Gludy - the Raggie

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Searush
I am not talking about small racing cats or even large ones.
Lifting a hull even a small amount in a cruising cat is a very dangerous thing to do.

All I am saying is that cruising cats are very safe and modern ones are designed not to sink even when holed etc.

They have their disadvanatges and advantages just like any boat - all boats are a compromise.

As regards disagreement I am not sure there are any. Many post react to something I have not said p for example I was analysing the situation with a boat stopped in a storm with a sea anchor - not a boat moving through the water.

Is anyone disouting what I =have written about this stopping the boat in a storm? No.

I would love to have clear points made were anyone disagrees - when that happens they get a straight answer from me.

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I'm just saying that they are DIFFERENT. They have different characteristics and you need to be aware of the weaknesses of any vessel you sail. the builders' blurb will never explain this - why should it, it won't encourage you to buy.

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I agree with every word of that and have not stated anything different.
 
ChartScribba

Can you not read - you blast off in total ignorance.

You talk about the length of warp in anchoring when we are talking about anchoring using a sea anchor!!! Something like a 24 foot diameter underwater parachute!!!!

As regards experience try reading Storm tactics or any modern book on the subject.

What I am stating about that is based on sailors experiences from all over the world - yet you just blast off in total ignorance throwing away the experience of those who have sailed around the world more times than you have had a cup of tea.

Just try reading some of the links that I posted above and educate yourself before blasting away in that pathetic ignorant style.
 
I'm sorry Gludy, but you will NEVER get a boat to be stationary "just moving up & down" in a blow. Sea anchors/ parachutes/ drogues, whatever you choose to call them CANNOT hold a boat still. They rely on some movement thro the water to work - just as a parachute cannot stop your fall thro the air. The drag they offer DEPENDS on that movement thro' the water.

Finally - "Full sail in a F10" FFS, the solent capsize was much less than that - you claim to pride yourself in not believing everything you are told, but this just looks like you are choosing to believe only the stuff that suits your purchase choice!

I know you like a good argument, but this is getting silly again.
 
Searush - please read back i did state that the speed was nominal like half a knot or so.

To all intents and purposes you are still and that is what everyone who has used them properly states and will tell you.:)

Iadvise you to read up on this matter - read Storm Tactics as a starter. /forums/images/graemlins/smile.gif
 
Some very good news

This is my last ever post on this forum.

Its impossible to have a rational discussion and I am totally fed up with it.

I was going to do a farewell video but frankly I can no longer be bothered.

I will now leave you in peace.

Safe boating
 
I've tried to find some pics to illustrate the concept.
All I could find was this YouTube clip
http://www.youtube.com/watch?v=GeT-8zEKpf4

You will see from the clip that the spinnaker "fluffs" briefly and the crew loose momentum. Then a gust hits and the aparent wind goes completely behind - no or little boat speed - there's only one outcome.

I did find, however a number of comments that indicate that it diesn't matter if it a sports (beach cat) or something bigger - the same thing will eventually happen if you push anything to its limits.

However, I should think that you wouldnt get to that extreme conditions and of course if you did, any mobo of the types we have on this forum wouldnt stand a chance anyway.

The only concern that I'd have would be your plans to do the long ocean passages where you could get caught out. Most cats have an aerodynamic (wing shape) mast and I have, in the past actually sailed the boat succesfully in very strong winds using just the mast as a sail. But then, it is possible to get winds where even a bare mast it too much sail.

Be carefull on this one - you could buy something that makes you feel very unsafe. Again, I know that the Firebird that I bought is a different animal BUT I became very frightened of it and I was very pleased to see it sold.
 
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Rick - I was repeating a claim by cat owners on another forum but yes it seems that that Solent one capsized - was it a racing cat or special one off. The statement mentioned production cat, so that would need to be established.

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It was an Iroquois, so think that meets your 'production' clause.

Rick
 
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The point is that you are talking about moving through the waves and I was talking about being still - zero velocity.

What I then said was simply that the kinetic energy would be halved if the mass was halved and therefore the energy and opportunity for damage would be lower (assuming the structure was strong enough).

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You did actually discuss the kinetic energy of travelling at different speeds and the reduction in kinetic energy due to mass improving interaction with the waves, but never mind.

Zero velocity results in zero kinetic energy, regardless of the mass. In this situation, reducing the mass will not affect the kinetic energy of the boat.

However, the wave still has kinetic energy, mostly in a vertical direction. It also provides an upward force due to buoyancy (potential energy). If the mass of the boat is lower, the vertical acceleration caused by a wave will be greater. What causes damage? Acceleration - especially to moveable masses within the boat, e.g. people.

Your cork analogy is valid, but the cork is a solid body with some ability to undergo elastic deformation and is unlikely to suffer damage.

There is also an intuitive aspect to this, which is what most contributors to this thread are applying.

Don't desert the forum. A good argument is, well, a good argument, and disagreements are what makes it interesting, even if some of the views expressed may seem unreasonable.
 
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There is also an intuitive aspect to this, which is what most contributors to this thread are applying.


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That is the problem. Too much intuition drawn on heavy monohull experience. I sail monos and cats but few people have weathered a storm on a modern cruising catamaran.

Watch Peter Blake video on Enza off Ushant after his round the world trip and I vow it would be enough to change anyones opinions. The weather shown in that video scared me s***less and led him to say how incredibly seaworthy this type of boat was.

Sir Peter Blakes opinion is good enough for me.
 
The majority of multi hulls have escape hatches and masthead flotation so the designers are obviously mindful of a good chance of inversion.....
 
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I've tried to find some pics to illustrate the concept.
All I could find was this YouTube clip
http://www.youtube.com/watch?v=GeT-8zEKpf4



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Its a shame the short clip stops short, you can see the crew opening the starboard side hatch where they keep the 4 hp outboard, once attached they are able to continue at 8.5 knots with a range of 2000nm, the rigging holds the boat nice and stable. /forums/images/graemlins/ooo.gif
 
Its actually quite easy to right a sports cat from total inversion.

You and the crew sit on the downwind rudder - the boat then skews sideways and lifts the opposite bow. Normally, the capsize will have been on a windy day so the wind then does the rest for you - it gets under the trampoline and pushes the boat until the top of the mast becomes level with the surface of the water. The crew can help by pulling on a righting line attached to the mast or better stil run from the mast under the windward hull and back to where they are sitting - on the downwind rudder.

Once the mast is level with the surface (normal non inverted capsize) the crew then spin the bows into the wind by walking along the inside of the lower hull and standing forward of the main beam. This puts drag on the bow of the hull thats in the water and so the rest of the boat falls to leeward.

Once in this position, the wind does the work again by getting under the mainsail - its very important that the helmsnan loosens off the mainsheet and traveller otherwise the boat simply wont right, Again the crew can assist by pulling on a righting line attached to the base of the mast and led over the upper hull.

The trick that experienced crew do is for one of them to crouch down and climb over the main beam as the boat comes up - the other crew continues to pull the upper hull until it crashes down on top of him - the great thing about having someone on the trampoline when the boat comes out of the water is that there is someone to stop the whole thing from flipping over and capsizing agian.

Its great fun to do but can be knackering - especially if the water is cold and your a fat git like me. One of the boats that I am in the process of selling is a single hander and thats even more of a challenge.
 
I estimate the mast weighs in at 6 kg, couldn't you just fasten half a dozen water buoys to the top of the mast /forums/images/graemlins/wink.gif
 
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As regards experience try reading Storm tactics or any modern book on the subject.

What I am stating about that is based on sailors experiences from all over the world - yet you just blast off in total ignorance throwing away the experience of those who have sailed around the world more times than you have had a cup of tea.



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I don't care if you read this or not, but you made the statement that breaking waves are not dangerous. That statement is misleading and frankly wrong!

It is dependent on the gradient of the wave and how and where it is formed. A 20ft wave on a wave length of 1000ft will have a gentle gradient and be more akin to a swell, but a 20ft wave with a 300 ft length will be much steeper and more dangerous. As we are in the main talking small boats here, the steeper the gradient the more dangerous the wave. There comes a point in terms of gradient where the wave becomes unstable and can no longer support it's own weight and the crest will start to break and fall to leeward. There are several factors that contribute to the steepening of the wave gradient. Here I quote Dag Pike, on of the foremost authorities on rough water small boat handling. He also recently competed in the Round Britain Race. In his book "Powerboats in Rough Seas" he states "as a breaking wave is probably the most dangerous type likely to be encountered by a small boat, it is worth considering in some detail"

I'm not going to quote verbatim, but lets just get one or two things in perspective. breaking waves, and lets call them white horses normally start to occurring in winds above F4. In open water I would agree that they are not particularly dangerous. However in shoal water waves break in a different way and it is this effect that can make the difference. Ahhhhhhhhhh bored now.
 
/forums/images/graemlins/laugh.gif

OK you've started me off

The orange Firebird (pic that I posted earlier in this thread) did more or less exactly that.
He had a inflatable bag at the top of the mast and AFAIK he is the only one to actuallr right a Firebird after a capsize.
He inflated his bag at the top of the mast and then by releasing the upper shroud (the one thats not in the water) and pulling on the lower shroud (he has all kinds of clever winches to do it) he was able to put the upper hull over the centre of ballance and the whole thing just righted itself.

Somewhere, I've got some video footage - I'll post it if I find it.

Origionally, he had a large buoyant disk attached to the top of the mast but one day he pitchpoled and it came off - just like a giant frisby.

I'm full of stories about cat sailing.

I'll try and shut up now - unless I find the video.
 
if you do find them I will be interested /forums/images/graemlins/smile.gif

I pass a firebird every week , it just looked like a rusting heap ( painted orange/brown).
Now I know what it is I will give her the respect she deserves. /forums/images/graemlins/cool.gif
 
Found it - bit of a struggle but I've managed to upload it onto YouTube

I dont have any editing software or skill to edit so unfortunately the clip is about 4.5 mins long and the stuff you wanted to see is in the last quarter of the clip.

At the begining you will see Orion (the orange one) and Phoenix. In this clip the boats are probably doing something between 20 to 30 knots - most of the time it would have been sub 20 knots though and keeping her in excess of 20 knots would require perfect conditions and a strong heart.

Two versions of the boat exist (Mk1 and Mk2). Phoenix was the last of the Mk1s and Orion was the second Mk2 built. There was a fire in the factory and all the moulds were destroyed - Phoenix was pulled out from the fire - hence her name and hence the need for two versions. All the boats were built at Gweek on the Helford River in Cornwall by Modular Mouldings and some still exist locally around Falmouth especially during Falmouth Sailing Week.

I owned Firebird II which was the first of the Mk2s - again hence the name - she makes a brief appearance in the clip about half way through.

Pete Goss in fact sailed one of these boats (Cornish Meadow) across the atlantic in a Transat Race. His book makes a very good read.

Orion was the boat fitted with the self righting equipment - the clip shows clearly how this is done. He even has a fabric ladder on the trampoline so that he can climb down from the upper hull. He fitted the whole righting system after competing in the Round the Isle of Wight Race and pitchpoled just after rounding the needles - he vowed that after that his ambition was to win the RTI even if he had a capsize on the way. IRYU rules insist that to continue racing a yacht must not have "outside assistance" so this was the system he came up with. The boat simply flies and in the years following he achieved his dream and won the RTI.

My boat (Firebird II) won the RTI as well a few years before and went on to win at the biggest Cat event in Europe (possibly the world) - The Round Texel race which attracts some 750 catamarans eacth year. I will just add that I didnt own or sail her during these prestigious events but I did compete a few times with her in the Isle of Wight RTI.

As I said earlier she frightened the ?hit out of me and I was very pleased to see her go. However she was part of a time of my life that I dont regret.

I hope you enjoy the clip.
Here
http://uk.youtube.com/watch?v=-FhEFCGdc0o

Mike
 
Great clip thanks.

righting was not at all what I expected, it looked very easy and so simple.

Hope Paul is still tunned in and saw that /forums/images/graemlins/smile.gif
 
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