Reply With QuoteOk I'll bite (not a sailor)
My guess is yes if you are traveling on a diagonal angle in relation to wind direction (downwind) which I think most sailboats do. Kind of like crossing the wake water skiing, you exceed boat speed on the diagonal angle.
I'm at the fire station today and we're having a little debate while eating dinner. The topic we're debating......
Under wind power only, is it possible for a sailing vessle to travel faster than the wind pushing it? If so why?
I'm only one out of eight guys that think it's possible, but for some reason I can't explain it.
Ok I'll bite (not a sailor)
My guess is yes if you are traveling on a diagonal angle in relation to wind direction (downwind) which I think most sailboats do. Kind of like crossing the wake water skiing, you exceed boat speed on the diagonal angle.
Not in the exact same direction as the wind, but at an angle to it, of course it is.
If the wind is blowing 10 knots, and the sail is almost at a right angle to it, the boat would most definitely haul ass.
I don't have enough of an education to explain why with big words and stuff, but it's f*cking common sense
If the angle is steep, then for air to move at 10 knots, the sail would have to get out of the way, and would move laterally way faster than the 10 knots.
Go punch the other guys out if they don't get it.
Good Luck
CA Stu
lol
I'm still pretty sure I'm right too, I just can't put it into English. I shoulda taken more Physics classes
Look at the velocity like a straight line graph where y=2x
To go 10 units vertically, you have to go 20 units horizontally. so if a point on the line is travelling in a fashion that moves it 10 units vertically in one minute, at the same time it will move 20 units horizontally.
It's not brain surgery, seems common sense to me...
Now kick them in the nuts if they don't understand that
CA Stu
Newsflash! Brawl at local fire station over sailing!
The fastest point of sail is a "broad reach". Wind from the side.
A sail is a wing. The more negative and positive pressure you can put on it (size) the faster the boat will move. the longer the water line of the hull the faster the boat will be because of the ability to run a bigger sail. But there is a point of diminishing return. There is a class called (I think) formula that is relativly small ( 2 man) that will run 38 knots in a 32 knot wind. Check out an Americas cup race if you can get past the boredom, a half a knot in speed is worth a TON. Check out the movie "WIND"
coolchange is right about the aerodynamic similarities between an airplane wing and a sail. The America's Cup boats can push 15 knots out of a 10 knot wind.
But he's wrong about the boredom of the Cup races. I've worked 2 of them, a World Cup, and a Louis Vitton race. It's amazing what those guys can do. (Also amazing how much them blow boaters can PAR-TAY!)
What's even more amazing is that the America's Cup now belongs to the Swiss. (a land locked country)
How in the hell did Dennis let THAT happen?
The boredom part I meant was the idea of watching a sailboat race and all the shi shi stuff that happens BEFORE the gun. Except the jockiing for starting position that is.
How do you get to work a race? Do you have to be a "Boatcop"?
Always wanted to crew on a Newport-Ensanada boat.
Yeah, you -can- sail faster than the wind. If you have good sail shape, easily driven hull and the right amount of wind. Oh, and your heading the right way.
How does it work? Well there are some forces on a sailboat..
Pull of sails.
Drag on sails.
Drag on hull.
Wind speed. <- Boost pressure for sailboats.
Sailing:
Imagine your suddenly plunked into a sailboat out in the middle of the ocean. The wind is blowing some.. Lets try to make it go..
First try heading with the wind. DDW, Dead down wind. The sails act kinda' like big wind bags. The faster you go, the less wind speed you feel while riding on the boat. You get less and less boost as the boat speeds up. And you don't get any of the airfoil effects that sails can give you. (It can also be dangerous in a for/aft rigged boat because of gybing.)
This is where you see those big colorful sails flying out in front of sailboats. Heading with the wind, you get little or no "boost" so you need the big lightweight sail to catch as much wind as possible. (Actually they do act somewhat like a wing, but lets ignore that for now..)
Now.. Start heading, lets say.. To the right.. Heading away from DDW is called, in sailing lingo, "Heating it up". As you start crossing the wind's path, you get a noticeable increase in the wind that you can feel. Boost goes up fast. If there is plenty of wind blowing and your not careful, you can have the sailboat equivalent of a turbo overrun. And/or a nasty crash.
What's going on? As soon as the wind begins to cross the sailboat's path, the sails stop being big bags and become airfoils. Efficiency skyrockets and pressure builds. As the boat speeds up, the wind you can feel while riding on the boat increases as well. Why is this? Because your boat speed is now adding to your wind speed. Not only that, but as you speed up the wind you feel starts to move forward, heating things even up more. Once the wind (That you can feel) pulls around ahead of the side of the boat, the big colorful sail comes off and the jib is hoisted. (Unless your running an asymmetric spinnaker and you can run that at a somewhat "hotter" angle. And go like a scalded cat.)
I friend of mine had a 41' racing trimarine. I've been on it doing about 25-30 knots in about 20 knots of wind. As we crossed the winds path at right angles, the wind -we- felt, and had to trim the sails to, came from about 20 degrees off the nose of the boat. And it was hootin!
Crossing the wind, you can go faster than the wind. If the hull is easily driven and everything is set up right. This is because you can use the sails at their maximum efficiency. At some point, your hull is not going to go any faster. But the wind can go up and up. So at some point, as the wind builds, you won't be able to go faster 'cause the boat just won't drag through the water that fast. (Ice boats can, and they scream!)
Now.. As you point more and more into the wind, the wind you feel on the boat gets even greater. Boost goes up even more. But, now the efficacy of the sails for driving you starts to drop off. They get less and less "bite". Pretty soon the Drag on the sails overcomes the pull from the sails and the boat stops, then goes backwards. This is called "Being in irons".
So how does one sail? Heading down wind, DDW, you let everything out like big bags and drift along. As soon as you start heating it up, you pull the sails in 'till they stop flapping. As you heat it up more.. You pull them in more. At some point you can't pull them in any more. That's as close as you can point into the wind. If you want to go the -other- way, cross past pointing directly into the wind, get your speed up and then turn as hard as you can to "Cross the eye of the wind" before your momentum drops to zero. Set your sails, as before, on the other side of the boat. (Don't let the wind cross your tail 'till you know what your doing.)
Clear as mud?
Hope this helps!
-jim lee
Originally posted by jim lee
Yeah, you -can- sail faster than the wind. If you have good sail shape, easily driven hull and the right amount of wind. Oh, and your heading the right way.
How does it work? Well there are some forces on a sailboat..
Pull of sails.
Drag on sails.
Drag on hull.
Wind speed. <- Boost pressure for sailboats.
Sailing:
Imagine your suddenly plunked into a sailboat out in the middle of the ocean. The wind is blowing some.. Lets try to make it go..
First try heading with the wind. DDW, Dead down wind. The sails act kinda' like big wind bags. The faster you go, the less wind speed you feel while riding on the boat. You get less and less boost as the boat speeds up. And you don't get any of the airfoil effects that sails can give you. (It can also be dangerous in a for/aft rigged boat because of gybing.)
This is where you see those big colorful sails flying out in front of sailboats. Heading with the wind, you get little or no "boost" so you need the big lightweight sail to catch as much wind as possible. (Actually they do act somewhat like a wing, but lets ignore that for now..)
Now.. Start heading, lets say.. To the right.. Heading away from DDW is called, in sailing lingo, "Heating it up". As you start crossing the wind's path, you get a noticeable increase in the wind that you can feel. Boost goes up fast. If there is plenty of wind blowing and your not careful, you can have the sailboat equivalent of a turbo overrun. And/or a nasty crash.
What's going on? As soon as the wind begins to cross the sailboat's path, the sails stop being big bags and become airfoils. Efficiency skyrockets and pressure builds. As the boat speeds up, the wind you can feel while riding on the boat increases as well. Why is this? Because your boat speed is now adding to your wind speed. Not only that, but as you speed up the wind you feel starts to move forward, heating things even up more. Once the wind (That you can feel) pulls around ahead of the side of the boat, the big colorful sail comes off and the jib is hoisted. (Unless your running an asymmetric spinnaker and you can run that at a somewhat "hotter" angle. And go like a scalded cat.)
I friend of mine had a 41' racing trimarine. I've been on it doing about 25-30 knots in about 20 knots of wind. As we crossed the winds path at right angles, the wind -we- felt, and had to trim the sails to, came from about 20 degrees off the nose of the boat. And it was hootin!
Crossing the wind, you can go faster than the wind. If the hull is easily driven and everything is set up right. This is because you can use the sails at their maximum efficiency. At some point, your hull is not going to go any faster. But the wind can go up and up. So at some point, as the wind builds, you won't be able to go faster 'cause the boat just won't drag through the water that fast. (Ice boats can, and they scream!)
Now.. As you point more and more into the wind, the wind you feel on the boat gets even greater. Boost goes up even more. But, now the efficacy of the sails for driving you starts to drop off. They get less and less "bite". Pretty soon the Drag on the sails overcomes the pull from the sails and the boat stops, then goes backwards. This is called "Being in irons".
So how does one sail? Heading down wind, DDW, you let everything out like big bags and drift along. As soon as you start heating it up, you pull the sails in 'till they stop flapping. As you heat it up more.. You pull them in more. At some point you can't pull them in any more. That's as close as you can point into the wind. If you want to go the -other- way, cross past pointing directly into the wind, get your speed up and then turn as hard as you can to "Cross the eye of the wind" before your momentum drops to zero. Set your sails, as before, on the other side of the boat. (Don't let the wind cross your tail 'till you know what your doing.)
Clear as mud?
Hope this helps!
-jim lee
Uh yeah, that's what I MEANT to say
Actually it does make sense. Way more sense than this stuff I found on the internet
http://www.***boat.com/image_center/...00/536pres.gif
Thanks for the explanation. I was right. Those fockers owe me something now.
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