Gybe preventer

[Gary Dawson]

I would like to rig up a preventer on my mainsail of my 35 Hunter to prevent accidental gybes when sailing wing and wing. One method is to move the vang to the toe rail, but I would prefer to use vang only for sail shape and rig a separate preventer.It seems you would want to have a controlled release of the main if a gybe did occur to reduce the tendency to spin the boat once the wind gets on the wrong side of the sail.What forces are involved? The force on a sail with a 15 kt winds would be considerable, but should that be the design force? The weakest link (sorry) may be the toe rail.My thought is to rig a line from mid-boom to a snatch block on toe rail at about a 45 degree angle and back to the jib winch. Here in the Pacific NW we have a lot of swirling current during tide changes and these tend to cause the most problems rather than wind direction change. Any thoughts appreciatedGary

 

[Steve Dion]

Have you looked at the Dutchman.

Gary:Have you looked at the Dutchman Preventer. Looks good. I think it could be setup with thru bolts into the cabin top, which would eliminate load on the toe rail. http://www.sailnet.com/dutchman/boombrake/bbindex.htm

 

[Ed Schenck]

Boom brakes.

There was a good test of boom brakes in recent memory. But I could only find this one in Practical Sailor(link below). From the descriptions of the various types it would not be difficult to build one. Personally I would put more faith in the toerail then a bolt through of the decking.

 

[Les Andersen]

Preventer

Gary,Using a preventer makes wing on wing much easier. And you do need to be able to release quickly if you get into a problem. That being said here's what I did. I went to Boat US when they had a sale and bought a midsize 4x1 vang and a couple of quick releases. The line in the new vang is slightly smaller than the line in my current vang. The vang has a set of jam cleats. I attach the preventer to the D ring in the middle of the boom where the sheet attaches and to the toe rail. Trim the boom, tighten the preventer and the boom is captured between the two forces and the sail. It doesn't move at all. The preventer line goes back to the cockpit and can be released with a single flick. Works great. I don't think the rail is in any danger from the preventer. The price was much less than the Dutchman boom brake. Less/v Mutual Fun

 

[Gary]

Preventer

Thanks Guys,I will look into a small vang (block and tackle) and rig it from the mainsheet attachment on the boom and the other end to the toe rail.Gary

 

[Anthony Bavuso]

Rig preventer at same point mainsheet attaches

Gary,Someone said it already but I thought it might be useful to make a point of it because I didn't really think about it until someone made it a point to me.The reason you need to attach the preventer to the same point on the boom as where the main sheet is attached is because if you don't you could accidentally bend the boom. Say you attached the preventer to the end of the boom and ran it to the bow. And then you cranked in on the main sheet forgetting that the preventer was attached. This situation could possibly bend you boom.