Boom preventers and vangs.

[Zen]

Do you use one?

Purchased or self rigged ?

If not why?

My old Ariel came with one. The guy who show me the ropes on sailing said, oh, this is something racers use do not worry about it.
Later I found out what it really was, after I took it off.
After finding out what it did and having the NEED to use it in near gale wind and had the boom fly across the deck, I put it back on. Another time I did need it , it came in handy.  Another it was in use and snapped one of the Pulleys, because it was old, but it did slow it enough for me to make the correction.

My current Islander done not have one. So I'm looking...Once saw a dutchman preventer on Ebay but, did not bid enough.

I have seen Vang connected as a brake, but that means going on deck to hook and unhook.

thoughts...?

[s/v Faith]

Put me in the camp of the 'serial vang abusers'.  ;)

  I have a pair of padeyes on the fwd corners of my cabin top, and can switch the vang in seconds.  Works great when going downwind, especially when the autohelm is steering and I am wing and wing.

  If I did not have the padeyes, I would just take the vang to the stansion base, or on another boat maybe one of those toe rails with the holes in it..... I would not want to sail long without some way to rig one..

[starcrest]

definatey use one.also I keep it a separate issue...I take it out only when necessary.....its a short legnthof rope that inmistakenly large in diameter...it gors from mid boom to a chainplate on the hull

[watsongs]

A cheap way to rig a dutchman preventer is to hook a carabiner to a boom bail, run a line from rail to rail or any suitably strong attachment point, and use a munter hitch on the carabiner - it's a bi-directional belaying knot - http://www.chockstone.org/TechTips/MunterHitch.htm

That way you can gybe in a controlled manner without touching the sheet.  Be sure to use a pear-shaped auto-lock biner so it doesn't accidentally open the gate - rare, but possible.

[oded kishony]

watsongs,

This looks great, let me see if I've got this right. You attach the carabiner to the bailer, the line goes from the lee rail/cleat etc through the bailer with this knot and you hold the other end of the line. When you're ready to jibe you pull on your end to lock the knot and controll the swing of the boom. Is this right?

Oded Kishony

[Solace]

I have been using a preventer religously for 2 seasons. You can probably guess that this came out of a desperate situation when finicky lake winds shifted to an accidental gibe. My setup is identical to the one described above. A line from the end of the boom bail through a snap shackle, clipped to the toe rail amidships then run back to the cockpit where I cleat it off on a horn cleat. Easy and safe. No more accidental gibes and very handy when trying to run wing on wing for long periods single handing.

Cheers!

John

[oded kishony]

My daughter goes rock climbing and it occured to me that her belaying equipment would make an excellent boom preventer.

Here's what it looks like:

http://swift11.swiftnet.com/rockempire/images/paradoxlg.jpg

Costs about $15 and is very easyand dependeble  to set up and use.

[CapnK]

Interesting stuff, guys! Karma for all! ;D

[starcrest]

it is in my humble opinion the the preventer line should be one piece of rigging that should stand out from all others.kinda like an emergency brake on a car.once sails are set on any kinda broad reach it should be the last thing set.....and the first thing removed b4  gybing.

[Solace]

I couldn't agree more - the line I used for the preventer is the only line on the boat with that colouring.
If you sail with a small crew or single handed - and do any amount of downwind sailing you should seriously consider rigging a preventer. It's simple to do and it may just save your life.
<gets off soap box>
Sail Safe

John

[captedteach]

On my Cal I reposition my vang if I need a preventor for a short period  But I try not to sail at an angle where I need one.   My boat is quite a bit faster if I foot off a bit, so while I sail farther I get there in about the same amount of time. 

[Zen]

Ok, now that I'm out sailing again and see the need for a preventer. I'm been thinking about what to do and re-read this thread here. I think I have it figured out about the mtn gear and using it on the boat.

http://swift11.swiftnet.com/rockempire/images/paradoxlg.jpg

so.. what I see is one would need two of these. One for each side, Right!!?
Then as the boom changed from Port to Starboard or..., one would just loosen the line let it switch (gently), then tighten the other side and lock/clamp/cleat it down....!
I'm I seeing this right?

[Captain Smollett]

Of course, you can do the same thing with just the caribiner by using the Munter Hitch.  It's a knot for a poor man's belay (no extra gear). 

See Munter Hitch Here

With the Munter Hitch, you won't need the ATC ( a very useful belay device, if single purposed).

EDIT: Apologies to Watsong; I even linked to the same site!! :-[

[Zen]

Ah So deska ! ( Japanese for; oh I see!)

I get it, now it makes sense. So instead of buying, line, pear-shaped locking carabiner, and 2 ATC's @15.00 ea. I can save the 30.00 and use this knot!

Cool. I'll give it shot. Attaching the carabiner to the base of a sanction.

and lets use the words a "cost conscious" or "thifty man's" belay  ;D ;D
poor men do not own yachts  ;)  8)  ;D ;D ;D ;D ;D

[AdriftAtSea]

The sail on the Pretty Gee can generate some pretty ferocious forces, so I've gone with a Dutchman Boom Brake system.  I'm in the process of mounting it, and will be happy to report back how it works out.  I'm planning on using a padeye that is already on the boom to mount it, and adjust the position to get the best response.  The line for the boom brake will run from the starboard chainplate, to the boom brake, to a rachet block on the port chainplate and then back to a Spinlock PX Powercleat on the port side cockpit coaming.  We'll have to see how this works. 

[Zen]

Adrift: I was looking at those on their website. Looked pretty good. Not bad in cost.  I still may end up doing that down river ( as in life )...However as a "cost conscious" sailor  ;) for now...
I if can save a couple hundred bucks and get the same safe effects, I'm for it!
anyway, yes please report back with your findings. inquiring minds want to know!



Captain Smollett : do you think a 5/16th line with a Breaking strength: 3,000lbs is good? too much or not enough for a 29fter? What size are you using?

[Captain Smollett]

Captain Smollett : do you think a 5/16th line with a Breaking strength: 3,000lbs is good? too much or not enough for a 29fter? What size are you using?

What size is your main sheet?  I'd probably size the preventer similarly.  The preventer I use on my 18 ft-er is a size smaller than my mainsheet, but that's because I had it lying around, and it's braided differently (different appearence and texture) from all the other lines on the boat.  Like folks said above, use something you can distinguish from other lines, so if you have to loose it in a hurry, there won't be ambiguity.

[AdriftAtSea]

The real determination of the preventer line size is how heavily loaded the line will be.  Using a line that is too small can be far more dangerous than one that is properly sized, as the wind can really load up the sail, and then when the line breaks, the kinetic energy unleashed is far higher...and more lethal.

At the Safety at Sea seminar I attended in March, statistics said the majority of serious-to-critical injuries were due to booms hitting heads... the majority of fatalities were due to going overboard, and in many cases this was caused by the boom.

Three things to remember:  1)  The preventer line is going to be under a slightly different load than the main sheet, based on where on the boom the two lines attach.  If you're using a fixed line to a padeye on deck, then the preventer should really at least as thick as the mainsheet, and attached as far outboard as possible.  2)  If the line is going through a brake-type device, then the location isn't quite as important, as the load on the line is more forgiving, as it will slip, unlike a fixed line. 3)  If a boat is being used to go offshore, then the preventer lines should be a bit larger than if it is just being used for daysailing or coastal cruising, as the loads on offshore boats are often higher, for longer durations, than on other boats.

I hope this helps.

[Zen]

excellent! Karma point awarded!  :D

In short: too much is better!

Thanks to both of you for the advice!

[AdriftAtSea]

Yes, a heavier line is better... another point to watch out for though is if the preventer line and the mainsheet are not in roughly the same position along the boom, then there is a possibility of breaking the boom under really high winds.  This can also happen where the mainsheet is connected mid-boom, and no preventer is installed.

The advantage of the brake-type preventers is that they do not cause the pressures on the boom to build continually, and risk failure, as they will allow the boom to move (hopefully) at a slow enough rate to eliminate most of the danger of accidental gybes or tacks. 

A lighter preventer line is exceptionally dangerous, especially in the static-type preventers, as it can allow very high loads to occur and rapidly fail without warning, and lead you into a very lethal false sense of security.