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Death roll recovery

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zailor View Drop Down
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Post Options Post Options   Quote zailor Quote  Post ReplyReply Direct Link To This Post Topic: Death roll recovery
    Posted: 12 Dec 09 at 7:09pm

Im so gald I was right to question the Byte class video guite

 

I did think that heading up would make the death part come faster.
Hoever today I did try simply pumping the sail and to be fair it did stop the roll.
I did induce the roll by letting out too much sheet but one tug did bring it upright.

The "rooster roll" by pushing down on the opposite gunnel did seem to add speed so a good tug on the sheet seems to fix it if im in a tight area surouned boy boats but the bear away which was my initial instinct does seem to beat the CII class video's

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tickler View Drop Down
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Post Options Post Options   Quote tickler Quote  Post ReplyReply Direct Link To This Post Posted: 12 Dec 09 at 4:47pm
I always thought that death roll was caused by wind spilling from the top of the sail pushing the mast sideways to windward, when it goes too far the righting moment forces shove the boat back and the rock and roll starts. Am I wrong then?
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Post Options Post Options   Quote Jamesd Quote  Post ReplyReply Direct Link To This Post Posted: 12 Dec 09 at 2:37pm
you are correct GarethT, it is all to do with the lift of the rudder rather than anything to do with the sails or your angle to the wind.

to test this without gettig wet, just find a boat with a cradle trolley, like an RS4/200, put it on the trolley as if its heeled, put the rudder on and then grab hold of the rudder blade and physically pull towards whatever gunwhale is higher, you will see the boat tries to heel even more.  this demonstrates pushing the tiller away when the boat is heeled to windward, or pulling the tiller towards you when heeled to leeward.

http://www.roostersailing.com/merchant2/merchant.mvc?Screen= hints&Store_Code=1 then click on the 4th dimension link.  this explains the theory quite well with some videos
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GarethT View Drop Down
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Post Options Post Options   Quote GarethT Quote  Post ReplyReply Direct Link To This Post Posted: 12 Dec 09 at 2:21pm

My understanding is that it has very little to do with the sail, and it's all about using the lift from the rudder to get the boat level.

If you push the tiller the lift acts in the opposite way and pulls the boat over on top of you.

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Post Options Post Options   Quote Rupert Quote  Post ReplyReply Direct Link To This Post Posted: 12 Dec 09 at 1:13pm
I always thought the bearing away thing is for when you are sailing by the lee, as effectively the sail is reversed. When on a run but not by the lee, luffing up will be the way to save yourself. I think I'd like some warmer water to fall into than we currently have to figure out which one works better when!
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Post Options Post Options   Quote Jamesd Quote  Post ReplyReply Direct Link To This Post Posted: 12 Dec 09 at 11:43am
pushing the rudder away from you to point up when the boat is heeled to windward is very unnatural, it feels awful, as the boat is trying to bear away and you are trying to stop it, its very slow!

pulling the rudder towards you is the correct way to do it, no if's or buts. you dont have to bear away too much, a sharp stab is usually enough to bring it flat again, if you dont want to bear off on a long arc.
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zzzz View Drop Down
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Post Options Post Options   Quote zzzz Quote  Post ReplyReply Direct Link To This Post Posted: 12 Dec 09 at 9:40am
When you are in a death roll situation, as in: if you do nothing you are going swim, the boat is already coming on top of you, kind of situation (hence the name DEATH ROLL, traditionally this is accompanyed by panic, a brown wetsuit and just enough time for a quick expletive before hitting the water pretty hard).  If you push the tiller away from you, best get your armbands on and book some swimming lessons at the local pool. The boat wants to bear away (windward heel), the rudder wants to head up, result: a big fight in which neither you or the boat will win, the water always wins that one hands down.  Gotta be bear away every time (in a laser or similar type of boat such as a byte).
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Post Options Post Options   Quote Alistair426 Quote  Post ReplyReply Direct Link To This Post Posted: 12 Dec 09 at 9:04am
The pointing up and sheeting in, bit more board down option is 'calming things down' the Rooster bear-away is more of a 'get out of jail when you tested the limits and just crossed them' approach. If you think about the plane of the rudder  as it provides the counter-intuitive lift to the bow, it has to be getting somewhere near horizontal in the water to have the dramatic effect you experience when you do it.
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tickler View Drop Down
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Post Options Post Options   Quote tickler Quote  Post ReplyReply Direct Link To This Post Posted: 12 Dec 09 at 9:01am
What if you are already sailing dead downwind, if you bear away you will be sailing by the lee or even gybe? Also it must depend on how close you are to the mark and whether you take it to port or starboard.
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Post Options Post Options   Quote craiggo Quote  Post ReplyReply Direct Link To This Post Posted: 11 Dec 09 at 11:04pm
Definately bear away harder. The rudder has a bigger effect than you may think. Also as your mast is effectively the leech downwind, then bearig away actually feathers the rig a bit easing some of the power.

Doesnt work on the 700 though as I cant let the main out that far!
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