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post #61 of 69 Old 5 Days Ago
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Re: What Kind of a Keel do you Have

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Originally Posted by Arcb View Post
Curious how much you can play the keel sailing. Is it all or nothing or can you rake the keel back a bit for different wind conditions?
I don’t play the keel for balancing purposes—only raising it for skinny water or for reducing drag when running downwind. I normally just leave it down. You need it down to go to weather, of course. The keel is down about 3/4 in the thumbnail below and you can see that it is not a blade, like the centerboard on my previously-owned catboat. I did play the centerboard on that boat, which—like all catboats—had significant weather helm.

I do have an electric winch to raise it (it weighs about 3000 lbs) and can raise it from the helm, but I need to go forward to lower it.

BTW, the rudder is raised and lowered like a centerboard and is almost all the way up in the thumbnail.
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Last edited by fallard; 5 Days Ago at 11:25 PM. Reason: Added info
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Re: What Kind of a Keel do you Have

After reading this thread I’d like to do a superficial pro/con of various keels and look forward to corrections of my thinking.
Full keels and their variants have the advantage that forces are spread over a large footprint. This was the major reason they were employed in wood construction. This was transferred to early grp construction but soon superseded as they suffer from poor pointing ability and high wetted surface compared with other forms. Given their high lateral plane in extreme weather they are unable to slide when broached so knockdowns can turn into a complete roll. Still they are at somewhat less risk of severe damage in a grounding and by incorporating the thinking of Sheel can be of low draft with quite acceptable righting motion. Personally think the execution by Cherubini is the pinnacle of this form.
Centerboards have the problem of trying to achieve both being an effective foil providing adequate lift when the wind is before the mast and an a adequate AVS. They have the advantage of being able to reduce wetted surface and parasitic drag when withdrawn during downhill runs. Unweighted centerboards often achieve an adequate foil as per NASA derived forms when totally down but add nothing to a better AVS. Being dependent on form stability presents its own set of risks. Hence the problem of getting enough weight low enough remains. Placing the centerboard inside a structure outside the canoe body allows lower placement of weight and less compromise of the interior but still isn’t as effective as other forms such as a fin bulb or lifting keel and does so with the burden of more wetted surface.
Wetted centerboards do not solve this problem entirely and create their own. There must be some place to place the weight. Low aspect boards increase wetted surface. Sections of a circle are similarly of low aspect and an inefficient foil as compared to other solutions. AVS will vary depending on position of the board. More total weight is required to create an adequate AVS. The Hood designs attempted to solve these problems with the whale body for the canoe allowing significant weight to remain low in the canoe body. A conundrum exists in heavy weather. Pull the board up to allow the vessel to slide down wave faces or down to increase swiftness. Recent designs such as Boreal or Allures solve this by not depending on the centerboard for a significant contribution to AVS.
Lift keels would seem a better solution. An effective foil can be employed. Even a bulb so weight is outside the canoe body. AVS decreases with retraction but can be quite reasonable. Without keel weight being dispersed a good gyradius is maintained. However, there’s the problems of complexity, compromise of interior design, expense and risk of damage from grounding.
The bulbed fin has dominated for a time. However at the expense of draft and risk to integrity of the canoe body with grounding or catastrophic failure if good engineering practices aren’t followed.
The same with canting keels but magnified as regards complexity and expense.
Foiling boats are outside my thinking as a cruiser except for limited applications such as rudders.
Okay folks rip this post apart. I’m going fishing.

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post #63 of 69 Old 5 Days Ago
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Re: What Kind of a Keel do you Have

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Thanks Jeff. No, it was just intended as a conversation starter.

I do want to go for a ride on a Columbia 50 on a Lake Michigan gale now though Sounds like fun.
Give me some time and let's make that happen...that will be a sweet ride.. For today though, 6 coats of Interlux 2000e...fun times with the gang.
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Re: What Kind of a Keel do you Have

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Me thinks someone loses those informal races too often.......

I sail with Sandero once in a while. His boat is fast. And fast for it's size.

Bringing Shiva over to Northport this spring from Stamford we got escorted/ picked up by a nearly identical Contest 36 with new sails. Great guys. They commented on it being an interesting race as we headed out and, not having met them before I said that Sandero's boat is pretty fast. In my head I know he probably has 3000 lbs of tools and spares on board so I wasn't really confident. I have no dog in this hunt really as I am not much of a sailing racer myself.

As it turned out we left them in our wake, and it was never even close. Don't know why as SanderO and I were just sitting in the cockpit on Autopilot.

But my estimation is he can get 7 knots of speed reaching in 15 mph wind, which is fast in my book.

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Re: What Kind of a Keel do you Have

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I sail with Sandero once in a while. His boat is fast. And fast for it's size.

Bringing Shiva over to Northport this spring from Stamford we got escorted/ picked up by a nearly identical Contest 36 with new sails. Great guys. They commented on it being an interesting race as we headed out and, not having met them before I said that Sandero's boat is pretty fast. In my head I know he probably has 3000 lbs of tools and spares on board so I wasn't really confident. I have no dog in this hunt really as I am not much of a sailing racer myself.

As it turned out we left them in our wake, and it was never even close. Don't know why as SanderO and I were just sitting in the cockpit on Autopilot.

But my estimation is he can get 7 knots of speed reaching in 15 mph wind, which is fast in my book.
That was weird. I think his new sails which had the foot raised might have something to do with it. But we did leave him behind pretty quickly.

pay attention... someone's life depends on it
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Re: What Kind of a Keel do you Have

Good to hear. Apparently everyone notices, even if they refuse to admit its a race.

I’m sure, by the multiple smileys in my post, everyone uunderstood this was light hearted.
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Re: What Kind of a Keel do you Have

Affirmative!


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Re: What Kind of a Keel do you Have

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I don’t play the keel for balancing purposes—only raising it for skinny water or for reducing drag when running downwind. I normally just leave it down. You need it down to go to weather, of course. The keel is down about 3/4 in the thumbnail below and you can see that it is not a blade, like the centerboard on my previously-owned catboat. I did play the centerboard on that boat, which—like all catboats—had significant weather helm.

I do have an electric winch to raise it (it weighs about 3000 lbs) and can raise it from the helm, but I need to go forward to lower it.

BTW, the rudder is raised and lowered like a centerboard and is almost all the way up in the thumbnail.
Interesting, I have never seen a Boat that size with a swing Rudder. I'm curious how much heavier it is steering (forward sailing) with it up. And backing with it up, my regular skeg hung rudder is scary how much force it (could) develop backing, but then again I have been accused of going pretty fast in reverse. We are the second Boat on a very long dock and I back all the way out every time. Going forward the force wants to straighten the rudder, backing it wants to turn it quite forcefully to the stop, if you let go of the wheel. Obviously I am aware and quite careful to not do that.
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Re: What Kind of a Keel do you Have

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Interesting, I have never seen a Boat that size with a swing Rudder. I'm curious how much heavier it is steering (forward sailing) with it up. And backing with it up, my regular skeg hung rudder is scary how much force it (could) develop backing, but then again I have been accused of going pretty fast in reverse. We are the second Boat on a very long dock and I back all the way out every time. Going forward the force wants to straighten the rudder, backing it wants to turn it quite forcefully to the stop, if you let go of the wheel. Obviously I am aware and quite careful to not do that.
Going forward is not a problem, but with the keel and rudder up, the boat steers more like a barge: there is no vestigial keel for tracking and the rudder in the raised position is a very inefficient foil, so the steering is sluggish. Plus, you can’t back and fill with the rudder up, as the rudder pushes the stern in the wrong direction when you try to back and fill.

Going in reverse with the rudder up requires a steady hand on the helm, or you will slam the rudder into the stops.

All that said, the boat has a light touch on the helm with the rudder down.
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