Boom Vang position on boom

[finefurn]

How do you determine the optimum placement of the Boom Vang on the Boom. I have a 1984 Hunter 27. There appears to have been a small strap screwed into the lover edge of the boom approx. 24 " aft of the gooseneck. If this is where the original Vang was attached, and judging from the size of the screw holes, it's no wonder that they pulled out. I'm thinking of installing a bail, similar to those used for the main sheet to attach the Vang. Any thoughts on this.

[StuM]

It's not a matter of how any inches from the gooseneck, it's all about the location of the lower attachment point and the resultant angle. A general rule of thumb is a boom to vang angle of 30-45° (35-40° being preferable).


A bail is good considering the loads involved.

[Jim Cate]

Rather than a bail, which of necessity involves adding holes (stress risers) to the boom, use a strop around the boom. This can be made of "seat belt" webbing or similar. On a much larger boat, I use three wraps, hand stitched to join the ends, and a D ring to attach the vang shackle. A lashing or small strip of metal can be used to keep the strop from slipping along the boom under load.

Inexpensive and easy to make and install, no point loading on the boom.

Jim

[finefurn]

Which point of the triangle should be 35 - 40 deg. The Boom or Mast base

[StuM]

Originally Posted by finefurn

Which point of the triangle should be 35 - 40 deg. The Boom or Mast base

Angle between vang and boom ("boom to vang angle")

[ferrailleur]

Originally Posted by StuM

Angle between vang and boom ("boom to vang angle")

boom supported by top lift only (no main) or by main only...
angle should be different.
Sorry if I'm too techical
Thanks

[Texasvlad]

Originally Posted by ferrailleur

boom supported by top lift only (no main) or by main only...
angle should be different.
Sorry if I'm too techical
Thanks

I understand that the top lift is needed to support the boom when the main is down. During sailing, when vang is used, all tensions on the main sail and the top lift plays small role.

[barnakiel]

It is very convenient when the attachment on the boom is far from the goosneck but this in turn creates acute angle of the vang - which is bad.


So most boats keep it at roughly about 45 degrees - attachment as far on the boom as the boom stands from the deck.


If you can move the vang point to the deck, you can move the point on the boom well aft. The same true if you have an extereme sheeting base - vang will not be required at all (some mono racers and many cats).


b.