Anti-Capsize Devices

[s/v Jedi]

Originally Posted by niel12

Guy's, perhaps we should considder a cruising catamaran section and a racing catamaran section.

Most of the cruising crowd can pickup useful tips from the racing guys so it might be helpf ull in another way?

We have a Chris White Atlantic 57 with cruisers aboard right here in the marina. Owner is member here too. All cat owners get better with this knowledge; much better than the old "only racers flip" saying. The bounderies between racers and cruisers are fading. A modern cruiser was considered racer 20 years ago.

cheers,
Nick.

[thinwater]

Originally Posted by beiland

I have however had occassion to use a releasing cam cleat. there was a German company that produced one that I placed on the 'kick-up' centerboard lines onboard a Louisiane 37' catamaran I imported from France, and on the Firefly trimarans I was involved with.

Basically this releasing cam cleat was mounted on a plate that was allowed to pivot forward in a manner that allowed the sheet line to escape from the top between the cam cleats. The control of that mounting plates 'rotation release' was by a spring loaded detent pin that was adjustable by a micrometer type screw knob. They worked very well.
Pfeiffer adjustable tension cam cleat - Boat Design Net Gallery

It appears as though the UpSideUp system is making use of this similar arrangement with harkem cam cleats mounted on various plates and/or arms of a certain length.

My question though is are these cam cleats really capably of carrying the sheet loads of these BIG multihulls??

a. Yes. It would only need to hold the tail on the winch; reduce the number of turns and the load on the tail is proportional to the total load.

b. Where are these sold? Couldn't find them.

[thinwater]

Originally Posted by Joli

Information is now starting to come out.

Joyon was on deck sailing with an ORC storm jib and tripple reefed main in 10 to 30 knots, squally conditions. When the gust hit he dumped the mainsheet and then the traveler. At that point he fell out of the cockpit but was able to grab the netting while the boat capsized on top of him. He crawled under water for 40 seconds in a random direction till he found the ama and came up. It sounds like he was pretty shook, who wouldn't be, and is lucky to be alive.

How much breeze does it take to flip a 100 foot tri flying a storm jib? 60, 70 80 knots..... How quickly did it hit? 5 seconds, 10 seconds, 15 seconds..........

Was this a pitch pole or a capsize? Was the boat close hauled or broad reaching? Unless close hauled, releasing the mainsheets is often ineffective (jib release still helps). If the bow had buried, it was already too late.

Would action based upon the windspeed make more sense?

[thinwater]

Originally Posted by thinwater

Was this a pitch pole or a capsize? Was the boat close hauled or broad reaching? Unless close hauled, releasing the mainsheets is often ineffective (jib release still helps). If the bow had buried, it was already too late.

Would action based upon the windspeed make more sense?

What information does the unit have? Heel? Yaw angle?

If I gave you the tail of the rope, sat you blindfolded in the cabin, and gave you responsibility for sheet release, how would you do? Terrible. It would be frightening for all on board.

You would want to know:
* wind relative course
* wind speed second-by second
* sea state
* sails set
* trim (are they tight or loose?)
* heel
* pitch angle
* rate of change of heel, pitch, and yaw
* prior expereince on the boat
* a view of the lee bow
* is the helmsman going to head up or bear off?
With less information, I don't want you holding the tail. You could actually make things worse.

I don't think we can call any system "state-of-art" until it can make the same predictions (watch for rising spray to windward) and apply the same adjustments a sailor would (including steering). A sailor would have looked at the squalls and recognized that there could be gusts he could not react to quickly enough.

[beiland]

Originally Posted by thinwater

a. Yes. It would only need to hold the tail on the winch; reduce the number of turns and the load on the tail is proportional to the total load.

b. Where are these sold? Couldn't find them.

Not avaliable for a long time now, but note that the UpSieUp system is utilizing Harken cam cleats on their own pivoting mechanisum.

Can we find some more photos of those installations?

[s/v Jedi]

Originally Posted by thinwater

What information does the unit have? Heel? Yaw angle?

* heel
* pitch angle
* rate of change of heel, pitch, and yaw

A single Airmar heading sensor provides:

10 times a second heading
10 times a second heel
10 times a second pitch
2 times a second rotation

any device listening to that can calculate rate of change of heel and pitch and calculate yaw too.

So it is not a big problem to get that information, other than a $700 price tag.

cheers,
Nick.

[thinwater]

Originally Posted by s/v Jedi

A single Airmar heading sensor provides:

10 times a second heading
10 times a second heel
10 times a second pitch
2 times a second rotation

any device listening to that can calculate rate of change of heel and pitch and calculate yaw too.

So it is not a big problem to get that information, other than a $700 price tag.

cheers,
Nick.

Yes. I should have read more re. specific system. It certainly has many tools.

But, still, mostly information a blind man would have. No or limited knowledge of:

* sail selection.
* trim (are they tight or loose?).
* prior expereince on the boat (could learn, within the limits of the information it does not have).
* a view of the lee bow. Angle isn't everything.
* is the helmsman going to head up or bear off?
* a veiw of the sky; is a downburst probable?
* a view of the sea to windward; is spray blowing off a gust?

What I did not get from the OP was a sense of whether any combination of actions could have helped. Perhaps not.

And there is a matter of programming. Setting it up for a specific boat in storm conditions would take time. Some of the above items could be solved by sailor input, but would that happen?

I think it's a great idea. But like air bags and helmets, we should understand there are limits, and look in the mirror when we capsize. I pitchpoled smaller cats many times; I could never blame the cat, only my misunderstanding of her limits or an excessive risk taken off the wind.

[wolfenzee]

servos and sensors will never replace the judgement and reaction of an experienced sailor in adverse conditions...add to that the inherent unreliability of electricity/electronics in the marine environment and trusting your life to yet another gizmo just invites disaster.

[four winds]

I would assume that the use of such a device does not prevent the skipper from using his skills and techniques as well.

So I don't think it's a step in the wrong direction to consider this additional technique.

[wolfenzee]

techie gizmos make great tools, the problem occurs when people rely on them too heavily.
k
,

[s/v Jedi]

Originally Posted by wolfenzee

servos and sensors will never replace the judgement and reaction of an experienced sailor in adverse conditions...add to that the inherent unreliability of electricity/electronics in the marine environment and trusting your life to yet another gizmo just invites disaster.

ciao!
Nick.

[niel12]

Wow........ A aeroplane cockpit on multihull ........... I guess sailing's better!

[beiland]

Great reply there Nick

I believe that is what we might get if we let the computer wiz kids of today design our anti-capsize device.

We need to try and stay with the KISS principle...

...some sort of simple pendulum and or gyro should be fully capable of determining excessive roll attitude

...and those releasing cam cleats that just pivot forward should be pretty reliable as well.

This system won't cost much, so there is less incentive to 'produce and market' such a system.

[beiland]

Originally Posted by four winds

I would assume that the use of such a device does not prevent the skipper from using his skills and techniques as well.

So I don't think it's a step in the wrong direction to consider this additional technique.

EXACTLY....a BACKUP system in the KISS theme

[beiland]

For those not believing how quickly the wind can come up at times, check this video out, (and watch the wind reverse direction after the initial burst):
http://www.mylefkada.gr/eidhseis/nea/6435-vlyxo.html[/URL]

"It was more than 60knots, more like 100 (with 35 years north sea experience I know the difference between 60 and 100 knots). We had about 30 seconds warning and managed to start the engine unlike most people. We were knocked flat at least three times and feel lucky to have survived with minor damage to the boat and only bruises to ourselves.
A truly terrifying experience."
http://www.ybw.com/forums/showthread.php?p=3144510#post3144510[/URL]

...and then check out the damage photos:
https://picasaweb.google.com/yachtleisha/VlikhoBay#[/URL