Adding weight to the stern to counteract weather helm
- Thread starter Iriegal
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I think you might want to start posting on the O'day forums: http://forums.sailboatowners.com/index.php?forums/ask-an-oday-owner.65/ I haven't heard anyone with a 272 complain about this.
Last summer was the first season I had this boat in the water. I put a new bottom on her myself before she went in and I didn't notice anything strange about the wing keel or the shape of the hull. Before I got her, she was on a trailer for 7 years in the previous owner's barn. He never sailed her.
As I was rafted up with a group of folks last summer, we were swimming behind the boats and one guy pointed out how high my boat's stern sat in the water, especially compared to his Oday 28. The end of my stern doesn't even touch the water - she's up in the air until about a foot foreward of the stern. Then I complained about weather helm all last summer and just couldn't get the boat to allow me to let go of the tiller for even a second before she started rounding up, no matter the weather conditions or sail trim. I sailed with a lot of different people last year and we all played around with the sail trim. Two of them who are very competent sailors suggested I add weight to the stern to help balance the boat better. I just came here to get some suggestions on how to do that. Instead I opened a whole new can of worms. That'll learn me. ;-)
As I was rafted up with a group of folks last summer, we were swimming behind the boats and one guy pointed out how high my boat's stern sat in the water, especially compared to his Oday 28. The end of my stern doesn't even touch the water - she's up in the air until about a foot foreward of the stern. Then I complained about weather helm all last summer and just couldn't get the boat to allow me to let go of the tiller for even a second before she started rounding up, no matter the weather conditions or sail trim. I sailed with a lot of different people last year and we all played around with the sail trim. Two of them who are very competent sailors suggested I add weight to the stern to help balance the boat better. I just came here to get some suggestions on how to do that. Instead I opened a whole new can of worms. That'll learn me. ;-)
You mean like this? I don't think that is abnormal. Many boats have the stern lifted above waterline.
http://www.sailingtexas.com/soday272100.html
Where is the waterline when you are sailing? Do you have a slightly reversed transom like this? The boat squats under sail and you want the waterline at the bottom of the transom, not riding up the transom, no?
No question that moving the top of the mast forward will decrease weather helm and increase lee helm. Also moving your genoa lead aft will make the top portion of the sail break sooner which helps depower the rig in windy conditions. Also, moving your traveler to the lee end of the track and adding a lot of boom vang will help trim your boat for heavy weather. Bring the draft forward by tightening your halyards on the main and jib and bring your draft down in the main by tightening your outhaul when close hauled. Decrease sail size and if you have a furler, depending on the make, it might be designed for reefing and to improve sail shape have a foam or rope luff installed in your genoa so that it doesn't get very flat and lose it's shape when furled. And, then there's always reefing the mainsail to decrease sail area and lower the center of effort of the sail. Weight in the stern will do nothing for you for helm pressure, but of course if the boat is trimmed fore and aft then it will sail better in any condition. There are times when you want your weight moved around via crew depending on the sails you are using, the point of sail and the wind velocity. Weight midships as always better than having weight at the bow or stern. Weight on the ends contribute to pitch polling more. That is why it is better to have crew not all sit in the cockpit squatting the stern (which doesn't seem to be your problem) and in very light air, sometimes crew closer to the bow will raise the stern out of the water decreasing wetted surface when running with the wind (but not going to weather). Somebody mentioned a mast-rigged sloop. Well aren't all sailboats rigged with a mast? He probably meant masthead rigged which means the forestay goes all the way to the top instead of a fractional rig where the forestay does not go to the top. Actually a fractional rig is easier to handle in high winds because first of all the headsail is smaller and next the mast is usually tapered and falls off at the top in heavy air, which helps depower the rig. Hope this helps.
Some random thoughts.
FIRST, the fore/aft balance will only be the culprit if it is way, desperately, tragically off. Sail balance is almost ALWAYS the rig and or trim. Or it might be your sailing. The fact that you can't get it to null out leans me in this direction.
FORGET what the boat looks like statically. What does it look like then you are sailing? Remember you are putting several hundred pounds (crew) onto the transom when you load up and sail.
Rudder. Is it factory and in good shape? Unmodified?
UNDER NO CIRCUMSTANCES add weight to the back of the boat. This is wrong for so many reasons that I don't have time to list them all there. On the off chance that this is part of the problem, find ways to lighten the bow. You don't want to turn you boat into a teeter-totter.
FIRST, the fore/aft balance will only be the culprit if it is way, desperately, tragically off. Sail balance is almost ALWAYS the rig and or trim. Or it might be your sailing. The fact that you can't get it to null out leans me in this direction.
FORGET what the boat looks like statically. What does it look like then you are sailing? Remember you are putting several hundred pounds (crew) onto the transom when you load up and sail.
Rudder. Is it factory and in good shape? Unmodified?
UNDER NO CIRCUMSTANCES add weight to the back of the boat. This is wrong for so many reasons that I don't have time to list them all there. On the off chance that this is part of the problem, find ways to lighten the bow. You don't want to turn you boat into a teeter-totter.
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After reading all this, and seeing the pic Scott T-Bird found, I'm inclined to suggest re-tuning the rig. Specifically, I'd rake the mast forward. This involves backing off the backstay and shrouds maybe 1 full turn, and taking up on the forestay. For boats that aren't an active racing class, there aren't tuning guides with exact measurements to set the rake. Rather, you just have to tweak it, go sail close hauled in 12 knots, and see if you get your desired 3-6º of weather helm at the tiller.
I was bummed the first year with my boat, I did this about 3-4 times. 'Round about the second time, I thought I had super neutral helm, until the wind got a bit stronger and I realized it really had lee helm. So I had her all dialed in, then I made some mods to my rudder headstock, which tipped the rudder blade just an inch or so aft. Had to go back out the second season, and adjust the mast rake again, because the helm feel was too heavy.
Then, this past season, I realized my mast step was sinking, so who know what tweaks I'll have to do once I cut that out and repair...
I was bummed the first year with my boat, I did this about 3-4 times. 'Round about the second time, I thought I had super neutral helm, until the wind got a bit stronger and I realized it really had lee helm. So I had her all dialed in, then I made some mods to my rudder headstock, which tipped the rudder blade just an inch or so aft. Had to go back out the second season, and adjust the mast rake again, because the helm feel was too heavy.
Then, this past season, I realized my mast step was sinking, so who know what tweaks I'll have to do once I cut that out and repair...
First of all an oday 272 is an old credible design with no built in problems. You say you have good sails. Are u sure? a baggy main sail is a known source of weather helm If you have to resort to pulling cement bags in the stern you have a big problem First, get the mast plumb no aft rake which causes weather helm. make sure the mast is not leaning either port or starboard 2 go ashore and look at the boat She should be sitting on her lines. make sure your rigging is tuned tight no wire swing ing in the breeze With the boat sitting on her lines and the rigging is tight and the mast plumb go out for a sail. If its breezy and you get some heel reef your main DO NOT ROLL THE JIB HALFWAY UP that will cause weather helm. If its light your helm should be neutral If you still detect problems
I would get a seasoned expert to look at the boat.
I would get a seasoned expert to look at the boat.
Well, in this case it's pretty simple: Jackdaw's answer is the one you should follow. He's absolutely correct. Loading the stern with bags of cement is a terrible idea. Please don't do that.One of the best things I like about sailing is all the different advice I get for the same problem. I can't wait for the day when I'm the one doling out advice to some rookie newcomer. Just to see their eyes cross like mine are now.
Boats are generally designed to have some weather helm, and from this description I'm not really sure yours is out of spec. How much do you have to turn the rudder to hold a straight course when you're underway? It's reasonable that you'll need to keep about 3 degrees of deflection. That deflection in itself means that if you let go of the tiller it will almost immediately begin turning.
Oh absolutely! I was hoping jackdaw would reply so I could leech off his knowledge. The cement bag thing was a joke. I would never do that. But I was hoping to find a simple answer. What was I thinking?!!! ;-) I'm just gonna keep playing with my boat. I'm having a blast with her and I love all the interesting challenges. I'll get myself straightened out one of these days. Cheers!
In the immortal words of Hercule Poirot, 'There are too many clues in this room'.
The trick is fault isolation. You have to eliminate things that it COULD be. The real trick to that is knowing how to do that, knowing that you might doing something positive, but it might not have a positive effect until you solve the problem.
I would start with standing rig tune. Make sure your mast is plum to start, and your stays have decent tension.
Sail.
How big is your genoa? The boat was spec'ed for a 130%. Get your sail shape as you can. Have someone really good on board looking at sail shape.
Sail.
Boat trim fore/aft. Try and effect helm with balance. If you can or cannot will be very telling.
Sail.
I'd like to see some pic's, sitting at anchor and sailing. or better yet, video. as others said, how bad is it really? how much heel is it when you round up?
It might be worth hiring a pro rigger, and if he can't figure it out, I'd be looking at the rudder next. Adding some leading edge would probably help, but it also might just mask the real problem.
It might be worth hiring a pro rigger, and if he can't figure it out, I'd be looking at the rudder next. Adding some leading edge would probably help, but it also might just mask the real problem.
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I'm gonna take Jackdaw's advice and just sail more for now. There are some easy tweaks that I can make to my sail trim, my style, and my boat. I definitely have a LOT more to learn and I'm looking forward to this year's lessons. More sailing, more beer, more friendships, and more fun! C'mon Spring!!!
There are - in general - two things that cause weather helm:
1) the center of EFFORT of the rig (the combination of sails) is aft of the center of LATERAL RESISTANCE of the underbody (keel/centerboard and rudder). This can be addressed in a number of ways - reducing the area of the mainsail (eg, reefing), reducing the *power* of the mainsail (by flattening the sail, letting the leech twist off, other trim options), or by shifting the center of EFFORT forward (generally by adjusting the headstay and backstay to move the mast forward). All of these are worth trying
2) when a boat heels, the underwater surface changes from a symmetrical shape to an asymmetrical shape - the leeward side of the hull is immersed, and the windward side of the hull is raised, resulting in a "volume" of displacement that is lopsided. Even if the sails are trimmed perfectly, allowing a boat to heel to leeward will tend to make it turn to weather. Any boat. So... adding weight "aft" will not help with your weather helm, but adding weight to *weather* (flattening the boat so that it is sailing more on its designed lines) will absolutely help weather helm.
It is possible that a trim issue is causing the bow-down trim, and correcting (getting the knuckle of the boat up out of the water) will help lessen the weather helm. But the root cause of the weather helm is (almost) always going to be related to either trim/rake or heel.
$.02
1) the center of EFFORT of the rig (the combination of sails) is aft of the center of LATERAL RESISTANCE of the underbody (keel/centerboard and rudder). This can be addressed in a number of ways - reducing the area of the mainsail (eg, reefing), reducing the *power* of the mainsail (by flattening the sail, letting the leech twist off, other trim options), or by shifting the center of EFFORT forward (generally by adjusting the headstay and backstay to move the mast forward). All of these are worth trying
2) when a boat heels, the underwater surface changes from a symmetrical shape to an asymmetrical shape - the leeward side of the hull is immersed, and the windward side of the hull is raised, resulting in a "volume" of displacement that is lopsided. Even if the sails are trimmed perfectly, allowing a boat to heel to leeward will tend to make it turn to weather. Any boat. So... adding weight "aft" will not help with your weather helm, but adding weight to *weather* (flattening the boat so that it is sailing more on its designed lines) will absolutely help weather helm.
It is possible that a trim issue is causing the bow-down trim, and correcting (getting the knuckle of the boat up out of the water) will help lessen the weather helm. But the root cause of the weather helm is (almost) always going to be related to either trim/rake or heel.
$.02
I hate to even mention this name "Walmart" but they sale or did anyways 70# bags of sand in tube form, they should slide in about any where, or can be opened and adjusted to anysize or weight
Regarding mast rake: Assuming you have your sails fairly well balanced and you are still rounding up, adjusting the mast rake is a worthwhile adjustment. In my experience, when you tend to round up, you should remove some mast rake. However, now instead of rounding up in a blow you will heel. These are all trade-offs.
Reading through this, there is a bunch of mention of rounding up - which would be a sign of bad balance but the OP only mentions rounding up when the tiller is released.. Does the boat "round up" when you are sailing and dont want this to happen? Or is the problem that you think you have to apply too much pressure on the tiller while sailing?
Rounding up while sailing when you are actively trying to make the boat go straight - balance problem. However, too much pressure on the tiller could be as simple as someone in the past boat ownership modified the rudder which moved the center of effort so that it is no longer in line with the pivot. The further the CE of the rudder is from the pivot, the larger the moment arm force that gets transferred to the tiller.
I mention this (and it has also been mentioned in this thread) - with kick up rudders on trailer boats, someone may have a problem where a lot of force is required on the tiller and its often that the rudder isnt held all the way down so that its center of effort is at least somewhat in line with the pivot. Often just getting the rudder held all the way down (where its supposed to be) dramatically reduces the tiller pressure.
Rounding up while sailing when you are actively trying to make the boat go straight - balance problem. However, too much pressure on the tiller could be as simple as someone in the past boat ownership modified the rudder which moved the center of effort so that it is no longer in line with the pivot. The further the CE of the rudder is from the pivot, the larger the moment arm force that gets transferred to the tiller.
I mention this (and it has also been mentioned in this thread) - with kick up rudders on trailer boats, someone may have a problem where a lot of force is required on the tiller and its often that the rudder isnt held all the way down so that its center of effort is at least somewhat in line with the pivot. Often just getting the rudder held all the way down (where its supposed to be) dramatically reduces the tiller pressure.
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