Boom preventer

[Paul S]

Was thinking about installing a boom preventer on our M.

Has anyone installed one? any tips or tricks?

Paul

[Bill at BOATS 4 SAIL]

Get a Vang. Attach it to a forward stanchion base, instead of the base of the mast. Most of my customers that want a vang convert their mainsheet blocks to a vang (which is the MacGregor vang), and upgrade to some better blocks for their mainsheet.

[Paul S]

good idea...like the price too

what about using something like this setup:

http://www.boatus.com/goodoldboat/vangprevent.htm

Too complicated for a mac?

Paul

[Duane Dunn, Allegro]

Wow. You may have solved the lack of a traveler issue on and 'X'. A setup like that would work great on mac and give you the control of a traveler, the sail shaping of the vang and the safety of a preventer all in one simple system. The only complaint I'd have is that now there is one more thing to trip over going forward, but I think I'll set one up anyway to try. It should work great with my boomkicker. I might skip the single line and have a separate one on each side to avoid the line crossing the cockpit.

Great link, Thanks! Finally a workable solution to the missing traveler problem.

[Paul S]

Wow. You may have solved the lack of a traveler issue on and 'X'. A setup like that would work great on mac and give you the control of a traveler, the sail shaping of the vang and the safety of a preventer all in one simple system. The only complaint I'd have is that now there is one more thing to trip over going forward, but I think I'll set one up anyway to try. It should work great with my boomkicker. I might skip the single line and have a separate one on each side to avoid the line crossing the cockpit.

Great link, Thanks! Finally a workable solution to the missing traveler problem.

I know..I would like to reduce the amount of line on the boat..not make more. I wonder if you could just not use the mainsheet traveler on the M with that setup? Pros/cons? Thought it was slick, but complicated with all the lines already on the boat.

Paul

[Rick Mathews]

The vang/preventer does look interesting. Duane: where do you plan to fasten it? Since using it as a vang would put it under heavy loads, I'm not sure that the forward stanchion would be strong enough to hold it safely. In any case, if you try the vang/preventer idea please post your findings!

[Duane Dunn, Allegro]

I don't know if it will help reduce lines on an M. You still need your mainsheet even with this setup, and since you already have a traveler you are ahead of the X's. While it may seem like we have a lot of lines, we really don't. You should see the amount of lines on a 'real' sailboat, particularly a racer. For an X boat like mine, this just adds a one more line setup. The current vang goes to one side and a mirror unit is added on the other. I think the forward staunchion bases are the place to attach, particularly for a test. They have 4 bolts thru bolted with washers, that's as well attached and anything else on the boat is including the dock cleats and the winches. I think they are easily up to the task. I'll have to sort through my spare blocks and line and see what I can come up with for a test.

[Catigale]

Paul - in heavy air I use my vang on one side of the boat, cleated to the rear cleat, and the standard main sheet moves to the other side

You get less heel cleating on the rear sheets as the heeling force now as no lever on which to roll the boat. You can also tighten the sheet enough so that the boom cant gybe on most points of sail

I give credit to this board for seeing this idea posted over the years - sorry to the author for not remembering whose idea it was.



Stephen

[Chip Hindes]

I think the forward staunchion bases are the place to attach, particularly for a test.

Agree with Duane, the stanchion bases are plenty strong enough.

However, doesn't the leeward sheet/vang need to be free to pivot well outside the lifelines? Can you drop the lifelines & do you intend to do so?

A better location from a workability standpoint would be the tops of the stanchions, but I believe based on the angles, lever arms, etc, the loads on the stanchions would be too high.

You get less heel cleating on the rear sheets as the heeling force now as no lever on which to roll the boat.

Not quite sure what you're saying. You can't reduce heeling by changing the sheeting angle, except as it affects sail shape. If the sail shape and angle of attack remain the same, heeling will be the same regardless of where the sheets are cleated.

[Mark Prouty]

This idea has incredible potential for a 26X. I found a traveler to be very benificial and miss one on the 26X. I'm going to try this one!

This may be simple mod of the year!

[Murv Barry]

I found a curved traveler for my 01X which I installed on sliding tracks above the hatch. The traveler is slid all the way back when in use and is forward when not in use to provide head clearance. This arrangement provides good control and eliminates the mainsheeet at the pedestal. The mainsheet bail is installed directly above the traveler. I installed a conventional boomvang and also a preventer. The bail for the preventer is about 4" astern of the boomvang bail on the boom. Each preventer line then goes through a ring which is attached to an eye strap secured to the bolts at the base of the fw'd stanchion. The lines then run astern to cam cleats near the cockpit. I used dock lines for the preventer lines.

I single hand a lot and although I am most pleased with the traveler, the safety provided by the preventer when setting the whisker pole is invaluable. I also use the preventer line to pull the boom down when running downwind. A bonus to the preventer is that the lines are also used when trailering. I made a PVC support for the mast and use the preventer lines to pull down on the mast securing the PVC support and mast.

Without a traveler it might work well to have a 3 to 1 or 4 to 1 purchase to make shaping the sail easier. A preventer is one of the most important and inexpensive mods you can make - especially when there are grandkids, or anyone else, moving about the boat.

[Mark Prouty]

Murv,

How do you think the preventer lines would work as a traveler alone without an actual traveler installed? They would pull the boom down but from my perspective this shouldn't matter much since a traveller is used close haul or close reach with the boom down anyway. Get that leech working just right. Also, I found a traveller handy for spilling the main in heavy winds or when a little tweaking is needed.

[Duane Dunn, Allegro]

I think there would be no need for a traveler with this setup. You can use the windward tackle to raise the boom above center just like a traveler does. It's really just a variation of leading the mainsheet itself out to the windward rail, or using two mainsheets, one to each side as some have done. With this setup you get rid of the lines crossing the cockpit. I do think you would still need the mainsheet though to get enough downward pull to take out the twist in the sail. It would seem to be a pretty simple setup, the two vang/preventers forward and the mainsheet at the pedestal. These three tackles would let you position the boom exactly where you want it for any sailing situation. This combined with a boom kicker to lift the boom gives you a lot of control over the main.

An advantage of this in heavy air is you can slack off the mainsheet without having the boom rise and make the sail to full. You can keep a flat sail as you swing it off the wind just like a traveler does.

[Mark Prouty]

Think of what it could do for controling a jibe in heavy weather.

[Catigale]

Chip - i was pointing out that the portion of the heeling force that the boat experiences through the sheet effective heels the boat less if its cleated on the lee side of the boat since its lever arm is reduced.

The heeling force through the mast is not affected by this to first order...i suspect this is larger than the sheet force.

Ive noticed I sail with less heel using this method.