will still be rolled back on its belly, if hit by a wave. Not many designs what I have seen here, can do that. Thus what do you all mean to badly reduced instability? Just a little more wobling boat, because it is smaller?
.

From all the designs I got, the designs were not really sufficient copyright protected.

Fine, speak to some patent laywers and ask them what should be changed to protect this industry better. Maybe some people will be more willing to give straight forward answers then accusations..
Bert

 

You don't understand. It's not my problem.

I wasn't accusing, I was advising.

You're the one going on an international internet site and talking about copyright problems...

But actually, re-reading it, I realize I don't know what you're talking about. Are you sure 'copyright' is the right word? Is maybe 'liability' what you're looking for?

 

Bertku--i can sympathize with some of the problems you are going through on here--

I havent read the whole thread so please forgive me if i get details wrong- perhaps i should go read through the whole thing but i am presed for time...

I cant say whether 13% is going to alter you design so much that it isnt seaworthy etc--im not sure what you mean when you say about the boat righting herself after a capsize(?) ...in the past i have taken risks-- and in the past i have been rewarded for it and i have learned from it. I think you should listen to your instincts about it--you will know whats best for you--
my understanding is that 10% increase or decrease is the max. But i have also known people to rescale more- recently i did soem calcs and decided against it...but the difference between 10% and 13% is a hard call to make if i am on the right track here about your thread, to figure out the characteristics of a vessel when the changes are made...
have you built a scale model to test??..this is always a good idea and i do it on all my designs...

hope it works out for you- nregardless of any ideas that may be stupid--some will work beyond logic...so you face a tough decision

to me and this is just my opinion--13% doesnt seem to be that big a deal only 3% more than the max of 10% but any more of an adjustment and id be leary- but its just my opinion...my guess is mythbusters will only choose what the public will want to see...so maybe the chances of getting help from them are slim??
and i disagree with some of their methods anyway...
have you thought about spending a few bucks to consult an NA--i am told it isnt that expensive...to consult? but i dont know. i never have.

 

Nor mine. I have paid for the designs.

My apology, I did not meant you personal, but in general people are too quick in knocking other people down. Could you please advise me on the questions I have listed under #1 ?

I have explained that in one of the threads.
Maybe, I maybe wrong with the perception, but if this industry is watertight protected by copyright, maybe I would get some more straightforward answers on questions I have. I have the perception that answers are being kept close to their hart. There are exceptions like Rick, Erik, Tom, CDK , Jeremy and a few others who are willing to give precise answers, instead of a vague not related story.

No definitely not.
Bert

 

Bertku,

I'm not sure how you are doing your calculations for your boats stability and having not done calculations on your specific boat I can't agree or disagree with you that this specific vessel is still safe or unsafe when scaled down 13%. That said I have to agree with those who warn you that scaling a boat is not that strait forward. Indeed, if you scale everything down evenly, using exact scaled scantlings and do calculations on an empty boat you will obtain similar results. The flaw in this idea is that the scaling of the scantlings isn't linear and mostly that the content of your vessel is not scaled (or mostly not on the same scale)....including passengers (which in the size boat your are experimenting with does have an impact).
All what your boat contains (batteries, engine, anchors, chains, tankage....you name it) is not scaled 13% and in relation with your boats proportions will have a very different position in its volume for the original design and the scale down design. Note that smaller the boat more impact our human size stuff impacts its stability and more difficult it becomes to scale. In fact playing with a boats content is a very easy way to cheat on the stability data of a smaller vessel. When provided, is the curve calculated fully loaded, empty, how much does it change? If someone brags to me about there boats stability, that's the first questioning I do.
More questioning is how much of that stability is shape stability, how much is ballast, how stiff is it, what motion can I expect? I'm wary of this ultimate goal of perfectly self righting boat. Not because it's a bad goal for a good design but it's too focused on only one element of a safe and stable vessel. Stability, like everything else in boat design requires some compromise and relative to what the boat is designed for. If one tells me this boat will always self right, it doesn't convince me to hop on board to ride a storm, I also want to know what does it take for it to roll. Personally I rather sail on a boat with great initial stability and high enough AVS than a boat with all around self righting, but tender.
I may be wrong but I suspect that most of the stability element you find in the design you are experimenting with is do to reserve buoyancy in its upper structures, this doesn't help it at all for its initial stability. Unfortunately I suspect that that initial stability is what is going to drop the most in your scaled boat and even more so when you load it.
I hope this somewhat simplified expression of my wariness for bluntly scaling a design clarifies the general mind set towards your modification questions. There is unfortunately no strait forward answer to scaling a hull, boats differ so much from one an other.

Murielle

 

At last , we have somebody we can talk to. Thank you tugboat.

The problem is , I am in a two mind. Make the boat at a reduction of 13% and it will be the perfect boat for me, but TOM gave the warning it becomes substantial less stable. My problem is, what is substatial. What for me is acceptable more wobbly, beacuse of a samller narrower 13% boat, may mean for somebody else dangerous life threatning.

How do I find out? Thus I made the calculation, that if the 13% reduced boat capzises, will I survive, will the boat stay with the hull up, or will the boat turn back to the normal position. The answer is yes, it turns back to the normal position. Thus I do not have to endanger other people to save me, I may just have a bult on my head.

Also, because I did not get answers on my question for myself, how could I improve the instability created by reducing the plans by 13%, I put the questions on the boat.net. All what I get are insults. (Not by you). That is not a very professional forum. Thus I decide , let me see whether somebody can tell me whether a reduced 13% boat will be the same as a from scratch same size hull. More insults (Also not by you)

Tom explained that small scale model may not give the same result.

So, Tugboat, I agree with you. I am on my own, except if all those who have insulted me can give an opinion on the questions I put up in #1.

Thanks Tugboat, truly appreciated.
Bert