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Old 09 July 2008, 03:29   #41
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I seem to remember the Millenium Bridge and our local harbour defences were both designed by experts using CAD - I don't think Brunel had access to computers and yet I would far rather trust his engineering............
Excellent point Codders .. the man was a genius
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Old 09 July 2008, 07:18   #42
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cookee...... im not sure i know of any Rib mfr's who have a Hydronamics expert on their books with the Savitsky spreadsheeds for working out all loads and stresses... when you have this data and model then put in your gucci design in to the cad machine, it works it all out to ensure nothing breaks and gives you the smoothest / optimum ride.

Thats why Halmatic cant make ribs for 30k!!!! the MOD takes no chances and Avon, Halmatic etc have departments that do nothing else other than model new boats and designs and work out the stresses, flexing momentum, maximum KW rating and rig the boats to a HUMS system to datalink the stresses through its operating environment and better understand computational fluid dymnamics and hydronamics.

Making fast ribs is fun, but making them properly that last for tens of years and remain structually sound for their life is something that the Rib industy is not renowned for.....!

I've only been messing about in them for 30 years, but as the saying goes - you get what you pay for, some rib mfr's are great, others are ok, and some we laugh at - but each to their own...
I'm uncertain as to what you mean by "Gucci Design", but I assume it wasn't a compliment.

Our 770 (I presume that's the boat you're talking about) was derived from our race boat hull that was designed by the very well respected Lorne Campbell, and I'm sure he is aware of all of the calculations and other stuff that went into many boats that have failed over the years.

What I am trying to point out that designing a mould and therefore a hull on a computer doesn't count for anything when you're swimming about in the icy cold North Sea in November with only a set of tubes above the surface. The reliability of any boat is down to the guy who built it and interpreted the drawings correctly. For example Kevin (Kitten on here) has building boats since he was in shorts, both for himself and for others including, Marine Projects who make Princess and Moody boats, and I would trust his experience and accumulated knowledge above many. You only have to see the sort of stuff we get in here to repair where respected builders have fallen short of what was needed to keep a race boat together. I am not claiming we are perfect, but as we have broken stuff at the extreme with offshore racing experience I can safely say our building techniques really have been tested! Indeed it is the associated products such as lifters and saddles that break first. We also have our CE surveyor take a very critical look at our boats (I have no idea what calculations he uses - life is too short!), and he agrees that our boats are are "Fit for purpose".

Lugnut - As Nikster says only very few manufacturers are big enough to do the whole thing by CAD with dedicated departments, but as Codprawn says basic engineering (and pre computer days) can still produce a product that is "fit for purpose", and designing a boat with the latest CAD technology doesn't guarantee a good product that any more than without.
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Originally Posted by Zippy
When a boat looks that good who needs tubes!!!
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Old 09 July 2008, 07:21   #43
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Cookee and I agreeing - what's the World coming to???
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Old 09 July 2008, 07:27   #44
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Cookee and I agreeing - what's the World coming to???
No need to be concerned I don't intend on making a habit out of it!
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When a boat looks that good who needs tubes!!!
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Old 09 July 2008, 08:09   #45
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im not sure i know of any Rib mfr's who have a Hydronamics expert ...
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Thats why Halmatic cant make ribs for 30k!!!! the MOD takes no chances and Avon, Halmatic etc have departments that do nothing else other than model new boats and designs and work out the stresses, .... ..and better understand computational fluid dymnamics and hydronamics.
ehh? is that not a contradiction then?

and I am quite sure halmatic could make boats for 30k if they wanted (they have already ammortised and recovered the development costs from the MOD and commercial contracts). They just don't want to. Its not where they have positioned themselves and they don't need the hassle for the relatively low returns in selling lower cost higher volume product.
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Old 09 July 2008, 09:54   #46
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Lugnut - As Nikster says only very few manufacturers are big enough to do the whole thing by CAD with dedicated departments, but as Codprawn says basic engineering (and pre computer days) can still produce a product that is "fit for purpose", and designing a boat with the latest CAD technology doesn't guarantee a good product that any more than without.
Whoa there, I am *NOT* one of the unwashed masses that blindly blieves CAD and CNC are the answer to everything. As I said before. Just another tool. You can drop a decimal point just as easily in a CAD application as you can with a pencil.

If you have a crummy engineer designing a widget it doesn't matter WHAT tools he uses, the result will be a crap product. On the other hand, if you have a competent engineer, why would you force him to use antiquated tools?

You certainly do not have to be a large company to use CAD technology. I regularly farm out jobs to a small machine shop. Some of those jobs were LITERALLY handed to them scribbled on paper grocery bags! They turned the ideas into working products, performed an FEA and thermal analysis, and turned out a prototype within two weeks. We finalized the design, passed both FAA and military flight certifications, and are now flying that widget in about 20 aircraft with more installations each month.

A competent engineer in my field commands a nice salary. I'd be a fool not to buy a 10K software package that would cut his labor costs and increase his productivity by a factor of **50** over hand calculations and hand drawings!

But first and foremost, you have to have competent engineers.
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Old 09 July 2008, 11:01   #47
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What sort of widget and what aircraft - another passion of mine!!!
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Old 09 July 2008, 12:38   #48
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Before going off topic, part of the point I'd like to remind peeps about is this :

Northcraft has stuck a label on their boat saying its rated to 300HP. < Edited at the request of Northcraft - JK >. The boat clearly cannot withstand that kind of load.

The argument that the Verado is heavy is not valid either, as 2 x150 optimaxes is even heavier than the single 275 Verado.

The CE marking is a waste of time as has been proved, so who is going to stop manufacturers claiming their hull is capable of performance when it clearly is not ? and slapping any old sticker on the transom to rate it for HP

Have I been conned ? < Edited at the request of Northcraft - JK >

And ofcourse the good old customer pays ,.. and takes the loss on the chin .. again ..
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Old 09 July 2008, 13:59   #49
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The boat clearly cannot withstand that kind of load.

The argument that the Verado is heavy is not valid either, as 2 x150 optimaxes is even heavier than the single 275 Verado.

The CE marking is a waste of time as has been proved, so who is going to stop manufacturers claiming their hull is capable of performance when it clearly is not ?

Have I been conned ? < Edited at the request of Northcraft - JK >

And ofcourse the good old customer pays ,.. and takes the loss on the chin .. again ..
My apologies, I certainly hadn't intended to hijack your thread with a discussion of CAD.
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Old 10 July 2008, 06:46   #50
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Before going off topic, part of the point I'd like to remind peeps about is this :

Northcraft has stuck a label on their boat saying its rated to 300HP. < Edited at the request of Northcraft - JK >. The boat clearly cannot withstand that kind of load.

The argument that the Verado is heavy is not valid either, as 2 x150 optimaxes is even heavier than the single 275 Verado.

The CE marking is a waste of time as has been proved, so who is going to stop manufacturers claiming their hull is capable of performance when it clearly is not ? and slapping any old sticker on the transom to rate it for HP

Have I been conned ? < Edited at the request of Northcraft - JK >

And ofcourse the good old customer pays ,.. and takes the loss on the chin .. again ..
The CE marking think is of use in instances such as this though - you can take the whole lot to trading standards and they should act on it. The fact that it was rated to that horsepower gives them some ammunition to use against the manufacturer.

Lugnut - I think we are in agreement then!
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When a boat looks that good who needs tubes!!!
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