Boom Vang during Jibe

[oldiesrocker2001]

While looking at a post regarding using the Vang as a jibe preventer a question for me came to mind regarding the vang during downwind sailing. When sailing pretty far off the wind I usually have my vang (which is run aft to the cockpit via my deck organizer/rope clutch) moderately tight. When preparing to jibe, should I be easing the vang or tightening it more to perhaps slow it down as it continues through the cockpit? Would having it tight put undue stress on the fittings if an unexpected jibe happend? :stirthepot:

 

[Brian M H23]

In light / moderate air, I wouldn't worry about tightening or losoening the vang. As the air gets heavy, I let some pressure out of the vang to get the boom higher up in the air. If the boat rolls, you don't want the boom ending up underwater.
As far as a gybe preventer, personally I feel that they should be attached mid-boom or farther back - if the air is heavy enough that you are worried about an accidental gybe, then (IMHO) you don't want your "preventer" attached at the mast end of the boom, where it has no mechanical advantage. A line from the end of the boom to the bow seems more desirable to me.

 

[JIM B]

On A Mac 25

On my old Mac 25 I had to have a boom vang to prevent the boom lifting and catching the back stay when jibing. I don't know how much room you have between the aft end of the boom and the back stay, but it really puts a lot of strain on the rig when they tangle. Other than that consideration, moderate tension while broad reaching and more tension when dead down wind should work in most conditions.

 

[Joe]

I'm hoping you understand that using the vang (soft vang, not rigid) as a preventer means you have to disconnect it at the mast and re connect it on the toe rail in order to keep the boom in position. When you turn the boat, the vang/preventer must be disconnected, for obvious reasons. However, rigging a dedicated preventer is fairly simple, and you will be able to operate it from the cockpit. All you need is a length of line a small turning block forward of the mast. There are a couple ways to rig it... I can explain if you like.

You won't have any problem with the boom rising on a jibe if you simply control it by grabbing a handfull of mainsheet tackle and pull the thing across, rather than letting the wind slam it over. You should never jibe the boat without controlling the boom, either by pulling it across by hand, or cranking in and letting out the mainsheet.

You shouldn't have to mess with the vang when jibing if you're using it in the normal way. If you're vanging in heavier air on a run or reach and you feel the boat heading up, out of control, (broaching).... release the vang immediately to keep the boom out of the water so you can regain control of the boat.

 

[alexco38]

You can always do the chicken gibe; tack-tack all the way around. Although I have dedicated preventers, I prefer tack-tack when not racing.

Alternatively you can turn into the wind first, sheet in the main and then gibe. After you crossed the wind let out the main sheet when on the other side.

Rule of thumb is not to gibe if you can't controll the boom. Bang it across can break the gooseneck.

 

[Don Guillette]

First, let's talk about what the boom vang does. It is the primary mainsail control for twist. It's second function involves draft position. While sailing downwind the boom wants to rise and the boom vang prevents this from happening. So, if you eases it off you'd spill the power from the top of the sail and you need all the power you can get to get through your turn.

Personnally, I would not sail downwind without a preventer. Here's why. During the Redondo Beach to long Beach race a few years ago I almost bought the farm due to a lack of a preventer. This race is 75% downhill. I was standing on the seat in the cockpit watching what was going on with the foredeck crew. The owners wife was driving. The boat had a tiller. She was sailing "by the lee" which I don't like because it is dangerous - as I was about to find out. The first time the drive started to get into trouble I saw it coming and gently moved the tiller back for her. A few minutes later for some unknow reason I took a step backwards and the next thing I saw was the end of the boom flying by my face. Had I remained where I was a few seconds before the boom would have cold conked me.

One other point - I was not wearing a life jacket either. That boom incident taught me a lesson. On the way home I bought a self inflator at West Marine. I always wear it regardless of the conditions because you never know when something will happen.

 

[oldiesrocker2001]

Thanks All for your input.
Since I'm mostly a lake sailor and used to fickle winds I very rarely sail 'by the lee' if I can avoid it. In truth, I rarely sail dead downwind since I don't have a whisker pole for my undersized jib unless it's the only course open to me at that moment.
My current boat WILL tangle the boom in the backstay in an uncontrolled jibe(which convinced me to never do that again) if the air is heavy enough to lift it and the vang is not attached or even hooked up. I'm not usually too worried about a planned jibe even with the recreation of the stock Venture's mainsheeting system's shortcomings. I was wondering mainly about the effects of an unplanned jibe with the soft vang in relatively tight setup on the vang(though I don't think I would normally want to turn all that fast to effect a jibe, so spilling power might not be a concern). I can assume then, that if I have the vang set a certain way for downwind I don't need to fuss with it in preparation of a planned jibe?
I am still considering a preventer, though.