I've been told by some racers that I need to have the tailtells always flowing, even when running to get the most performance from my sails. I've been trying but I can't get them to stream backwards when anything more then 115 AWA. Is it just me or are they nuts in trying to get the tailtells flowing in all angles of sail? My boat is a Hunter 380 (fractional rig with large main and a 105 jib). Is it because I have such a small jib? All the stuff I read on the web about trimming for broad reaching says that there isn't any trimming to broad reaching or running, just get the sails perpendicular to the wind. Which is true?
- Status
No expert
But it's my understanding that to get a sail to have attached flow downwind, you need a lot of camber/belly, because rather just having the wind "bounce" off your sail, it it hitting it and turning, the entire time pushing "into" the sail as well as flowing along it. -with a small jib, you don't have enoug area to bein with, so if you were to curve it enough, your effective area is *really* tiny.
But it's my understanding that to get a sail to have attached flow downwind, you need a lot of camber/belly, because rather just having the wind "bounce" off your sail, it it hitting it and turning, the entire time pushing "into" the sail as well as flowing along it. -with a small jib, you don't have enoug area to bein with, so if you were to curve it enough, your effective area is *really* tiny.
main
I'm more concerned about the main as it's the driver of the boat but understand that the jib is what helps with the slot flow. Was just thinking that if I had a larger head sail that I might devert more wind backwards around the main. Just a thought. I will try the "more belly" idea. Problem with this boat is the swept back spreaders not letting the main out much.
I'm more concerned about the main as it's the driver of the boat but understand that the jib is what helps with the slot flow. Was just thinking that if I had a larger head sail that I might devert more wind backwards around the main. Just a thought. I will try the "more belly" idea. Problem with this boat is the swept back spreaders not letting the main out much.
This is some good stuff!
I don't have telltales on my sail (yeah I know) but I think it depends on angle of the wind and windspeed. I doubt that when it's blowing 30+ off my quarter that the wind is flowing fore and aft across my sails on a Broad Reach. When it hits the fan, I sheet everything tight to reduce exposed area and angle of attack. Does the wind still flow aft? I highly doubt it.
I don't have telltales on my sail (yeah I know) but I think it depends on angle of the wind and windspeed. I doubt that when it's blowing 30+ off my quarter that the wind is flowing fore and aft across my sails on a Broad Reach. When it hits the fan, I sheet everything tight to reduce exposed area and angle of attack. Does the wind still flow aft? I highly doubt it.
The telltales on the main will not fly on a run
Jackie- Your tell tales will not fly on a broad reach or a run. At that point you are not driving the boat on the lift produced from the sail but rather from the force of the wind pushing your boat forward. So the broader you are sailing the less you are looking at telltales to trim your sails. Actually, at that point you are looking at projected area to maximize your speed, which is why you will see genoas or jibs poled out to windward - or spinnakers. It increases the area of sail exposed to the wind.
Jackie- Your tell tales will not fly on a broad reach or a run. At that point you are not driving the boat on the lift produced from the sail but rather from the force of the wind pushing your boat forward. So the broader you are sailing the less you are looking at telltales to trim your sails. Actually, at that point you are looking at projected area to maximize your speed, which is why you will see genoas or jibs poled out to windward - or spinnakers. It increases the area of sail exposed to the wind.
I don't see how
No way can I see how a tell tale is going to fly when the apparent wind is much aft of the beam, and why you would pay any attention to them. At this point you have the wind pushing, not flowing across, the sail. At this point, the slot doesn't matter either. It's just how much sail you can get out that is exposed and not shadowed. Of course, I have been wrong more than once in my life.
No way can I see how a tell tale is going to fly when the apparent wind is much aft of the beam, and why you would pay any attention to them. At this point you have the wind pushing, not flowing across, the sail. At this point, the slot doesn't matter either. It's just how much sail you can get out that is exposed and not shadowed. Of course, I have been wrong more than once in my life.
telltale comment.... get a gennaker!
on a broad reach or a run the headsail's luff telltales aren't very useful like they are on higher points of sail. The main's leech telltales can be somewhat helpful when broad reaching, but probably not with your rig, so learn to trust your senses and the knot log more. Forget the larger headsail stuff. You don't want to buy a larger jib/genoa so you can go downwind faster, that's what spinnakers are for. With your large main and 105 jib for upwind sailing, an asymetrical chute would be a perfect fit for everything from a beam reach on down.
on a broad reach or a run the headsail's luff telltales aren't very useful like they are on higher points of sail. The main's leech telltales can be somewhat helpful when broad reaching, but probably not with your rig, so learn to trust your senses and the knot log more. Forget the larger headsail stuff. You don't want to buy a larger jib/genoa so you can go downwind faster, that's what spinnakers are for. With your large main and 105 jib for upwind sailing, an asymetrical chute would be a perfect fit for everything from a beam reach on down.
boat speed v. vmg
Your statement of the advice says a lot -"to get the most performance from (your) sails." Basically, if you are pointed too far down wind, your sails stop acting as airfoils and become lumps in the wind. Your telltails will be very dead at this point due to lack of attached airflow. Your boat speed will be down unless the wind is very strong, since your appearent wind speed will begin to approach 0. Steering somewhat higher to maintain attached airflow keeps more greater power in the sails, thus greater speed through the water, at the trade-off of a longer distance to travel. My all time favorite book on sails and sail trim is "Sail Power." Highly informative, reasonably easy to understand (I first read it before I began sailing, making some concepts harder to understand at the time), with an excellent dicussion of the slot effect at various angles of sail. I think that is also where I learned about polar graphs or charts showing boat speed at various angles of sail, along with why the differences in speed. I strongly recommend it, or similar books. (I will admit to trying to understand Marchand, but it was too technical for my then knowledge and understanding.) Back to VMG, for many boats, the difference in velocity for a broad reach with attached flow and wind angles with detached flow is so large that they can make better VMG traveling the longer distance with attached flow. Therefore they look to keep an attached airflow. One question, are you certain your main's not blanketing your jib, rather than having the airflow detach. My experience on my h23 is that I can maintain attached airflow on my 100% jib or 150% genny until they are blanketed. One trick you can try, carefully - smoke from a 4th of July type smoke bomb. Hold it well away and upwind of the sail, pointing away from the sail to avoid burning it, letting the smoke stream over the sail. You can get an excellent view of wind flow, including whether its detaching at some point. Good luck. Jim Kolstoe, h23 Kara's Boo.
Your statement of the advice says a lot -"to get the most performance from (your) sails." Basically, if you are pointed too far down wind, your sails stop acting as airfoils and become lumps in the wind. Your telltails will be very dead at this point due to lack of attached airflow. Your boat speed will be down unless the wind is very strong, since your appearent wind speed will begin to approach 0. Steering somewhat higher to maintain attached airflow keeps more greater power in the sails, thus greater speed through the water, at the trade-off of a longer distance to travel. My all time favorite book on sails and sail trim is "Sail Power." Highly informative, reasonably easy to understand (I first read it before I began sailing, making some concepts harder to understand at the time), with an excellent dicussion of the slot effect at various angles of sail. I think that is also where I learned about polar graphs or charts showing boat speed at various angles of sail, along with why the differences in speed. I strongly recommend it, or similar books. (I will admit to trying to understand Marchand, but it was too technical for my then knowledge and understanding.) Back to VMG, for many boats, the difference in velocity for a broad reach with attached flow and wind angles with detached flow is so large that they can make better VMG traveling the longer distance with attached flow. Therefore they look to keep an attached airflow. One question, are you certain your main's not blanketing your jib, rather than having the airflow detach. My experience on my h23 is that I can maintain attached airflow on my 100% jib or 150% genny until they are blanketed. One trick you can try, carefully - smoke from a 4th of July type smoke bomb. Hold it well away and upwind of the sail, pointing away from the sail to avoid burning it, letting the smoke stream over the sail. You can get an excellent view of wind flow, including whether its detaching at some point. Good luck. Jim Kolstoe, h23 Kara's Boo.
attached airflow
Yes, you can have attached airflow on all points of sail, but not on your boat. Don't listen to those who say the telltails are meaningless as they are wrong and they aren't racers, or if they are racers, they aren't very good. However, because of the limitations on the boom on your boat, you can't let out the boom enough to get the proper angle on the main for a run, but you can for a broad reach, as you seem to already know. I forget the URL, but there is a link in the archives to a web page that has a little java app that will show you the angles you need to get proper attachment for the different AWA. The downside to the app is that it is using a single sail boat, much like a Cat boat, so the slot isn't part of the calculation which of course will throw off the angles. You can find this by searching for broad reach or broad reach or something like that. When playing with the java app, you will notice that the boom is never perpendicular to the wind when on a broad reach or running and the boat is performing it's best. It doesn't show you that the air is attached, but that IS why the boat is performing better then when the boom is perpendicular to the wind. Jim had a great idea of using smoke while you are sailing to see the wind in action. I suggest you other sailors try this as it's clear you don't understand how the wind works on sails. I'll try to explain it: As the wind passes the sail from behind, there is a void that needs to be filled. That void is filled by the air rounding the edges of the sail. If the boom is perpendicular to the wind, as most are taught, the void is filled from both edges and the wind stalls (no air flow). If the boom is sheeted in a bit, the air from the luff edge will backtrack to fill the void and attach to the backside of the sail. In light air it is difficult to get it to go all the way around to the leach but it can be done and that is when the sail is performing at it's best. You can't do this on a dead run with both sails as the main disrupts the airflow around the headsail (even if it's wing on wing) and that's why you will never see racers go wing and wing or dead downwind unless it's blowing hard enough that you can still reach near hull speed and the mark is dead down wind. Summary: you will not get them flowing on a dead down wind run on your boat and your boat has a wide range where the main shadows the headsail, so to get the best possible speed to dead down wind in light to medium air, you will need to get a sprit pole to poll out a cruising spinnaker far ahead of the boat so you can do a broad reach deeper and still use the main. Best of luck to ya. Franklin
Yes, you can have attached airflow on all points of sail, but not on your boat. Don't listen to those who say the telltails are meaningless as they are wrong and they aren't racers, or if they are racers, they aren't very good. However, because of the limitations on the boom on your boat, you can't let out the boom enough to get the proper angle on the main for a run, but you can for a broad reach, as you seem to already know. I forget the URL, but there is a link in the archives to a web page that has a little java app that will show you the angles you need to get proper attachment for the different AWA. The downside to the app is that it is using a single sail boat, much like a Cat boat, so the slot isn't part of the calculation which of course will throw off the angles. You can find this by searching for broad reach or broad reach or something like that. When playing with the java app, you will notice that the boom is never perpendicular to the wind when on a broad reach or running and the boat is performing it's best. It doesn't show you that the air is attached, but that IS why the boat is performing better then when the boom is perpendicular to the wind. Jim had a great idea of using smoke while you are sailing to see the wind in action. I suggest you other sailors try this as it's clear you don't understand how the wind works on sails. I'll try to explain it: As the wind passes the sail from behind, there is a void that needs to be filled. That void is filled by the air rounding the edges of the sail. If the boom is perpendicular to the wind, as most are taught, the void is filled from both edges and the wind stalls (no air flow). If the boom is sheeted in a bit, the air from the luff edge will backtrack to fill the void and attach to the backside of the sail. In light air it is difficult to get it to go all the way around to the leach but it can be done and that is when the sail is performing at it's best. You can't do this on a dead run with both sails as the main disrupts the airflow around the headsail (even if it's wing on wing) and that's why you will never see racers go wing and wing or dead downwind unless it's blowing hard enough that you can still reach near hull speed and the mark is dead down wind. Summary: you will not get them flowing on a dead down wind run on your boat and your boat has a wide range where the main shadows the headsail, so to get the best possible speed to dead down wind in light to medium air, you will need to get a sprit pole to poll out a cruising spinnaker far ahead of the boat so you can do a broad reach deeper and still use the main. Best of luck to ya. Franklin
Jackie, are you confused yet?
Most of the posts have given reasonable though different descriptions of the situation, so let me try. You get much more power with laminar flow as you already know, and you almost never sail directly downwind unless you can do hull speed (it would be blowing like stink), or its required for navigation. I think you know all that. But you are correct in saying that when the AWA goes aft,you cannot get your boom out far enough to keep all the telltales flying outboard, horizontal, and tight to the sail, as you would on a reach,--- and no one else can either. To do that your boom would have to swing forward of the beam and no standard boat with shrouds can do that. Even on a Nonsuch with a free standing mast gets some turbulence from the size of the mast interference and their backside telltales will disrupted. The only way you could keep all your telltales streaming correctly would be is if you had a free standing, pivoting, mast. So although Franklin and others gave reasonable explanations as to why you try to have the flow always moving across the sail, his statement "Yes, you can have attached airflow on all points of sail" isn't totally correct. When you are in that area between broad reaching and running, or just running with your maximum advantage to leeward, (as determined by the polar speed curve for your boat) you will have your main out as far as it will go, and you will have air flow across the main; but it won't be perfectly laminar and your telltales will not all be flowing. That is also the case for any boat, and In no way is anyone here, saying that your main should be perpendicular to the wind. Thats the stalling trim that should be avoided. Most boats with standard rigging (Where they can let the boom out almost 90 degrees to the centerline) let there booms out all the way when the wind gets to about 115 AWA and just leave it there, vanged as tight as possible. If your boat has no backstay or angled back uppers you can't get your boom as far, so to make your most advantaged course and consequently speed to leeward (as determined by a polar diagram for your boat in that particular wind speed) you probably can't steer quite as far off the wind as the next boat. With the combination of sails you have there isn't much you can do about it. If you had a spinnaker however, that was much more effective going down wind, you could sacrifice some mainsail drive for increased power in the spinnaker and sail with less attention to the main except for its affect on the spinnaker. I hope I didn't add to any confusion. Joe
Most of the posts have given reasonable though different descriptions of the situation, so let me try. You get much more power with laminar flow as you already know, and you almost never sail directly downwind unless you can do hull speed (it would be blowing like stink), or its required for navigation. I think you know all that. But you are correct in saying that when the AWA goes aft,you cannot get your boom out far enough to keep all the telltales flying outboard, horizontal, and tight to the sail, as you would on a reach,--- and no one else can either. To do that your boom would have to swing forward of the beam and no standard boat with shrouds can do that. Even on a Nonsuch with a free standing mast gets some turbulence from the size of the mast interference and their backside telltales will disrupted. The only way you could keep all your telltales streaming correctly would be is if you had a free standing, pivoting, mast. So although Franklin and others gave reasonable explanations as to why you try to have the flow always moving across the sail, his statement "Yes, you can have attached airflow on all points of sail" isn't totally correct. When you are in that area between broad reaching and running, or just running with your maximum advantage to leeward, (as determined by the polar speed curve for your boat) you will have your main out as far as it will go, and you will have air flow across the main; but it won't be perfectly laminar and your telltales will not all be flowing. That is also the case for any boat, and In no way is anyone here, saying that your main should be perpendicular to the wind. Thats the stalling trim that should be avoided. Most boats with standard rigging (Where they can let the boom out almost 90 degrees to the centerline) let there booms out all the way when the wind gets to about 115 AWA and just leave it there, vanged as tight as possible. If your boat has no backstay or angled back uppers you can't get your boom as far, so to make your most advantaged course and consequently speed to leeward (as determined by a polar diagram for your boat in that particular wind speed) you probably can't steer quite as far off the wind as the next boat. With the combination of sails you have there isn't much you can do about it. If you had a spinnaker however, that was much more effective going down wind, you could sacrifice some mainsail drive for increased power in the spinnaker and sail with less attention to the main except for its affect on the spinnaker. I hope I didn't add to any confusion. Joe
dead down run = 55 degree boom swing NOT 90+
(http://www.nationalgeographic.com/volvooceanrace/interactives/sailing/index.html) to go to the java app. If you go to this site and run the app, you will see that for a dead downwind run, it defaults to boom out 90 degrees. As you sheet in the boom to around 55 degrees, that is where you get the most performace of your one sail boat (two sails should allow more sheeting). So, yes, you can get air flow around a main on a standard rigged boat on a dead run, but not a 30 degree swept back spreader as you will only be able to let the boom out about 35 degrees.
(http://www.nationalgeographic.com/volvooceanrace/interactives/sailing/index.html) to go to the java app. If you go to this site and run the app, you will see that for a dead downwind run, it defaults to boom out 90 degrees. As you sheet in the boom to around 55 degrees, that is where you get the most performace of your one sail boat (two sails should allow more sheeting). So, yes, you can get air flow around a main on a standard rigged boat on a dead run, but not a 30 degree swept back spreader as you will only be able to let the boom out about 35 degrees.
Franklin, that's a nice link and Jackie should be able to use it
But if I understand what you are saying, you are saying what I said. That the fastest position is with the boom out, but Jackie can't do that because the shrouds prevent it, so it has to be let it out as much as possible, and either steer less downwind or forget about the telltales streaming. Am I missing something here? The only quarrel I had with your previous post was your absolute statement "Yes, you can have attached airflow on all points of sail". Because I have never seen it in my 50+ years of sailing, and I used to be a pretty reasonable racer.
But if I understand what you are saying, you are saying what I said. That the fastest position is with the boom out, but Jackie can't do that because the shrouds prevent it, so it has to be let it out as much as possible, and either steer less downwind or forget about the telltales streaming. Am I missing something here? The only quarrel I had with your previous post was your absolute statement "Yes, you can have attached airflow on all points of sail". Because I have never seen it in my 50+ years of sailing, and I used to be a pretty reasonable racer.
pretty reasonable racer
That's because "pretty reasonable racers" don't normally go dead down wind (unless it's really blowing). Dead down wind will only get the flow on the main, not the head sail/spin as the main blocks the luff's edge if it's wing and wing and totally blocks it if it's not wing and wing. Now on Cat boats like our little java app, that's not an issue
I did agree with some of what you said but not these two points: "To do that your boom would have to swing forward of the beam and no standard boat with shrouds can do that." See last post. " his statement "Yes, you can have attached airflow on all points of sail" isn't totally correct. " See last post. I think there is a little confussion as to the differences of how some of us think. Jackie, as well as myself, are Fractional rig sailors. Our mains are our power so we are conserned about the flow over the main. Mast head sailors, which is the majority as they are cheaper to make, are conserned mainly with the headsail. I personally have never gotten my telltails to flow on the headsail off the wind and not even sure you can as the telltails may be too close to the edge. Maybe I need practise there (not too conserned with it as I fly a cruising spin in low/med winds and I use the luff wink trick for trimming that), but have gotten them to flow on the main for a low broad reach.
That's because "pretty reasonable racers" don't normally go dead down wind (unless it's really blowing). Dead down wind will only get the flow on the main, not the head sail/spin as the main blocks the luff's edge if it's wing and wing and totally blocks it if it's not wing and wing. Now on Cat boats like our little java app, that's not an issue
I did agree with some of what you said but not these two points: "To do that your boom would have to swing forward of the beam and no standard boat with shrouds can do that." See last post. " his statement "Yes, you can have attached airflow on all points of sail" isn't totally correct. " See last post. I think there is a little confussion as to the differences of how some of us think. Jackie, as well as myself, are Fractional rig sailors. Our mains are our power so we are conserned about the flow over the main. Mast head sailors, which is the majority as they are cheaper to make, are conserned mainly with the headsail. I personally have never gotten my telltails to flow on the headsail off the wind and not even sure you can as the telltails may be too close to the edge. Maybe I need practise there (not too conserned with it as I fly a cruising spin in low/med winds and I use the luff wink trick for trimming that), but have gotten them to flow on the main for a low broad reach.whe you do get them to flow
whe you do get the telltales to flow downwind..do they flow backwardS?
whe you do get the telltales to flow downwind..do they flow backwardS?
Thanks
Thanks all. So maybe it works on the racing boats but they are nuts if they think I can get my Hunter to have flowing tailtells on a run. I could get them to flow towards the leach on wind angles up to about 115 but not deeper. Good to know I'm not that clueless.
Thanks all. So maybe it works on the racing boats but they are nuts if they think I can get my Hunter to have flowing tailtells on a run. I could get them to flow towards the leach on wind angles up to about 115 but not deeper. Good to know I'm not that clueless.
Franklin..... and all other lesser sailors......
I just erased a lenghty response to Franklin's comments because I didn't want him to crawl back under the rock he's been for the last year or so.... I was curious about where the attitude came from.... however.... here's an excellent link on telltales that EVERY sailor, cruiser, racer, novice or expert should find usefull. http://www.wb-sails.fi/news/95_11_Tellingtales/Tellingtales.html The second link is rather technical, but replaces the smoke bomb example suggested by Franklin and Jim. http://syr.stanford.edu/SAILFLOW.HTM Oh...uh...Jackie... here's the greatest sail trim advice you will ever receive.... "when in doubt, let it out"
I just erased a lenghty response to Franklin's comments because I didn't want him to crawl back under the rock he's been for the last year or so.... I was curious about where the attitude came from.... however.... here's an excellent link on telltales that EVERY sailor, cruiser, racer, novice or expert should find usefull. http://www.wb-sails.fi/news/95_11_Tellingtales/Tellingtales.html The second link is rather technical, but replaces the smoke bomb example suggested by Franklin and Jim. http://syr.stanford.edu/SAILFLOW.HTM Oh...uh...Jackie... here's the greatest sail trim advice you will ever receive.... "when in doubt, let it out"
Joe
First I want to thank you for posting those fantastic articles. I hope everyone takes the time to read and understand them. But I have to say that the smoke bomb idea originated from wanting to move from the theoretical knowledge I had from reading similar earlier books and articles to a concrete knowledge of what was happening on my boat under sail by applying that information to real world observations. Frankly, some of my friends thought I was nuts to light a smoke bomb anywhere near a sail, but I felt the insight was worth it. I mentioned it here as another tool that might be employed to better understand what we're trying for and what we're actually accomplishing. Therefore, a toast to better sailing and more of it. Jim Kolstoe, h23 Kara's Boo
First I want to thank you for posting those fantastic articles. I hope everyone takes the time to read and understand them. But I have to say that the smoke bomb idea originated from wanting to move from the theoretical knowledge I had from reading similar earlier books and articles to a concrete knowledge of what was happening on my boat under sail by applying that information to real world observations. Frankly, some of my friends thought I was nuts to light a smoke bomb anywhere near a sail, but I felt the insight was worth it. I mentioned it here as another tool that might be employed to better understand what we're trying for and what we're actually accomplishing. Therefore, a toast to better sailing and more of it. Jim Kolstoe, h23 Kara's Boo
Links
Sorry Joe but your links didn't do me any good as none of it dealt with down wind. I'll take Franklin's advice and the advice of my racing friends. Talked to them last night and they agreed with Franklin that my boat's spreaders are swept back too far but for standard rigs, one should always get the tailtells flowing towards the leach.
Sorry Joe but your links didn't do me any good as none of it dealt with down wind. I'll take Franklin's advice and the advice of my racing friends. Talked to them last night and they agreed with Franklin that my boat's spreaders are swept back too far but for standard rigs, one should always get the tailtells flowing towards the leach.
Franklin...What in the world are you talking about
Aside from your rather snide remarks and assumptions about the level of experience of some of the people posting here, you have made some pretty blanket statements - a few of which I really don't understand. So I just have few questions as to the points you were making As to the use of telltales when trimming sails downwind, Joe submitted 2 very informative links. And he pointed out that one was more technical than the other. Why do you suppose that neither link addressed, in any way, the position of tell tales for a downwind run? In fact the link from the study being done by Stanford Yacht Research shows a diagram of the wind flow around the sails on a downwind run and it screams detached flow. Sailing downwind is all about projected sail area. Ever watch laser sailors race downwind? They heel the boat to windward and ease the boom all the way out with the tip of the boom pointing to the sky. And they aren't doing this to get laminar flow. They are doing this to get maximum projected area in the area of the least disturbed air - which is higher off the water. Now I grant you that in heavier conditions, and being that these are planing boats they will sail higher until they get on a plane and then as the apparent wind moves forward they will sail deeper on a plane - but that is not how our displacement, cruising boats will perform. As to your theory about creating flow on a downwind run by sheeting in the main - When sails are driving a boat foward they are either being used as foils to create lift or they are being used for resistance to push us along. When beating or reaching the lift being provided is enhanced by the increased apparent wind speed as the boat moves faster. How in the world are you getting any benefit out of creating a foil on a downwind run? With a decreasing apparent wind speed any benefit from the lift created from your sail being used as a foil would be decreasing and you would be decreasing resistance. That makes no sense. In fact, on heavy air runs we will purposely over trim the mainsail and spinnaker to depower the boat by reducing projected area. But by your theory, we would actually be creating power by over trimming the sail. And how do you come up with that blanket statement that pretty reasonable racers never sail dead downwind unless it is really blowing? I sail downwind according to my boatspeed relative to other boats, the waves if I can get a push, and my position with respect to other boats if I feel I can maintain my position inside the competition. The deeper I can sail with speed the faster I get to the mark - and that is relative speed not hull speed. So when my speed is up, my bow is down - even ddw and sometimes even by the lee. As soon as my speed drops relative to my competition I head up for more speed, then I might catch a wave and my bow is down again. So there is no blanket angle with which to sail the fastest to a downwind mark and sailing DDW is not always slow. And finally, where in the world did you come up with that statement about masthead rigs being more numerous because they are cheaper? That statement is just strange.
Aside from your rather snide remarks and assumptions about the level of experience of some of the people posting here, you have made some pretty blanket statements - a few of which I really don't understand. So I just have few questions as to the points you were making As to the use of telltales when trimming sails downwind, Joe submitted 2 very informative links. And he pointed out that one was more technical than the other. Why do you suppose that neither link addressed, in any way, the position of tell tales for a downwind run? In fact the link from the study being done by Stanford Yacht Research shows a diagram of the wind flow around the sails on a downwind run and it screams detached flow. Sailing downwind is all about projected sail area. Ever watch laser sailors race downwind? They heel the boat to windward and ease the boom all the way out with the tip of the boom pointing to the sky. And they aren't doing this to get laminar flow. They are doing this to get maximum projected area in the area of the least disturbed air - which is higher off the water. Now I grant you that in heavier conditions, and being that these are planing boats they will sail higher until they get on a plane and then as the apparent wind moves forward they will sail deeper on a plane - but that is not how our displacement, cruising boats will perform. As to your theory about creating flow on a downwind run by sheeting in the main - When sails are driving a boat foward they are either being used as foils to create lift or they are being used for resistance to push us along. When beating or reaching the lift being provided is enhanced by the increased apparent wind speed as the boat moves faster. How in the world are you getting any benefit out of creating a foil on a downwind run? With a decreasing apparent wind speed any benefit from the lift created from your sail being used as a foil would be decreasing and you would be decreasing resistance. That makes no sense. In fact, on heavy air runs we will purposely over trim the mainsail and spinnaker to depower the boat by reducing projected area. But by your theory, we would actually be creating power by over trimming the sail. And how do you come up with that blanket statement that pretty reasonable racers never sail dead downwind unless it is really blowing? I sail downwind according to my boatspeed relative to other boats, the waves if I can get a push, and my position with respect to other boats if I feel I can maintain my position inside the competition. The deeper I can sail with speed the faster I get to the mark - and that is relative speed not hull speed. So when my speed is up, my bow is down - even ddw and sometimes even by the lee. As soon as my speed drops relative to my competition I head up for more speed, then I might catch a wave and my bow is down again. So there is no blanket angle with which to sail the fastest to a downwind mark and sailing DDW is not always slow. And finally, where in the world did you come up with that statement about masthead rigs being more numerous because they are cheaper? That statement is just strange.
sorry, Jackie.....
....but getting your telltales (not tailtells, BTW) to flow backwards when sailing downwind will continure to frustrate you, I guarantee it. I won't argue with your friends, but you did ask the questions. Here's an interview with Tom Whidden about downwind sailing. I would certainly choose Tom's advice over anyone here because he has been one of the leading authorities in sailing for over 30 years. http://www.sailingworld.com/from-the-experts/technique/steering-downwind-with-tom-whidden-200957.html Since your racing friends are adamant about the telltale issue, why not invite them out in your boat for a demonstration? My guess is they will only get them to fly backwards up to the same AWA 115 that you did.... proving that you are not nuts(and just as good a sailor as they are).... and reminding you that the points of sail (close-hauled...broad, beam or close reach...run) are based on TRUE wind direction, not Apparent Wind. So your 115 AWA will vector out to be a somewhat higher number depending on boatspeed, say 150 at 6 knots. When I'm tacking downwind I am trying to keep my AWA somewhere between 90-110, as my speed picks so does my AWA so I can sail deeper. As the speed slows the AWA will start rising so I head up again. I can still use the main's telltales, but I focus on the shroud telltails, or wind indicator, and the speed log, while feeling for pressure on the headsail and trying to steer a good course. By the way, there was a reason sailing dead downwind wasn't mentioned in the telling tales article..... can you guess? Good luck
....but getting your telltales (not tailtells, BTW) to flow backwards when sailing downwind will continure to frustrate you, I guarantee it. I won't argue with your friends, but you did ask the questions. Here's an interview with Tom Whidden about downwind sailing. I would certainly choose Tom's advice over anyone here because he has been one of the leading authorities in sailing for over 30 years. http://www.sailingworld.com/from-the-experts/technique/steering-downwind-with-tom-whidden-200957.html Since your racing friends are adamant about the telltale issue, why not invite them out in your boat for a demonstration? My guess is they will only get them to fly backwards up to the same AWA 115 that you did.... proving that you are not nuts(and just as good a sailor as they are).... and reminding you that the points of sail (close-hauled...broad, beam or close reach...run) are based on TRUE wind direction, not Apparent Wind. So your 115 AWA will vector out to be a somewhat higher number depending on boatspeed, say 150 at 6 knots. When I'm tacking downwind I am trying to keep my AWA somewhere between 90-110, as my speed picks so does my AWA so I can sail deeper. As the speed slows the AWA will start rising so I head up again. I can still use the main's telltales, but I focus on the shroud telltails, or wind indicator, and the speed log, while feeling for pressure on the headsail and trying to steer a good course. By the way, there was a reason sailing dead downwind wasn't mentioned in the telling tales article..... can you guess? Good luck
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