Boom vang bail location?

[burningwizard]

I am adding a boom vang to my DS2. Where should I locate the vang bail on the boom? The many photos on the forums look like the vang bail is about halfway between the mainsheet bail and the gooseneck, but I can't seem to find any 'stock' dimensions.

If it's helpful, my primary intention with a vang is to prevent the boom skying while sailing downwind. Not looking at serious racing.

I have mid-boom sheeting, and my mainsheet bail is 68" from the gooseneck.

[tomodda]

It doesn't matter all that much, whatever fits and gives you more or less a 45° angle between boom and vang. Ony biat, that meant the boom bail was about 6" aft of the cuddy lip. That will vary depending on where your vang is attached to the mast, and how high you usually carry the boom. And you'll need some extra vertical space if you presently or in future use a cascade. Expirement and find out!

[GreenLake]

Judging from t the photos I posted here, I'd say my vang bail is just a bit over 6" aft of the cuddy. I don't think it's as far as 10". The angle seems a bit more shallow than 45°, but I think that's typical. Attachment is to a U bail that hinges 1" aft of the mast.

The "I'm not racing" isn't a useful way to think about vangs.

You can keep your main from skying while sailing downwind, but there is a second scenario where the main has a tendency to raise the boom in unwanted ways. And that's when you are sailing upwind in a gust. Without a vang, as you ease the main in response to a gust, the sail will pull the boom both up and out. If you ease more, to get the boom to move as far out as you intended for your gust response, the boom also will rise further.

That changes not only your angle of attack, but also your sail shape. Unfortunately, that change is not beneficial in terms of what is required in your gust response.

With a vang, you can keep that boom under control. The effect is that as you ease your main, the sail shape remains flat, even as you change the angle of attack. My personal experience tells me that with a vang the boat is easier to handle in somewhat stronger, gusty winds than before. And that's a benefit whether I'm cruising or racing.

For that you want a cascade, or two, so you can set and adjust the vang while sailing upwind. With a 6:1 purchase, a single cascade will get you 12:1 which is just about the minimum required. With a 3:1 purchase, you would need two stages. I found a nice pair of blocks for a 6:1 purchase and added the single block needed for the cascade.


Now, if you were into serious racing, you would route the tail of the vang to where it could be adjusted on the fly by the helmsman. But that's not absolutely required to get a benefit from your vang going upwind.

[tomodda]

Yeah, that looks more like a 30-60-90 triangle, but as I wrote to the OP here, there is not rule. @burningwizard should experiment with it. Besides, a 12:1 purchase kind of makes the exact "sheeting angle" irrelevant, brute force overcomes the shallow angle .

GL: Fully agree with you, that even though one is "not racing," that's no reason to turn your back on the many advantages of Vang Sheeting. I think last time we discussed this, we came up with the analogy that while the main sheet is the "gas pedal" for the MainSail, the Vang is the "gear shift." I had eventually set mine up with the tail of the Vang sheet coming up the centerboard like you mentioned, straight into my mainsail trimming hand. Made life very "interesting" when I was single-handing.. juggling tiller, Mainsheet, Vang, and Jib (although I usually kept Vang cleated, just held the tail so I could make adjustments without getting my butt off the rail). But with crew to tend the Jib and fetch beer our of the cooler, it was perfect! Like holding steering wheel, accelerator, and gear shift in my two hands... and sometimes teeth, or wrapped around my wrist, or whatever....

[GreenLake]

Uh, Oh, wrapped round your wrist.

I was always taught was a no-no.

[tomodda]

>I was always taught was a no-no.

Indeed. For what it's worth, only took a turn around my wrist while the tail was cleated down, so no tension... but I wanted to keep it in hand (wrist) for next maneuver, rather than reach over. But yeah, the ergonomics of single-handing with all those controls was definitely a "work in progress."

[Watson]

I am also adding a boom vang this season. There was already a vang plate with key slot installed on the boom, so I will use that.

But nothing set up on the mast as far as attachment point. What is the best option for a bracket on the mast, and what is the recommended location on a split mast with tabernacle? Is it okay to install the bracket below the mast hinge, or is that not recommended (pressure on the hinge) ? If not, where else would you locate it?

As far as the bracket, I’m considering one of those v-shaped tangs offered for lasers, but am open to better ideas.

Thanks

[tomodda]

For what it's worth, for the lower attachment on my vang, I use a boom bail attached to the rear pin of my tabernacle. In other words, the bail is just the right width to fit over the width of the tabernacle, and I hold it in place with the pin - and the pin takes the load of the vang. The vang itself goes to a pulley that attaches to a snap-shackle that then attaches to D-shackle that rides on the bail. Advantages of my setup (IMHO) are that it puts load on a place that is already very strong - the tabernacle joint; It doesn't take up any extra space at the base of the mast (things get awfully tight down there!); you're not drilling any extra holes into the mast; you can rig the bail and the tabernacle at the same time (one pin!); and the bottom of the vang will move with your boom angle (as it rides the bail), so you don't have to make adjustments as you sheet the main. Disadvantage is that it's fiddly to rig, you need to make sure the bail and the tabernacle holes are all lined up properly before putting the pin in. And you wind up with lots of friction when you ship and unship the pin from all those holes - I use a rubber mallet and an old sawed-off screwdriver to help me get that pin in and out. Anyway, if this approach interests you, I can dig up some photos.

Otherwise, put an eyestrap (stamped not forged!) as low as you can go on your mast (above the tabernacle) or better yet a Shaefer padeye. Mount it vertically, flush to your mast slot, drilling your screw-holes into the back of the mast slot itself, put in some spacers between the hole and the padeye/eyestrap.

A possibility to explore, that gives you the benefits of my boom bail idea without the drawbacks - a heavy duty folding padeye. Harken makes one, and there's a cheaper knock off from SunCor. Anyway, you'd have to mount it horizontal, so the folding part is vertical... which means that you'll have to fold the "ears" back to the angle of your mast, meaning some fun work with a bench vise, blowtorch, and heavy pliers, which is my kind of party! Maybe better off just going to your local metalworking shop with a press brake and way more know-how, esp. cuz you may have to de-anneal and re-anneal the piece. Anyway, I'm spit-balling. Suffice to say that my 12-1 Vang setup cost me nearly $300 - peanuts for a "big boat", but quite a lot for our little DS'es. But I wanted it "done right" and done to my own tastes. You can definitely get away with spending less, and if this is your first vang, I'd keep it simple till you get more experience/develop your personal preferences for this very useful piece of rig. Vang sheeting is so much fun! But walk before you run....

Hope this helps!

T

[GreenLake]

I'm effectively mounting mine in a way very similar to Tom's. The use of a shackle riding on a bail, but my bail is attached to a special contraption I have that is also hinged, but isn't an actual mast hinge. You could always drill a hole through your mast and fit a bail into the bottom end of your mast. That way you can leave it in place and don't need to reassemble it every time you step the mast.

[GreenLake]

PS: I definitely didn't spend anything close to $300 on my setup.

[tomodda]

May not have been $300, it's been a while since I put my vang together. Was more than I budgeted, that's for sure! Nevertheless, it's nothing compared to "big boats" and I save a lot of $$ by patiently scouring the various places to find used and end-of-stock boat parts.

[GreenLake]

Well, I started with the 6:1 purchase w/ integral cleat. I bought that one, almost on an impulse, and then added the other bits when I was finally ready to put the vang in place. So, I don't have a single bill, I can point to, but I know that one of the reasons I went for it, was that I could get that purchase for a good price. Still, it was the most expensive piece. Which kind of implies that the rest was reasonable as well. But, pre-pandemic prices.