Gybe Preventer

[kappykaplan]

I've been following this thread with some interest. My boat has a hydraulic vang that attaches to the mid-point of the boom. There's also a shackle at that point, and I've always attached my preventer there. Prevailing opinion here seems to be that I should attach the preventer at the end of the boom, but that would create some rather interesting angles in running the preventer to the toe rail. The mainsheet is attached to the end of the boom. What am I missing?

 

[centerline]

I've been following this thread with some interest. My boat has a hydraulic vang that attaches to the mid-point of the boom. There's also a shackle at that point, and I've always attached my preventer there. Prevailing opinion here seems to be that I should attach the preventer at the end of the boom, but that would create some rather interesting angles in running the preventer to the toe rail. The mainsheet is attached to the end of the boom. What am I missing?

You probably arent missing anything except thet the preventor does not have to be tight, it just has to be attached and enough slack removed so it wont allow a gybe if the wind angle changes in relation to the boat angle.
Another thing is, the farther forward it is attached to the boat, the tighter it can be without affecting the sail trim controls.... this is one of the reasons the fore cleat is the preferred place of connection by long range cruisers/racers... and, when the preventor is attached at the toe rail abeam of the mast, as a lot of day sailors seem to like to do, if there is ever a need to adjust it at the rail, its much tougher to do on the lee side of the boat and near the water...
At the bow its always safer and easier to access.

 

[centerline]

Any reason I can not run a line to both ends of the boom with a loop in the middle and attached the preventer to the loop?

Its not the same and it wont allow the full potential of the preventor... but it would still be better than attached to the vang bail.

Ive spent 20 minutes trying to figure out how to explain why, without a long and lengthy presentation, but
Basically the angles would be wrong and it could induce compressive stress in the boom, which could cause it to buckle much in the same way as the boom being forced out of column by the preventor being attached to the vang bail.

And using a sling on the boom to attach the preventor to only adds unnecessary complexity to an otherwise simple process.
When you change tacks, you.would have the move the sling aroung the vang to the other side of boom as well as moving the preventor line...

When a person rigs the preventor from the fore cleat, all that needs to be done to change tacks is unhook the preventor line from the boom, take it around the mast and reattach it to the boom on rhe other tack.

My boat is rigged with 2 preventor lines... one going to port around the mast and one going around to starboard.. both attached to the bail at the end of the boom
All the crew has to do is loosen one line from the fore cleat, let me tack around, and as soon as the jib clears the deck on the new tack, the other preventor line is then snubbed down.. this prevents the need for uncleating at the bow, then returning to unclip at the boom, taking the line around the mast and reclipping on the other side, then going forward again to cleat it down.. with two lines its fast and simple.
As ive said, the preventor lines are rigged with a deep clew hook that clips to a bail on the boom end, so to set it up and take it fown for stowage, its just a matter of slipping it on the bail and running the lines... or unclipping it and coiling the lines together..

 

[chuckwayne]

chief is correct - the boom brake has 2 adjustments, a knob that adjusts sheave tension and the tension you put on the line (I lead mine thru a line stopper to a winch). Others I have used have similar controls. Set tight enough, it becomes a preventer

 

[ALNims]

Hi Don,
We put a Boombrake (from Dutchman) on our 356. t works really well and is adjustable from the cockpit to keep the boom from slatting to holding it out in a blow. Makes for very controlled jibes with no drama. The brake is mounted on our boom on the same fitting that holds the top of the rigid vang. The restraining/control line runs from the stbd chain plate, thru the brake, to a block on the port chain plate and then back to a line cltch on the cabin top.
Highly recommended

Can you provide any photos of this arrangement?

 

[centerline]

Can you provide any photos of this arrangement?

for good quality photos of it rigged up, google it... if you type boom brake into your browser, and then click on the "images" tab at the top left of the page, it will have many more photos of several different styles of boom brakes than you will care to look at...

 

[centerline]

the Wichard gyb'easy boom brake is another popular option.... I had it confused with the dutchman in an earlier post, but they are both effective tools...

 

[chuckwayne]

Hi Al,
If I don't have anything here I'll shoot some tomorrow - I'll be on Escape

 

[ALNims]

Hi Al,
If I don't have anything here I'll shoot some tomorrow - I'll be on Escape

Great! Thank you.
Andrew

 

[Jerry Clark H356 SV Persi]

Paul: Thanks for the advice and your personal experience using my technique. I wouldn't have thought the loads would get high enough to blow out that connection at the vang. I'll reevaluate my technique based on your experience.

 

[PGIJon]

Jon: Looks like it will work great and not a 300 dollar item! I have never used a preventer. Does the line secure to one end on port rail, through the preventer and other end secured to stbd rail? Chief

Chief... Haven't really given it much thought yet, but from what I've read, I was going to run one continuous line from aft starboard through a swivel block through the end of the boom through the "Preventer" and back aft port.... However now that I've read what you wrote and thought about it.. I think your description make more sense... My only other thought until the device arrives, is what type and diameter of line I should use. I'm sure something chafe resistant is important. -Jon

 

[Chief RA]

Jon: From what I am learning it would not be a taut line and catches the boom in it jibe before it moves more than a foot or so. It then metes out the line slowly to control the jibe?
Chief

 

[PGIJon]

Thanks Chief.. I've checked out how they rig Gyb'easy http://wichard.ingenie.fr/documents/notice_gyb_easy.pdf which brings the line back. There is also a video: http://www.wichard.com/documents/videoFDBGB.wmv However, I don't see why they cannot as you point out be secured on the port and starboard rail. -Jon

 

[Chief RA]

Jon, check out the 1st diagram and picture. It is exactly as we are discussing. "F" appears to be the port and stbd rail mounting. I think that would be ideal as I would expect it to tend its self set up that way and NO surprise jibes! Chief

 

[PGIJon]

Can't wait to try it!

 

[chuckwayne]

Hi Al, sorry for the delay... Escape's finally in the water and sailing!
Here's some pictures of the boombrake.

 

[ALNims]

Hi Al, sorry for the delay... Escape's finally in the water and sailing!
Here's some pictures of the boombrake.

Thank you for this. Very helpful.
Al