Boomvang needed or not

[CowbaySailor]

I have a 25 ft C&C that doesn't have a boomvang. My question is do I need one ? What are the benefits of having one ? What are their purpose besides down hauling on the boom. Their is a cable hanging from the bottom of my boom aprox 3 ft from the mast and their is a place to hook one at the bottom of the mast. How much distance do you need to hook a boomvang up ?

[jackdale]

Yes, a boom vang is essential for maintaining twist in the main after the traveller has run its limit.

[sailjunkie]

To add to what Jack says, you'll use it to control sail shape when you are running downwind.

[Faster]

YES.... as far as I'm concerned it's a piece of safety gear.

Something like this should do you:



(From C34 website)

[jackdale]

Originally Posted by Faster

YES.... as far as I'm concerned it's a piece of safety gear.

And that too.

[CowbaySailor]

Thanks Faster for the diagram. My boom only has one short cable sticking out of the bottom of the boom with a carabeaner on it. Seems a little to far forward to get a good pull on the boom but how much pull do you need.

[Tempest]

The picture shows approx. approx. a 45 degree angle, which is about right.

When off the wind....let's say a broad reach. Your main sheet is eased and the boom is out 50 or more degrees from the centerline. So the mainsheet doesn't have much ability to apply a downward pull on the boom at that point.

The boom will tend to bounce or ride up and down spilling air and depowering the main. The boom vang allows you to apply that needed downward pressure/pull to the boom and keep it from riding up spilling air.
If the angle of pull is too shallow it will be ineffective..

How much tension is a factor of wind velocity, wave action, point of sail etc.
Generally speaking....tight enough to keep the boom from bouncing.
In very light air, you may want a little more shape..ease it a little..

[Jeff_H]

And to pile onto the safety issue, without a boom vang the boom can rise and hit the backstay, taking down the rig during an accidental jibe.

I don't know what the carribeaner is for, but since you have the wire and bail, a boom vang should be inexpensive and easy to rig.

Jeff

[Faster]

Originally Posted by CowbaySailor

Thanks Faster for the diagram. My boom only has one short cable sticking out of the bottom of the boom with a carabeaner on it. Seems a little to far forward to get a good pull on the boom but how much pull do you need.

The loads on a vang can be surprisingly high. In order to be effective you need enough purchase to make it easily adjustable under all conditions, at the same time it needs to be quickly releasable in the event of a broach and the boom goes into the water (it should be led aft to the cockpit for that reason)

Attachment points need to be quite robust.

A 4:1 would be a practical minimum for your boat. Using the existing cable as a doubler would be really effective and may be the original purpose of that cable.

[JoeDiver]

IMHO and my experience so far, yes you need one.

I don't have one either, but I do have the collar and attachment points on the boom and base of the mast.

I've found that when I'm sailing anything beyond a close reach, ie the boom is farther out than say, 5:00.....the boom will raise and bounce with waves and puffs because the mainsheet doesn't have enough ability to hold it down. This spills air and I lose speed....it's also a little weird in puffs because she'll heel over, spill air and right....rather than get a nice heel angle and sail right along.

You can build your own vang...not hard. The most expensive part is the one fiddle block with becket and cam...those buggers cost $$$....I got lucky and a fellow sailor on the association forum let me have one of his extra's, a really nice Harken, for $50...so all I need is the other fiddle block and 35' of line and I'll have my vang....by this weekend I hope.