Ballast in ODay 22 ?

[Sea Drifter]

My ODay 22 (1978) is designed to have 600 lbs lead in the keel. It is fine under sail, and I reef down when needed. However it seems more "tippy" just lying on the mooring as I move side to side in the cockpit ... more than what I remember from the same model boat I had 20 years ago. Would adding more lead ballast in the keel "sump" change this very much?..or am I just older now!

 

[Shoaldrafter]

Ask N. A.

My ODay 22 (1978) is designed to have 600 lbs lead in the keel. It is fine under sail, and I reef down when needed. However it seems more "tippy" just lying on the mooring as I move side to side in the cockpit ... more than what I remember from the same model boat I had 20 years ago. Would adding more lead ballast in the keel "sump" change this very much?..or am I just older now!

This question would appropriately be asked of a Naval Architech who has written on sailboat stability such as David Gere of Westlawn N. I., see:
http://www.westlawn.edu/who/faculty.asp
Ted Brewer has also written about this subject.

Ed K
26

 

[Shoaldrafter]

Re: Ask N. A.

I mispelled David's last name. It is Gerr. And I cannot access his articles on Stabiliy written several years ago, but look here:

http://www.boatus.com/goodoldboat/stability.asp

and:

http://www.sailingusa.info/design_winds.htm

and:

http://www.radford-yacht.com/stablty1.html

and:

http://www.boatdesign.net/forums/boat-design/sailboat-stability-2342.html

Ed K
26

 

[jackhartjr]

I have somewhere an article about the Oday 22 that mentions adding up to 200 pounds more lead in the bilge.
I will look for the article today and post what it says.
Now as to weather it would help that much with stability...I do not know.
Jack

 

[Joe11688]

My ODay 22 (1978) is designed to have 600 lbs lead in the keel. It is fine under sail, and I reef down when needed. However it seems more "tippy" just lying on the mooring as I move side to side in the cockpit ... more than what I remember from the same model boat I had 20 years ago. Would adding more lead ballast in the keel "sump" change this very much?..or am I just older now!

I still think that adding internal ballast as close to the keel as possible will give you pretty good results, Tony. Not only that, you will still attain the same shoal draft. I think that Ed will disagree with me on this, and that's quite Ok. We can both agree to to disagree. I know from past experience that when I load my bilge up with can goods in 2.5 Gal containers w/lids, plus all the other odds and ends that I carry, my boat seems more stable. It doesn't hurt to give it a try. I'd be more inclined to try this first, than to add more weight to the bottom of my keel.
Joe

 

[Sea Drifter]

ODay 22 Ballast Calculations

Thanks to everyone above who has commented on this for me! I have reviewed all the articles! Most of the ballast calculations I see are related to heeling when underway and give combinations of form stability and righting moment from the lead in the keel. My issue seems to be slightly different, as I am looking at the boat lying stationary on the mooring. This is most probably related to "form stability".

If I add 200 lbs of extra lead in the keel "sump", the boat will "sink" approximately 0.42 inches (based on a waterline cross sectional area of 90 square feet). This would not appear to have a lot of effect.

The 600 lbs of lead already in the keel has an approximate static righting moment of 1000 ft lbs. An ODay 222 (Keel/CB model) has a shallower draft, but 800 lbs of lead, giving a static righting moment of approximately 800 ft lbs.

So .. in theory ... my boat should be at least as stable as the ODay 222 wihtout adding extra ballast. Unless this is related in some way to a "rolling stability", I think the next best step is to add some weight in the Spring after launch, and just see how much of a difference it makes.

If anyone has other comments, I would much appreciate them!

 

[jackhartjr]

I do remember reading somewhere...and I do not know where...that it takes 300 pounds of weight to sink an Oday 22 1 inch.
Jack

 

[Shoaldrafter]

Joe said that I would not agree "that adding internal ballast as close to the keel as possible will give you pretty good results." But isn't that where naval architects try to add ballast for stability?

I would say that you have studied and calculated what you want to do and the comments indicate it should have positive effect. Jack's comment and your calculations indicate the depth increase to be reasonable. Just think that it adds just one more person who happens to be in the bilge.

So, now for the test. What material do you plan to use? Mold some lead ingots that will lay flat and in the limited cavity space? A way to secure them from moving while heeling or bouncing on waves?

Best of luck and fair winds.

Ed K
26

 

[jackhartjr]

In a private post I said this;
"I have a copy of a manual that I think is from 1972. It is a rigging manual, I can fax it if needed.
It is not a great copy.
I says this;
The Oday 22 has 600 pounds of lead ballast glassed into the keel, which is more than adaquate; however you can add more if you want more stability. The easiest way is to pour lead shot into the keel area through the bilge drain plug. You may even mix with catalyst and resin for a more permanant job. We have customers who have added 200 pounds in this manner, but be sure to add positive flotation at the same time in order to support the extra weight should the hull take on water through a leak or hull puncture!"
Thought I would post what I said I would last week.
Jack

 

[Sea Drifter]

ODay Ballast - First Test in the Spring!

Shoaldrafter, Joe, Jack, ... Thanks for all the replies and information. The simplest test I can think of after launch in the spring, is to "invite" my 200 lb son for a sail, and have him lie on the floor in the cabin while onthe mooring, and test the "mooring stability"!

I am much inclined to believe this is a "form stability" issue, as my previous ODay 23 (see photo below) has a very broad, stern under the cockpit and feels like an "ocean liner". I think the narrower ODay 22 has more "initial heel" ("quick heel") and I am not used to it!

The spring/early summer will tell!