Boom Vang

[danstanford]

Wasn't the premise that ADDING a vang would be adding a safety device? Not having a vang would remove the need to release or ease it.
I am certainly not arguing against a vang, just wondering how adding one would be adding a safety feature.

 

[jssailem]

how adding one would be adding a safety feature.

You are correct in my thinking. A Vang is a trim control tool. I do not know any special safety functions it provides. It does help to keep the boom in a fixed plane... yet the boom is free to swing sweeping across the deck.

 

[lakesurfsailor]

Picture show the boom is Z spar. View 4 shows an eye for attachmentl Are there two of them one for the boom vang and the other for the mainsheet

there are 2 attachment points, one is probably for the vang but I will have to check the angle when we launch this season. Thanks again for all the advice

 

[lakesurfsailor]

Picture show the boom is Z spar. View 4 shows an eye for attachmentl Are there two of them one for the boom vang and the other for the mainsheet

I just found ZSpars website and catalog- this must be my mast plate! This diagram is super helpful and shows that this must be designed to take the load of the vang. I will call tomorrow morning when they open. Cant thank you enough!

Catalog link:

https://www.usspars.com/wp-content/uploads/2011/03/preY2KCatalog.pdf

 

[Joe]

The vang's primary purpose is to stabilize the boom (prevent bouncing) when it is swung outside the range of the traveler. The skipper will call "vang on" when the mainsheet is no longer effective at controlling leech tension. Now the vang takes over the boom's vertical movement while the mainsheet is relegated to replacing the traveler's lateral control function.

If conditions change quickly, (perhaps an intense wind gust) the boat will often try to round up violently, heeling over severely, threatening the loss of rudder contact, resulting in a broach. The skipper calls "vang off" to avoid burying the boom into the water so the boat can get upright, avoiding further catastrophe while the crew recovers control of the boat.

I have never thought of the vang with a "power up" or "power down" mentality.
I had always visualized it as an upwind or downwind tool.( Upwind - no.....downwind - yes.)
But, for me, over time, the vang has evolved to a simple question: "is the boom bouncing".
Heh, heh... just gettin' lazy, I guess.

 

[Hollyberry]

Re vang as a safety device....
This comes from the classic 'Royce's Sailing Illustrated' (image credit)
When sailing deep downwind without a vang the mainsheet has no downward component, leaving the boom free to lift if any forces cause it to do so.
Esp. in a big sea with lots of motion, a gibe, accidental or otherwise, can turn into a goosewing (half the sail fills on one side, the other half on the other. Now the leech is a big S curve with the boom at a high angle , but eventually the sail will decide with way to go. Now the uncontrolled boom can slam violently to the extent of the mainsheet - if it's still cleated - and fetch up hard. This might break fittings, or do other damage possibly including striking a shroud.
I've only experienced this in a small sailing dinghy but thereafter we added a fixed strop as a 'vang' and it never happened again. On a larger boat the potential forces would be exponentially higher.
And I think a vang (as a safety device - fixed or adjustable) is especially important when newbies are learning.

Most of the time, agreed, it serves as a leech tension trim control, with a spring loaded or hydraulic one capable of up and down adjustment...

Sermon over......

 

[jssailem]

Sailing down wind, a smart sailor applies a preventer.

 

[Hollyberry]

Sailing down wind, a smart sailor applies a preventer.

AKA a 'toerail vang'.....

 

[kappykaplan]

AKA a 'toerail vang'.....

Never heard that terminology applied to a preventer before!