Rigging a boom preventer, and gybing deliberately. Got it wrong.

[dunedin]

In windy, rolly downwind conditions the best solution is often much simpler than worrying about boom preventers and gybes.
Simply leave the mainsai down, unroll the genoa and make a cup of coffee, sailing downwind almost as fast and no boom to worry about. When reach destination furl genoa. Lots of experienced sailors have travelled thousands of miles in this way.

 

[Daydream believer]

In windy, rolly downwind conditions the best solution is often much simpler than worrying about boom preventers and gybes.
Simply leave the mainsai down, unroll the genoa and make a cup of coffee, sailing downwind almost as fast and no boom to worry about. When reach destination furl genoa. Lots of experienced sailors have travelled thousands of miles in this way.

Not with a small self tacking jib

 

[dunedin]

Not with a small self tacking jib

That is precisely why small self tacking jobs are a fashion that net creates extra work, with asymmetrics etc needed that a conventional genoa avoids
PS. You would be amazed how effective even a 110% blade jib can be downwind, using the conventional tracks forward to control twist. And a dawdle to tack upwind as well, best of both.

 

[doug748]

I rig two preventers, one each side. They lead forward inside the shrouds to the bow fairleads then back outside all to a position level level with the cockpit where they are attached to the guardrails with a snap-shackle until required. Attached to the extreme aft end of the boom is a single short strop, having a ring in its free end.

When I want to rig a preventer I unclip it from the guadrail and clip it to the ring on the strop. Then pay out the main sheet and take up the slack on the preventer, finally tightening it by hauling in the mainsheet as necessary.

To gybe I pay out the active preventer and haul in the mainsheet hard and unclip the preventer that has been in use. Then transfer the strop to the other preventer, gybe and tension the new preventer as before.

(takes longer to decribe than it does to do it! )

Well, that's at least three of us using this set up. On a downwind course I leave both preventers set up, with one lazy.
The lines are quite light and also do duty as spinnaker pole downhauls and for the tack of the cruising chute.

I think attempting to cushion a gybe with anything but the mainsheet, in time honoured fashion, would lead to problems. The exceptions being the various devices that have been designed for the job - which may have put the plan into Dave's head in the first place.

 

[Daydream believer]

That is precisely why small self tacking jobs are a fashion that net creates extra work, with asymmetrics etc needed that a conventional genoa avoids
PS. You would be amazed how effective even a 110% blade jib can be downwind, using the conventional tracks forward to control twist. And a dawdle to tack upwind as well, best of both.

I sail single handed and would not be without the ST jib.that being said i do not recall ever running down wind with just a genoa on my last 2 boats. By the time one has messed about booming it out one may as well use the main.
Personally I just always feel the desire to get on with it, so have always kept the main working

going back to the thread- i attach the preventer to the boom at the mainsheet attachment point. I do not use a snap shackle but tie a loop with a bowline. The loop is very large and the reason for this is that once set i can release the knot whilst standing in the cockpit and not have to reach outboard to the boom attachment point to relese it. Nor do i have to pull the boom in to do so in a big rolly sea.
however, i rig my preventer different to everyone else as i flick it over the spring cleat and back to the cockpit winch.
I find that it is good enough and use one line that can be swopped over. I tend not to run dead down wind if on autopilot or using the Aeries so the angle of the preventer is OK. I also keep more sail off the spreaders

as for gybing in heavy weather, i have an ST jib and sail single handed & getting the main in whilst helming then feeding it out can be awkward in big seas in a fin keeled boat which is directionally unstable. My solution is just to do a simple chicken gybe. The boat spins in a sixpence and as long as i check the slack mainsheet does not catch i do not have to pull any sheets whatsoever and ther is no strain on the rig.

 

[Poignard]

I like to have the main up all the time in case I have to suddenly turn into the wind to recover a man overboard or a hat, or to heave to. Also i like the look of it!

 

[FairweatherDave]

Thanks for the further posts, lots to study, but safe to say my new preventer system will be conventional and I won't be using it to dampen the gybe.
With regard to using both genoa and main in rolly conditions I confess there was an element of thrill seeking, as much as there can be in a Konsort on a run without a spinnaker (something we are definitely not ready for......well I am but no-one else is). So we got 8.2knots SOG with the help of surfing the swell and a bit of tide. But my other motivation was to get there as quickly as possible to keep my family interested and happy in a somewhat uncomfortable sea state. I like booming out and preventing, it feels safe! However in different circumstances, proper steady cruising, my genoa alone is a very effective option. We managed five hours from Newtown Creek to the top of Chichester harbour sailing all the way which is a long passage for my lot.
Particular thanks to Steveberry for the detailed post. Good stuff. (My head is less on the ball today, A level results for our boys, all good, phew........no domestic revision stress for next summer's sailing plans.....)

 

[Sgeir]

That is the most appalling diagram but you are excused detention because it is actually a very good way to manage the problem:encouragement:

 

[LadyInBed]

I like to have the main up all the time in case I have to suddenly turn into the wind to recover a man overboard or a hat, or to heave to. Also i like the look of it!

Ok for short legs of a passage but if the leg is more than a couple of hours I ditch the main and run under twin headsails.

 

[dunedin]

J

I like to have the main up all the time in case I have to suddenly turn into the wind to recover a man overboard or a hat, or to heave to. Also i like the look of it!

Our boat will go to windward fine under jib only. But if an MOB downwind under genoa quickest solution would be rapid furl and motor back. Quicker than removing a preventer, gibing and sailing back.
Coincidentally it was a breezy downwind day in the Sound of Mull this morning, and of the dozen boats closest to us a full 10 of 12 were under jib only, one sailing main only - and one motoring downwind without even unfurling their jib, going slower than the sailors. Nobody had two sails set until the breeze dropped down.

 

[[163233]]

I read (after the event) about attaching to a forward cleat, makes complete sense (as does stretchier line).

Don't tie it forward, if that's what you mean, hook it round something and then back to the cockpit so you can release it without going forward.

You should be able to just uncleat it from the cockpit.

 

[webcraft]

Cheers all. Love the forum! Learnt loads here. Going to have to find yet another long bit of rope. Not going to repeat what is now known in our family as "The West Pole incident"

Make sure the dedicated preventer line is a different colour, so it is easy to find in the locker when you need it. Take it forward (all teh wayu oputside everything, of course) and round a snatchblock, cleat or fairlead near the bow so it can run freely, then back along the side deck to a winch. Let the boom all the way out then winch the preventer in to tighten it. To gybe, just slacken the preventer, gybe and re-rig it on the other side afterwards before going back on a dead run.

Make sure the genoa pole is rigged with the sheet free to run through the eye and an after guy holding the pole back. This means you can just roll the genoa away if you need to without having to go forward or de-rig the pole. Now you have complete control from the cockpit.


- W

 

[FairweatherDave]

More good stuff. JBJag27 just rubs in the basic mistake. My preventer was fixed and unreleasable in the event of a gybe, accidental or otherwise. Not clever.
Thanks Webcraft. Re. rigging the genoa pole that is already what I do..... nice and easy to furl . Sort the pole later.
The whole event emphasised to me how much better things are if controlled from the cockpit.

 

[Ruffles]

Also if you run the preventer forward (we use the spinnaker downhaul block) you can still scandalize the main if you get caught out; release the kicker and heave on the topping lift. It's amazing how much less scary an overloaded mainsail is when the boom is sticking up at a stupid angle. A lot safer on deck too.

 

[Birdseye]

I have a strop pemanently attached to the end of the boom - when not in use it is kept tight to the boom by a bungy attached near the goose neck. The preventers are run through toe rail blocks just aft of the shrouds with lines led back to the winches.

I would never pole out the genoa and rig preventers at the same time unless on a reasonable leg in open water. Just too much to disconnect if you need to do so urgently for any reason. MoB or collision etc. So I use the preventer on its own most of the time - ots the jibing boom that can kill not the genoa.

 

[lw395]

This preventer in a F4 stuff is perhaps the wrong thing to be doing?
Just head up a few degrees and spend some time on the tiller improving your helming, get better at sailing through the waves keeping the boat more stable?
Head up 15 degrees, you won't need to sail much further and you may go a bit quicker, as you get more skilled or know the boat better, you can safely sail progressively lower if you want to.

Just to be awkward, we do sometimes set a preventer in the smaller boat from the vang to the toe-rail, but only in light airs when a sloppy sea or wash is shakng the boom around disturbing the main, not to resist big forces like a gybe or dipping the clew in the sea.

A proper preventer from the clew end of the boom led well forwards is needed when it gets rough and you really need to be close to a dead run.

 

[FairweatherDave]

No doubt my helming can improve and I know some people like to go from reach to reach and avoid a dead run. But the course was dead down wind and with pole and preventer we were making good speed and I was enjoying the surfing. I hate the genoa collapsing and refilling and in a rolly sea state I think holding a downwind course broad reach just right is quite a challenge too. With a properly rigged preventer plus the pole I would have been fine. I feel I would have had to deviate a good bit more than 15 degrees to fill the genoa, more like 30. However the wind was very much a F4, I had a single reef in the main and I was expecting to take a few rolls in the genoa after the gybe for the broad reach into Chichester.

 

[stuartwineberg]

+1 for this. Amazing how many of my sailing pals don’t know the word. A very safe way to depower.

Also if you run the preventer forward (we use the spinnaker downhaul block) you can still scandalize the main if you get caught out; release the kicker and heave on the topping lift. It's amazing how much less scary an overloaded mainsail is when the boom is sticking up at a stupid angle. A lot safer on deck too.

 

[LadyInBed]

How I rig my preventer (10m Ketch) (note: normally I'm solo)
The rope is 10mm braid on braid.
One end goes round the end of the boom and I form a long loop and tie it with a bowline with the bitter end looped back through the knot. The knot is about a meter or so from the boom so that it's easy to reach from the (center) cockpit and untied with just a pull on the bitter end.
The rope then goes forward, hooks over the forward horn of the forward spring cleat, then back along the deck to a cleat outside the cockpit.
To tension, I let the boom out more than is required, put a little tension on the preventer and cleat it off, I then tension the preventer by tightening the main sheet.
I like the idea of sending the preventer forward around the bow cleat and back to the cockpit on the leeward side but I think it might be a bit of a hassle if I have to rig snatch blocks. I will try it and see.

 

[lw395]

No doubt my helming can improve and I know some people like to go from reach to reach and avoid a dead run. But the course was dead down wind and with pole and preventer we were making good speed and I was enjoying the surfing. I hate the genoa collapsing and refilling and in a rolly sea state I think holding a downwind course broad reach just right is quite a challenge too. With a properly rigged preventer plus the pole I would have been fine. I feel I would have had to deviate a good bit more than 15 degrees to fill the genoa, more like 30. However the wind was very much a F4, I had a single reef in the main and I was expecting to take a few rolls in the genoa after the gybe for the broad reach into Chichester.

You could have poled out the genny without a preventer on the main. You should then be able to sail happily around 10 degrees up from true DDW?
Keeping the genoa filled does require some skill, but also correct setting of the pole.
I see a preventer as a second backstop to an involuntary gybe, it's there just in case rather than to be routinely relied on.
A bit like ABS in a car.
Of course every sea is different and if you feel you want a preventer, rig one.

Even with a correctly rigged preventer, if a sea catches you badly and the boat spins around the clew, it's not pretty.