The Hull Challange

steverow

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Re: The Hull Challenge ABCD categoroes

Thats just the directive...ie the politics.
On CE Directives there are usually reams of technical annexes that go with them.
You should see the ones for CEPT mobile radio..mega.

Steve.
 

MapisM

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Re: A bold statement

Well, I can understand your skepticism.
I personally know one of their dealers, and I fully stand my point.
...besides, ahem, "JUST the makers word": they would already be belly up, under the pressure of legal claims, by not delivering what they promise!
But as I said, either you trust me or just contact them, and maybe purchase one of their boats, to finally check the CE certificate!... /forums/images/graemlins/grin.gif

Anyhow, I'm not saying that I'd afford 14 m wawes with one of those boats, of course. That's another story.
The point - as I understood it - was whether a planing boat can be built to A specs or not.
 

Gludy

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Re: A bold statement

Yep that's the point, not if we would actually do it and go out in a boat

Having looked again at their boats its difficuot to imagine how a 30 odd footer can get Class A. It would be interesting to check out if they could even fit the range requirments like 500 miles of fuel because if they could not do things like that then they are simply not telling the truth.

I do not know of any 30 odd foot motor cruiser of any hull type that is Class A rated. There may be some, but I know of none because size itself is important in being class A and getting a high STIX number.

Can you ask them for the STIX number of their 37 footer please? The reply would be intersting. It totally beleive you but I am still very sceptical about them. They make small open sports boats which look to me as if it would be impossible to get a Class A.
 

MapisM

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Re: A bold statement

Sorry, but I'd rather allow you to think that I was just joking, than going further into this matter.

Frankly, one of the last nights, when I read most of the posts when the hull debate started, the smarter contribution which came to my mind was this one, though I must say that my impression was more driven by some of the replies than from your original post as such.

Afterwards, I was tempted to throw in a more serious 2 cents in this thread, but as a matter of fact I still find the whole hull debate rather boring, thus I'm not going to bore myself further with my own posts!...

On the other hand, if you're interested, I guess that they would give you any detail, if you just call or send an e-mail.
...possibly avoiding to mention that it is just a curiosity, to increase the chances to get a serious reply...

Cheers, Mario.
 

BrendanS

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Re: A bold statement

Your big mistake here is to try and quantify everything by Stix or RCD, and whether D or SD is superior to planing.

Have a look at this post here I'd find the original post which laid it out in more detail, but the search engine here won't go back beyond a year now.

What you really need to ask are for peoples real life experiences.

A Trader coming past in conditions I'd been through less than 2 hours ago was really stuffing into the waves, and wasn't comfortable to watch. I doubt they could see where they were going most of the time. I'd done the same trip into the waves and had a great time. Took a lot of throttle control, but very little upset inside the boat.

The downwind trip home was an absolute hoot, and I doubt the Trader would have given that same level of comfort in those conditions?
 

Gludy

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Re: A bold statement

Brendan
You read too much into my questions. I tend to ask questions, then piece all the things together at the end. Because I ask a question does not mean that I assume all sorts of things that are attributed to me.

"What you really need to ask are for peoples real life experiences."

I agree with that but I also have to ask for the theory because that helps understand real life experiences. The way I work I need both. I read a lot of books on experiences and found the post you referred to very interesting.

The SIX number is still of importance to know if only to find that in time it has no value, some value or a lot of value.

Also when I discuss aspects of say hull design I try to do it in isolation so that the discussion can get somewhere.

The largest thread in the last 4 years on this forum was on jets and folks took the Mickey out of me, attributed all sorts of opinions to me that I did not have .. The net result was I did not go for the Cara jet boat and looking back that was a wise decision. However I did not accept anything I was told unless I could understand it and place it logically in its place,

My current opinion on hulls is that whilst there is almost an infinite range of styles - in effect a whole range of sd hulls alone, the comfort level of the sd and d is much higher than the planing hull. I also believe, in general they are better at sea keeping. There is good and bad in all hulls, so I am assuming a good standard of design in any hull.

If I was wrong and the planing hull could be said to be as good at displacement speeds etc then only planing hulls would exist and pilot boats would all be planing hulls ..... so the market seems to support my general opinion.

It is not a simple subject!
 

BrendanS

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Re: A bold statement

No I'm not reading too much into them. I'm trying to give a considered response.

For example, go out with a fleet of 20 odd boats of similar size. Ignore the helming factor for now. Some boats seem to cope with all conditions thrown at them, some members start seeing that certain boats seem to cope with all conditions thrown at them, and start commenting, some members buy same boat.

Going further afield, different size boats, some still handle better, and some bigger boats can't keep up same speed, and even then, crew get soaked while smaller boat is bone dry.

Repeat experiment over multiple trips in different conditions over many years.

You start to build up some experience of which boats handle well, are comfortable, and bigotry is not part of the process.

Then eventually, you start culling out bad helmmanship from the equation, as you see similar boats helmed by different people. Some boats are just better, even though their hulls look similar.

Come out with me for a trip sometime, I'll show you what a hull on a sportsboat should be capable of

If you want to see a good example of what a planing hull is capable of, take a trip out in a Bosnia. Not the prettiest boat in the world, but extremely competent in rough conditions, and the hull doesn't look much different from others in the class. Anyone that's been on one in rough conditions will tell you how much better it handles than anything similar, and no Stix or any other measure would tell you how much better this hull is to the average for the class

Same goes for Windy's and Fasttrac Regals.
 

Gludy

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Re: A bold statement

Brendan
I agree with all you have stated and accept it is true ... I agree the STIX factor would not tell you which boat was the best.

However, I am not saying that.

What I am saying is that whilst that sifting out of the good hulls was going on it would be helpful to know some of the theoretical aspcts so that a better understanding could be obtained as to why hull A is better than Hull B, not just that hull A is better than Hull B.

I have sent for some books on hull design because knowing some more theory may begin to help me understand why this and why that, not just this and that.

My general points still apply. Pilot boast are not planing hulls but SD hulls - why is that ? They have to go out in rough weather and have to keep control to let the pilot on board.

I answer your general points, in fact I agree with them, can you please answer mine?
 

BrendanS

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Re: A bold statement

I'm not sure which question I should be answering. I thought I already had, forget technical analyis of hull design, some seem to get it right, others go badly wrong. Just pick the particular boat that does what it needs to do.

If you are trying to understand why pilot boats are semi displacement, I suspect that is historical, and rather like why in IT terms, people bought IBM because you couldn't be fired for taking the easy route. There are many designs of boat out there that would fit the task perfectly, but it takes an adventorous leader or two to beat down the bigotry and hypocrasy first. If I was in the position of deciding which boat to buy for that function, I'd have to think long and hard about my career history before recommending something different or radical. I'd like to think, I might possibly go with the radical.
Have you seen the QHM volunteer pontoon with outboards...goes like stink and does everything it needs to do
 

Gludy

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Re: A bold statement

Thank you for the answer ... so you are the rebel then? Everyone else is wrong, the entire maritime industry but just carry on through habit?

I thought I was the rebel but it turns out I am the traditionalist and side with history and experience ......

If what you are claiming was true there would only be planing boats, SD boats and displacment boats for leisure use would just disappear.... agreed?
 

Gludy

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Re: A bold statement

Brendan
This is what I have just this monent read in the Dag Pike book Power boats In Rough Seas:-

"In a planing boat travelling at very high speed this dynamic lift factor accounts almost solely for the stabiliy of the boat as there is so little of the hull in the water.

A planing boat when stopped will often roll very heavily, and it is this loss of stabilising effect of the dynamic hull lift which accounts for this. In a following sea when the crest of a breaking wave is overtaking the boat, the dynamic lift stability can be very much reduced, and this again,accounts for the increased angles of roll experienced under these conditions."

This is what I meant when I earlier referred to the stability of a planing boat depending on its forward speed through the water and hence the lift from the water due to its speed.
 

BrendanS

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Re: A bold statement

This is why no one will carry on a debate with you. You try to force words into people's mouths.

Do you wish to continue this debate as a debate. If so, we set some ground rules here an now
 

Gludy

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Re: A bold statement

Brendan
Forget it.

From my perspective, this last exchange of posts with you has been to the point and constructive.

You made a bold statement and simply pointed out the effect of what you were saying. If cannot discuss on that rational basis then so be it... lets not discuss.

There is no way I am going to pretend to conform to any artificial constraints of discussion set by you. What are the ground rules .. That I cannot comment on statements you make ..... that is absurd. Nor did I force those words into your mouth, you clearly stated them. I , in a friendly, manner commented on them because they clearly out you against the traditional approach and against the accumulated wisdom of the marine industry.

On the other thread on stabilisers I was asking questions and your answer gave me the lead with the result that you get a clear 'you are right' response from me.

Its sad but it seems that you cannot discuss issues without making personal claims like I try to force words into peoples mouths!

This is what you said without any force:-
"If you are trying to understand why pilot boats are semi displacement, I suspect that is historical, and rather like why in IT terms, people bought IBM because you couldn't be fired for taking the easy route. There are many designs of boat out there that would fit the task perfectly, but it takes an adventurous leader or two to beat down the bigotry and hypocrisy first. If I was in the position of deciding which boat to buy for that function, I'd have to think long and hard about my career history before recommending something different or radical. I'd like to think, I might possibly go with the radical.
Have you seen the QHM volunteer pontoon with outboards...goes like stink and does everything it needs to do "

A set of statements that does not accept conventional maritime wisdom and policies but resists them and tends towards the radical approach. Those that resist this change are considered bigots and hypocrites. My comments back to you were perfectly valid, in good humour, and did not require the same old personal attack stuff.

I did not force one single word of that out of you and to claim that my response was in any way wrong is unacceptable to me. I suggest, if you do not like being held responsible for what you write then you do not debate anything with me. That would solve your problem. I do not have a problem as I am more than capable of being held responsible for my own actions.
 

Gludy

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Re: A bold statement

Brendon,
I really think it is pointless having any dicussion with you. If anyone tries to reply to very point in every post it is me.
You make clear statements and then attack me in a personal manner because I comment and make statements that are exactly based on your statments.
It would be appreciated if you would knindly not respond to my posts then you will not get so wound up about what you say.
 
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