Cobra ribs

[jambo]

Originally Posted by Searider

All of the above might be true to an extent - but it might also be that there are proportionately more Cobras around than other brands?

You may possibly be right but in my experience I would have to disagree with you.


Sent from my iPhone using RIB Net

[Mollers]

Originally Posted by jambo

You may possibly be right but in my experience I would have to disagree with you.

So you may possibly be wrong??

[Pikey Dave]

Originally Posted by Searider

All of the above might be true to an extent - but it might also be that there are proportionately more Cobras around The Solent than other brands?

Ftfy!

[Mollers]

Originally Posted by Pikey Dave

Ftfy!

I can't think of any around here and there are plenty of ribs.

I doubt if Cobras add up to any significant number on the Solent either, as a % of total number of ribs.

[Pikey Dave]

Originally Posted by Mollers

Cobblers either way. I can't think of any around here and there are plenty of ribs.

I doubt if Cobras add up to any significant number on the Solent either, as a % of total number of ribs.

I was being ironic😎
Am I getting too subtle😄

[Mollers]

Originally Posted by Pikey Dave

I was being ironic��
Am I getting too subtle��

Clearly.

[gareth9702]

In my humble opinion ... In normal use why would you ever need to turn sharp enough and fast enough for hooking to occur? The tightness of the turn required can be seen in the video and can only happen by intention. If you were towing a wake boarder/water skier/ringo etc. then you would know tight turns were involved and take the necessary precautions. I agree with all the comments that the danger does not lie in the design of these ribs but with the use of these ribs.

[ShinyShoe]

Originally Posted by gareth9702

In my humble opinion ... In normal use why would you ever need to turn sharp enough and fast enough for hooking to occur? The tightness of the turn required can be seen in the video and can only happen by intention.

In the Padstow case there was a last minute change of direction made because they didn't think they would clear an obstruction. SO... Yes it was an intentional manoeuvre but that didn't mean they understood the consequence of it until too late.

Yes if you do tight turns all the time you will get used to how it behaves. If you only do one High speed tight turn you may discover at the wrong moment.

Kill Cord - the padstow guys normally used theirs. They had PB2. They just forgot during a helm change. The needles incident it was not the helm who went over.

I'm not sure if there is something fundamentally wrong with Cobra Ribs. BUT if I was about to get on a plane and AAIB said they should change the landing gear and they said 'nowt wrong with the gear if used correctly' would I get on the plane? There are three options in my opinion why they haven't changed:

1. There is genuinely no way to make it better. I'd like to see what they tried.

2. There is genuinely no issue. I'd like to see the head to head comparison between it and competitors.

3. They know changing going forward opens up (a) consumer liability to fix previous models (b) (some) liability for the deaths.

Did the changes made to design in the past make hooking worse?

[gareth9702]

Aren't there two fundamental questions:

Will any 8m rib "hook" if driven into a tight enough turn at a high enough speed?

Does the particular model of Cobra do this at a significantly lower speed and wider turn?

I suspect the answers are "yes" and "no - but a little lower and a little wider because of a hull that is slightly flatter than most".

[John Kennett]

Originally Posted by gareth9702

If you were towing a wake boarder/water skier/ringo etc. then you would know tight turns were involved and take the necessary precautions.

You'd hope so, but I wouldn't want to rely on it. Anyone can tow something behind their boat, but it doesn't necessarily follow that they are competent.

[Last Tango]

There was a time when the formula, based on transom, beam and length dimensions was used to determine the maximum safe engine size for a boat and would have put about 100hp on the back of a six meter boat. Back then a 100hp engine was a “monster” and, despite this, there was a consensus that the best engine for your boat was the biggest the manufacturer recommended.
Then came ISO and RCD, and with that, a new formula that let us put engines twice this size onto the back of our boat. Construction techniques had move on, engines had got bigger and we weren’t going to rip the 4r5e out the boat with all that power. Still the standing advice was to fit the maximum or near maximum recommended by the manufacturer.
Moving on, ISO11592 now allows manufacturers to rip up all the formulas and basically, if a highly trained, very skilled and experienced stunt-helmsman (who likes living life on the edge) can pull some defined manoeuvres within given parameters, the manufacturer can recommend the engine they used as the “safe” maximum.
Now.....I’m not a killjoy. I’ve owned and played with boats that were outrageously overpowered but always recognised and respected them as being such. If you have a burning desire or need to do over 60mph (maybe you’re running drugs or fleeing a scorned spouse)...then hell, yes.... go for it, but we can’t keep advising novices that the best bet for them is the maximum sized engine the manufacturer recommends because that figure is just becoming a “d**k sizing” contest.
If you’ve read the MAIB report on “Milly” ask yourself this......had that boat been fitted with what would have been deemed a “safe maximum” 30 years ago (probably less than 200hp) do you think the engine would have produced enough thrust to “ hook-out” that hull.?
Maybe it’s time for both a “recommended engine size” and a “maximum engine size”.
Perhaps a scale where we could quote recommended engines for different applications based on hp/ton....a “lookup table”...ranging from light leisure use to “death wish”.

Rant over !!!