sailFar.net

Cruisin' Threads => Boat Bits => Topic started by: ntica on May 17, 2012, 03:39:24 AM

Title: preventer
Post by: ntica on May 17, 2012, 03:39:24 AM
a tip from a friend of mine. (unespected gybe) (?! right word?) he has connected a line at the end of his bom and then forward to a "block" and back to the winches to prevent an unexspected gybe. The "downside" is many lines on deck...
But I also think, if just connected "the short way" to the side eg. would be to much pressure and risk for damage when going over?!
How have you solved this on your boats?
Title: Re: preventer
Post by: Timbo on May 17, 2012, 08:05:11 AM
I always carry extra twisted nylon rope for that purpose alone!  On smaller boats, I tie one end to the boom and one to the stanchion base.  If your stanchions are loose, it's probably not the best idea.  ;)  Maybe it's not a good idea at all since any force from an accidental gybe could loosen a perfectly good stanchion?!
Title: Re: preventer
Post by: Godot on May 17, 2012, 10:51:36 AM
I use a preventer when sailing deep down wind. I have not been using a block, instead just leading the line through the open base of a bow cleat back to the cockpit where I cleat it off. Right now I just have one long line that I switch back and forth on whatever side of the boat seems appropriate.  I have considered, though, putting a line on each side, and even using blocks at the bow, although it's hard to see why it's necessary on a boat my size.

I highly recommend doing this. It will save the drama of an unexpected gybe.
Title: Re: preventer
Post by: wristwister on May 17, 2012, 01:49:33 PM
How is your boom vang connected to your mast base? In my case, it's a shackle. I can easily unclip it and move the vang over to one of the shroud mounts. Makes a great preventer, and also offers 4:1 mechanical advantage to pull the boom over nice and hard for downwind runs.
Title: Re: preventer
Post by: Godot on May 17, 2012, 03:27:59 PM
Quote from: wristwister on May 17, 2012, 01:49:33 PM
How is your boom vang connected to your mast base? In my case, it's a shackle. I can easily unclip it and move the vang over to one of the shroud mounts. Makes a great preventer, and also offers 4:1 mechanical advantage to pull the boom over nice and hard for downwind runs.

I don't know if that is directed at me, but...

I don't actually have a boom vang. I think it would be a good thing to have; but the boat didn't come with one and I never got around to installing it.

My description above, btw, missed the connection to the boom.  I connect the preventer line to the end of the boom, though an open base cleat at the bow, and back along the side deck to a cleat by the cockpit. It works just fine and isn't all that much of a hassle to set up unless I decide to hook it up after the wind and sea gets up a bit, at which point it gets a bit wet.
Title: Re: preventer
Post by: CharlieJ on May 17, 2012, 03:47:30 PM
A method I intended to install on Tehani ( and may on Necessity) is a wire fastened to a bail at the boom end, and led forward under the boom to a cleat just aft the goose neck, ending in a thimble. A short pennant would tie it to the boom.

Then when wanted, your line from the bow could be fastened to the thimble on the  wire under the boom AT THE GOOSENECK. The under boom wire uncleated and the line from the bow set up hard. Reachable even with the boom totally broad off.

Could be unclipped and changed to other side if and when a gybe was needed, without stretching out to reach.

Unneeded, wire would live along under side of boom.

Hope I explained well enough to be understood-really very simple.
Title: Re: preventer
Post by: gpdno on May 17, 2012, 08:38:17 PM
Quote from: ntica on May 17, 2012, 03:39:24 AM
a tip from a friend of mine. (unespected gybe) (?! right word?) he has connected a line at the end of his bom and then forward to a "block" and back to the winches to prevent an unexspected gybe. The "downside" is many lines on deck...
But I also think, if just connected "the short way" to the side eg. would be to much pressure and risk for damage when going over?!
How have you solved this on your boats?

This is pretty much how I have the preventer rigged up on my boat.  I have a line that runs down both sides of the boat to the bow where I have a block.  Depending on which side I am running the boom, I will rig one end of the line to a "Shockle" then clip into the boom bail.  The other end of the line is secured to the cabin top winch.  The "Shockle" allows the line a degree of stretch to reduce the shock load on the boom incase of an intentional jibe.

Title: Re: preventer
Post by: marujo_sortudo on May 17, 2012, 08:56:38 PM
In my case, a 4:1 block and tackle with snap shackles on either end becomes a vang/preventer on downwind runs, if needed.  The lower snap shackle connects to one of the loop genoa cars that pretty much lives at the front of my genoa track.  The top snap shackle connects to a doubled up loop of de-cored double-braid dacron that goes around the boom between two slides after the main sail is put on.  A couple of u-shaped pieces of teak and some screws lightly hold it in position.
Title: Re: preventer
Post by: ntica on May 18, 2012, 12:32:14 PM
It sounds like a good idea :D any pictures of your instalations?
Title: Re: preventer
Post by: marujo_sortudo on May 18, 2012, 12:38:14 PM
You can see the attachment point on the boom in this pic:

https://www.facebook.com/photo.php?fbid=245394298842779&set=a.245394078842801.51835.188527351196141&type=3&theater

Alas, I don't see any pics with it rigged up.