Do you use one?
Purchased or self rigged ?
If not why?
My old Ariel came with one. The guy who show me the ropes on sailing said, oh, this is something racers use do not worry about it.
Later I found out what it really was, after I took it off.
After finding out what it did and having the NEED to use it in near gale wind and had the boom fly across the deck, I put it back on. Another time I did need it , it came in handy. Another it was in use and snapped one of the Pulleys, because it was old, but it did slow it enough for me to make the correction.
My current Islander done not have one. So I'm looking...Once saw a dutchman preventer on Ebay but, did not bid enough.
I have seen Vang connected as a brake, but that means going on deck to hook and unhook.
thoughts...?
Put me in the camp of the 'serial vang abusers'. ;)
I have a pair of padeyes on the fwd corners of my cabin top, and can switch the vang in seconds. Works great when going downwind, especially when the autohelm is steering and I am wing and wing.
If I did not have the padeyes, I would just take the vang to the stansion base, or on another boat maybe one of those toe rails with the holes in it..... I would not want to sail long without some way to rig one..
definatey use one.also I keep it a separate issue...I take it out only when necessary.....its a short legnthof rope that inmistakenly large in diameter...it gors from mid boom to a chainplate on the hull
A cheap way to rig a dutchman preventer is to hook a carabiner to a boom bail, run a line from rail to rail or any suitably strong attachment point, and use a munter hitch on the carabiner - it's a bi-directional belaying knot - http://www.chockstone.org/TechTips/MunterHitch.htm
That way you can gybe in a controlled manner without touching the sheet. Be sure to use a pear-shaped auto-lock biner so it doesn't accidentally open the gate - rare, but possible.
watsongs,
This looks great, let me see if I've got this right. You attach the carabiner to the bailer, the line goes from the lee rail/cleat etc through the bailer with this knot and you hold the other end of the line. When you're ready to jibe you pull on your end to lock the knot and controll the swing of the boom. Is this right?
Oded Kishony
I have been using a preventer religously for 2 seasons. You can probably guess that this came out of a desperate situation when finicky lake winds shifted to an accidental gibe. My setup is identical to the one described above. A line from the end of the boom bail through a snap shackle, clipped to the toe rail amidships then run back to the cockpit where I cleat it off on a horn cleat. Easy and safe. No more accidental gibes and very handy when trying to run wing on wing for long periods single handing.
Cheers!
John
My daughter goes rock climbing and it occured to me that her belaying equipment would make an excellent boom preventer.
Here's what it looks like:
http://swift11.swiftnet.com/rockempire/images/paradoxlg.jpg
Costs about $15 and is very easyand dependeble to set up and use.
Interesting stuff, guys! Karma for all! ;D
it is in my humble opinion the the preventer line should be one piece of rigging that should stand out from all others.kinda like an emergency brake on a car.once sails are set on any kinda broad reach it should be the last thing set.....and the first thing removed b4 gybing.
I couldn't agree more - the line I used for the preventer is the only line on the boat with that colouring.
If you sail with a small crew or single handed - and do any amount of downwind sailing you should seriously consider rigging a preventer. It's simple to do and it may just save your life.
<gets off soap box>
Sail Safe
John
On my Cal I reposition my vang if I need a preventor for a short period But I try not to sail at an angle where I need one. My boat is quite a bit faster if I foot off a bit, so while I sail farther I get there in about the same amount of time.
Ok, now that I'm out sailing again and see the need for a preventer. I'm been thinking about what to do and re-read this thread here. I think I have it figured out about the mtn gear and using it on the boat.
http://swift11.swiftnet.com/rockempire/images/paradoxlg.jpg
so.. what I see is one would need two of these. One for each side, Right!!?
Then as the boom changed from Port to Starboard or..., one would just loosen the line let it switch (gently), then tighten the other side and lock/clamp/cleat it down....!
I'm I seeing this right?
Of course, you can do the same thing with just the caribiner by using the Munter Hitch. It's a knot for a poor man's belay (no extra gear).
See Munter Hitch Here (http://www.chockstone.org/TechTips/MunterHitch.htm)
With the Munter Hitch, you won't need the ATC ( a very useful belay device, if single purposed).
EDIT: Apologies to Watsong; I even linked to the same site!! :-[
Ah So deska ! ( Japanese for; oh I see!)
I get it, now it makes sense. So instead of buying, line, pear-shaped locking carabiner, and 2 ATC's @15.00 ea. I can save the 30.00 and use this knot!
Cool. I'll give it shot. Attaching the carabiner to the base of a sanction.
and lets use the words a "cost conscious" or "thifty man's" belay ;D ;D
poor men do not own yachts ;) 8) ;D ;D ;D ;D ;D
The sail on the Pretty Gee can generate some pretty ferocious forces, so I've gone with a Dutchman Boom Brake system. I'm in the process of mounting it, and will be happy to report back how it works out. I'm planning on using a padeye that is already on the boom to mount it, and adjust the position to get the best response. The line for the boom brake will run from the starboard chainplate, to the boom brake, to a rachet block on the port chainplate and then back to a Spinlock PX Powercleat on the port side cockpit coaming. We'll have to see how this works.
Adrift: I was looking at those on their website. Looked pretty good. Not bad in cost. I still may end up doing that down river ( as in life )...However as a "cost conscious" sailor ;) for now...
I if can save a couple hundred bucks and get the same safe effects, I'm for it!
anyway, yes please report back with your findings. inquiring minds want to know!
Captain Smollett : do you think a 5/16th line with a Breaking strength: 3,000lbs is good? too much or not enough for a 29fter? What size are you using?
Quote from: Zen on May 17, 2006, 06:04:40 PM
Captain Smollett : do you think a 5/16th line with a Breaking strength: 3,000lbs is good? too much or not enough for a 29fter? What size are you using?
What size is your main sheet? I'd probably size the preventer similarly. The preventer I use on my 18 ft-er is a size smaller than my mainsheet, but that's because I had it lying around, and it's braided differently (different appearence and texture) from all the other lines on the boat. Like folks said above, use something you can distinguish from other lines, so if you have to loose it in a hurry, there won't be ambiguity.
The real determination of the preventer line size is how heavily loaded the line will be. Using a line that is too small can be far more dangerous than one that is properly sized, as the wind can really load up the sail, and then when the line breaks, the kinetic energy unleashed is far higher...and more lethal.
At the Safety at Sea seminar I attended in March, statistics said the majority of serious-to-critical injuries were due to booms hitting heads... the majority of fatalities were due to going overboard, and in many cases this was caused by the boom.
Three things to remember: 1) The preventer line is going to be under a slightly different load than the main sheet, based on where on the boom the two lines attach. If you're using a fixed line to a padeye on deck, then the preventer should really at least as thick as the mainsheet, and attached as far outboard as possible. 2) If the line is going through a brake-type device, then the location isn't quite as important, as the load on the line is more forgiving, as it will slip, unlike a fixed line. 3) If a boat is being used to go offshore, then the preventer lines should be a bit larger than if it is just being used for daysailing or coastal cruising, as the loads on offshore boats are often higher, for longer durations, than on other boats.
I hope this helps.
excellent! Karma point awarded! :D
In short: too much is better!
Thanks to both of you for the advice!
Yes, a heavier line is better... another point to watch out for though is if the preventer line and the mainsheet are not in roughly the same position along the boom, then there is a possibility of breaking the boom under really high winds. This can also happen where the mainsheet is connected mid-boom, and no preventer is installed.
The advantage of the brake-type preventers is that they do not cause the pressures on the boom to build continually, and risk failure, as they will allow the boom to move (hopefully) at a slow enough rate to eliminate most of the danger of accidental gybes or tacks.
A lighter preventer line is exceptionally dangerous, especially in the static-type preventers, as it can allow very high loads to occur and rapidly fail without warning, and lead you into a very lethal false sense of security.
Does anyone have a Spinlock PowerVang for sale? I'm interested in getting one, but Spinlock discontinued the product back in September, and I haven't been able to find one for sale anywhere. If you see one for sale, please let me know.
(http://www.dankim.com/assets/pg_bb1.jpg)
I just installed a Dutchman Boom Brake on the Pretty Gee. I've written about the installation and posted the story and photos on my blog, and you can read it here (http://blog.dankim.com/2006/06/20/dutchman-boom-brake-install/).
Although the Pretty Gee is a trimaran, the installation should work quite well on almost any sailboat with a similar chainplate setup.
Let me know what you think.
Dan
Looks like a very clean setup. I'd be interested in hearing how it works.
I missed getting a dutchman brake system on ebay by $1.00, Arrrrrr
I'd be happy to tell you how it works out, now that it is all installed... now, if only the weather would cooperate. :D 10-15 knots out of the west would be ideal... that's what I think we'll have tomorrow.
One more point on preventers and the ropes used in them. A little bit of give is actually good, so using a nylon or other "stretchy" rope is ideal. There are a variety of hi-test stretchy ropes available and the one we use is a climber's dynamic rope in 12 mm. Being a climbers rope it is also of different colour and feel then anything else that leads back to the cockpit, so we are always sure of what we are dealing with. We use 12mm...which is probably overkill...but is very pleasent on the hand.
I crewed ona 36foot race boat last year where every rope on board (sheets, halyards, vangs and cunningham) was 5 or 6 mm spectra. Sail a race, throw away a pair of gloves and go looking for band aids and hand lotion. Really harsh way to a save a little weight aloft!
Alex.
12mm may be a bit overkill for most of the boats used by people on this site... after all this is a small boat site... My boat, being a trimaran probably has greater issues, as my boat doesn't really heel to spill the wind from the sails.
Going with too small diameter a line, however strong it may be, is also a mistake. Small lines are far more vulnerable to chafe, and much harder on the crew's hands. Lines that are used often should be 3/8" minimum, preferably 7/16" or 1/2" if possible. The sheets on my boat are all 7/16" or 1/2" line.
Thinner lines are also harder to grip and handle, especially if your hands are cold. Being harder to grip securely, makes for a more dangerous boat... imagine the amount of problems you can be in if you are trying to uncleat a mainsheet and your hands slip off the sheet before you get it uncleated... you could capsize the boat pretty easily in such a situation.
Had something like that happen last fall, and it was snowing that day, so not a great day to end up in the water. Part of the problem was that the cam cleats weren't really properly maintained and were sticking, and part of it was that the line was too small to get a solid grip on in the cold, with gloves on... and part of it was the cockpit of the boat was lined with ice...so my feet ended up going out from under me as the boat heeled, and I had problems getting the sheet freed from the camcleat. It worked in the end, but I was on my butt in the bottom of the cockpit when I finally freed the main.
7/16 IS 12mm
25mm equals one inch.
Quote from: Fortis on August 09, 2006, 10:20:33 AM
7/16 IS 12mm
25mm equals one inch.
Actually, 25.4mm = 1 inch... and 7x25.4=177.8
177.8/16= 11.1125 12 mm is closer to 1/2" than it is 7/16", which is a bit overkill for the preventer on most boats the size on this board.
If you're going to be picky about measurements, please use the correct ones at least. Being so picky and using the wrong conversion factors just shows your ignorance.
Well, let's all calm down. ;D
12 mm is close enough to halfway between 1/2 and 7/16 that an arguement over the issue pragmatically pointless.
12 mm / (25.4 mm/in ) = 0.472 in (to three significant figures)
1/2 in = 0.500 in, or 0.028 in more than 12 mm.
7/16 in = 0.438 in (to three significant figures), or 0.034 less than 12 mm.
Halfway between 7/16 and 1/2 in would be 0.469 inches. This makes 12 mm only 3 thousanths of an inch, less than a human hair, different from halfway.
I got a boom brake this weekend from the Marine swap meet, it came already with a large line that was comfortable to hold and small enough to cleat :)
Quote from: Captain Smollett on August 09, 2006, 12:35:52 PM
Well, let's all calm down. ;D
12 mm is close enough to halfway between 1/2 and 7/16 that an arguement over the issue pragmatically pointless.
12 mm / (25.4 mm/in ) = 0.472 in (to three significant figures)
1/2 in = 0.500 in, or 0.028 in more than 12 mm.
7/16 in = 0.438 in (to three significant figures), or 0.034 less than 12 mm.
Halfway between 7/16 and 1/2 in would be 0.469 inches. This makes 12 mm only 3 thousanths of an inch, less than a human hair, different from halfway.
I do understand that the difference between the two is pretty neglible... I just dislike being lectured by someone who doesn't have their facts straight... The brake line on my boat is 3/8" just for the record.
Hey Zen-
Congrats on the purchase... if you have any questions, let me know. :D
Quote from: AdriftAtSea on August 09, 2006, 04:06:52 PM
I just dislike being lectured by someone who doesn't have their facts straight... The brake line on my boat is 3/8" just for the record.
Well, you can choose to interpret his comment as "lecturing" if you wish.
You stated in YOUR post use 7/16 but 1/2 is preferred, after writing that 12 mm was overkill. He was pointing out that 12mm is BETWEEN those two (that you were recommending) and as you also later pointed out, is slightly smaller than than the line you said one should use.
I think the point he was making was how can 12 mm be overkill if 1/2 in (which is slightly larger) is recommended.
The bottom line is that each of us uses on our boats what we think is best. There is no right or wrong MOST of the time. Heck, I once used a crappy old trailer winch line (complete with rust stains) as a boom preventer. Sometimes we use what we have available when the need arises.
The idea of SailFar, if I may speak for Kurt, is to exchange ideas and experiences. Calling someone ignorant is not really conducive to such free exchange. We all have something to offer (well, at least I HOPE that I do :) ).
You're actually quoting me out of context. For the boom brake, I believe that 1/2" line is a bit overkill, but for commonly handled lines I've gone with larger diameter lines, to make them more comfortable to handle.
The boom brake line on my boat, which is not often handled, is only 3/8". The sheets, which are handled very often, are 7/16" or 1/2". I do believe that for most boats in the small boat range, a preventer of 1/2" is going to be a bit overkill. The Dutchman Boom Brake, which I am using, recommends lines of 3/8"-7/16" for sails up to 500 sq. ft., which is considerably larger than those on the boats we're discussing.
Most boats in the 20'–30' range will have mainsails less than 250 sq. ft. They recommend lines only 1/4"–5/16" for sails of that size. I made the decision to get the larger boom brake, as my sail is quite near the top end limit for the smallest model, being 242 sq. ft., based on their recommendation that you go up a size if you intend on going out in any heavy conditions or on very long passages.
Oh yes, I can tell Drifty and I are going to get along famously.
If you believe I was lecturing you, then it is only because you have not seen me in full blown pompous glory as I hold forth on sundry issues that the common masses cannot seem to encompass into their meagre collective wisdom.
And I do not think I read you out of context when, as Cpt Smollet points out, You went from calling my 12mm overkill after I ststed it was mostly that size for comfort-on-the-hand issues and then stated exactly the same thing to identify the same size rope in Imp. measurements as being ideal.
I am indeed ingorant about a great many things, and every day learn more about things that I know nothing about....But I think I am pretty solid on my metric/imperial conversion table.
Though farenheit tempretures make no sense to me and I find it easier to go from celcius to kelvin to farenheit then just between the two.
In short it was not my intention to lecture you, or influence your own choice of rope, for that matter. Given my whithers I would far prefer that people who read my post took away the info about considering dynamic or "stretchy" line for preventers then what size I find ideal and comfy. I am sure they can read a spec stress chart at the rope shop as well as I can.
Good day, sir.
Alex.
I have this long hunk of rope, y'know? I tie one end to the boom with a knot-thingy and run it up front on the boat and than back to the other end where it is tied off.
12mm double-braid, the LEAST stretchy stuff I could find. Someone with lots of miles (Evans Starzinger I think) made the point on another board that if you hold the boom stable then shock loading is less of an issue. I think that's a good point, so I set up my preventer with the minimum amount of stretch I can.
I use a bowline to the boom end (end-boom sheeting also). It's soft, easy, and doesn't jam. Some people have given me grief about not using a shackle "to make it easier to undo in an emergency." Frankly, if I'm using a preventer the boom is way out over the water and there are much better ways to get it off than climbing out there.
In an emergency, I'll cut the preventer at the forward shrouds (about where it comes in reach on my boat). If I have to I'll cut the return length anywhere along the deck. I'd rather not do that if I can avoid it since it leaves line in the water that can end up around the prop.
I run the line from the boom end forward, through a bow cleat and back along the deck to a stern cleat where I cleat it off.
To gybe, I release the stern cleated end, center the boom, gybe the boat, and let the boom out. I do have to go forward to rereeve the preventer for the other side, but downwind on my boat that isn't a huge concern.
I have seen people using this approach put a ring and shackle in the preventer near the mast, so you don't have to go all the way forward. That improvement is on my to-do list along with all the other splicing chores I have piling up.
Nothing like sitting in the cockpit at sunset, a glass of wine, a good companion, heaving on a g*& d&*%ed fid trying to get a double-braid eye splice to close all the way.