Absolutely! There really needs to be some documented performance data.
Not this flying a hull because you are seated on the lw hull. This is
a harryproa, not a pacific proa.

It would really be great if we can get some videos out of Rare Bird
also, but they really, really, really have to show both windspeed and
boat speed. Does Rare Bird have a anenometer? If not, I know I would
be willing to make a contribution to at least buying a handheld one.

Practice that on the harriette before you go! <grin>

- Gardner

On Thu, Mar 26, 2009 at 10:32 AM, Doug Haines <doha720@yahoo.co.uk> wrote:
> Hey there,
>
> I have been over Rob's house to get something moving on his elementarry,
> namely fitting the rudder back on.
> I see the calls for video of eciting action and wouldn't say that harriette
> video really shows off the possible performance.
> Anyway this is a encouragement post to egg Rob on for a quick sail with the
> video camera (plus his brand new GPS), before he leaves for brisbane next
> week.
> This is work, so work excuse is a relative thing.
> Who thinks this kind of thing is important?
>
> Doug
>
> --- On Thu, 26/3/09, Gardner Pomper <gardner@networknow.org> wrote:
>
> From: Gardner Pomper <gardner@networknow.org>
> Subject: Re: [harryproa] Bending foam?
> To: harryproa@yahoogroups.com.au
> Date: Thursday, 26 March, 2009, 11:47 PM
>
> Rob, you should know by now that answering questions just creates more
> questions <grin>. Mine are inline.
>
> On Wed, Mar 25, 2009 at 11:08 PM, Rob Denney <harryproa@gmail. com> wrote:
>>
>> G'day,
>>
>> Me and my big mouth! Notice the "at this stage". ;-). Pretty easy
>> design brief though. Faster than anything else out there, big and
>> comfortable enough for a big guy to cruise solo, dead simple to build,
>> trailerable and must not capsize.
>>
>> Crew weight and payload 700 lbs/320 kgs (I have to work weights in
>> kgs or make some embarassing mistakes, 2.2 kgs/pound)
>>
>> Boat weight 900 lbs/410 kgs
>
> Are you just restating what I said for specs, or do you actually think
> the boat can weigh 410 kgs? I just made up numbers for rig and beams
> and stuff.
>
>>
>> Sail area for BN of 2 = (assuming empty boat), SA= 370 sq'/34 sq m.
>> Assume 5:1 aspect ratio, boom length is 2.6m, luff length is 13m.
>> This assumes a una rig. It is not possible to (easily) telescope an
>> easy rig. Thinking about it, it is not so complicated, but the loads
>> will increase. Maybe have a 3/4 height jib, which is removed for the
>> 1st reef, then telescope the top quarter of the rig for the second
>> reef. Although for sailing in 5 knots of breeze, height is king, so
>> the una rig is probably a better bet. Worth some more discussion, I
>> think. Definitely a wing section, either way.
>
> I was thinking to set it up as a "normal" easyrig, then be able to
> raise just the main an extra 10' (guess) when in really light airs.
> Have the jib forestay attached to the non-telescoping part.
>
> I don't understand the unarig. On a monohull, a single sail is always
> far forward, like a cat rigged boat. I don't understand how the
> unarig, placed in the center of the boat works. I know it is in the
> design plans for Rapscallion, but I never saw an explanation. Have you
> tried this?
>
> Oh, and did I forget to mention that I want to be able to pack the
> boat in a container, so the mast should not be longer than 39'
> collapsed, or it should be able to come apart the way I have shown in
> the camper_mast. pdf file in the Files section.
>
>>
>> So far, so good, now the tricky part. No capsze. Not sure that I can
>> guarantee this. That is a big rig on a little boat. I will pass
>> responsibility for this requirement back to you and your sailing
>> ability.
>>
>
> I think we can safely count on my being chicken to prevent capsize, so
> long as I can reduce sail. I was taught the old adage that if you
> think it might be time to reef, then it is time to reef.
>
>> Files are now open again.
>>
>> Assuming the dimensions and calculations are correct (I rough checked
>> a couple and they were), the drawings look good. I assume you have
>> drawn it in the other view and 3d to be sure it all fits. If
>> possible, I would extend the lee hull length to 35', and leave out the
>> kink in the topsides.
>
> I uploaded my 3D rendering to the files area. It looks ok to me.
>
> Is there a specific reason to extend the lw hull to 35', or just the
> "longer is better" idea? That hull already has a l/b ratio of 25:1.
>
> Is the "kink" the part that raises up in the middle, like rapscallions
> boat? Are you saying that I should raise the deck the whole way along,
> or just slope it up from bows to the mast? I did it like this to give
> me a convenient place to mount the crossbeams and because it was done
> that way on Rapscallion. I am not disagreeing; I just am not sure I
> follow what you are telling me.
>
>>
>> Righting moment is 300 kgs at 4.25m (not quite correct, but near
>> enough) = 1.275 tonne metres, which will need a decent bury for the
>> mast, or a stronger lee hull. You can either pay $aus1,000 to have
>> this engineered, or go with my gut feeling, which I will post you off
>> list with the usual cautions and conditions. I would advise the
>> engineering.
>>
>> Easiest build is flat panels, partially or fully glassed with glassed
>> polystyrene in the compound curve areas outside the beams, below the
>> water. Either I can calculate the panel shapes, or you can and send
>> it to me for comments. The deck can either have a deck edge radius,
>> or you can use a timber stringer and glue the hull and decks to this,
>> round the edge and apply a layer of external glass. Easier and
>> quicker, but not as rounded or as neat as the der. You should be
>> able to make the deck panel pretty accurately, but no big deal if it
>> is a little bigger. Adding rebates to areas of the panel where there
>> will be joins will make it neater/less fairing.
>
> Why timber stringers? Would it be possible for me to just use glass
> covered foam for stringers?
>
> The simplest I can think of is to have the middle 50% of each hull
> bent up, and use foam for the keel section of the end 25%. That would
> require carving a 1'x8' solid foam block for the bow and stern of the
> lw hull. Is that ok? Then I don't have to worry about the compound
> curves in those areas.
>
> What is a "rebate"? Is it just an overlapping flap of fiberglass?
>>
>> Telescoping beams are tricky. They need to be a tight fit when out
>> and a loose fit for sliding. Plastic over pvc pipe will not release
>> if the whole thing is laminated on it. Lay up your internal skin with
>> a piece of plastic under the 2" overlap. When cured, remove the skin
>> from the pipe, then glue the overlap so it is a loose fit on the pipe.
>> Then layup the rest of the laminate. Build up the ends for the
>> tight fit, the rest for a loose fit, fair it and use it as a mould for
>> the other half beam, building it the same way.
>>
>> Telescoping beams are easier to build as square sections as you can
>> work on the inside. Again, you have the choice of engineering the
>> beams or going with my gut. More on this off list.
>
> The beams can wait. Hopefully I can get these made in China, along
> with the mast and rudders. I am mostly concerned with being able to
> start the other parts of the boat. If I end up with some sort of
> swinging crossbeam system, that might raise the deck, which will
> cascade changes to all parts of the boat, so I probably need to
> decide that before I start building it.
>
> Do you think that telescoping is the best (simplest, most reliable)
> way to do the reduction in beam? I know there have been alot of ideas
> tossed around on the forum. Also, can you give me a figure for how
> much overlap there needs to be in a telescoping beam? Roughly 10% of
> length? 20%? I know this is someplace where engineering needs to be
> done, but I just want to work out the approimate minimum and maximum
> beams I can do.
>
>>
>> Anything else, let me know.
>
> I can't believe you are still saying that <grin>
>
>>
>> regards,
>>
>> Rob
>>
>
> Thanks very, very much!
>
> - Gardner
>
>> On Wed, Mar 25, 2009 at 11:23 PM, Gardner Pomper <gardner@networknow. org>
>> wrote:
>> > Rob,
>> >
>> > Ok, you asked for it! <grin>. I haven't moved this to a new thread, but
>> > maybe I should.
>> > These questions are all based on the camper files I uploaded to
>> > Files->Gardner' s Layouts->Camper. Yahoo won't let me get to them at the
>> > moment, but hopefully that is a temporary problem.
>> > First, the purpose of the boat is to be a long distance single person
>> > cruiser. I want to do the same type of thing that Doug is doing with
>> > his,
>> > but I probably weigh twice what he does and have a higher minimum
>> > comfort
>> > level, I expect. Secondary purpose is as a fast, fun daysailor for the
>> > family (2 adults, 1 child, total weight 550 lbs). But, I do *NOT* want
>> > to
>> > capsize. I don't want to fly a hull. I want relaxation at speed, not
>> > adrenaline rush.
>> > As I have mentioned in prior posts, we live in an area of light winds.
>> > Summers here often have winds light and variable, 5 kts or less. Over 10
>> > kts
>> > is uncommon. Over 15 and I don't go daysailing. Because of all this, I
>> > want
>> > a large sail area that can be easily reduced to cope with higher winds.
>> > I
>> > also want to be able to sail in 30+ kts, for those times I am cruising
>> > and
>> > get caught.
>> > The primary building characteristic of the boat must be simplicity. I
>> > have
>> > no boatbuilding experience and want something forgiving. To this end, my
>> > concept for this boat is that it can be built in 3 major sections, lw
>> > hull,
>> > ww hull and deck. The idea is to build the deck first, as it is simplest
>> > and
>> > least important to the structure, which will give me some experience
>> > before
>> > I tackle the hulls.
>> > One last thing; ignore the bicycle pedal idea for now. I may go with a
>> > sculling oar and/or a portable electric outboard. That is all undecided
>> > and
>> > I don't want it to hold up the rest of the boat.
>> > Questions:
>> > 1) I figure an empty weight (all up) of  200 lbs per hull, 200 lbs for
>> > the
>> > deck, 100 lbs for rig (guess), 100 lbs for crossbeams (guess) and maybe
>> > 100
>> > lbs misc, for about 900 lbs. Payload about 700 lbs (150 lbs equip + 550
>> > lbs
>> > crew for daysailing; 200 lbs equip, 300 lbs crew, 200 lbs stores for
>> > cruising). Does all that seem reasonable, given the measurements in the
>> > drawing?
>> > 2) 3/8" core throughout, except for horizontal deck surfaces wehre I
>> > walk.
>> > Use 1/2" there. 6oz fiberglass everwhere, except under the waterline,
>> > where
>> > 18oz for grounding protection. All ok?
>> > 3) Build telescoping beams by wrapping carbon fiber around PVC tubing
>> > wrapped in plastic sheeting and vacuum bagged. Slide the PVC tubing out
>> > after resin sets. What diameter tubing should I use? should I wrap
>> > carbon,
>> > then wrap foam around, then another layer of carbon, or just 1 thick
>> > layer?
>> > I seem to be able to get 12 oz carbon fiber twill reasonable cheap
>> > ($26/yd
>> > in 47" width, so just over $2/sq ft).
>> > 4) If I can still get it, there might be a few sheets of 3/8" airex
>> > available at about the same price as corecell. If I just use it for the
>> > keel
>> > sections, I figure I can cut 2'x8' pieces for teh keel and use 4 pieces
>> > for
>> > the lw hull and 2 pieces for ww hull, so just 3 sheets of it. That
>> > should
>> > allow me to make the 4" radius bend in the ww hull and 6" radius in the
>> > lw
>> > hull.
>> > 5) When I get to the rig, I want to look at your ideas for a telescoping
>> > mast. That sounds appropriate for the light wind days, and I can just
>> > keep
>> > it down on days with more wind and reef when it gets really windy. I
>> > have
>> > not done the calcs yet for bruce number, but I would like to get close
>> > to a
>> > 2 when loaded for sailing.
>> > 6) I would like to start building the deck first. Given my idea of just
>> > dropping it on top of the ww hull, I am assuming that we can make minor
>> > changes in the hull specs without my having to redo the deck. I was not
>> > planning on having the hull/deck vertical transition be seamless; I was
>> > just
>> > going to make the deck rectangular and let the corners stick out, to
>> > simplify building. Do you think I can get away with that?
>> > 7) What would you change in the design, given my requirements?
>> > Thanks,
>> > - Gardner
>> >
>> > On Wed, Mar 25, 2009 at 6:13 AM, Rob Denney <harryproa@gmail. com>
>> > wrote:
>> >>
>> >> G'day,
>> >>
>> >> My Elementarry is 3mm foam with carbon each side. 10mm/3/8" will be
>> >> heaps for yours. Flat floors on ww hulls hit with a bang after a
>> >> capsize. Definitely 18 oz either side. Airex wil do, but it is very
>> >> expensive. I'd persevere with the Core cell.
>> >>
>> >> No need for any money at this stage. Ask questions, I'll answer. I
>> >> am away for 2 weeks from next week, so ask before Sunday, please.
>> >>
>> >> regards,
>> >>
>> >> Rob
>
>