|Topic Review (Newest First)|
|07-17-2007 02:53 PM|
Thanks for the Information
I really appreciate all of the great information. This forum is great. I learned a lot of things here.
|07-13-2007 10:32 PM|
First, you really shouldn't be running DDW with an Asym Spinnaker... Most asyms aren't efficient for that point of sail. If you're broad reaching with an Asym Spinnaker, it is pretty unlikely to broach or jibe. The most likely cause of a broach with an asym spin is a radical change in wind direction, which generally doesn't happen on the ocean.
Freeing the sheet is the simplest way to prevent a broach with an asym spin.
BTW, I would recommend you use a Dutchman Boom Brake or something similar rather than a preventer, especially if you're cruising or sailing short-handed. A Preventer can cause some problems in an accidental jibe, including running the risk of breaking the boom or pinning the boat rail down.... A boom brake serves much the same purpose but doesn't have as much of risk of breaking the boom or pinning the boat.
|07-13-2007 07:05 PM|
Most assym spins are dogs on a dead run, they're more of a reaching and broad-reaching sail. So the "jibe-broach" really isn't a concern to you. It's the "involuntarily head up and broach broadside" you're concerned about.
To avoid it, ease the main first, it'll help you bear off and put the wind more behind you, which should steady you up..
If that doesn't work, then the boat's going to head up on its own, so let both sheets out and just hang on. It helps to cross-sheet the spin sheet to the windward winch, so no one has to dive to leeward to ease or trim, which you don't want.
I'm not a big fan of the assym spins, am more old school and like the symmetical ones with the pole. Clearly I'm in the minority here...
|07-13-2007 04:13 PM|
According to my wife, the best way to avoid a broach is to leave the kite(s) at home.
A point to remember is that the spinnaker trimmer is for a large part, in control of the boat. As stated earlier, he needs to change the sail’s angle of attack by easing the sheet in order for the helmsman to drive the boat deeper and steer out of the round-up. The sail can easily over-power the rudder. If he doesn’t, helm can easily stall out the rudder, loosing control of the boat. Thus turning a simple round-up into it’s more exciting cousin, the broach. At that point we’re dumping the vang both to de-power the main and (more importantly) to keep the boom out of the water (and breaking). Meanwhile, helm centers the rudder and waits for water to reattach itself, at the same time, lending encouragement and advice to the crew while maintaining his calm and composure.
We have tended to get into trouble when: Trying to carry the kite too high (depends upon the kite, but in our local conditions anything above 100-90* AWA is high risk). Far better to go down to the Code 1 or white sail; When the wind speed is greater than the sail’s polar’s. (I believe North now when they say “don’t fly the G-2 in winds (AWS) greater than twenty, twenty-five tops”); Gusty conditions – spin trimmer and grinder have to constantly adjust – a lot of work and it wears them out, but it keeps the boat pointed in the right direction and happy; And lastly, reaching through big waves. This is when helm and spin trimmer really need to act as one. Helm needs to “square” the rudder as we catch the next wave (to avoid that broach) while the trimmer eases the sheet. Once we have caught the wave, we can return to base course and harden up on the sheet. The result is a slightly serpentine course through the water. Do a good mainsheet pump at the same time and its surf’in USA time!
That was fun! Next week, can we talk about “after the broach, how the heck are we going to get the boat out of the water and back on her feet?”
|07-13-2007 01:50 PM|
Situation as I read it above:
While on a Port reach with the Assym and the wind at about 210* you would steer to Starboard (fall off) if she was headed for a broach. You could also ease the sheet while falling off to change the angle of attack and dump power out the Leech because the way an Assym works as opposed to a Symmetrical chute. You other folks feel free to chime in here....
|07-12-2007 07:47 PM|
Allow me to underscore...
Knotalaud did sat "fall off" not "head up a bit". Heading up to avoid a broach is tantamount to takint a high speed turn arounf a corner in a car where the road is banked the wrong way. You would be helping a broach to happem, versus falling off, which would arrest the tendancy to broach.
I know... against all natural tendencies when on a close reach, which is to head up...
|07-12-2007 07:37 PM|
I'm not sure what you mean when you say you shouldn't run dead down wind, as you're not likely to broach when running, but when reaching it can be an issue for sure. Unless you're talking about the main, and then yes you should use a preventer (although I don't). As far as avoiding a broach with the spinnaker flying, I wouldn't let go of the sheet, (unless you're knocked over) and certainly don't "head up, abit". You need to be very aware of the wind direction and the power behind the main. Any hint of a broach, depower the main and bear off the wind.
Also, I've sailed around and near Point Roberts a few times, you get some serious wind and waves up there.
|07-12-2007 07:09 PM|
Avoiding a Broach
I am not very experienced using my Asymetrical spinnaker, but I do have some knowledge about adjusting it's trim.
My question is, what circumstances can cause an accidental broach? If you are becoming over powered, can you just dump the A-sym sheet and "head up" abit, or??? to avoid a problem. Have any of you experienced problems in this area?
I am well aware of the dangers of an accidental jibe, and am very wary of running dead down wind (don't do it). I have not as yet used a preventer, but am looking at ways to rig one that will work for my boat. By the way, I do mostly coastal cruising.
I am looking to be forewarned and to exercise prevention, rather than "reaction". Any advise would be appreciated.