Ballast Question

[Bob Cruickshank]

Hi Folks!-


I'm not a regular contributer to this fine forum, but I wonder if someone can help answer a question for me. The other night I was talking to some sailing friends about the displacement of certain boats. During the conversation, one of the guys said he knew of a production boat (not a CD) 32' LOA with a displacement of 12,500 pounds and a total ballast of 2,500 pounds. He also stated the boat was a narrow beam design, I think 9 feet. The boat was cutter rigged with a moderately high aspect rig. My question for anyone who knows boat design is - are these numbers possible? That seems like way too little ballast for a boat that size and weight. I know my CD-30 displaces 10,000lbs and has 4000lbs ballast and she is also narrow on the beam. Can anyone comment on these design parameters to settle this for me?


Thanks in advance, sorry it's not a Cape Dory question.


Bob Cruickshank CD-30 Osprey.

[Dana Arenius]

Bob,

Sure it is possible but I would not put up too much sail!
If I had to guess I think your friend made a simple error in recall.
If it is a cutter (none racing), narrow beam (9'), etc. the numbers don't "add up". All I can think of is a very deep bulb keel with narrow fin appendence. See if you can a manufacturer's name.

Dana



darenius@aol.com

[John]

Hi Folks!-


I'm not a regular contributer to this fine forum, but I wonder if someone can help answer a question for me. The other night I was talking to some sailing friends about the displacement of certain boats. During the conversation, one of the guys said he knew of a production boat (not a CD) 32' LOA with a displacement of 12,500 pounds and a total ballast of 2,500 pounds. He also stated the boat was a narrow beam design, I think 9 feet. The boat was cutter rigged with a moderately high aspect rig. My question for anyone who knows boat design is - are these numbers possible? That seems like way too little ballast for a boat that size and weight. I know my CD-30 displaces 10,000lbs and has 4000lbs ballast and she is also narrow on the beam. Can anyone comment on these design parameters to settle this for me?


Thanks in advance, sorry it's not a Cape Dory question.


Bob Cruickshank CD-30 Osprey.

Hi Bob, I have a CD30 also. Those are quite the numbers! I think the
tall rig is a major factor if the numbers are correct. I refer you to
a great book on yacht design called " Offshore Yachts " by John Rousmaniere published by Norton. You can get it at Boat U.S. and I've
seen it at West Marine too. They have a lot to say about tall rigs
and how they play a strong role in vessel stability. They use the
metaphor of a figure skater spinning - slower with arms outstretched
and faster as they bring their arms inward. They make some very interesting observations in the book. Maybe thats why Catalina 30 tall
rig versions are so fast and quite stable for their displacment? The Catalina has substantial beam though. Do any CD's have tall rigs com-
ared to boats of similar size?