Rigging boom vang on main sail help

[Kelkara]

I have a question ...



Is a riveted on eye-bolt going to be strong enough? The boom in the picture clearly used to have a bail with three screws/rivets on each side for the vang to attach to, which looks much stronger than the current eye-bolt.

[theglo]

Originally Posted by Kelkara

I have a question ...



Is a riveted on eye-bolt going to be strong enough? The boom in the picture clearly used to have a bail with three screws/rivets on each side for the vang to attach to, which looks much stronger than the current eye-bolt.

Kelkara - Thanks for seeing that. Those three holes are indeed on each side - and there was an eye bolt that had been ripped out underneath. I wasn't sure what the three screw holes were but now that you say that I'm going to look into this boom bail. That's likely what was on there originally. Thanks! (So much group-brain on this site.)

Also - After reading the other posts, I believe I will just invert my set-up and use the cam cleat to adjust everything at the base of the mast. Then will adjust the setup if necessary when I grow up experience-wise.

[Rising Tide]

Kelkara's post was the most important. You should make sure the attachment points you made on the new fitting are to marine standards. If not, there could be a risk. The forces on your main and boom are thousands of pounds. You may not want a failure here (not sure if a failure of vang is serious). You probably already considered this...

[tenchiki]

I am going to differ on the "its upside down" bit. With the cleat end on the boom, there is an extra part for more power, and you don't have to leave the cocpit as far to adjust it.. You do have to lead the tail somewhere safe.

Just because "everybody does it" one way doesn't mean it is correct or the best way.

[hlev00]

Try turning the whole block and cleat upside down so the jaws open downwards. Then when you pull you will be pulling up into the clam cleat. To release, pull downwards. Whether this works will depend on the angles. The other possibility is that the position of the cleat might be adjustable to fix the geometry.

I am sure the designer of the boat did not intend for it to be adjusted at the base of the mast.

[theglo]

Originally Posted by jsestes1

Kelkara's post was the most important. You should make sure the attachment points you made on the new fitting are to marine standards. If not, there could be a risk. The forces on your main and boom are thousands of pounds. You may not want a failure here (not sure if a failure of vang is serious). You probably already considered this...

I think a bail is likely the way to go now that I know one was there in the first place. I simply replaced a U bolt in the bottom of the boom as that is what was there that I could see. However, it was likely a bail BEFORE that. The U Bolt I replaced was pulled out and destroyed (not at the rivets but at the U-bolt itself). I'm guessing that's a good indication that it wasn't up to the force placed on it at one point in time. This boat's done years crossing the Pacific and years in the Bering Sea so likely saw something that placed those forces on it.

Justin

[AKA-None]

Mine is rigged like that and I uncleat it with a flip of the line. I also center the main when I jib but the I usually single hand my little boat. Ymmv

[psk125]

Originally Posted by tenchiki

I am going to differ on the "its upside down" bit. With the cleat end on the boom, there is an extra part for more power, and you don't have to leave the cocpit as far to adjust it.. You do have to lead the tail somewhere safe.

Just because "everybody does it" one way doesn't mean it is correct or the best way.

Tenchiki has a good point. Moving the cam end of the tackle to the base of the mast means having to go to the base of the mast to adjust it, instead of perhaps only mid-boom. Secondly, there are times when it can be urgent to uncleat the vang, so that the boom can rise up and not drag in the water in a knockdown. You can flick the line out of the cam easily when it is mounted on the boom. Not so easy with it down at the base of the mast.

A third idea might be to put the cam end on the bottom, but to attach it to the toerail (port or starboard) instead of at the base of the mast. The vang then serves as a preventer and is still quick to uncleat. Pulling up on the tackle also allows you to exert more force on it. You can only pull down with your full weight, but you can pull up more than your weight.

[Suijin]

Looks to me like what you installed for the vang may actually be the boat’s cunningham. Did it have hooks at each end? I agree that I would reverse it; allows you to more easily tension it, pulling up, and release it with your foot.

As an aside, that padeye you riveted to the underside of the boom is not going to last long. First decent gybe and it’s going to rip right out. As you can see even the previous strap, with six fasteners, met the same fate. Vang attachment points can encounter severe shock loads and need to be engineered accordingly.

[jrphil]

Hi,

Just something to check?
When you swing your boom out well to the side , will the boomvang catch on the stainless steel frames that are the above hatches in the deck?
These may need to be reshaped to allow fot the normal arc of aboom vang ?
Could they be used to support wind sock style canvas chutes to direct air below on hot days?

good luck with your new boat,
Sounds like you know how hasten slowly!
Cheers
john Phillips

[Mossy Man]

Unless you do things differently in the northern hemisphere compared to us down under you have it installed upside down as a couple of posters have pointed out. It does not normally need that much attention so I would not consider that it needs to be run to the cockpit.

[theglo]

Originally Posted by Suijin

Looks to me like what you installed for the vang may actually be the boat’s cunningham. Did it have hooks at each end? I agree that I would reverse it; allows you to more easily tension it, pulling up, and release it with your foot.

As an aside, that padeye you riveted to the underside of the boom is not going to last long. First decent gybe and it’s going to rip right out. As you can see even the previous strap, with six fasteners, met the same fate. Vang attachment points can encounter severe shock loads and need to be engineered accordingly.

Hey, just a question I couldn't get on a fast Google search. How would I use one of these as the boat's Cunningham? It did not have hooks on both ends - but did have carabiners.

[AKA-None]

I don’t see how you could use a Vang as a Cunningham simultaneously. One pulls down on the sail and the other pulls down on the boom.

[theglo]

Originally Posted by AKA-None

I don’t see how you could use a Vang as a Cunningham simultaneously. One pulls down on the sail and the other pulls down on the boom.

Oh, I know you can't use them simultaneously. I'm talking the same set blocks/cam cleats/etc setup but used as a Cunningham? A previous poster mentioned that may be the case and I have a few extra rigs of varying lengths that I'm not sure WHAT they do.

Thanks,
Justin

[TrentePieds]

TheGlo:

Vangs and Cunninghams serve different purporses. We've already discussed the the vang (kicking strap) both in cruisers and in racers. The cummningham's function is to tension the LUFF OF THE SAIL independent of what you do with the boom. By tensioning the Cummingham you pull the belly of the sail ("the bunt") forward so that the airfoil described by the sail full of wind will have less of a camber to it. That is advantageous as the wind rises, and/or as the wind is brought further forward of the beam.

Again, these sort of things are niceties that a novice in a cruising boat needn't be too concerned about. Once he begins to develop a feel for the boat as his experience level and competence increases comes the time to put this sort of fancy embroidery on the boat and on his sailing technique.

Coming back to the attachment point: Remember that fastener(s) in SHEER will always outperform in TENSION.

TP