Gludy - the Raggie

[hobiecat]

Making a general seaworthiness comparison between a cat and a mono is very difficult. Comparing a Broadblue ocean going catamaran with a small Bayliner obviously favours the catamaran.

A Nordhaven in my opinion is a seriously good sea boat. There are also equally good cruising catamarans a fraction of the weight. However, in my experience, I think a quality catamaran is more seaworthy.

My reasoning is that the greater stability of a catamaran provides relatively more comfort. Usually crew give up well before the boat in survival conditons. Therefore, in relatively more comfort the skipper is likely to be able to cope longer and take some of the actions described (sea anchors etc) to make the boat as safe as possible in survival situations.

.

 

[Gludy]

Victor
Just compare the NordHavn - a ni boat from good people with a Modern good sailing cat.

Nordhavn uses fuel at greater than 1 mpg and cruises at about 7.5 to 9 knots - the cat is faster under power and uses about 1/8th of the fuel.

Nordhavn rolls a lot at sea but cn be stablised using power - the cat is basically stable without that roll.

Nordhavn and cat can both be protected by sea anchors.

In the case of a broach the Nordhavn sinks the cat floats upside down.

The Nordhavn cost about 2.5 to 3 times the cat.

The Nordhavn has a much lower range than the cat.

So why should I buy a Nordhavn to travel more slowly, at much greater cost, with less safety?

I have nothing against Nordhavns as they are very good boats.

 

[JKay]

South Africa also made "Wildcats" Here Be careful
The idea of a big cat really appeals,We chartered one for a few days in Mauritias and it was awesome

cheers Joe

 

[Searush]

Sorry Gludy, I was trying to inform & encourage discussion. I hadn't realised that your mind was so closed. I will not try to help again, you clearly do not want to listen. Perhaps your wallet is blocking your ears.
/forums/images/graemlins/tongue.gif /forums/images/graemlins/grin.gif

 

[timgriffin]

Used to have a little Hirrondelle Cat loved it to bits, great fun and fast , only down side to cruising cats is too much cruising kit kills the speed but if that is not an issue then go for it .There is an amazing 50 footer in East Cowes Marina looks fantastic and would love to have a nose around her and even try and blag a ride.
Good luck with it all look forward to reading all about your adventures.
Cheers Tim

 

[jimg]

I have to agree, I know nothing about sailing cats, but what could have been an interesting discussion, has turned into the usual lecture of my view is the only one of any value.
As they say on Dragon's Den........ I am out!
/forums/images/graemlins/laugh.gif

 

[Gludy]

Searush
I was not trying to offend and I apologise if I did.
I am simply trying to discuss the issues and thought that I had properly answered the points you raised.

My mins is not closed and I do not even know what you disagree on?

 

[Gludy]

jmj
In my view its not a lecture but a discussion of the issues and facts. If that offends then I cannot help it, I am not taking it personally nor do I expect other to do so.

I actually bought the proper para drogue for my powerboats and I really think that any cruising boat of almost any type would gain from having at least a proper drogue on board.

There are a number of issues to discuss and I still do not have a clue where any disagreement is!!!!

My mind is far from closed, I am willing to discuss any issues openly and learn from them.

The examples to date with people surviving in a a multi-hull have only reinforced the points I am making so where is the disagreement?

The way I am trying to present the sea maybe be a bit of a jolt to some people - it was for me to understand it fully, so it is no surprise that it jars others but that is what should make for a good discussion.

Really all I am saying is that cats are very safe - ask the insurance companies because they often give cheaper insurance than a mono hull or at least never more.

I am also saying that weight is not always the best defence against the sea - often the best defence is to heave to and wait out the storm - that has been done for thousands of years but when I say it for some strange reason it seems to offend.

I am saying that over the last few decades major strides in drogues and parachute anchors have been made and anyone traveling offshore should consider buying one and learning how to use it.

Where are the issues? How can defending that stance offend? I am amazed!!

 

[Gludy]

For anyone out there worried about the safety of a sailing cat and I know there are a few of you considering this option hre is a claim made by others with access to the facts.

Not one production cat is on record has ever being capsized by its owner!!!!

yes racing cats sailed to their limits.

Yes home made special cats.

Yes delivery crews sailing to a time table and being stupid.

But not one production cat sailed by its owners...

That is amazing.

 

[MapisM]

Oh, dear.
I wish I wouldn't have thrown in what was actually, re-reading it now, a rather obvious and pointless statement.
I compared the options you're now considering with some alternatives I had in mind (and actually considered) for an ocean crossing vessel.
But of course those choices are, if I can steal a famous motto, oceans apart.
Oceans apart under many respects, cost being one of the most relevant (both for purchasing and running the boats I was unproperly daring to compare).
So, in a nutshell, I could just say forget what I said.

But there are some comments which sure raised my eyebrows.

1) You told that Victor was right when he said If modern kevlar is stronger and a fraction of the weight why would you still prefer the weaker boat. Pounding into a heavy sea battleship style in a weaker boat or cutting through the sea like Ellen Macarther in a stronger boat.
Now, bearing in mind what I just admitted re. my comparison being unfair in the first place, are you and Victor really convinced that a boat which I generally defined as an 80 tons self-righting steel trawler is weaker than Ellen Macarther racing boats, or than a 6 tons Fastcat 455?!? /forums/images/graemlins/shocked.gif

2) I accept that a capsized cat can float while most other boats don't. But then again, my (biased) comparison was with a self-righting boat. Which clearly implies (though admittedly I didn't mention it) designed to survive capsizing with no structural damages.
So, when you asked me if I prefer to be in a very stable upside down hull designed for just that or ... floating in your life jacket, well, with apologies for using the same irony, I'd reply that my preference goes for being in a very stable vessel which just survived a capsized and returned to cruise safely with neither power interruption nor structural damages, strapped in a seat with belts and shoulder harnesses.
And having a nice lunch as soon as the storm is over. /forums/images/graemlins/wink.gif

3) In a following post, you said that had the Titanic been made out of the same materials as a modern cat it would still be floating.
Now, that's exactly one of the classic examples where only a steel hull could have had a chance to stay afloat, if properly built.
So, I can only guess/hope that you said this with your tongue firmly in cheek... /forums/images/graemlins/confused.gif

Best of luck for your project anyway.
Having the guts to seriously think about it is something which deserves utmost respect, already as such, and regardless of the type of boat.

 

[hobiecat]

Gludy - the arguments for cats are incredibly persuasive for long distance passagemaking boats. Why are there not more around? No idea - but give it time.

 

[rickp]

[ QUOTE ]
But not one production cat sailed by its owners...

That is amazing.

[/ QUOTE ]

What about this one then?

Rick

 

[thefatlady]

Gludy,

My earlier comment was too brief. I didn’t have time. Even now, I am not going to get into a protracted discussion, but your simplistic comments on kinetic energy and the consequent benefits of keeping the mass down do not bear scrutiny. This is nothing to do with single or multi-hulls.

Kinetic energy is as you say. However, it is a minor part of the analysis. If you were running into a rigid object of infinite mass (a “brick wall”) it would be all important.

A wave gives, the boat is designed to cut through it and the mass of the boat (inertia) relative to the inertia of the water moved out of the way is very important. Conservation of momentum is relevant. For a given wave, the greater the mass of the boat, the greater the momentum retained by the boat and the less you will feel it. Hence my QE2 comment. In the extreme, reducing the mass of the boat to zero would result in the boat being totally at the mercy of the waves.

As a C.Eng, you don't need me to expand on this. You should apply Bernoulli and consider what happens to the kinetic energy of the boat/wave system when a wave is struck.

What your Link 1 said was that, all other things being equal and ignoring mass, then reducing the kinetic energy of a given boat helps (although I wish he had used proportionality instead of an equation).

All this raises the question of what is the optimum mass for a given situation. That could open a whole new can of worms. Everything is a compromise.

John

 

[hobiecat]

I have heard of production cats capsize so I am not sure this is correct. There was a Catalac upside down on the beach in a Yachting magazine many years ago. The surprising thing about this capsize was there were a couple of huge keels sticking out of each hull which the owner had added. Not surprisingly when on the wind the boat fell over.

I believe Fountaine Pajot have had capsizes on their smaller boats. I vaguely remember one was on charter off Channel Isles in force 10 with full sail and it pitchpoled. I think there were fatailities on that one. There is usually much less longitudinal stability than lateral stability. Risk of capsize is therefore greater on a run with too much sail up - burying the nose in a wave in front and pitchpoling. Pretty idiotic thing to do and far too scary for sensible people to attempt. A good chance that the rig will come down before that point is reached. Cruising cats wont carry enough sail to pitchpole.

As a rough guide I remember using boat length overall compared to mast height to decide if I was looking at a cruiser or a racer. A ratio of 1.2 was a very much cruising and a ratio of 1.6 was cruiser/racer. The one in the picture looks like a racer to me. It is perfectly safe to go around the world in a cruiser/racer provided you sail the boat within its limitations. Compare it to driving a ferrari full speed down a country lane - accidents are bound to happen if you are idiotic enough, but it is nice to have some power available when the winds are light.

 

[Searush]

[ QUOTE ]

What about this one then?

Rick

[/ QUOTE ]
That's interesting, a WAVE lifted the weather hull in a shallow water area. It then appears that the cat flipped. Now, the wind pressure on the rig decreases as the weather hull lifts, but the lift caused by wind under the deck increases. This is exactly what I was trying to tell Gludy earlier when he didn't seem to want to listen.

I have sailed cats - I love sailing them flying a hull, it is fast & exciting - but releasing the mainsheet doesn't always bring 'em back down again. I never actually capsized mine, but I did get close a few times!


I'm not saying they are no good, or that they are not as good as monohulls or whatever. 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.

Gludy, your posts imply that you genuinely believe you are right & everyone else is wrong. That MAY be true, or it may be the road to hell. I know which you believe, I sincerely hope you are not dissillusioned again.

 

[ChartScrubba]

[ QUOTE ]

In a storm we talk about the waves pounding us and the danger of a breaking waves - really that is wrong.

Its more like we pound the waves because we are heading into them. The water in a breakibng wave is a lot of froth and not to dangerous the real danger is hitting the bottom of the wave in front or going on broadside so it can broach you.

[/ QUOTE ]

Oh the joy of theory!

[ QUOTE ]
The lighter the boat the lower this energy a Fast Cat would have about half the weight and hence half the energy of a normal cat.

[/ QUOTE ]

Hmmmmmmmm, wonder if Pete Goss' designer had the same thought?

[ QUOTE ]
So the good news is that you can anchor your boat anywhere out there in the ocean

[/ QUOTE ]

4 times depth with chain, 6 times with warp and chain - interesting concept!

Jesus you talk, sorry type bollox!

Maybe time spent reading Dag Pike may intrigue you.

So now you have pissed off the powerboat designers you are telling us all what clever things cats are. I suspect that the boating world has been alerted to you by now and will be very wary.

This will all end in tears - again!!!

 

[Hurricane]

[ QUOTE ]
but releasing the mainsheet doesn't always bring 'em back down again

[/ QUOTE ]

This is actually a very big problem.
Think of this scenario.
Cat going downwind - wind behind - running.
Under normal circumstances you wouldnt have the wind further aft than the beam - no point.
But in a blow it always seems safer to let the wind come aft.
The boat can then be going at about the same speed as the wind so it feels safer.
Now a gust hits.
This causes the apparent direction of the wind to go further aft.
The leech of the sail (aft edge) now becomes the leading edge to the wind.
So letting the sheet out only presents MORE sail to the wind and you will be in danger of pushing the bows in thus slowing the boat - the rig still wants to go fast so the sterns will rise and the boat starts to go "head over heels" - clasic formula fo a pitch pole. Most capsizes in cats result from this scenario. A full head on pitch pole doesnt happen every time but a form of cart wheel rotatong round one hull will also cause a capsize.

The solution is a brave one.

PULL in the mainsheet and BEAR away (steer more downwind).

Everything that conventional mono sailing and instinct tells you not to do.

What happens then is that the boat actually speeds up and you maintain the apparent wind angles.

So the golden rule again
On the gusts pull in the mainsheet and bear away.
Keep this up until you can go no further (the boat is on the edge of jybing)
A Jybe at this stage would be fatal and you cant head up any further - now is the time to say your prayers.

I have heard this referred to as "Coffin Corner"

I've been there a few times - its scary.

 

[Gludy]

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.

 

[Gludy]

The fatlady
Thank you for a food contribution to the discussion.

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).

Then I stated something which I have not yet myself resolved in my head.

A low mass, light item like a cork from a bottle will survive a savage storm untouched. But it will be thrown all over the place because it has very low inertia. I therefore think that a heavier boat of the same size may be more comfortable because of its higher intertia - I have asked this question of many cat experts but have yet to have an answer.

[ QUOTE ]
A wave gives, the boat is designed to cut through it and the mass of the boat (inertia) relative to the inertia of the water moved out of the way is very important. Conservation of momentum is relevant. For a given wave, the greater the mass of the boat, the greater the momentum retained by the boat and the less you will feel it. Hence my QE2 comment. In the extreme, reducing the mass of the boat to zero would result in the boat being totally at the mercy of the waves.

[/ QUOTE ]

Nothing I have stated disagrees with that analysis - you are talking about a boat moving through the waves - I am talking about a boat holding its position, going up and down and not cutting through the waves.
[ QUOTE ]
ll this raises the question of what is the optimum mass for a given situation. That could open a whole new can of worms. Everything is a compromise.

[/ QUOTE ]

I totally agree again - there must be an optimum mass even for the still boat as there is the up and down movement of the wave to deal with rather than the cutting through of the wave.

If you read the links I gave or read most of the storm tactics books you will see what I am getting at.

 

[Gludy]

Victor - we are talking about unmodified production cats - I understand the person who made this claim knows of delivery skippers doing it as well as racing cats. You have to go to extremes to fo it like having a full sail up in an f10. /forums/images/graemlins/smile.gif