Automatic sheet release

[Whimsical]

Given the recent threads where some have been a little paranoid about the prospects of a cat going turtle if the sheets are not released quick enough why not an auto release triggered by an inclinometer.
Nos produits
Don't know the price but it sounds dear with the inteligence that is built in.
I thought it would be good if triggered by one of those overboard alarms so a single hander had a chance of swimming back to the boat.

Mike

[Adaero]

Originally Posted by Whimsical

Given the recent threads where some have been a little paranoid about the prospects of a cat going turtle if the sheets are not released quick enough why not an auto release triggered by an inclinometer.
Nos produits
Don't know the price but it sounds dear with the inteligence that is built in.
I thought it would be good if triggered by one of those overboard alarms so a single hander had a chance of swimming back to the boat.

Mike

I personally would never fit an inclinometer as I always try and sail well within the boat and my capability. It might be useful for anyone who wants to spend their time sailing on the edge and aren't sure how far they can push it. I have always been told the most dangerous situations are not from capsizing but pitchpolling from too much speed in big seas, if that's the case an inclinometer wouldn't do you any good.
Just my 2 cents worth
Adaero

[David M]

Given it could not hurt and it might work, I would try it. Sailing on the ragged edge is not something I would do with a catamaran but it could happen that you have full sail up and get hit unexpectedly with a big gust, combined with just the wrong sea condition. There are no guarantees, just safety devices that might help. I will take "might" over "nothing" any day.

David

[Joli]

For curious (and worried) non-record-obsessed sailors, Joyon's boat is reported to have an automatic system that triggers the release of the main and jib sheets if the boat reaches a certain heel angle, allowing him to sleep without the risk of capsizing.

Somewhere In The Indian Ocean

[SkiprJohn]

I sailed on a Cross trimaran from Kauai to Oahu (upwind) back in the early 80s. It had automatic sheet releases. All mechanical. Didn't depend on an inclinometer it was activated by pressure. I'm certain there must be some old drawings out there somewhere of the trip mechanism.
Kind Regards,
JohnL

[Nordic cat]

There is a french built system available that is based on detecting the conductivity in 2 pipes that go down through the bottom of each hull. You can set it to release if the water disaapears from one tube (maximum safety) or from both.

It releases a solenoid that opens and releases an intermediate 4:1 system in the sheet. This has strong bungy cord attached to soften the release.

Some of the early Catanas had this system as a standard option.

A have played around with some ideas as I work in process control, but I'm not keen on having 4 extra holes in the boat.

The option I'm looking at is the one that some of the ocean racing tris use, some have headboard locks that can be manually released, others have a spinlock cam cleat at the top of the mast above the headbord that also can manually be activated or released.
This system depowers the sail without risk of damaging the battens up against the stays. Just leave an appropriate amount of slack on the halyard before fixing it at the bottom of the mast. But this is not automatic, but could be made so using e.g. a small CO2 cylinder to drive a piston to pull the cord.

Regards

Alan

[David M]

It would be interesting to put together a list of who makes these devices for comparison.

[waikikin]

John Hitch or maybe Lock Crowther had drawings for one, pretty much a hinged board that had a cam cleat on it that was held back by some elastic cord. Regards from Jeff.

[44'cruisingcat]

Bob Oram being Bob Oram, he has suggested the cheapest and simplest system I know of. Tie your mainsheet block onto the boom with spectra with the appropriate breaking strain. When sheet loads exceed that the boom will automatically be released.

[Jacana]

Famous last words "what the f.............."as the wind picks up and the boom automatically releases sweeping all before it overboard.Think i would rather a manual system.

[Tropic Cat]

I'm wondering who is it that is concerned about their boat going over?

[multihullsailor6]

The French company Ocean Data Sysyems Informatique embarquée marine électronique marine, ordinateur, portable, logiciel, écran, étanche, navigation, navlight, feux led, feux à leds, Ocean Data System offer a sheet release system they call UpSideUp developped with the help of and for Alain Gautier for use in the Route du Rhum. It comes in a cruising and racing version and is based on various inputs into an electronic "clever box". Am awaiting pricing for the cruising system.

Roger

[Nordic cat]

This is also based on using up to 6 "level" sensors as far as I can make out, my french is not too good though.

Please post the info you get from them

Regards

Alan

[SkiprJohn]

Aloha Jeff,
Yes, that's the one. Much cheaper and doesn't have electrical things to fail. I remember it working very well. Thanks
JohnL

[multihullsailor6]

Originally Posted by Nordic cat

This is also based on using up to 6 "level" sensors as far as I can make out, my french is not too good though.

Please post the info you get from them

Regards

Alan

Have received the quote for the UpSideUp system. The system in cruising version costs €3,150 all in ex France complete.
Roger