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Old 24 June 2003, 13:32   #31
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I am still not convinced.

My point is you need look a little further into why the tubes came off the rib,It dosnt hold water with me that it is only a Cabin rib problem with a bow locker?

I am not sure what the logics behind those assumptions are,maybe Nick could explain ?

Nick could you give us any details of any work you have had to do as far as Cabin ribs go to stop the problem of bow tube loss on cabin ribs?

Before I suggest any changes to a design that is used commercialy and tested with in exess of 5yrs safe operation commercialy offshore, I would like more info.

I dont buy into the idea that its only a Cabin rib problem with a fixed bow locker and that it has to have a hard nose? but I do buy into the idea that people want to sell there concept of rib and they will try and find a unique selling point to justifie this.

Nick have you done any tube work on any Cabin hard nosed ribs that have coused you to come to the conclusion that a Cabin rib needs hard nose to be seaworthy?,as the stats prove this to be the opposite for commercial ribs used all day and every day ?

I appologise if I sound a little sceptical on this point, but I can understand the joy and satisfaction for those selling hard nose ribs, if they are able to establish that it is there ribs only, that are the way forward for a seaworthy boat, this tries and prohibits otheres ever owning one with a soft nose.

And its Salesmans Dream and total crap in my oppinion.

If its design right then its hard or soft in my oppinion both have advantages and disadvantages,but its not terminal unless eithere is designed and built badly and they come off,when you dont want it to.

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Old 24 June 2003, 18:23   #32
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Reading NIck's comments, it occurs to me that whilst a tube attachment failure is bad it is made much worse if the intial tear is able to travel down the attachment strips to release a whole length of tube. Since fabrics tear most easily longitudinally or transversely, there is a case for cutting these strips diagonally so that both the weave and the weft are across the joint strip. It is likely that a tear would run off to the edge rather than travel along the strip.
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Old 24 June 2003, 18:29   #33
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I've just checked a couple of bits of hypalon. I should have done it before the last post 'cause some of what I've suggested is bollocks. Nothing new in that I suppose. One type is woven with the fibres diagonally placed but the other make is not. So maybe tube builders need to be selective depenent upon which fabric they use. Perhaps some are.
Just a though, no criticism intended.

JW.

CH, just another though about bolt on tubes...Tear along the dotted line. Perhaps.
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Old 24 June 2003, 18:39   #34
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Quote:
Originally posted by jwalker
One type is woven with the fibres diagonally placed but the other make is not.
Were those pieces as they came off the roll? Or is it possible that one of them had actually been cut on the diagonal?

John
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Old 24 June 2003, 18:50   #35
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JW We all might as well go get a hard boat Eh ?

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Old 24 June 2003, 19:14   #36
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JK, the diagonal fabric is a couple of metre length off the roll. The other bits are cut off a length also. They are wear patches which I cut a couple of years ago but never fitted.

JW.

CH, calm down. You've been over on the other channel too much!
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Old 25 June 2003, 06:00   #37
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JW, thats excellent lateral thinking! very similar thinking is used with the woven matt in many of the structural bits of my boat, although it's a little wasteful cutting matt diagonally (+ &- 45 deg matt is available on the roll but it's not woven)

I think a more important aspect to this hard nose business is how fast the boat is! at 70mph, the stagnation pressure of water is around 70psi, with only a few psi in your tubes they will just get pushed out of the way in a serious stuff, once they're deformed and "flapping" around on the front of your boat(during the stuff), starting the tear line would seem almost inevitable. so I reckon if you're gonna go quick, and hull design is of a type that means the fwd tube is likely to do a lot of head-plants, you need a hard beak!

Were the cabin ribs with failures refered to, "high performance"?

soon you'll extend the hard nose right round the topsides and hey-presto, a real boat!
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Old 25 June 2003, 06:25   #38
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Quote:
Originally posted by Jon Fuller
you need a hard beak!

Isn't that what Manos had fitted to his racing Rib.
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Old 25 June 2003, 06:57   #39
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Just a thought If you had a pressure release valve on the bow section then if you stuffed it harder then usual would the pressure be released rather than the bow ripping off?

Not sure if it would release fast enough any comments?
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Old 25 June 2003, 07:03   #40
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Quote:
Originally posted by dgpw
Just a thought If you had a pressure release valve on the bow section then if you stuffed it harder then usual would the pressure be released rather than the bow ripping off?

Not sure if it would release fast enough any comments?
After a few 'stuffs', you'd be all deflated LOL
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