Questions about fixed boom vang

[ThereAndBack]

To be honest, I'm not even sure what the correct wording is for this piece... So be gentle. I'm a long time monohull sailor but relatively new to multihulls.

I have a voyage 430 that has what appears to have been a rigid boom vane which is mounted from the base of the mast to the underside of the boom. The strange thing though is that it appears to have been a strut or spring at some point, but the vang has been welded together. This effectively makes it a set constant length and it holds the boom at exactly the same 90 degree angle to the mast at all times.

There is no topping lift.

I've seen some other boats of this vintage and reached out to other owners. Some other folks have this same fixed length vang, but at the same time those owners still have a topping lift, which I don't understand.

I can understand the advantage of this setup if one was to use in boom furling which requires a very strict angle, but this boat does not use roller reefing on the main. Can anyone shed some light on the reasons for this setup? Is it the sins of a past owner or is there any good reason for this that I am missing?

[44'cruisingcat]

Well the rigid vang does allow for the deletion of a topping lift, which can be a slight hassle with a roachy mainsail.

But most cat's with wide mainsheet travelers don't have a vang at all. You can control sail twist using mainsheet.

A rigid fixed vang wouldn't allow any control of twist. It will also put very high loads on the boom and the gooseneck.

[ThereAndBack]

Originally Posted by 44'cruisingcat

Well the rigid vang does allow for the deletion of a topping lift, which can be a slight hassle with a roachy mainsail.

But most cat's with wide mainsheet travelers don't have a vang at all. You can control sail twist using mainsheet.

A rigid fixed vang wouldn't allow any control of twist. It will also put very high loads on the boom and the gooseneck.

You may be on to something here as our traveler is quite wide. Perhaps they just did it to delete the topping lift. The main is also pretty roachy.

[44'cruisingcat]

My preference would be to not have a vang. As I said before, they can put large bending loads into the boom, and really give the gooseneck a workout.

You'd need to replace the topping lift though.

[Sand crab]

Most Voyages have a boom strut dinghy hoist? It's an aluminum tube that fits inside the boom which can be extended and then lifts the dinghy. Is the OPs like that? Could that be part of the design?

[Tupaia]

Originally Posted by 44'cruisingcat

My preference would be to not have a vang. As I said before, they can put large bending loads into the boom, and really give the gooseneck a workout.

You'd need to replace the topping lift though.

Remove the vang. Vangs are primarily compression struts designed to support the boom not really for tension. So I agree the bending loads on the boom while running or if reefing downwind for example will be massive.

[Jeff F]

Are you sure it's fixed on the boom end? There might be a sliding attachment with a stop that allows the boom to rise.

[bmz]

I have always use my boom vang at one setting only. It works so well that way I don't even have to use the traveler. I set my traveler amidships, and set my boom vang to provide the right amount of tension off the wind. As I sheet in to sail closer to the wind, the main sheet becomes more vertical and provides more and more downward force on the boom; this offsets the fact that the boom vang provides less and less downward force as you sheet in.

At all points of sail, this very simple, set and forget, method has provided me with just the right amount of sail twist. This may have been what your previous owner did. This also tends to limit the amount of tension on the boom provided by the boom vang. It has been working very well for me going on 38 years.

[Factor]

Vangs have little place on a multi that has a wide traveller.

[Jim Cate]

At all points of sail, this very simple, set and forget, method has provided me with just the right amount of sail twist

Not to be contrarian, but the "right amount of twist" changes a lot with varying wind speed and point of sail. No one fixed amount is gonna be right some (most) of the time.

It may "work", but it will not be optimal.

Jim

[Sand crab]

As I mentioned before Voyages are mostly equipped with a boom assisted dinghy lift. There is an internal tube that fits in the boom which extends out to lift the dinghy. Some call this a boom crane or a stinger. You lift the dinghy and rest it on chocks on the rear transom. So no davits to worry about. I don't see davits in the OPs pic. One guy said that he can even launch the dinghy while under sail! This video on a V440 which is the improved version on the OPs boat mentions the boom crane very briefly at about the 3:30 mark:

https://www.youtube.com/watch?v=BGgzviD6CTk

The OPs boat does not have a topping lift so what holds up the boom when he's lifting the dinghy? Maybe there's a line running up the mast from the end of the stinger? Google Voyage catamarans and try to find one with davits, I couldn't.

[44'cruisingcat]

Originally Posted by Sand crab

As I mentioned before Voyages are mostly equipped with a boom assisted dinghy lift. There is an internal tube that fits in the boom which extends out to lift the dinghy. Some call this a boom crane or a stinger. You lift the dinghy and rest it on chocks on the rear transom. So no davits to worry about. I don't see davits in the OPs pic. One guy said that he can even launch the dinghy while under sail! This video on a V440 which is the improved version on the OPs boat mentions the boom crane very briefly at about the 3:30 mark:

The OPs boat does not have a topping lift so what holds up the boom when he's lifting the dinghy? Maybe there's a line running up the mast from the end of the stinger? Google Voyage catamarans and try to find one with davits, I couldn't.

This doesn't sound like what the OP described. He described a rigid strut from the mast base to the underside of the boom. Basically a fixed length rigid vang. This is what holds the boom up.

[Sand crab]

Right 44, I was addressing some of the previous posters who said the solid vang should be done away with which would leave the boom/dinghy lift with no support. I'm thinking that the boat had a topping lift at some point and when that went away or wore out the decision was made to weld the vang.

[ThereAndBack]

I spoke to some other Voyage owners and apparently the topping lift should be there, so I need to rerig that. And yes, I lift the dink via a boom derrick that extends out the end of the boom and then use the mainsheet over the end of that to lift.

I'm wondering if the "strut" is actually extendable but perhaps has just frozen. The boat was poorly cared for before I took ownership and I've been slowly working through the systems.