rigging a preventer

[steve yates]

This is something I have read about folk doing a lot, but never done. What is the best way to do it? As a former climber, I have descendeurs, which I have always thought might be quite good for this sort of thing?

Its a bit of a broad sectrum question as I will looking at doing it in my 18 ft bradwell, my mates 28ft twister and my 32ft longbow.

Anyone know of some good youtube links too?

 

[Fr J Hackett]

This is something I have read about folk doing a lot, but never done. What is the best way to do it? As a former climber, I have descendeurs, which I have always thought might be quite good for this sort of thing?

Its a bit of a broad sectrum question as I will looking at doing it in my 18 ft bradwell, my mates 28ft twister and my 32ft longbow.

Anyone know of some good youtube links too?

Do a search on "Boombreaks" but the simplest gybe preventer is a line from the end of the boom taken forward at the bow and then via a block back to the cockpit and made off there. It is common to have a short single line with an eye or shackle from the boom end ( when not in use this can be secured at the mast, so make the length suitable) this line is then clipped on to the longer line from the cockpit, you can use two lines one each side to make gybing easier.

 

[webcraft]

Do a search on "Boombreaks" but the simplest gybe preventer is a line from the end of the boom taken forward at the bow and then via a block back to the cockpit and made off there. It is common to have a short single line with an eye or shackle from the boom end ( when not in use this can be secured at the mast, so make the length suitable) this line is then clipped on to the longer line from the cockpit, you can use two lines one each side to make gybing easier.

+1 - but you don't even necessarily need a block at the bow, I usually just put our preventer outside everything, through the bow fairlead and back down the sidedeck to a winch. I have a dedicated line for this which is a different colour to the rest of the string on board.

The most important things are:

a) take the line from the end of the boom. Preventers rigged elsewhere can break booms.

b) Always take the line back to the cockpit so you can release it if you need to.

- W

 

[geem]

Do a search on "Boombreaks" but the simplest gybe preventer is a line from the end of the boom taken forward at the bow and then via a block back to the cockpit and made off there. It is common to have a short single line with an eye or shackle from the boom end ( when not in use this can be secured at the mast, so make the length suitable) this line is then clipped on to the longer line from the cockpit, you can use two lines one each side to make gybing easier.

We sail a 44ft boat. We have a flush deck and wide side decks. We do all reefing at the mast. We used to have our preventer rigged so the line went from the end of the boom to a block forward then back down the side decks to the cockpit. We found that the line lying on the deck was a trip hazard and would roll under your feet when going forward. We now take our preventer line from the block forward to another block at the base of the mast and to a spare winch on the mast. It works better for us as its safer on deck. If you have to go forward to reef you need a safe route

 

[Deleted member 36384]

I use a line attached to the end of the boom (eat cast into boom fitting) with a round turn and two half hitches.

It’s fed through a snatch block connected to the fair head with a loop of rope. The Gybe Preventer preventer runs to the Genoa sheet winch cleat in the cockpit. The Genoa sheet is secured on the sheet winch self trailers.

I just use one of my mooring lines, one of the long springs.

 

[Poignard]

I don't take the preventer to a winch. I just tighten it by hand and then sheet in the main a bit (as described by Eric Hiscock in "Cruising Under Sail")

 

[Stemar]

I have a line with a snap shackle on the end that goes from the pushpit forward outside everything to the bow, then back via a block to the cockpit, run throgh the stanchion bases. Ideally, I'd have two lines, but I can change sides fairly easily as I wouldn't sail with the main up deep enough for a preventer to matter if conditions were bad enough that I didn't want to go forward. If I needed to run, I'd lose the main first in those conditions.

The line is also very useful picking up my mooring in blowy conditions. I can pick up from the cockpit, attach the preventer and let everything go. I'm now attached, held into the wind and can pull the line in at leisure.

 

[Poignard]

...
The line is also very useful picking up my mooring in blowy conditions. I can pick up from the cockpit, attach the preventer and let everything go. I'm now attached, held into the wind and can pull the line in at leisure.

I like that idea

 

[lw395]

+1 - but you don't even necessarily need a block at the bow, I usually just put our preventer outside everything, through the bow fairlead and back down the sidedeck to a winch. I have a dedicated line for this which is a different colour to the rest of the string on board.

The most important things are:

a) take the line from the end of the boom. Preventers rigged elsewhere can break booms.

b) Always take the line back to the cockpit so you can release it if you need to.

- W

^^This.
At least for a heavy weather preventer.

We sometimes rig a preventer from the kicker to the toe rail in light airs when there's swell or wash disturbing the main, due to the weight of the boom swinging around.

 

[Stemar]

I like that idea

It's not perfect, but it does work. There was a time when it was blowing so hard, I couldn't pull my little Snapdragon 24 in against the wind, so I tried to use the halyard winch on the mast. I soon stopped when I saw how much the mast was bending! It took me half an hour to get the line pulled in, a foot at a time in lulls, and the chain over the samson post. Still, without it, there's no way I could have got the boat to bed.

 

[ithet]

A couple of replies have mentioned the preventer going to the end of the boom. My understanding is that to protect from damaging the boom the line should go to the boom's mainsheet attachment point, which is not always at the end. Then if the mainsheet is accidentally tightened without first releasing the preventer the boom won't bend.

 

[lw395]

A couple of replies have mentioned the preventer going to the end of the boom. My understanding is that to protect from damaging the boom the line should go to the boom's mainsheet attachment point, which is not always at the end. Then if the mainsheet is accidentally tightened without first releasing the preventer the boom won't bend.

If you're 'accidentally' hauling on the mainsheet while the preventer goes to the clew, this could possibly damage the boom if the mainsheet goes to the middle of the boom and you are really ,really strong and don't notice that the sheet is much harder to pull in than it should be.

Much more likely, in conditions where a competent sailor needs a preventer, the boat might roll the clew into the water. When this happens, if the preventer is not close to the clew, then a serious bending force can be applied to the boom.
I think if the sheet attaches in the aft 1/4 of the boom that's likely near enough to the clew.
Particularly as when I'm serious about the preventer, there will likely be a reef in, so the clew will be moved inboard effectively. But the drag of the boom end touching the water at 7 knots is quite serious, even without the clew itself going in the water.
If you rig a prevent then madly tension the sheet, you could do other damage, it's a lot of sidewise force on the mast and gooseneck.

Main thing is, rigging a preventer from near the vang attachment is asking a lot from the boom in serious conditions.

 

[Dockhead]

If you're 'accidentally' hauling on the mainsheet while the preventer goes to the clew, this could possibly damage the boom if the mainsheet goes to the middle of the boom and you are really ,really strong and don't notice that the sheet is much harder to pull in than it should be.

Much more likely, in conditions where a competent sailor needs a preventer, the boat might roll the clew into the water. When this happens, if the preventer is not close to the clew, then a serious bending force can be applied to the boom.
I think if the sheet attaches in the aft 1/4 of the boom that's likely near enough to the clew.
Particularly as when I'm serious about the preventer, there will likely be a reef in, so the clew will be moved inboard effectively. But the drag of the boom end touching the water at 7 knots is quite serious, even without the clew itself going in the water.
If you rig a prevent then madly tension the sheet, you could do other damage, it's a lot of sidewise force on the mast and gooseneck.

Main thing is, rigging a preventer from near the vang attachment is asking a lot from the boom in serious conditions.

+1

Mid-boom sheeting is bad enough by itself; a mid-boom preventer might as well not be rigged!!

 

[Gryphon2]

Using some of your old climbing rope as the preventer will also take a lot of the shock loads out of the unexpected gybe as it behaves more like knicker elastic more than any yachtie rope.

 

[Daydream believer]

I attach to the boom at the mainsheet point , but I make the loop very big so that I can undo it without having to reach right to the attachment point. I then pass the line round the spring cleat using the boat hook so i can stay in the cockpit. From there it passes back to a winch on the cabin top. I use a stretchy rope.
It does not have to go right to the bow & if conditions are such that I might gybe accidentally in heavy weather & a rolly sea I tend to round up a bit anyway.

 

[Gitane]

I do very much as many others, a line from the end of the boom, through the bow cleat and back to the cockpit on the opposite side of the boat from the boom.

But, the preventer line is long enough to also permanently attach the other end of the preventer to the boom, but still tie the preventer to a cleat on the opposite side from the boom. So both ends of the preventer line are permanently attached to the boom.


So, when gybing, I just undo the preventer from the cleat, then gybe, and attach the preventer to a cleat on the opposite side of the boom. The preventer line is long enough so that it can be routed not to get in the way in the cockpit.

 

[Fr J Hackett]

+1

Mid-boom sheeting is bad enough by itself; a mid-boom preventer might as well not be rigged!!

The mid boom ones are not so much preventers but designed to absorb the shock loads and allow the gybe to happen slowly if not exactly under full control, better than nothing but generally expensive. Not I think for the OP.

 

[Yngmar]

Our setup is a dyneema strop from the boom end (Selden marks the fitting with "Preventer only"). Spliced thimble on the other end, stored on a small plastic cleat I mounted under the boom when not in use.

One preventer rope per side, turned at the bow (used to be turned at the bow cleats, but see below), with a snapshackle to hook the thimble on either side of the mast, so we can gybe without having to re-rig things. Other ends lead back to the cockpit and usually on the secondary winch on the appropriate side when in use. This allows controlled release after an accidental gybe.

Two low-friction rings on the stemhead fitting now turn the rope at the bow instead of the bow cleats, and this winter I added a large folding padeye for attaching them, rather than on the back of the anchor roller.

 

[William_H]

Well from the OP initial comments I wonder if he really needs a boom preventer. Especially on the smaller boat I would not imagine he would get into conditions of huge seas and following wind and waves to get that unexpected gybe.
I would advocate a good vang system to keep the boom held down and of course good reefing systems if he is going into the wild. Meanwhile a light weight boom with minimum of protrusions on the bottom can minimise injuries to heads. Just be diligent with down wind helming preferring to sail a little off the wind to avert gybe. Deliberately gybing as necessary to keep a course. Well I have sailed my 21fter for 40 years in mostly sheltered waters and never felt the need for a preventer. ol'will

 

[steve yates]

I'm thinking more of having the little boat on autopilot (when it's installed) running downwind. Easy for her to yaw off course. The bigger boats will be heading for the Faroes and across the Atlantic at some point. And those booms will have a lot of power in an accidental gybe.