[Public-List] Incline test on an Alberg 30?

[Dennis K. Biby]

>
> " That means that you  have to roll us 170 degrees before the yacht stops
> trying to right herself."
>
> Hmm!  170 degrees means the mast is 10 degrees short of straight down.  How
> does one trim the underwater sails?
>
> Dennis
> s/v Ferrity
>
>
>
>
> On Sat, May 8, 2010 at 7:06 PM, Gordon Laco <mainstay at csolve.net> wrote:
>
>> Anyone concerned about our boats' stability characteristics should have a
>> squint at C.J. Marchaj's book 'Seaworthyness, the Forgotten Factor'.   It
>> is
>> a learned and uncompromising examination of trends in yacht design...
>> While
>> the A30 is not named, her type is defined as an ideal.
>>
>> While traditional or classic hull types may have lower resistance to
>> heeling
>> initially, the combination of deep full keels and narrowish beams result
>> in
>> very high LPS numbers.  LPS, Limit of Positive Stability, is the number
>> that
>> counts.  The A30's LPS is somewhere around 170 degrees.  That means that
>> you
>> have to roll us 170 degrees before the yacht stops trying to right
>> herself.
>>
>> Your average beamy, fin-keeled yacht, the type that clobbers us in light
>> airs and may even gloat about its 'stiffness' in 15 knots of wind, could
>> have an LPS between 80 and 110 degrees.  Those low numbers mean that over
>> a
>> very wide swath of a circle (roll) they are as stable upside down as right
>> side up.  The extreme of this is a multi hull yacht, which has incredible
>> stability for the first 20 or 30 degrees of heel... And is then so stable
>> when capsized that in cannot be righted without outside help.
>>
>> The A30 and its type are very good seaboats.  Provided you can keep the
>> sea
>> out, in the Alberg 30 we have a boat that will continue to look after its
>> crew through extreme conditions.  (but I DO wish Mr. Hansen had followed
>> Mr.
>> Albergs wishes and given us lighter fractional rigs and lead ballast..)
>>
>> Gord #426 Surprise
>>
>

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