[Alberg30] Ballast

Gord Laco gord at transatmarine.com
Mon Mar 5 08:44:19 PST 2001


Hi,

Now that you've mentioned it, the A30's trim does bug me.  I noticed that
the bow high attitude does not show on Carl's drawings... I suppose that the
positioning of the ballast and the fact that it is iron resulted in
something other than what the designer intended.   When you put people in
the cockpit, and get the boat moving the squat gets worse.  Keeping the
water tank full, and trimming the bow down (my 100' of anchor chain) helps -
and actually makes the boat faster in flat water, but you pay a penalty in
increased pitching moment.   I tested this by time vs distancing the
boatspeed before and after trimming.  Trimming the bow down with the chain
and water gave me a tenth of a knot at 5knots.

We discovered this while engaged in a water/food fight with another Alberg
during a glassy calm.   Same engine, same prop; we had our people crowded in
the bow to throw, they had crew on the stern also throwing... we were much
faster until we reversed the "gunners" positions - and found that the speed
situation also reversed.  I did a little experimenting after that.


Gord

----- Original Message -----
From: Bob Johns <rjohns3 at optonline.net>
To: <public-list at alberg30.org>
Sent: Friday, March 02, 2001 4:21 PM
Subject: Re: [Alberg30] Ballast


> Lee, Gord, et all.
>
> This is a little off the subject but related to it. Before we bought our
> A30 we looked at another one that had lead pigs added under the sole up
> forward. This was added, not to  increase stability, but to improve the
> fore-and-aft trim. (I remember hearing a good sailor commenting that the
> Alberg designs tended to squat in the stern.) I always meant to try this
> myself but never got around to it even though I have always been aware
that
> our A30 does squat in the stern.
>
> My second comment relates to heel while beating. The Alberg designs do not
> like to be sailed completely rail down. I first became aware of this when
I
> was crewing on a Alberg 35. We were going to be late for the start of the
> race and the skipper was pressing hard trying to get there in time for the
> start. The rail was down to the level of the water and we were really
> plowing through the water. When we realized that we could not make the
> start we shortened sail and found that we picked up almost a knot and were
> sailing much more comfortably.
>
> Forgive me if I am just stating the obvious.
>
> Regards,
> Bob Johns, Wind Call #397
>
>
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