Candanski
2010-11-05T21:02:39Z
Hi there

Does anyone know the ballast ratio for the 28 lifting keel.

Regards

David

Mike Edwards
2010-11-05T21:44:06Z
Hello David

The figures quoted in the hand book are;

Displacement 3272 kg

Total Ballast 1318 kg

(Lifting fin weight 453 kg)

that works out as 2.48:1

Mike Edwards

Seal 28 "Aztec"


Mike Edwards

Seal 28 "Aztec"

Candanski
2010-11-13T17:26:18Z
Thank you for that,Thats about 40% then?. Ive been looking at ballast ratio/righting moment, discussions on various forums. Do you know how well 28s right themselves after a knockdown?. Im trying to get a feel for what she could be capable of in terms of weather.
Mike Edwards
2010-11-13T21:49:08Z
I have been dismasted once and run aground a few times (thank god for a lifting keel) but never had a knockdown.

Personally, I have adopted the position that as the keel cannot be locked in the down position this class of boat is intended to be used in coastal type waters, not for Offshore in extreme conditions. Although I am not saying the boat wont handle rough seas. I have never had any cause for concern when sailing in up to force 7 in the Thames and force 6 in the channel. I have been in some 33 foot modern boats and in the prevailing conditions I would rather have been in Aztec. (I feel there would have been less slamming)

Mike Edwards

Seal 28 "Aztec"


Mike Edwards

Seal 28 "Aztec"

Candanski
2010-11-14T13:12:14Z
Interesting points Mike. Yes the inability to lock down the keel has given me pause for thought. I have been considering mechanisms/devices that might hold it in place in case of emergency, the best I can think of is a steel bar that could be inserted through an aperture in the table and fastened to the bulkhead post. Not very sophisticated I admit but may give piece of mind if caught short, as it were, and could be a relatively simple adaptation.

Mike Edwards
2010-11-14T19:32:48Z
Check the water line height against the keel case.

Mike Edwards

Seal 28 "Aztec"


Mike Edwards

Seal 28 "Aztec"

Candanski
2010-11-14T20:16:30Z
I don't follow
Mike Edwards
2010-11-15T07:37:28Z
I was just thinking if you are considering drilling a hole through the keel case and inserting a bar then consider how you will seal the hole as it will almost certainly need to be below the waterline in order to make contact with the keel in the down position.

If you have a sound plan I would be interested to see it as I have often considered a similar project.

Mike Edwards

Seal 28 "Aztec"


Mike Edwards

Seal 28 "Aztec"

Candanski
2010-11-15T09:29:30Z
I wasn't proposing going in through the case but through the table top at an angle, braced and bolted near the top of the bulkhead post maybe into a socket of some kind. As I said, Inelegant but could be quick to deploy and probably strong enough to prevent any movement and therefore momentum building in case of inversion. keel could possibly be winched back slightly to ensure a tight fit. I just thought the bulkhead post would be one of the few places strong enough to brace against.

Regards

David

David Bamber
2011-07-11T15:22:12Z
This weekend whilst on the way to RIOW Race (that wasn't) we ran into a Force 7 storm and Sea Lady took broadsides from waves at 3m. She recovered well and I at least did not feel in danger of knock down.

I think that you can take it that Seals (850 or 28) are very seaworthy.

regards

David Bamber

David Bamber


David Bamber
Candanski
2011-07-11T21:32:57Z
That's good to hear. Thanks for that.