After having sailed my Grampian 23 for almost 2 years, I am still frustrated by the apparent lack of pointing ability. I think the best I can do is about 60 degrees off the wind. In winds under 10 mph, I have a fair amount of lee helm, 10 - 15 mph some lee helm and only over 15 mph does the boat start to have weather helm. Both tacks. I am using a 100 % jib and full main. These are the sails I got with the boat. They are in good condition, but I do not know the age of the sails. The main could be bigger; larger roach and about 8 inches longer on the foot. The mast has perhaps a couple of degrees aft rake; I don't have any extra length on the forestay to ease the mast further aft.
The rudder is definitely not the original. It is a 1 inch thick piece of plywood which has the leading and trailing edges rounded and that's about it.
My question (after that long intro) is how best to correct this condition? Should I try raking the mast further aft? Should I take the time to shape the rudder into a proper section? Anything else?
Thanks for any suggestions.
Cheers,
Ian
Pointing ability.
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grampianman
- Master Varnisher
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Figment
- Damned Because It's All Connected
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Refresh me.... your boat has a swinging centerboard? If so, are you sure it's swinging all the way down/forward?
I ask because it sounds like your Center of Lateral Resistance is too far aft. It sounds like you've done all you can to bring your sailplan's Center of Effort aft, so I'm focusing on the CLR.
The rudder is not original.... is it the same SHAPE as the original design? Asking in terms of profile, not section. I don't think the section has much to do with your problem, unless you're hearing cavitation (really unlikely). If your rudder doesn't match the original design, but reaches farther aft, or even if it's just larger, that may be your problem.
How about hull trim, in terms of fore-and-aft ballast placement? If memory serves, it's a fairly lightweight boat, and weight placement can have significant effect on trim. If you have too much weight aft, and the hull "squats", that can move the CLR aft enough to make a difference, particularly with such a low-aspect underwater profile.
I suggest the issue of hull trim primarily because you say that your lee-helm goes away only when the wind picks up, which is when the pressure of the sailplan presses the bow down into the water. Load everything but the kitchen sink up into the vberth and go for a sail.
Heeling the boat to leeward a bit more in light air may help as well.
This probably won't instantly turn your boat into a super-pointer, but curing your lee-helm sounds like a great place to start!!
(yeah, yeah, gotta get my boat in the water and sail all of this physics crap out of my head!!!)
I ask because it sounds like your Center of Lateral Resistance is too far aft. It sounds like you've done all you can to bring your sailplan's Center of Effort aft, so I'm focusing on the CLR.
The rudder is not original.... is it the same SHAPE as the original design? Asking in terms of profile, not section. I don't think the section has much to do with your problem, unless you're hearing cavitation (really unlikely). If your rudder doesn't match the original design, but reaches farther aft, or even if it's just larger, that may be your problem.
How about hull trim, in terms of fore-and-aft ballast placement? If memory serves, it's a fairly lightweight boat, and weight placement can have significant effect on trim. If you have too much weight aft, and the hull "squats", that can move the CLR aft enough to make a difference, particularly with such a low-aspect underwater profile.
I suggest the issue of hull trim primarily because you say that your lee-helm goes away only when the wind picks up, which is when the pressure of the sailplan presses the bow down into the water. Load everything but the kitchen sink up into the vberth and go for a sail.
Heeling the boat to leeward a bit more in light air may help as well.
This probably won't instantly turn your boat into a super-pointer, but curing your lee-helm sounds like a great place to start!!
(yeah, yeah, gotta get my boat in the water and sail all of this physics crap out of my head!!!)
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Tim
- Shipwright Extraordinaire
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I'd say offhand that your problem is most likely a combination of the design of the boat (nothing you can do there) and the condition of your sails and their trim. 60 degrees off the apparent wind is not beyond the realm for many boats. You may simply never point 40 or 45 degrees to the wind in that boat. Some boats don't do it, period. Still, you should be able to do better than you are; you're not sailing a square rigger, after all.
Your sails may look fine, but cloth gets worn out and simply doesn't provide the lift required for pointing ability. Blown out sails contribute more to poor sailing than anything. Yes, it seems obvious, but until you see the difference firsthand it's hard to appreciate.
Sail trim and mast tuning are also important factors. Look to the small stuff first and forget about big changes till you exhaust all the likely candidates first. A bigger mainsail roach will reduce lee helm, as will new sails. Minor rig adjustments might work wonders too. I'd go for a nice straight mast on both tacks, adjust the rake as you see fit, and then concentrate on sail trim, sheeting leads, and/or new sails.
Sometimes (usually) it's better to forget about pointing and just figure out how to make the boat go as well as she will go in the best direction possible. With that done, often pointing ability follows, as you see what effects certain changes have. Everyone seems so hung up on pointing that they often forget about some of the fundamentals of sailing and sail trim. Pointing ability is good, but sometimes it's unrealistic to hope for excellent performance. There are simply too many unchangeable factors involved sometimes.
Good luck--this is the fun stuff.
Your sails may look fine, but cloth gets worn out and simply doesn't provide the lift required for pointing ability. Blown out sails contribute more to poor sailing than anything. Yes, it seems obvious, but until you see the difference firsthand it's hard to appreciate.
Sail trim and mast tuning are also important factors. Look to the small stuff first and forget about big changes till you exhaust all the likely candidates first. A bigger mainsail roach will reduce lee helm, as will new sails. Minor rig adjustments might work wonders too. I'd go for a nice straight mast on both tacks, adjust the rake as you see fit, and then concentrate on sail trim, sheeting leads, and/or new sails.
Sometimes (usually) it's better to forget about pointing and just figure out how to make the boat go as well as she will go in the best direction possible. With that done, often pointing ability follows, as you see what effects certain changes have. Everyone seems so hung up on pointing that they often forget about some of the fundamentals of sailing and sail trim. Pointing ability is good, but sometimes it's unrealistic to hope for excellent performance. There are simply too many unchangeable factors involved sometimes.
Good luck--this is the fun stuff.
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grampianman
- Master Varnisher
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Thank you, Professer Tim
Thanks very much for the reply. You're right, get her sailing to her best and the rest will follow.
Actually, my Grampian is a fixed keel. I think there is a possibility of the cast iron keel being flat on one side (which introduces another small problem; the boat goes straighter on starboard tack than on port!), but I'll see that when I haul in July.
Friday evening when I went sailing, the wind was blowing 15 - 20 with gusts as high as 30, the little boat revelled in the conditions. I'll be looking at your suggestions and will post the outcomes.
Thanks again,
Cheers,
Ian
G-23, #299
Actually, my Grampian is a fixed keel. I think there is a possibility of the cast iron keel being flat on one side (which introduces another small problem; the boat goes straighter on starboard tack than on port!), but I'll see that when I haul in July.
Friday evening when I went sailing, the wind was blowing 15 - 20 with gusts as high as 30, the little boat revelled in the conditions. I'll be looking at your suggestions and will post the outcomes.
Thanks again,
Cheers,
Ian
G-23, #299