Are "Performance Cruising Catamarans" safe?

[Lee Jerry]

Originally Posted by Factor

So a car that accelerates better, brakes better, handles better, is less safe than a car that is slower has comparatively crap brakes and all the dynamic behaviour of a wet sponge on a soapy floor?

Yes, they are less safe. Did you read the post? A Ferrari at the same speed as a “normal” car is just as safe (or safer). But the Ferrari is capable of more extreme performance – higher straight speeds, higher speed in corners, harder breaking – and when operated like that it is less safe. Sure, most of the time everything works out fine. But when things hit the fan the consequences are worse at higher speeds. If the breaks fail, is the expected outcome better starting from 65 mph or 105 mph? I consider that to be less safe, YMMV. So you could only drive the Ferrari around safely at the speed limit, but to paraphrase a popular saying, that is not what Ferraris are built for.

[Lee Jerry]

Originally Posted by smj

Basically what I stated in post #3, of course the performance cat would have much less stress on both the boats structure and the crew.

As much as I hate to start another one, I can't let this go. Even if it is just a detail.

But this is probably not true (possible, but probably not). The LOADS are lower or less, but the structure is also built lighter (isn't that part of the point), so the STRESS is going to be SIMILAR (no, not the same). Otherwise, the structure is over built. Of course it gets more complicated with different materials (and no, 20 kt is probably not the/a design point), but you get the idea. Hopefully without another debate.

I'm not going to comment on the crew's stress.

[Lee Jerry]

Originally Posted by fxykty

Yes, you’re wrong about a large number of things, including that the Danson cats weren’t performance oriented. They absolutely are - arguably more so than the modern Outremers.

If we’re double reefed at 20 knots and a staysail (equivalent to 2/3 of our full self tacking jib) then according to our reefing plan we’re good to 45 knots. So a 30 knot puff will be fine. One of the benefits of a lighter weight performance cat is that it accelerates quickly, reducing the force of a strong gust. Reaching or downwind the boat squirts away and AWS rise is minor. Upwind, she accelerates, which brings the AWA forward and feathers the sails. No worries either way.

But at 35 knots TWS point we’ll have a triple reefed main and a storm jib, and at 50 knots TWS just one or the other. And we’ll still be sailing along just fine.

We recently got hit by a 50 knot TWS squall while sailing upwind in 15 knots TWS. We had a single reef mainsail and full jib. For the 20 minutes that the squall lasted (thunderstorm cell that we had thought we’d avoided according to radar, so we also had lightning all around) we feathered at a 20* AWA and kept the sails half inside out but not flogging. Boat speed was 8-10 knots and the windward hull wasn’t anywhere close to lifting. Admittedly, it would have been a whole lot more exciting had we been reaching at the time - the turn downwind would have kept us upright and the 20+ knots boat speed would have kept the AWS manageable for the sail area.

How would a heavier, slower, more powerful cat have reacted in either of this situations? Who knows, but if the rig didn’t give way then the much larger forces acting on that weight of boat could certainly capsize it. There’s huge surface area to those high hulls and vertical cabin sides, so that kind of boat cannot sail itself out of trouble. The performance cat can. That is safer! And I do mean staying upright and with the ability to keep sailing.

jfc.

I never said they weren’t performance. Obviously they are compared to many (lagoons, etc.) But I did question if they (older ones) are the same category as today’s “performance cruising catamarans” (and said in my opinion that they are not). But I don’t know where they fall because I still haven’t gotten any response on what that delineation might be. Even looking at the current lineup of Outremers, are the 45 and 50 series boats the regular cruising cats and the 4x and 5x the performance cruising cats?

Should I point out where you contradict yourself - double reef and staysail in 20 kt and then good to 45 kt; but in 35 kt it’s triple reef and storm jib? No, I won’t do that.

When you were hit by the 50 kt squall, was there a person on the helm or under autopilot? Or did a person grab the helm from the pilot as the first gust hit?

Note I never said they were unsafe or dangerous. Just less safe. By at least one measure. Arguably the most important measure. Let me try this: performance cruising cats are more tender, and therefore more prone to capsize if not handled with care. Is that any better?


Do you agree that there have been “several” incidents of performance cruising cats flipping recently? (I can think of three right off the top of my head, like the O45 or 4x last summer, I’m sure there are more.)
Do you see that happening at the same rate (either per boat sailing or miles sailed) in the heavier cruising cats?

[smj]

Originally Posted by Lee Jerry

As much as I hate to start another one, I can't let this go. Even if it is just a detail.



But this is probably not true (possible, but probably not). The LOADS are lower or less, but the structure is also built lighter (isn't that part of the point), so the STRESS is going to be SIMILAR (no, not the same). Otherwise, the structure is over built. Of course it gets more complicated with different materials (and no, 20 kt is probably not the/a design point), but you get the idea. Hopefully without another debate.



I'm not going to comment on the crew's stress.

Just because a performance catamaran is lighter doesn’t mean it’s weaker. There’s a reason they’re way more expensive per pound.
Also the lighter weight cat sails on top of the water rather than through the water which greatly reduces stress.

[Lee Jerry]

Originally Posted by Chotu

You really DON'T get it.

I don’t understand how you can almost have a grasp of science here, but at the same time not understand basic principles of logic and children’s mathematics.

In your post, again, you are only looking at half of your momentum equation. If you throw the person against a brick wall, and then you throw the person against a brick wall again at a different speed you are forgetting half of the equation. (Again)

We are talking about things that have different mass here. You cannot discount the mass or the velocity when you are calculating momentum. I calculated it all out for you. I’m sure you can understand it if you look back.


And if you’re using doctored light ship for your boat, trying to finesse these numbers as you are, when I am counting mine for laden with all fuel and water and all of my stuff and food inside? Sure. Will use your doctored numbers. No problem. Even if we do your boat still has twice as much momentum when it hits something as mine does. And that means for the same momentum, you can hit something at 8kn and I can hit something at 16 kn. And it’s the same momentum. And I doubt you have two watertight bulkheads forward and a sacrificial bow. And I doubt yours is made out of material that can absorb impact.

Why don’t you go back and review the math in my post? You didn’t even answer any of that because it’s airtight. For some reason you are trying to apply science but you are not applying science. You are only applying half of the equation. You need to get a little more understanding of this most simple equation. It has 2 parts. Mass and velocity.

A boat most definitely does not mean the same boat. Because you are trying to compare performance Catamarans which weigh nothing and are made out of different materials with heavy fiberglass boats. So it’s apples and oranges. They are different. And you don’t understand anything about the differences. I mean look. There is an entire thread here saying you are wrong. All over this entire thread. Not a soul agrees with you. And you don’t even own a catamaran. Did you ever stop to think you are wrong? That you don’t have any idea what you are talking about? Because you don’t.

Further, if you ever had anything to do with science and mathematics , you are giving it a bad name. Because you are trying to twist it to support faulty assumptions that you have made.

You are doctoring the mass of the boats, you are continually ignoring one of the terms in the equation for momentum. And worst of all you just skipped over everything I put in about momentum. Because you don’t want to face the facts that the math SHOWS your assumptions are wrong.

All the facts are there. My post stands. You can’t refute the actual numbers with your wishy washy bs

Dude, I DO get it just fine. I gave you the momentum equation. Just because I didn’t reply to every new edit of your post or repeat mass this and mass that in every other sentence...sheesh.

So skipping a bunch of stuff...

I tried giving you a hint, but apparently you had too much momentum to see it or grasp it as it flew over your head, so let me briefly explain. Here’s what you don’t get: if you want to talk about collisions, then momentum is the wrong parameter. I don't believe I ever calculated momentum in this thread, you did, so I can't really be accused of (at least not fairly) leaving half the equation out. So your hull, the one that is built to absorb momentum, doesn’t have to absorb any momentum at all; it has to absorb KINETIC ENERGY. And KE is also a function of both mass and velocity, but there’s a wrinkle: there’s a squared term in there. Spoiler alert, it’s not on the mass. So my monohull of twice your mass (2m) at a given velocity (V) has HALF OF THE KE as your catamaran with lower mass (m) and twice the velocity (2V). I’ll let you find the equation and work out the math and show the class. So process them apples (or oranges) and I'm sure you'll then tell me where I'm wrong.

What I DON’T get is why we are talking about collisions of cat vs mono in this thread.

Originally Posted by Chotu

OK. Too forceful. Lol posting from the helm. I should stop doing that. It’s just so mind numbingly boring in the intercoastal out here. I have done this run way too many times.

My apologies to everyone for being a little bit forceful.

The ICW, huh? Where you headed to and from?

[Lee Jerry]

Originally Posted by smj

Just because a performance catamaran is lighter doesn’t mean it’s weaker. There’s a reason they’re way more expensive per pound.
Also the lighter weight cat sails on top of the water rather than through the water which greatly reduces stress.

You generally design TO A STRESS LEVEL, some percentage of the yield stress - pick material(s), pick your factor of safety - presto, there's your design stress. Then pick design load(s) - presto, out comes the required material thickness. It's a pretty basic process (although grossly simplified here). So yeah, for same material lower load gives less material. It's weaker in an 'ultimate' sense (it can support less load), but it's the same strength in a relative sense (the material acts the same - same stress) because it doesn't need to support that higher load.

Differing materials complicates the comparison, but the process is the same - you still design to a stress (probably different since the material's strength is different).

[chrisr]

btw, talking about the benefit of performance cats : i know of an outremer 50 which recently did Galápagos to Marquesas in 13 days

most (including condo-cats) take 25-30 days

it's arguable that a shorter time at sea equals increased safety.

"but..." i hear you say "it's the journey, not the destination...why hurry ?". well, it's easy to reduce sail and slow down if that is what you want.

on the other hand, it's hard and dangerous to try to push a slow boat too much

another thought is that it is not just lightness that makes a performance cat. look at hull beam...our hulls are literally half the beam of similar size condo-cat. sure we cannot carry the weight these boats do, but we carry enough...and with a lot less boat to push through the water.

cheers,

[Factor]

Originally Posted by Lee Jerry

Yes, they are less safe. Did you read the post? A Ferrari at the same speed as a “normal” car is just as safe (or safer). But the Ferrari is capable of more extreme performance – higher straight speeds, higher speed in corners, harder breaking – and when operated like that it is less safe. Sure, most of the time everything works out fine. But when things hit the fan the consequences are worse at higher speeds. If the breaks fail, is the expected outcome better starting from 65 mph or 105 mph? I consider that to be less safe, YMMV. So you could only drive the Ferrari around safely at the speed limit, but to paraphrase a popular saying, that is not what Ferraris are built for.

OK Mate, you win, I cant argue with that logic. (that is sarcasm BTW- just to be clear). I also note from some of your posts that The old "heavier is stronger" school of thought still persists in many minds. You may have missed the development of concepts like monocoque construction a few decades back.

[boatman61]

Originally Posted by Lee Jerry

Yes, they are less safe. Did you read the post? A Ferrari at the same speed as a “normal” car is just as safe (or safer). But the Ferrari is capable of more extreme performance – higher straight speeds, higher speed in corners, harder breaking – and when operated like that it is less safe. Sure, most of the time everything works out fine. But when things hit the fan the consequences are worse at higher speeds. If the breaks fail, is the expected outcome better starting from 65 mph or 105 mph? I consider that to be less safe, YMMV. So you could only drive the Ferrari around safely at the speed limit, but to paraphrase a popular saying, that is not what Ferraris are built for.

Plus they consistently bottom out on speed bumps..

[Franziska]

Originally Posted by Lee Jerry

Yup, I said crew was an important factor up-thread. Thanks for agreeing with me.

Ha, it's more the other way around, thanks for agreeing with me.
Read the first reply in the thread [emoji846]

[fxykty]

Originally Posted by Lee Jerry

jfc.



I never said they weren’t performance. Obviously they are compared to many (lagoons, etc.) But I did question if they (older ones) are the same category as today’s “performance cruising catamarans” (and said in my opinion that they are not). But I don’t know where they fall because I still haven’t gotten any response on what that delineation might be. Even looking at the current lineup of Outremers, are the 45 and 50 series boats the regular cruising cats and the 4x and 5x the performance cruising cats?



Should I point out where you contradict yourself - double reef and staysail in 20 kt and then good to 45 kt; but in 35 kt it’s triple reef and storm jib? No, I won’t do that.



When you were hit by the 50 kt squall, was there a person on the helm or under autopilot? Or did a person grab the helm from the pilot as the first gust hit?



Note I never said they were unsafe or dangerous. Just less safe. By at least one measure. Arguably the most important measure. Let me try this: performance cruising cats are more tender, and therefore more prone to capsize if not handled with care. Is that any better?





Do you agree that there have been “several” incidents of performance cruising cats flipping recently? (I can think of three right off the top of my head, like the O45 or 4x last summer, I’m sure there are more.)

Do you see that happening at the same rate (either per boat sailing or miles sailed) in the heavier cruising cats?

Yes, I do agree that a performance cat that is being pressed for maximum speed with more sail area up can be more vulnerable. It is about how they are handled. The same as going fast in the Ferrari is not suitable for a casual driver.

But the point the experienced cat sailors are trying to make to you is that a performance cat does not need all that sail area to keep sailing well. So in most cases, a conservatively sailed performance cat will have a lower sail area to displacement ratio than a typical cruising cat. Less force!

There was one O45 flipped by a squall due to operator inexperience. There were 2 Atlantic 55s capsized quite a few years ago now, one during a waterspout and one during a squall - one was an operator error and the other ???. And several other Gunboat and other cats that were racing, which don’t apply to this discussion.

That is basically the soft line between performance cruising and accommodation-oriented cats - the ability to sail at low wind levels and to sail in all wind conditions in any direction. Other than sail area to displacement we can use specified engine size and fuel capacity - performance cats will have much smaller engines and less fuel capacity. I don’t think you would separate out any of the Outremer line up, especially as compared with Lagoon or others like that. And my point is that the older Outremers are more performance oriented than most of the current designs.

No contradiction in my sail plan vs reefing plan. The point I made with our double reefed main and staysail is that while we can happily sail with that rig in 20 knots, our reefing plan says that rig is appropriate up to 45 knots AWS. However, by the time we usually see 35 knots we’ll have already reefed down to triple reef and storm jib, which is good up to 55 knots.

When the squall hit we were manually helming and handling the sheets. Because that’s SOP when in the area of a thunderstorm. Which we keep aware of using sight and radar and any available weather reporting.

[AKA-None]

Originally Posted by Factor

So a car that accelerates better, brakes better, handles better, is less safe than a car that is slower has comparatively crap brakes and all the dynamic behaviour of a wet sponge on a soapy floor?

It might be when you turn off the traction and stability controls

[chrisr]

Originally Posted by AKA-None

It might be when you turn off the traction and stability controls

or exceed the driver's ability

cheers,

[Lee Jerry]

Originally Posted by Factor

OK Mate, you win, I cant argue with that logic. (that is sarcasm BTW- just to be clear).

I know anecdote does not equal data, but here you go with three examples:

Crash of Two Speeding Ferraris Ends in Flames
Ferrari splits in half, kills one in California crash
2 die when Ferrari crashes head-on in car in Pinellas Park, police say

All happened in the last year. I stopped at three, the 3 of the first 4 hits (the fourth was a repeat).

I also note from some of your posts that The old "heavier is stronger" school of thought still persists in many minds. You may have missed the development of concepts like monocoque construction a few decades back.

Where specifically did I say that?

[Lee Jerry]

Originally Posted by fxykty

Yes, I do agree that a performance cat that is being pressed for maximum speed with more sail area up can be more vulnerable. It is about how they are handled. The same as going fast in the Ferrari is not suitable for a casual driver.

But the point the experienced cat sailors are trying to make to you is that a performance cat does not need all that sail area to keep sailing well. So in most cases, a conservatively sailed performance cat will have a lower sail area to displacement ratio than a typical cruising cat. Less force!

There was one O45 flipped by a squall due to operator inexperience. There were 2 Atlantic 55s capsized quite a few years ago now, one during a waterspout and one during a squall - one was an operator error and the other ???. And several other Gunboat and other cats that were racing, which don’t apply to this discussion.

That is basically the soft line between performance cruising and accommodation-oriented cats - the ability to sail at low wind levels and to sail in all wind conditions in any direction. Other than sail area to displacement we can use specified engine size and fuel capacity - performance cats will have much smaller engines and less fuel capacity. I don’t think you would separate out any of the Outremer line up, especially as compared with Lagoon or others like that. And my point is that the older Outremers are more performance oriented than most of the current designs.

No contradiction in my sail plan vs reefing plan. The point I made with our double reefed main and staysail is that while we can happily sail with that rig in 20 knots, our reefing plan says that rig is appropriate up to 45 knots AWS. However, by the time we usually see 35 knots we’ll have already reefed down to triple reef and storm jib, which is good up to 55 knots.

When the squall hit we were manually helming and handling the sheets. Because that’s SOP when in the area of a thunderstorm. Which we keep aware of using sight and radar and any available weather reporting.

This is assume! I agree with 99% of it. A couple follow-ups, if you care...

Your first paragraph is exactly what I'm talking about w.r.t. a cruising boat and a performance cat being less safe. Are you familiar with the many quotes that say something like 'a cruising boat should take care of the crew?' The performance cat seems to be the opposite of that. If that's your choice, that's great.

Re: Gunboats - (a) except that they market them as cruisers; (b) they were being sailed by experts and crashed anyway; (c) wasn't one of them a photo shoot?

Many cruisers, including me, leave the steering to the pilot or vane "all" of the time. My typical reaction to a squall as it hits (if unexpected) is to trim one sail, tweak pilot/vane (if necessary), trim other sail (headsail first upwind, main first downwind). This is possible by one crew member because the boat is not in danger of being capsized at any moment even though over-powered. I consider this safer. But again, you (cumulative, all of you cat sailors) do you.

Cheers,