BOOM VANG!!!

Mar 6, 2017
37
Bristol Corsair 24 Tampa
Hey guys
Once again to consult tbe sailing oracle, the library of Alexandria of sailing. That being said here's the question.
For a 151 square feet main on a Bristol 24. Im in the need of getting a boom vang. Im all eyes to read your input.
Let it roll!
 
Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
The vang is pretty straight forward, basically a 4:1 or 6:1 block system with a cam cleat. Garhauer, Ronstan, Harken, and others sell kits or you can assemble your own.

A boom kicker is nice as it holds the boom up without a topping lift.

The two important parts are the attachment to the mast and the boom. The vang can develop a lot of pressure and the attachment points need to strong enough to withstand those forces.

Additionally, the vang, mast, and boom should be in the same plane and form a triangle. As the boom moves across the deck the entire vang should follow. This means the vang must be attached to the mast and boom, not the mast collar or a deck fitting. If the vang forms a rhombus because it is attached to the deck, in a gybe the forces increase on the vang rather than remaining constant, this can bend the boom or rip out a fitting.
 
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Likes: sailingsoon
Apr 26, 2015
660
S2 26 Mid On Trailer
If you do decide to go with a kicker you may consider more purchase than normal. You have to overcome the forces of the sail and the kicker. I did a cascade system which gave me 8:1 using 4:1 tackle and an extra block. Another thing, if you raise and lower your mast make sure the fitting you put at the mast base will clear the deck when lowered and still pinned in the step. I drilled a hole in the mast near the base and used a dyneema strope that will flex out of the way and not damage the deck.

Here is a video of my setup.

The lines are in their stored position so it's hard to see how some of it works. Just aft of the Boomkicker track is a bail with a line attached that runs down to a block which is attached to the strope. On the lines return toward the boom there is a loop that the 4:1 tackle attaches too. The 4:1 tackle is then attached to another bail. Having 2 bails that are through bolted spreads the load like @dlochner alluded too. The Garhauer 4:1 has snap shackles at both ends. This allows me the luxury of taking one end to the toe rail and use as a preventer. Unfortunantly I could not get a single frame from this video so it's shortened.
 

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Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
If bails are used the need to have a compression tube to prevent damage to the spar
 
Apr 26, 2015
660
S2 26 Mid On Trailer
If bails are used the need to have a compression tube to prevent damage to the spar
Depends on how they are installed. The bolts in these are not tightened completely and use nyloc nuts. They actually will rotate. I upsized the bolts to keep elongation to a minimum and 3 years in, the holes are still like new. If they do elongate I will add bushings or rivet plates on.

There are also thousands of riveted bails that have no compression tube in use. Maybe you were just speaking of through bolted units.
 
Jul 6, 2013
221
Catalina 30TR, Atomic 4 2480 Milwaukee
Here’s a guide from Harken. You could buy a full kit from Harken, Garhauer, or others, or you could put together the necessary components. For myself, I used some parts I already had, plus a fiddle block from Garhauer, for 4:1 purchase.


My next project will be a Boomkicker, because I hate the topping lift.
 
Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
Depends on how they are installed. The bolts in these are not tightened completely and use nyloc nuts. They actually will rotate. I upsized the bolts to keep elongation to a minimum and 3 years in, the holes are still like new. If they do elongate I will add bushings or rivet plates on.

There are also thousands of riveted bails that have no compression tube in use. Maybe you were just speaking of through bolted units.
Boat and sail size makes a difference. Larger boats with larger sails will obviously develop more force on the fitting. Matching the attachment point strength and the boat size is important. The vang fittings on Second Star are ½" thick aluminum welded to the mast and boom.
 
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Likes: LeeandRick
Apr 26, 2015
660
S2 26 Mid On Trailer
Boat and sail size makes a difference. Larger boats with larger sails will obviously develop more force on the fitting. Matching the attachment point strength and the boat size is important. The vang fittings on Second Star are ½" thick aluminum welded to the mast and boom.
Agree, the OP has 24' boat.