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Heavy wind trim

#trim #upwind

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#1 artsimons

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Posted 18 June 2013 - 09:23 AM

Hi! I'm fairly new to sailing ang looking for some answers to help settle a little debate. In heavy winds when upwind vmg sailing, is it better to trim off the sail by letting it out to re-establish a reasonable heel and maintain course or to trim by leaving the sail in and loosing heel by pointing further upwind?



#2 RobG

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Posted 18 June 2013 - 10:32 AM

Crank on the vang and cunningham so you can keep the boat flat (skiff) or with optimal heal (dinghy). Sheet for best VMG (speed vs heading). 



#3 Ben G

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Posted 18 June 2013 - 10:38 AM

I would say maintain heading and ease sheet to keep flat- but that's for a skiff or boats that generate a fair amount of apparent wind. Not sure when it comes to say, a laser, which is slow but won't lose so much speed in turns- maybe the opposite? I've never sailed one.

#4 RATM

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Posted 18 June 2013 - 11:02 AM

Welcome to the biggest challenge in sailing and what makes it fun.



#5 BalticBandit

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Posted 18 June 2013 - 11:18 AM

Really depends on

  • The type of boat
  • The type of sea state
  • how far above the "design wind" (ie overpowered) you are
  • how steady the wind is (gust/lull pattern)
  • the rig dynamics of the boatt
  Most modern skiffs are planing hulls, which means that optimal VMG is planing, and that means sail it flat.  Most non-planing dinghies are designed to sail with a small amount of heel to increase righting moment (at a small price of slightly more leeway)

 

All of the above require dynamic tradeoffs on a continuing basis. and that's where the challenge is.  Perhaps you should start by telling us what sort of boat



#6 artsimons

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Posted 18 June 2013 - 12:24 PM

I was thinking of a simple two-man dinghy like a 470 or similar.



#7 surf nazi

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Posted 18 June 2013 - 01:14 PM

Hi! I'm fairly new to sailing ang looking for some answers to help settle a little debate. In heavy winds when upwind vmg sailing, is it better to trim off the sail by letting it out to re-establish a reasonable heel and maintain course or to trim by leaving the sail in and loosing heel by pointing further upwind?

 

ease, hike, trim.



#8 Cement_Shoes

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Posted 18 June 2013 - 01:27 PM

I was thinking of a simple two-man dinghy like a 470 or similar.

 

If you can plane upwind, which a 470 can do in conditions that it needs to depower in, you better be planing or you are going to be left behind.  You need to twist off the sails and depower enough to control the boat but you need to stay low enough to plane.

 

When you pinch you are giving up power to gain height which is ok on heavier boats in flatter waters when the boat itself has enough inertia to glide to windward when you luff up usually in response to a gust.  The bigger the seas in comparison to the size and weight of the boat the less it pays to pinch because the waves are going to slow the boat enough that you lose the gained ground to windward.   At this crossover point it pays to depower the rig and go sail lower but faster and more steady.



#9 BalticBandit

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Posted 18 June 2013 - 01:58 PM

Note also that with boats that can plane, there is a curious phenomenon (more so with boats like 29ers, Mustos, I14s, but true also of 5ohs and 470s) in which the foils are more efficient at speed and hence need less angle of attack to generate the same amount of lift.  So by cracking off 5 degrees, building speed you can then dial back up 3 or so degrees, but track actually higher than the boat that is still pointing above you hullwise but tracking lower.

If you are in big waves, on a fat hulled boat like a 5oh or a 470, you need to steer actively up and over the waves.  This means pinching a bit as you climb the face, and then falling off as you come down the back.  For this you actually ease vang and increase twist in the sails to give you that wider groove.  In some boats like the 49er, and I--14, it is actually faster to pinch a bit on the front side so you are going slower as you near the top because if you don't, you risk launching off the wave.   And while launching looks cool, feels wild and makes great photos - it sucks for boat speed, because as you drop, you have no lateral resistance so the wind is in effect blowing you to leeward.  You then land and it takes 1-3 seconds before the foils are fully working again, i the meantime your trim is also off.

So you are better off pinching up the front, and then bearing off before the top to accellerate down the backside - rinse lather and repeat



#10 Steam Flyer

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Posted 18 June 2013 - 02:24 PM

Hi! I'm fairly new to sailing ang looking for some answers to help settle a little debate. In heavy winds when upwind vmg sailing, is it better to trim off the sail by letting it out to re-establish a reasonable heel and maintain course or to trim by leaving the sail in and loosing heel by pointing further upwind?

 

Ah, settling a little debate. Well you've gotten some good answer but not sure if any are really helpful.

 

1- you should not let out the sail (ease sheet) to "re-establish a reasonable heel" because in a dinghy, you should be very quick on the sheet(s) in both directions (ease & trim).

 

Heel = slow

 

Easy to remember, for many it's not so easy to believe until it's proven multiple times.

 

2. pointing further upwind (often termed "feathering") to reduce heeling force can be a very good technique... several other people have answered in great detail above. However the imperative is to keep the boat moving effectively (ie fast) and as noted above, heeling is slow.

 

So your little debate is basically set up so that both sides are wrong. Sorry. It not unusual though for some pretty good dinghy sailors to want to drive their boat like station wagons. Pull in, cleat, hike, steer to the gusts. Sometimes they are clever enough at sailing in other regards that they do quite well in races, but a sailor who has an equally well-tuned boat and an equal grasp of tactics, but who is very pro-active on sheets, will wallop them every time -especially- when the wind is gusty.

 

BTW the same is true for leadmines but the difference is less dramatic, and even fewer people believe it. Plus, it's too easy to sit back and steer with one hand and a beer in the other, which is what leadmines are for.

 

FB- Doug



#11 BalticBandit

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Posted 18 June 2013 - 09:33 PM

One of the things we learned to do in the 49er is for me (skipper) to say (as the boat just was about to feel sluggish) "ease my nose down" (in the 49er, many crews hold the sheet) .

 

At which point my crew would ease enough for the bow to go down 3 or so degrees (varied by wind and wave conditions).  at which point he would start to slowly bring the sheet in at about a ratchet click every other second.

 

and this would repeat roughly every 5 seconds all the way upwind.
 

If a big puff hit, the main would get eased enough to keep the boat flat and the speed on.

 

If it was a nuclear puff coming and we saw it (shame on us for not seeing it)  Skipper would uncleat the jib and actually ease the jib in anticipation of the puff.  again, the goal is to keep heel down and the boat moving.



#12 SimonN

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Posted 18 June 2013 - 11:23 PM

To pinch or foot, that is the question. And the answer for all dinghies is that it can pay to do either. It is totally condition dependent. Wind strength, waves, tide, position of other boats and course to the next mark (tactical considerations) all add up to working out what is best. The answer is that simple, but as mentioned above, it's one of the most complex things in sailing



#13 Gouvernail

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Posted 19 June 2013 - 04:42 AM

I was thinking of a simple two-man dinghy like a 470 or similar.

Until the wind is too strong to continue doing so, keep the jib trimmed and the boat heading right on the wind and trim teh main to shoot the bow up and over waves and practice practice practice until you do it well.

 

Exception, if you can crack off a bit and plane, that is the thing to do and then head up until you don't quite fall off plane but are pointing as high as you can.



#14 bruno

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Posted 19 June 2013 - 05:09 PM

simple...470?

#15 Rum Runner

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Posted 19 June 2013 - 08:52 PM

Hi! I'm fairly new to sailing ang looking for some answers to help settle a little debate. In heavy winds when upwind vmg sailing, is it better to trim off the sail by letting it out to re-establish a reasonable heel and maintain course or to trim by leaving the sail in and loosing heel by pointing further upwind?

 

 

I was thinking of a simple two-man dinghy like a 470 or similar.

 

Too much heel is usually very slow.  Trim to keep the boat flat.  In high waves you can't point as high as you would be able to do in flat seas so just keep it moving as much as possible.



#16 duncan (the other one)

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Posted 20 June 2013 - 03:01 AM

I was thinking of a simple two-man dinghy like a 470 or similar.

simple? hmmm..

Go on youtube, search 470 olympic strong wind, watch and learn.

eg:


flat flat flat... and in wind, foot and speed! I don't see any pinching going on.

#17 artsimons

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Posted 20 June 2013 - 11:01 AM

Thanks Duncan, that has answered my question! You can clearly see sails flapping / let out / trimmed, on close hauled (or not as the case would be) upwinds.



#18 BalticBandit

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Posted 20 June 2013 - 03:44 PM

Not quite AS... notice how part of the sail is flapping, but the aft lower section is still drawing.   You need that to keep the jib from pulling the bow down and generating lee helm



#19 Major Tom

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Posted 20 June 2013 - 04:01 PM

In a big gust upwind you need to first start heading up before easing the sheet, once you are on the high or de powered side of your course then ease the main to keep the boat flat and pull it in immediately you have the correct heel or the jib will pull the bow to lee. The mainsail leach is vital to maintain a balanced feel on the helm and to counter the sideways force generated by the jib. A good crew will also ease the jib slightly in a gust as this allows the course to be maintained and less rudder and main sheet need to be used resulting in more speed.




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