|Subject: Re: [harryproa] Re: harry gami. (Todds square harry)|
|From: "Rob Denney" <email@example.com>|
|Date: 5/30/2008, 7:56 PM|
On Fri, May 30, 2008 at 10:56 PM, tsstproa <bitme1234@yahoo.
> Wow above the waterline doesn't alter anything are you serious?
> One thing I learned from you that you stress is windage on hulls!!!
It obviously alters the sailing, but not the below water
characteristics, which is what the rest of the numbers were about.
You need more than just height and width to determine whether the
height at the bow, beams and mast is sufficient.
> Knowing 36''height at center of reverse sheer seems high for a 16'
> wwh. 30'' sheer height at center on 24'lwh with reverse sheer might
> increase it to 36''
> You think the 3,ooo + lbs displacement on 24' lwh submerged to the
> tops of its bows 24'' will be enough reserve buoyancy for descent
> sail carry capacity?
No idea, depends on rig height, crew weight and location, beam overall
and shape of the hull above the waterline at the bow.I would need at
least a lines drawing and a rig picture to form an opinion.
> I just wanted to compare your 24 WWH with My flat bottom 24 LWH
> wetted surface are to see how much difference the wetted areas would
> be. That is all. I gave you all the numbers except waterline beam
> width so I think that was the confusion.
> As far as weight of boat and weight carried by boat. I figured plan
> for the worst (heaviest) or extra load on sundays in the bay with
> family and friends and build for the (lightest)
> possible with materials used. You have a cushion between the two to
> get it right for most any load/weight within reason.
Building light and sailing heavy seems to be the wrong way round to me.
> --- In harryproa@yahoogrou
>> On Wed, May 28, 2008 at 1:32 PM, tsstproa <bitme1234@.
>> > Rob I didn't give waterline beams widths, sheer widths, or height
>> > from keel to sheer.
>> Above the waterline doesn't alter anything, but the waterline
>> is critical for comparison.
>> > I just wanted your numbers of your boats wetted surface area.
> What is the wetted surface area for what waterline/displacem
>> > both hulls.
>> For the trailer sailor in the files section, the wetted surface for
>> the ww hull at 450 kgs/990 lbs is 4.4sq m/46 sq', beam 485mm/19".
>> lee hull at 300 kgs/660 pounds is 4.sq m/51 sq', waterline beam 370
>> mm/14.6"and at 750kgs/1,650 (hull flying) is 7.5 sq m/81
>> sq',waterline beam 440mm/17.3" . Prismatics are .8 The
>> of short fat hulls in light air, where friction from wetted
> surface is
>> important is obvious.
>> > My 24' square harry I'm getting a total area of 156sqft and
>> > area of 47sqft at 6''waterline for a displacement of 795lbs at a
>> > prismatic coefficient of .783 17/1 length to width ratio
>> > 16' wwh with out cabin , 129sqft 46sqft wetted area at a
>> > 8''waterline with a displacement of 882lb prismatic
> coefficient .764
>> > 12/1 length to width ratio.
>> > total displacment 1,675lbs total weight of boat 800lbs. 800lbs
>> > and gear, 250-300sqft sail area.
>> > Todd