Boom Brakes & Preventers

[MMNETSEA]

Not wishing to pre-empt the findings of the investigation into the latest tragedy in the ARC rally.

But taking a good hard look at preventing injuries from being hit specifically by booms:-

During racing the controlled gybe manoeuver may be performed many times without the use of a boom preventer - this is understandable.

However, when in a cruising mode and when setting a course for a distant destination, is there a good reason for not using a boom preventer, so that if an unplanned gybe occurs - possible injury is averted ???? (not sure about the commonly used term "accidental gybe" means)

There are many ways to prevent the boom swinging uncontrollably from one side of the boat to the other. Many commercial accessories are available - many simple techniques have been adopted and improved on, I have just gone through such a process.

What do our cruisers do to minimise the risk of being clobbered by the boom ???????

Richard

[Nausikaa]

Originally Posted by MMNETSEA

What do our cruisers do to minimise the risk of being clobbered by the boom ???????

Keep my head down!

Seriously though, there is a very simple technique for rigging preventers. From the end of the boom (or very close to it) a line is rigged on each side to a block forward of the mast from which it then leads aft to the cockpit. When the vessel is settled on a run, the preventer on the side of the same side of the boat as the boom is simply pulled taight and belayed on a cleat in the cockpit. Don't forget to let it go before tacking or deliberately gybing!

The arrangement is simple and the cost almost negligable.

Aye // Stephen

[imagine2frolic]

I used a preventer when singlehanding my 30ft. Columbia from S.F. to Mexico. It came in handy several times. On the cat the traveller is 17ft, and there is a bimini between my soft noggin, and the boom.

[redbopeep]

That two block system described above also works well on staysails that have their own boom, too. Before the sheets are run aft to the cockpit they are run forward through blocks about 1/3 to 1/2 of the way forward of the end of the staysail boom. As you know, those staysails frequently do their own jibe unexpectedly on anything from a beam to broad reach or run because of wind blanketing of the main sail. If someone is on the foredeck, its a matter of safety.

[MMNETSEA]

If it is accepted that it is obligatory for every skipper to prevent unsafe and destructive boom movement by ensuring the boom is rigged for gybe control, perhaps further discussion is needed on preventing 'Boom injuries'.

A better solution to a preventer is probably a boom brake as these units do not require the immediate crew attention that a rigged preventer requires (definitely more expensive but safer - examine that aspect further on)

Examples on the market (in no order of preference - no commercial interest here declared)

Walder (French)

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Dutchman (Netherlands)

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Wichard (French)

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Of the above 3 ( sure there must be more!) the Wichard is definitely the simplest - the Dutchman is a lot cheaper than the Walder.

Returning to question of a preventer vs. a boom brake - it must remembered that if the boom 'dips' in the water at any time while held by a preventer, a shock absorber should be included in the preventer's line to minimise damage before the preventer can be eased.

All in all, if considering which is safer and easier to manage - the boom brake wins hands down, except for cost.

Richard

[Francis]

Boom brake seem the safer device and since they are mounted on a permanent basis, there is no risk of forgetting rigging up a gybe preventer or getting injured while doing so. Raising the boom works nicely too, I did that in order to stand at the helm, it works well and I had to cut only a couple of square feet at the head sail. Granted a higher boom moves up the center of gravity but on a 23 tons cruiser, 1 1/2' up is not making a lot of difference.

[MMNETSEA]

Hi Francis,

What was entailed in repositioning the gooseneck/boom etc etc eg.. moving blocks fairleads

winches

Richard

Hi

I have spent much I my sailing with racing crews and have had many hands in a gybe. Now I have started cruising and without much knowledge of boom brakes decided that to put up a boom brake sounded desirable. I fitted one and have not regretted it, it does allow a well controlled gybe and takes the slap away from the sail when its rolly in a lesser breeze. It also is a benefit when reefing during a reach. I do not enjoy the additional lines in the cockpit but the benefits outweigh this. I am not sure about the most effective placement of blocks in relation to the mast and also was unclear if the boom brake might be able be used as a boom vang?

[svmoose]

Originally Posted by MMNETSEA

Not wishing to pre-empt the findings of the investigation into the latest tragedy in the ARC rally.

Richard

Hi Richard, Along the same vein as "keep your head down", but not tongue-in-cheek, when I go forward at sea I try to keep forward of the after lower shrouds, ie. using them as protection from an unplanned gybe. On SV Moose we run two 3/8 lines from the boom vang attachment point outboard to bullet blocks on the toerail. The lines run parallel to the toerail back to a second set of blocks, and then up to cockpit coaming cleats. It's worked great for the last year, and it's been a busy year.

Duncan

[roverhi]

I use a double vang set up, 4 part tackle from boom to deck on each side. It acts as a preventer keeping the boom from swinging wildly in a jibe It also allows me to immobilize the boom by cinching both sides tight whether the sail is up or down as well as vanging the main down. Bitter end of the vang lines are run back to the cockpit. With the halyard and reefing lines also run back and lazy jacks, can work the main without leaving the cockpit from hoisting, to reefing to dropping the sail entirely. You do have to remember to release the vang in a planned jibe but something that gets imprinted in your mind when you forget it once.

I went with the double vang system since I didn't want to give up the realestate under my boom that a boom to mast vang does. Boat came with one but one boisterous sail and it pulled the fasteners out of the mast.

Aloha

Peter O.

[Seeratlas]

I vote for raising the boom. Did it on my previous sloop, but mostly because it was large enough and heavy enough that pretty much for sure if it hit you, it could kill you. But for any cruiser, it seems a bit silly to take a chance of serious injury for a few extra square feet of sail. Especially for someone sailing short handed, you have a million things on your mind, one moment of inattention, one time forgetting to rig the vangs/preventer and WHACK!...out of the gene pool.

Think of it this way. How about if we were all talking about LOWERING THE BOOM, testing the 'limbo' principal as to how much cockpit diving we'd be willing to do to gain a few extra square feet. Who was it that decided that we'd raise the boom starting from waist height and stop raising it when it was just right for whacking the hell out of someone's noggin....When you look at it that way, seems silly as hell NOT to put it over your head...doesn't it?

seer

[MMNETSEA]

Hi Seer,

Thanks for input , agreed that if the design of the sail plan provides for raising the boom.

cutting the sail to a smaller triangle , usually along the foot - so that the boom misses the tallest crew member - then that may be a good option. However, this modification may not be that simple :- consider internal reefing lines, fairleads , gooseneck , new sail , new higher mast ,COST, Raise how much ? What will it do to the main's efficiency - eg : on a fully battened main ?

Etc ........................ .

Even when modified , the boom will still need controlling - this is where a brake comes into its own - while a preventer will still need crew attention during an unplanned gybe.

Richard

[JeanneP]

I agree with Richard's opinion. When you raise the boom, everything becomes more difficult, depending on the boat's deck height under the boom, for example. When the boom is so high that it clears everybody's head, it becomes difficult and tiring to work on the lines on the boom, especially reefing lines, etc. Things that used to be doable from the cockpit now require going forward onto the deck, and even then the increased height will make it more tiring. Even when you have a higher boom, a boom brake or preventer is still going to be necessary for the times that you have to work on the lines or the sail on the boom while underway.

I wish that we had had a boom brake rather than Peter's having to rig a preventer whenever we sailed downwind. However, I diskliked downwind sailing so much that we rarely did so. It took some time for me to convince Peter that a broad reach zig-zag course got us to our destination faster and more comfortably than DDW. Once he realized how much easier it was on both of us, DDW became a rare point of sail for us.

[Francis]

Originally Posted by MMNETSEA

Hi Francis,

What was entailed in repositioning the gooseneck/boom etc etc eg.. moving blocks fairleads

winches

Richard

Hi Richard,

Sorry for the slow answer but I was sailing for a while, mind you motoring as the little wind I had in the strait of Malacca was bang on the nose. Back to the subject, all I had to do was drilling new hole in the mast about 50cm higher to fit the gooseneck. I then recut the main sail head but she was already short of the mast head so no trouble there. I also had to recut the leech in order to avoid rubbing on the double backstay, that had to be done anyway as the sail was not cut properly in the first place.

The down side, I supposed, is when reaching for the head sail to attach the halyard a normal size person needs to do a little climbing, same for putting on the sail cover but I'm 6' 6" so that suit me fine.

I really appreciated being able to stand at the wheel as I was able to raise the bimini as well, it might not seem so important for an average size person but tall people need to rearrange the space around them....

[redbopeep]

A reminder on the shoutbox came up--boom brakes and preventers are IMPORTANT to prevent injury.

Anyone recently put on a new boom brake or preventer system?

[redbopeep]

Regarding the shoutbox comment:

"Boom brakes (and preventers) are good things. You can also change your main sheet setup to help prevent such things."

I'll try and find a pic or two of this, but there are two ways I know of that one can have a mainsheet set up to help prevent a wild swing across the cockpit. The use of a preventer or a boom brake aside...

The first is where, rather than allowing your mainsheet to ride along a traveler as many folks do which allows the equiv. of a single point attachment from the boat to the boom, you can have two blocks--one on each side of the traveler or one on each side of the boat that BOTH go up to blocks on a bail on your boom. Then, when tacking, you've got more work to do because one of these sheets is tight at all times--your boom cannot freely swing across the cockpit, you must manually release the lee one in the tack so the boom can cross over to the new lee side. Then, you reset the new lee side sheet to be tight so the boom cannot go wildly back across the cockpit unless you release the sheet. There's a pic in a book by Ross Norgrove (I think that's his name) on "Cruising Rigs and Rigging."

That set up works okay unless you're really on a run...in which case both sheets are so loose that the boom can come back across with an accidental gibe. That's when a preventer set up works wonderfully. Or, a boom brake helps.

If you don't want a boom brake or a preventer which can point load your boom depending on set up, you can set up a single mainsheet through a series of blocks to dampen the quick motion as well. Across the back of the cockpit, that's a block on port with line leading up to the boom then back down to a block in the mid-section which may be on a small traveler or horse (if traditional boat) then back up to a block on the boom then down to a block on the starboard side. With this set up, you might have a winch on one side or the other but don't need them both so you can actually couple it with running backstays nicely and use the lee side winch if needed. You can increase the "friction" of this as a boom brake by adding purchase to your block situation (with line up from port to boom, back down to port, up to boom, down to middle block, up to boom, down to starboard side, up to boom, down to starboard side...) and have a set up that is practically impossible to move. The larger the mainsail the more likely such a set up is desired OR a boom brake is wanted.

Clear as mud?

[captstu]

I've added a Gyb'Sea boom brake to the boom end of my Gemini 34' catamaran. In the "weakest" setting, it still provides to much brake action in all but the very highest winds - where I have long since reefed anyway.

Has anyone used a smaller diameter line to reduce the effectiveness of the brake? I was thinking of trying an 8mm line.

I suppose I could move the brake to mid-boom - but it is so convenient on the boom end and reduces the stress on the boom that I'd rather keep it where it is installed. thank you

[MMNETSEA]

Originally Posted by captstu

Gyb'Sea boom brake to the boom end of my Gemini 34' catamaran.

Hi ,

Have you got a picture of the brake and the setup? What placement instructions came with the model ?

Reducing line diameter will certainly reduce friction - but how much will also be effected by angles and the radius set by the boom - the answer will probably be found in trial and error.

Richard

[captstu]

Thje photos of the setup are at:

http://shearwater-sailing.com/Gemini%20Res...Sail%20Plan.htm

I was hoping to avoid some trial and error by leaning on the experience of others. My guess is 8mm line will work. The vendor is not really any help - they (and Dutchman) don't recommend boom end installations - but given the layout that is typical of catamarans, boom end is a better bet - the loads are lighter and the control more fine -- except there is to much friction for the light load. Thank you

[mico]

Originally Posted by captstu

Thje photos of the setup are at:

http://shearwater-sailing.com/Gemini%20Res...Sail%20Plan.htm

I was hoping to avoid some trial and error by leaning on the experience of others. My guess is 8mm line will work. The vendor is not really any help - they (and Dutchman) don't recommend boom end installations - but given the layout that is typical of catamarans, boom end is a better bet - the loads are lighter and the control more fine -- except there is to much friction for the light load. Thank you

We've just installed a Gybe-easy mid boom - about 2 ft aft of the boom vang. In a following sea of about 15kts it works well on the lightest setting with the 8mm line. We like its small size and no real moving parts. Still experimenting with the line tension which seems to have more of an impact to its hold than the actual setting. Take your point about the layout and the boom end set up for cats. Is your gybe easy aft or forward of the mainsheet? The reason for a mid boom recommendation seems to be that the swing of the boom is arrested quicker and eases the fulcrum stress of a boom end installation. Try an experiment, in light wind grab the boom vang and swing the boom across. Then do the same swinging it over from the boom end. You'll notice a big difference in the force exerted on the rig. Even with all the best advice in the world, every set up is slightly different so trial and error is often unavoidable. Our onboard bread making is still more error and certainly a trial!

Fair winds,

Mico