Rigid Boom Vang input

[Chuck Baier]

We are considering adding a rigid vang to Sea Trek and would like some input and first hand experience with different manufacturers .

[Vasco]

I've had two, an Isomat and a US Spars. Both work well as they came with the masts. Have had no experience with aftermarket ones but I would think most do the job.

[delmarrey]

My boat has had one for a long time but it's main purpose, other then being a vang, is to really take some of the weight off the topping lift. And, if the topping lift happens to come loose (a slip of the hand) it cushions the drop of the boom to almost nothing.

I actually I have to pull the boom down below head level while flaking the sail and use the mainsheet to keep it in place.

But I think it's one of those personal choice things. I have a hyd. vang sitting in my shop but just can't get myself to switch over. The rigid vang has done me right for so long.

Mine is an old Sparcraft w/ the external blocks, but I really like the new ones now!



sparcraft

[Alan Wheeler]

I made my own. works great and I compleatly removed the topping lift. The Vang supports the boom with ease.

[Hud3]

I have a Garhauer rigid vang. Works great, and I did away with my topping lift, which always tried to wrap around the SSB backstay antenna lead.

[Chuck Baier]

Thanks for the feedback guys. We too want to eliminate the topping lift as well as improve sail shape and keep the boom from lifting when we don't want it to.

[Steve Pope]

Hi Allan,
Can you share the plans of the vang you made? I have been thinking of getting one, but I have only seen one on trademe that was too big, I hadn't thought of making one. My email is <pappas@xtra.co.nz>

[Ex-Calif]

We have a Selden Rodkicker. Works fine.

[SkiprJohn]

My friends have a Garhauer that they swear by. They can't believe they put up with the old system as long as they did. Now they don't have a topping lift.
JohnL

[Alan Wheeler]

Steve, I will get a Photo of it and reply with some diamensions. But it may also be too big if you simply copied. However, it was dead simple to make, if you have a little engineering ability.
The Vang is simply two SST tubes that one fits down the other. You will never have one perfectly fit, nor do you want to. You don't want metal to metal contact. I made a "nose" from teflon that acts as a sleave for the smaller tube to slide in. Then a sleeve on the other end to hold the inner tube at it's opposite end. So to clarify, the "nose" was fitted to the larger tube, the sleeve to the smaller tube and the two slide into one another. The end caps I machined from Aluminium and fitted 2 sheeves in each end to take the line. These caps had the toggles that also fixed the vang to the Mast base and the Boom. Inside I placed a good havey spring. This was the only difficult part. I could not track down a SST spring, so I used Galv. It needs to be a heavy winding of a spring. Some Vangs use Gas struts as the spring, and I played with that idea at first. But I found it too complex for my likeing. A spring is simple and easy.

[beetle]

The boat has a Navtec hydraulic vang on the boom, it works very well, though it is expensive. If I were to add a vang to a boat without hydraulics I'd look for a vang that uses compressed gas for the return force rather than a metal spring - Vang Master in Southern California builds a nice bit of kit. For the metal spring folks, the Hall unit works well. That said, there are a lot of Garhauer vangs about and the folks that have them like them - there are too many sharp edges on that vang for my taste.

Vang-Master
Hall Spars&Rigging | America's Cup Winning Spars & Rigging

Be aware that a rigid vang using a spring or air return (compressive upward force) will allow the boom to swing in an arc from side to side once the upward centering force of the topping lift and/or main halyard is removed from the boom and the mainsail is not raised, especially true when motoring with the mainsail down in a seaway. I tie a short length of line to the boom and run it laterally to a toe rail padeye - the line pulls the boom down against the vang's return force and laterally against the mainsheet to quiet the swinging boom.

Some rigid vangs use a pin-stop device (non-compressive upward force) that the boom lands on and stops the boom from bouncing vertically, though the boom will still swing horizontally. These vangs don't work so well at supporting the weight of the boom when sailing in light air.

It's quite funny to watch someone lean against the boom and see their surprised look as it swings away from them...

- beetle

[Alan Wheeler]

But??....I don't quite understand why it would be unsupported. I simply pull the mainsheet up tight and the boom is held in place. Ummm....perhaps my desing has an aspect others don't. My vang has a "bottoming out" limit of travel. I don't want the boom hitting the pilot house roof, so I have limited the travel that the boom can compress to. So by pulling the mainsheet up tight (when the sail is down of course) the vang bottoms out and the mainsheet will not pull the boom down any further. You don't apply too much tension or the boom will bend and excessive load is placed ont he goosneck, but just enough to hold the boom in place. At the end of the day, I can bring the halyard from the mizzen to the main boom and use it like a topping lift. That way I can really crank down on the mainsheet. I only do this when we are berthed back in the marina again.

[Steve Pope]

Thanks Allan for the explanation of "how to" I have no problem with the engineering side. Now to find some ss tube, I imagine around 50 to 60mm wouls be sufficient?

[beetle]

Originally Posted by Alan Wheeler

But??....I don't quite understand why it would be unsupported. I simply pull the mainsheet up tight and the boom is held in place.

I'm not certain what you mean by 'unsupported'.

In the slip I normally keep the main halyard tied off at the end of the boom and pull up against the mainsheet - the vang is left in a neutral position as I don't particularly want to bottom it out (applies continuous pressure to the spring/gas system that isn't necessary) - in this configuration the boom will not swing from side to side. However, there are certainly times when the boom is just sitting there quietly without the halyard attached, and someone decides to lean against the boom and it swings away from them.

Pulling the mainsheet tight and bottoming out the vang presents an upward load on the boom at the boom vang bracket as the boom attempts to swing; I use the tie-off line when there's no vertical support at the aft end of the boom (e.g., halyard already attached to mainsail) to avoid bottoming out the vang and avoid pushing up real hard on the boom (the vang brackets I've seen are designed for small loads upwards and high loads downwards).

- beetle