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Death Roll and how to avoid it...?

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RS400atC View Drop Down
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Post Options Post Options   Quote RS400atC Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jun 12 at 10:24am
Originally posted by maxibuddah

that's cos we basically deep broad reach due tobthe shrouds and the boat has a flat aft section with hard chines round bottom bottom boats roll more. the beginner comment only related to death rolling experience


That's why most modern boats have chines.
Is the EPS one of the 'we don't need to design for ply wood' era, all rounded?

In my varied but selective experience, rolling is fiirstly caused by the top of the main driving the mast to windward.
It is kept in check by:
Kicker
Steering
Sheeting in and heading up a bit.
Possibly heeling to windward a bit, rig centre over hull.

I say kept in check rather than stopped, because in some boats, rolling a bit or being on the edge of it is not slow.
The real cure is to get the kite up, speed up, get the apparent wind off the stern.
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Rupert View Drop Down
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Post Options Post Options   Quote Rupert Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jun 12 at 12:11pm
Before Lasers started doing it so well, this was called the "Firefly Death Roll", and once it started, the helm would be screaming at the crew (me) to sit still. The answer in a boat with shrouds was always to sheet in and drop the centre plate a bit, but with a shroudless rig like the EPS, bearing away to rebalance the boat certainly works, as the rig can go so much further forward.
Firefly 2324, Lightning 130, Puffin 229, Minisail 3446
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G.R.F. View Drop Down
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Post Options Post Options   Quote G.R.F. Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jun 12 at 12:16pm
Originally posted by RS400atC

Originally posted by maxibuddah

that's cos we basically deep broad reach due tobthe shrouds and the boat has a flat aft section with hard chines round bottom bottom boats roll more. the beginner comment only related to death rolling experience


That's why most modern boats have chines.
Is the EPS one of the 'we don't need to design for ply wood' era, all rounded?

In my varied but selective experience, rolling is fiirstly caused by the top of the main driving the mast to windward.
It is kept in check by:
Kicker
Steering
Sheeting in and heading up a bit.
Possibly heeling to windward a bit, rig centre over hull.

I say kept in check rather than stopped, because in some boats, rolling a bit or being on the edge of it is not slow.
The real cure is to get the kite up, speed up, get the apparent wind off the stern.

Yes it has an edge to edge curve as well as a nose to tail parabolic rocker with what looks quite close to a shift to flat that we use windsurfing, sailed flat it really is as 'quiet' a wake as you could wish for, it doesn't like to be on its ear and all that rocking is not good news. The obvious answer is never dead run but then on a lake with a short buoy to buoy course, comes the time you have to point right at them and should that coincide with a shift.....

You don't get death rolls with kites, well not that I've ever experienced it seems to be the province of certain single handers, I bet that 300 would get five stars if ever death rolling were in the michelin catalogue.


Edited by G.R.F. - 21 Jun 12 at 12:17pm
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pondmonkey View Drop Down
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Post Options Post Options   Quote pondmonkey Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jun 12 at 12:25pm
Originally posted by G.R.F.

 I bet that 300 would get five stars if ever death rolling were in the michelin catalogue.

4.5... the reverse flare gives some crucial face saving opportunity... if you're alert (or have exceptional fitness LOL)
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Post Options Post Options   Quote maxibuddah Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jun 12 at 12:42pm
never really used to death roll the 300. the hull accelerated as quickly as the rig meaning the generated lift on the sail didn't happen so much. of course if it got a little on the draughty side of things you could just move aft and dig both wings in to act as stabilisers, again slow but safe. the wings stopped an awful lot of rolling if needed.
Everything I say is my opinion, honest
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Post Options Post Options   Quote RS400atC Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jun 12 at 2:12pm
Originally posted by G.R.F......

You don't get death rolls with kites, well not that I've ever experienced it seems to be the province of certain single handers, ......
[/QUOTE




I've seen a keelboat roll with the kite up, to the point where it filled up and sank. So a kite is not a total cure. But a dinghy with a kite would have been going much fast


I've seen a keelboat roll with the kite up, to the point where it filled up and sank. So a kite is not a total cure. But a dinghy with a kite would have been going much faster, got the apparent forward etc.
Enterprises were always known for rolling, less chines that say a GP and no kite, and in the days I sailed them, mickey mouse kickers.
The 400 is certainly much happier with the kite up, at least until it's time to gybe.
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G.R.F. View Drop Down
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Post Options Post Options   Quote G.R.F. Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jun 12 at 4:25pm
Originally posted by RS400atC

 So a kite is not a total cure. But a dinghy with a kite would have been going much faster, got the apparent forward etc.

It probably only has been in my case since I've only ever experienced assyms that are loaded to one side come what may.

It also occurred to me, the longer and lower the boom the more likely it must be, although I've not seen boats like Contenders engage in the habit, then they have flatter hulls.
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Post Options Post Options   Quote pondmonkey Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jun 12 at 4:36pm
how many contender sailors would run2run gybe?  I'd have thought it was be tippy as hell with the relatively high aspect rig, low freeboard and narrowish beam???
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Post Options Post Options   Quote fab100 Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jun 12 at 5:29pm
You could always just spray the mast-top with WD40, GRF. It repels water after all, so the effect should get stronger, the more the boat heels
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Steve411 View Drop Down
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Post Options Post Options   Quote Steve411 Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jun 12 at 6:11pm
Originally posted by pondmonkey

Originally posted by G.R.F.

 I bet that 300 would get five stars if ever death rolling were in the michelin catalogue.

4.5... the reverse flare gives some crucial face saving opportunity... if you're alert (or have exceptional fitness LOL)
 
The 300  may occasionally heel a bit to windward on a run in a blow, but so will any boat sailed incorrectly - the 300 just tells you quicker than most boats. Smile
 
As Sargesail mentioned, there is more than one way to get downwind safely. I love this picture as it's all there - http://www.chunkypics.co.uk/photoalbum/Sport/Sailing/2007/RS300%20Inland%20Champs%2001-12-07%20NSC/Saturday/Page%202/E5013673.jpg
 
Sargesail is in 506 - bit of kicker, boom well out, rock steady. I'm in 411, bit less kicker, boom in a bit more, rock steady. The thing in commom is that both of us have the top batten in line with the mast. Letting the top batten go in front of the mast is what causes death rolls - http://www.chunkypics.co.uk/photoalbum/Sport/Sailing/2007/RS300%20Inland%20Champs%2001-12-07%20NSC/Saturday/Page%202/E5013590.jpg
 
 
Steve B
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