In Part 1 I wrote about why rigging a proper end boom preventer is vital when sailing off the wind. In this post I’m going to share how we have made rigging a preventer easy on Morgan’s Cloud.
This is information that will help you set up your boat so that you can, like us, always have a proper preventer rigged when the boom is far enough out to make it possible.
But first, let’s start off with a short video to demonstrate how easy it is to use this system in practice.
Now, let’s dig into the details and look at the two parts of our system, which I have named the boom line and the deck line.
Nice description of the proper method of rigging a preventer, John. We just got back from an awesome trip racing on a friends boat in the RORC Caribbean 600, and now I know we were doing it all wrong (dock line tied off at mid-boom, through a turning block aft of the shrouds to a winch). Funny thing about Ultrex Plus, though- when I Googled the term, looking for comparable line from other companies, the first link was from the National Library of Medicine- http://www.ncbi.nlm.nih.gov/pubmed/9788107
Who knew it had more than one use!
Ray
Hi Ray,
Glad the post helped.
And on the link, what can I say but Yikes, who knew?
That looks a lot like the preventer I rigged on our last boat, a 24′ gaff yawl. The only significant difference is that rather than screw extra fittings into the wooden boom, I simply made an eye-splice right round it. The loop passed through the eyebolt used for the clew lashing, but this was just to help locate it, all significant load would be around the spar and not on the bolt.
This is quite a common approach on traditionally-rigged craft; most of the high-load attachments involve a strop passed right round the spar rather than trusting fittings screwed or bolted onto it. Seems very sensible to me.
Hi Pete,
Thanks for the comment, that makes a lot of sense to me.
As Helen mentioned on Facebook, we have used pretty much this approach since reading Eric Hiscock in the 1970’s
The line along each side of the book is made fast to a cleat near the gooseneck. That way it is a good grabrail/harness attachment when working on our (rather high) boom.
We keep it a bit simpler by simply tying the preventer off at the bow, with the mainsheet eased off, then tensioning the mainsheet. Less control, but simpler.
I wonder about the best line? We use 1/2″ nylon, breaking strain about 4000 lbs. (47 foot boat) The few gybes we have had were quite tame, with the line stretching a lot, in up to about 25 knots. We have no experience in extreme winds.
I think, (but am not sure) that a pretty elastic line is preferable to a lower stretch.
Hi Neil,
To take your points in reverse order, I think you are right that having a bit of give in the system is a good idea, although I think that using nylon might be a bit too much of a good thing since when caught aback the boom is going to move a lot before being restrained, so I would go with Dacron, which still has some stretch, rather than nylon.
While, as most readers know, I’m a big fan of simplicity, I really don’t like the idea of cleating off the preventer on the foredeck for two reasons:
I would strongly suggest installing a block forward and then bringing the preventer aft to a winch, as recommended in the post. Also, after doing that, you will have about doubled the length of the preventer, so probably a good time to change from nylon to Dacron.
Could you please post a picture of your forward attachment on the bow and describe in more detail what a MOORING FAIRLEAD is? That would be helpful. I am thinking of using padeyes with backing plates on port and starboard about 5′ aft of the bow.
Great post. I am building one now.
Hi Larry,
I have added a photo of our bow area showing the enclosed fairleads.
Thanks John,
I get that its the round pad eye. But you have gotten me even more curious to see how you have the line led. It appears to go straight up. Please show the rest of your set up. I am working on the boom lines and want to install padeyes or fair lead ASAP.
Your web site is really great and I am learning a lot from you and the people who post here.
Hi Larry,
No, it’s not the round pad eye that we use. We pass the line through the fairleads—the oval holes in the toe rail that you can see each side in the small shot I added next to the “Notes that will help” heading. The deck line is rove from the winch forward, through the fairlead (inboard to outboard) and thence back to the boom line. You can see this in the large pic with the caption that starts “Note the snatch block…
As I say in the post, if you are not blessed with nice rounded enclosed fairleads like this, you will need to add two strong blocks up forward to accomplish the same function.
Is it viable to consider attaching a large snatch block to the forward cleat with jackline webbing (or perhaps spectra line) as the turning block?
Also: Any thoughts about doing double duty on the preventer line – to also act as the pole foreguy? Thinking it would reduce clutter on the deck… Problem I see is when flying both genoa and main deep on the same side…
Hi Bill,
Yes, I think that might be a very good alternative, as long as the cleat and its attachments are strong enough to take the load. I’m going to guess that on most good quality boats they will be since said cleats should be designed to take full mooring and anchoring loads.
As to double duty. It’s certainly an idea, but, as you say, what happens if, say, you are goose-winged and decide to gybe and leave the jib on the pole, as we often do? I guess there may be ways to do this, but my gut says that since the preventer is such an important piece of safety gear, maybe we shouldn’t be using it for other things since so doing always adds the risk that we will be tempted to say, “oh, the preventer line is in use for someone else and we are not going to be on this gybe long…”
We use a similar system but with a continuous line that runs through blocks at the bow and along each side deck. After attaching the leeward end of it to the appropriate permanently installed boom line we haul in on the windward side.
This means less rope on the side decks and no need for an extra winch on the leeward side since a sheeting winch to windward will normally be unused anyway.
This could also used as a fore guy for the pole but it’s often already in use.
Hi Pat,
Sounds like a good system, and, as you say, solves the winch problem on many boats.
I like the idea of this arrangement, and would like to implement it, but wonder if I am missing something in the application:
The author says, “After attaching the leeward end of it to the appropriate permanently installed boom line we haul in on the windward side.”
What does one do to set up the preventer on the opposite tack? If I am right, the bitter end is now tied to the boom line on the opposite side of the boat. It seems that the only way to rig the preventer on the new tack is to go forward and bring the line aft to the winch to tension it AFTER the boom is on the opposite side of the boat. I am hoping I am mistaken because it sounds like good option and cure for the single cockpit winch situation that I have on my boat. Although running backs would keep the windward winch busy unless I installed clutches.
Hi Larry,
Good point, I think your analysis is right.
One thought, you could have two lines, as we do, but just cross them over so that the boom end was on the leeward side and the winch end to windward. That way you could use the windward winch but still be able to set up for a jibe more easily with the new preventer to go on the new (after the jibe) windward winch as soon as the jib sheet was transferred during the jibe.