From: Doug Haines <doha720@...>
Subject: Re: [harryproa] static moment righting test
To: harryproa@...
Date: Wednesday, 6 May, 2009, 6:32 PM

also used gps for halh an hour: reaches across melville water and back - the port hand marker out in the midlle of the water has the bureaus recording station mounted on it. The figures for 8:30am are 9knots gusting to 12knots, and for 9am 11 knots gusting to 15knots. I think I was out there from around 8:30 'till 9am, and the gps reading were giving 6-7 knots inshore starting off, 8-9 knots out in the middle, with a couple of reaches at about 9 knots and gusts shooting speed up over 10,11,12 knots. Unfortunately rudder turbulence shuts off any acceleration after that, so guesses of potential speed are around 13 knots today and with more wind top speed could be well over 15!   doug --- On Wed, 6/5/09, Doug Haines <doha720@yahoo. co.uk> wrote: From: Doug Haines <doha720@yahoo. co.uk> Subject: [harryproa] static moment righting test To: harryproa@yahoogrou ps.com.au Date: Wednesday, 6 May, 2009, 3:13 PM hi,   got the sidecar up on its side (based on lw hull), with the ww hull sitting up in the air. It was quite a lift even using halyard to the mast top (me) and lifting/pushing hull (Rob).   got stuck in too tight mast out horizontally with wiggling the wing rotator.   dougg --- On Wed, 6/5/09, Gardner Pomper <gardner@networknow. org> wrote: From: Gardner Pomper <gardner@networknow. org> Subject: Re: [harryproa] Re: Fine tuning design questions To: harryproa@yahoogrou ps.com.au Date: Wednesday, 6 May, 2009, 1:41 AM Hi, That helps alot. I am looking at 500mm lw and 600mm ww, with semicircular bottoms and vertical sides, so I can tell from your numbers that I am not fatter (well, I am, but the hulls aren't) than yours. I need to rework my weight calcs. I think the latest pass made a flat bottom ww hull too deep to use the hull as the floor, so I might as well go semi-circular if I have to put a floor in anyway. - Gardner On Tue, May 5, 2009 at 10:50 AM, Rob Denney <harryproa@gmail. com> wrote: > > > G'day, > > No idea, sorry. Lee hull was 600 wide (I had to be able to get > inside) and had semi circular sections, but I can't remember where it > floated. ww hull was probably 800 wide, also with semi circular > sections, but again, no idea where it floated. > > regards, > > rob > > On Tue, May 5, 2009 at 9:36 PM, Gardner Pomper <gardner@networknow. org> > wrote: >> >> >> I was looking for the waterline beams and the draft of each hull. Are >> those the numbers you don't remember, or other sailing numbers? >> >> - Gardner >> >> On Tue, May 5, 2009 at 9:29 AM, Rob Denney <harryproa@gmail. com> wrote: >>> >>> >>> G'day, >>> >>> Harrigami managed 15 in 15 on a reach in flat water. I don't remember >>> any other performance numbers. >>> >>> regards, >>> Rob >>> >>> On Tue, May 5, 2009 at 8:27 PM, Gardner Pomper <gardner@networknow. org> >>> wrote: >>>> >>>> >>>> Rob, >>>> >>>> I would like to compare to a known quantity. I know you have sailed >>>> Harrigami, and said that it sails at wind speed up to about 15 kts, so >>>> could you give me the figures for it? I know it is a bit smaller, but >>>> not that much. >>>> >>>> I am very happy to hear that John is anxious to quote. I thought he >>>> might not be ready for the bigger boats yet and I would have a hard >>>> time getting his attention. I have just been holding off until I sort >>>> out the final hull shapes, so that the panel drawings that I send will >>>> have the correct areas on them. Hopefully I will have that ready by >>>> the end of the week and can send it off. >>>> >>>> Thanks, as always, for all the help! >>>> >>>> - Gardner >>>> >>>> On Tue, May 5, 2009 at 2:05 AM, Rob Denney <harryproa@gmail. com> wrote: >>>>> >>>>> >>>>> G'day, >>>>> >>>>> Aroha has 600mm/2' beam clearance, beams are 200 high x 300 wide (8" x >>>>> 12") waterline beams are 750 and 500mm (30" and 20"). >>>>> >>>>> I have not sailed on Aroha, so can't comment on the accuracy of these >>>>> numbers, nor how well it works. I would prefer more lee hull beam >>>>> clearance,and would see if the beams could be smaller. Probably go >>>>> with a mostly solid bridgedeck to help with this. >>>>> >>>>> Only other change would be to make it from panels, if I was paying for >>>>> it. John in China is busting to give you a quote. Any idea when you >>>>> will have something for him? >>>>> >>>>> regards, >>>>> >>>>> Rob >>>>> >>>>> On Mon, May 4, 2009 at 9:13 PM, Gardner Pomper <gardner@networknow. org> >>>>> wrote: >>>>>> >>>>>> >>>>>> since my design turned out to be practically identical to harry in >>>>>> length, width and weight, I would like to check against that design. >>>>>> Can you tell me what the height is above the water for the beams, and >>>>>> about what the size of the beams is, since I am just using 1 foot >>>>>> squares for placeholders now? >>>>>> >>>>>> Also what is the waterline beam of each hull? >>>>>> >>>>>> Would you change any of that is you were redesigning harry now? >>>>>> >>>>>> Thanks >>>>>> - Gardner >>>>>> >>>>>> On Monday, May 4, 2009, Rob Denney <harryproa@gmail. com> wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> G'day, >>>>>>> >>>>>>> The weight transfer does not happen until the breeze is pretty >>>>>>> strong, >>>>>>> and the speed exceeds the hull speed of a short, fat hull very >>>>>>> quickly. eg, the 33' windward hull on Rare bird has a hull speed >>>>>>> (1.34 * the waterline length, in feet) of 7.6 knots, which it gets to >>>>>>> in under 10 knots of breeze, but the windward hull barely lifts at 20 >>>>>>> knots of wind speed when the boat is capable of 15 knots plus, at >>>>>>> which speed the drag of the short hull would be immense. >>>>>>> >>>>>>> regards, >>>>>>> >>>>>>> Rob >>>>>>> >>>>>>> On Mon, May 4, 2009 at 4:37 PM, jrwells2007 >>>>>>> <jrwells2007@ yahoo.com. au> >>>>>>> wrote: >>>>>>>> >>>>>>>> >>>>>>>> Rob, I have read somewhere that cats and tris aim for a minimum of >>>>>>>> 8:1 >>>>>>>> to >>>>>>>> prevent stern squatting in the manner of a mono-hull. For the ww >>>>>>>> hull >>>>>>>> an >>>>>>>> 8:1 >>>>>>>> would have lower surface area for a given displacement than an 11:1 >>>>>>>> so >>>>>>>> less >>>>>>>> resistance at low speeds. At higher speeds some of the displacement >>>>>>>> of >>>>>>>> the >>>>>>>> ww hull would be carried by the lw hull and therefore the greater >>>>>>>> wave >>>>>>>> making resistance of 8:1 would be less of a factor. Are there other >>>>>>>> more >>>>>>>> important considerations such as drag on the steering? >>>>>>>> >>>>>>>> Longer and skinnier is still better for speed probably. >>>>>>>> >>>>>>>>> >>>>>>>>> The longer and skinnier the better, but as long as it does not drop >>>>>>>>> below 11:1 l:b, you will be fine. >>>>>>>> >>>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>> >>>>> >>>> >>> >>> >> > g t;