Gybe Preventer

[s/v Beth]

Thanks Pete and Barny for responding. I already have a line going from one side through the mid beam and back to a winch that I use to slow down the boat when solo docking. It would be easy for me to duplicate the other side. My boom is massive with the mainsheet at the aft end. I could use a carabiner brake the same way you guys use the figure 8. That is what we used before they came out.
The problem I face is when the wind is either light or aft and the swells are coming across the beam. I know- it is not spost to happen very often but it seems to happen a lot up here in the North Pacific.
Lots of ideas to play with on the boat. I am going to try and get out today.

[phantomracer]

another dutchman user. works great. simple to set up and use. Won't go to sea without it.

Best thing is it is easy to adjust from allowing the boom to be free to locking it down...as well as allowing it to slowly gybe (brake)when the need comes.

tried the gybe easy. found it hard to adjust. could get it to lock down.. or be free.. but not to be able to 'brake'. A traditional preventer is simpler and cheaper.

[memelet]

I installed a figure 8 but could not get the tension right. Either it locked the boom down or did nothing. I tried verious size lines (double braid and regatta) as well as some dynamic climbing rope. For the first the friction seemed too much. For the second the was too big (11mm). Im hoping that 7mm dynamic will work.

I also read of similar problems adjusting tension with the gybe easy.

[capn_billl]

I saw a picture recently of a guy that had two mainsheets, one on each side. It looks like you loosen one to tighten the other. That should work as a preventer.

[Paperbird]

Speaking mostly from rock climbing experience. The effectiveness of a figure 8 depends on 2 things:

- the rope going thru it (diameter and surface type) - larger D = higher friction
- the tension on it - more tension = higher friction

Varying those 2 things should make it possible to achieve a decent preventer rig.

[Butler]

Originally Posted by s/v Beth

Has anyone just tried snatch blocks at each midship cleat with one end tied to the boom and the other secured in the cockpit? two more lines but (only one more for me) adjustable and secure for night sailing....
Note: this is just a thought experiment- it has not been tested on the boat yet!

I've used this set-up. As others have noted, needs watching but can be handy. May not be do-able on Molly B as I suspect it will make access to the raised deck problematic, will see.
I think I first read of it in Royce's Sailing Illustrated many years ago... he dubbed it a "Pre-Vang".

[Dockhead]

Originally Posted by s/v Beth

Has anyone just tried snatch blocks at each midship cleat with one end tied to the boom and the other secured in the cockpit? two more lines but (only one more for me) adjustable and secure for night sailing....
Note: this is just a thought experiment- it has not been tested on the boat yet!

I've always done this. Except instead of snatch blocks, I just loop the preventer around the cleat. Lead it back to a winch. Works a treat. In fact I don't know how else you would do it -- you have to be able to tension the preventer and adjust it when you adjust the main sheet.

[conachair]

Originally Posted by Dockhead

I've always done this. Except instead of snatch blocks, I just loop the preventer around the cleat. Lead it back to a winch. Works a treat. In fact I don't know how else you would do it -- you have to be able to tension the preventer and adjust it when you adjust the main sheet.

Me too, works great. I have them permanently rigged with snapshackles through blocks midships back to cleats on the toerail. Plus a short line between them and to boom keeps the spare line down and makes it easier to gybe. Just ease the boom a bit more forward than you want it then take up the tension on the mainsheet. Gets a lot of use. Another useful easy mod was to lead the topping lift back to a cleat on attached to the backstay, Then in light airs downwind it takes seconds to get the main a bit baggier by lifting the boom a little, between the preventer, mainsheet and topping lift you can lock it off wherever you want.

[nigel1]

Originally Posted by Dockhead

I've always done this. Except instead of snatch blocks, I just loop the preventer around the cleat. Lead it back to a winch. Works a treat. In fact I don't know how else you would do it -- you have to be able to tension the preventer and adjust it when you adjust the main sheet.

Whereabout on the boom do you make fast to??.
I've a similar set up, but the lines are lead from end of the boom, then through a snatch block on the foredeck, and back to the cockpit.

[DSDman]

Please excuse my ignorance, but a picture would be most instructive for me as I am a visual learner.

[NDH]

As I originaly posted this some while ago I thought I would just update the situation.

I first tried a figure of eight climbing descender, not very good results on our 40ft boat with a big boom and despite several different ways of threading it to increase friction nothing that prevented the boom to a level I was happy with.

We settled on a continuous line that meant you could use it without having to leave the cockpit.

We connect one end of the line to the end of the boom with a snap shackle, run the line port side outside all shrouds to a block forward of the inner forestay and return down starboard side to the snap shackle on the boom to form a continuous loop.

The line is about 2.5 x boat length.

With the boom fully out the line runs from boom end over the guards rails to the front block and then returns tucked behind mid ships cleat to the genoa winch for tensioning ( the line can be tucked behind and released from mid ships cleat with extendable boat hook without leaving the cockpit).

We have used this now for best part of two years and it works for us.

[charliehows]

Originally Posted by barnakiel

Well, the best gybe preventer is your driving skills!

Alas ;-) have a look at that small Wichard gizmo. You just shackle it to the boom and lead a line thru it. It is very simple to set up. It is a bit pricey though.

My fave method is to rig a line from boom's end forward to a block and then back to a cleat in the cockpit. I hang the preventer(s) down from bungee attached so that when you gybe the preventer(s) does not catch deck equipment. Inexpensive (line, 2 blocks, 2 cleats) and efficient.

b.

i made a copy of the wichard from some 12mm stainless round bar i had lying around - damn thing works brilliantly, gybe is slow and easy, all i have to do afterwards is tighten the cross rope up so its ready to gybe the other way.

[Andrew Troup]

Originally Posted by barnakiel

This is the proper boom braker - will break your boom if you catch a wave. If you tie the lines to the boom's end then it is not very preventive - due to the angle the line goes from the cleat to the boom.

Another risk is when your boom is sheeted aft but braked this way to the center of the boom - you can either bend or brake the boom this way, if you 'forget yourself'.

Still, it works. Just beware of the pitfalls.


b.

Good points, especially with long and/or skinny booms and/or narrow beamed and/or roll-prone and/or tender boats (whew!)


What causes parts of me to distance themselves from my underpants is the notion (which I vaguely remember might have been raised earlier in this thread; certainly it is often sug
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Yikes: I just made a minor edit on a LOOOONG post proposing a safer way to protect the boom from unfair loads from a mid-boom preventer (when the boom end dips in the tide at speed) than the 'lighter line' fuse which is often suggested.

And when I saved it, I found I'd lost virtually the whole post. I thought I had highlighted a short section of text to delete, but it must have included the part of the post below the window (I'm working on a laptop I'm not accustomed to, and my palms tend to brush the touchpad, creating spurious mouse clicks). And it's after midnight. So if anyone's interested, I'll try and recreate it when time allows.